# ABA block and JH head- compression ratio and ping control



## Ben B (Bengineer) (Dec 20, 2006)

I am using a 2.0L ABA block (1997 stock block with polished, smooth piston tops) and stock JH counterflow head with polished chambers. I have cc'd everything and found the compression ratio is 10.3:1....seems too high without knock sensor and using 89 winter/92 octane in the warm weather. 
Waiting to install head with one or two metal layered head gaskets. Two head gaskets does not sound like a good idea, but several people have used them without problems (clean, resurfaced 0.003 in. and new metal layered gaskets). There goes my quench! Two gaskets equates to 9.1:1 cr.
Techtonics and local tuners say 9.3:1 is as far as you should go with using 92 octane...but I think this is with all other components stock. 
I think with these mods one *could* run higher compression:
1. Recurved ign distributor, less total advance and stronger springs for less aggressive curve.
2. larger/low restiction exhaust (mine is TT 2.25 in w/ dynimax muffler)
3. cooler thermostat and fan switch (have fast acting 180 degree thermostat. and coolest switch)
4. larger radiator (26.5 inch core) (have)
5. thermal spacer to intake manifold (have on)
6. insulated heat plate (between exh manifold and intake manifold)
7. polished piston tops and combustion head chambers
8. cooler spark plugs
9. insulated fuel lines in engine compartment (did this and solved hot starting problem)
10. small waterpump pulley (on P.S. cars)- (+ water flow and volume)
11. conservative ignition timing- initial setting ...4 degrees BTDC ????
*Question*: Who is running this set-up and what are your experiences with high compression (9.4:1 + without knock sensor)

Who has this set-up and is driving in stop and go traffic (ABA block and JH counterflow head = 10.3:1 cr. What kind of pinging, detonation, hot start... problems have you had??????????????????


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

You left one important item off of your list and that's a bigger cam, the more aggressive the cam the higher static compression ration you can run. Also you could try Evan NPG coolant, I've never used it myself so all I'll say about it is that some people have good result with it beyond that, you'll have to do the research for yourself.


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## chickenfriend (Jan 31, 2005)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

Why do you not want to use a knock sensor ignition, like a CIS-e setup?


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

I've been running a c-flow/ABA hybrid (CR 10:1) since 98. 160,000 miles with no failures on junky CA 91 Octane. This is a CIS-E w/no-knock control appication in my Fox wagon. For reference:
Little bitty Fox radiator
180 deg thermostat
stock adv curve dist
std. water pump speed ratio
big valve hydro head
Big throttle body
Hydro G cam (.400 lift)
Dual outlet manifold/TT downpipe
Hi-flow cat
2" TT cat-back
no 'insulation' between manifolds/head or on fuel lines.
Timed at 6 BTDC
The only time I have any pingy stuff going on is heavy throttle input at low rpm/high load when the temps are up over 90 F. (There is a part of my daily commute that tends to be bumper-to-bumper stop-and-go on a 7-8% grade that can be challenging...)
Like a previous poster mentioned, why not add a knock box? I have one, I just haven't wired it up yet...


_Modified by snowfox at 8:04 AM 1-26-2007_


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## The Quinner (Dec 10, 2001)

*Re: ABA block and JH head- compression ratio and ping control (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_You left one important item off of your list and that's a bigger cam, the more aggressive the cam the higher static compression ration you can run.

Just a detail here...but, I would qualify that statement by replacing the word "aggressive" with the term "longer duration." I realize that most aftermarket cams fall into that category, but if one were to install a high pop cam with identical durations, the effective compression would remain the same. It's even possible to run a high pop cam with LESS duration or to fiddle with the valve timing and end up with _increased_ effective compression.


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (The Quinner)*

Quinner, thanks for the clarification.
BTW, Ben, Snowfox is not alone sucessfully running without a KS system, many other people have done so sucessfully too. I ran mine like that for a couple weeks, I had no problems either although I don't consider two weeks long enough for a serious evaluation. You can think of a KS system sort of like an insurance policy, you may not absolutely need it but it's very nice to have.


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_Quinner, thanks for the clarification.
BTW, Ben, Snowfox is not alone sucessfully running without a KS system, many other people have done so sucessfully too. I ran mine like that for a couple weeks, I had no problems either although I don't consider two weeks long enough for a serious evaluation. You can think of a KS system sort of like an insurance policy, *you may not absolutely need it but it's very nice to have*.

Definitely. Like I said, I have a full KS system from an 87 GLI 8V ready to put in my Fox, but I haven't found anyone who knows enough about the tweaked Fox version of CIS-E to help me properly install/integrate it. As excessive knock has not been a problem, I haven't had a whole lot of impetous to do the install either.


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*


_Quote, originally posted by *snowfox* »_
but I haven't found anyone who knows enough about the tweaked Fox version of CIS-E to help me properly install/integrate it. As excessive knock has not been a problem, I haven't had a whole lot of impetous to do the install either.

Personally, I wouldn't integrate it at all, I'd just install it completely independant of the fuel system, just as though it were going on to an engine with CIS-basic or carbs. It's really pretty easy, here's the wiring diagram.


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (ABA Scirocco)*

<<Right-click, Save-as Thanks!!







>>
Here's a question...
(Now, I'm sitting at work and don't exactly have my stuff in front of me to compare to the diagram, so bear with me.) What do I do about the WOT and Closed Throttle switches? Do I just leave those hanging out in space? And what's the deal with the special note about cutting the wire between pins 3 and 11? Inquiring minds want to know...


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## The Quinner (Dec 10, 2001)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*


_Quote, originally posted by *snowfox* »_<<Right-click, Save-as Thanks!!







>>
Here's a question...
(Now, I'm sitting at work and don't exactly have my stuff in front of me to compare to the diagram, so bear with me.) What do I do about the WOT and Closed Throttle switches? Do I just leave those hanging out in space? And what's the deal with the special note about cutting the wire between pins 3 and 11? Inquiring minds want to know...

Both of those switches are in the diagram...to the right of the control box. The cutting of the wire for the extra HP only applies to the 1985 GTI/GLI. In 1986+ it was basically already done. The story is that for 1985, VW chose a slightly less aggressive advance and limit for their transverse layout vs. the Audis' longitudinal layout. By 1986 they decided that it could take it and went with the more agressive curve.


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (The Quinner)*

I suppose I should clarify a little bit... The Fox CIS-E system doesn't have any throttle switches. When the Fox went to Digi, it got a closed throttle switch, but never WOT.


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*

Can't you make a little bracket to hold a WOT switch? Have a look at the way it's done on the CIS-Lambda systems in a Scirocco or the early GTi, my digital camera's out on indefinite loan or I'd take a picture of mine. 
Anyways, the switches really have little effect on the way the system operates considering that the switches only do something when the throttle is fully closed or fully open and do nothing in between, you could leave them out entirely and you'd probably never notice the difference. I've tried it both ways and couldn't notice any difference as have several other people I've talked to.
Now, you're probably wondering "what do they do then?" and frankly so am I. I've never heard or read an explanation of their function that withstands careful scrutiny. The purpose of the idle switch is a complete mystery to me, the WOT switch make a bit more sense to me. I think it adjusts the knock sensitivity at WOT to make the advance curve a little more aggressive then it might otherwise be. I should say however, this is pure speculation as I have no way of testing this hypothesis, it's based solely on my own observations and my discussions with others on this topic.
And as for cutting that wire, afaik, it's just what the Quinner said.


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## The Quinner (Dec 10, 2001)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*


_Quote, originally posted by *snowfox* »_I suppose I should clarify a little bit... The Fox CIS-E system doesn't have any throttle switches. When the Fox went to Digi, it got a closed throttle switch, but never WOT.









It's been a long time since I had my 85, so correct me if I'm wrong...but, isn't that simply a matter of swapping your throttle body for one with the switches? I believe I have one that's just collecting dust, if you need it.


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## chickenfriend (Jan 31, 2005)

*Re: ABA block and JH head- compression ratio and ping control (The Quinner)*

There are very helpful wiring diagrams of the CIS-e with knock control in the archived 16v swap section in the mk1 Vortex forum.
I remember reading that the idle switch activated makes the ignition ignore the manifold vacuum signal. If the switch is not there, one needs to remove the knock box vacuum hose and plug the manifold hole, to be able to adjust tming at idle.
Does anyone know the purpose of the check valve that is in the vacuum line between the knock box and the manifold? Perhaps to prevent back pressure from the manifold from damaging the knock box diaphram?



_Modified by chickenfriend at 5:20 AM 5-26-2007_


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (The Quinner)*

The Fox layout is, uh, a bit different... Most TB's don't work due to the linkage configuration, but thanks. I can probably fab something up in the way of mounting bracketry.








As for the switches, I always thought that they were related to the fueling system. The closed switch was to shut off fuel above a certain rpm when you lift completely, and the WOT was supposed to allow a bit of enrichment at the top end... I've been running without any switches, obviously, but I don't know if there is any impact to being 'switchless' when you have the KS system in place.


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (chickenfriend)*


_Quote, originally posted by *chickenfriend* »_Did I remember reading that the idle switch activated makes the ignition ignore the manifold vacuum signal, and that if the switch is not there, then one needs to remove the knock box vacuum hose and plug the manifold hole, when adjusting static timing?
By the way, does anyone know the purpose of the check valve that is in the vacuum line between the knock box and the manifold? Guess it is to prevent back pressure from the manifold from damaging the knock box diaphram?


Thanks! that's the first plausible explanation for the idle switch that I've heard. Not sure about the check valve though as the system I've got doesn't have one.

_Quote, originally posted by *snowfox* »_As for the switches, I always thought that they were related to the fueling system. 

I've never bothered to get into that end of things as my cars have all been CIS-Lambda not CIS-e but I believe the switches, in their original installation, serviced the fuel system too.


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## EuroKid83 (Jan 26, 2005)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

You can also run a load sensitive WUR, this will give you more fuel when you put your foot into it. Also:
272 cam
bump system pressure up
180 degree thermostat
180 degree fan switch
Turbo WUR
stock ignition timing 6 deg BTDC
If you can get colder air into the motor that would help as well.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (EuroKid83)*

Thanks all of you...I really appreciate the info (good stuff).
I am going to try the *10.3:1* compression ratio.. As summer approches (hot weather) we will see what happens. I will just implement the other ideas listed at the top of the page to help with heat issues and play with the ignition timing.
I have heard the stock timing program for knock sensor is conservative and frankly have never seen a knock sensor car that quick at the track. Several tuners offer damper kits to make the knock sensor less sensative. If the knock sensor is not working perfectly than it slows it down. 
I would install a ignition system like my 76 Scirocco before the knock sensor system. MSD 6 AL (adjustable soft rev), timing control at the dash, adapter to run factory tach, low resistance wires, non resistor spark plugs.... 15.1 sec /90 mph (with Original CIS) with an 86 1781 cc JH (stock block).
I did forget the cam...you guys are right. I have a G cam (0.430 lift) I will initially use for a better comparison to the old set-up. I want to establish before and after block swap acceleration numbers, with everything else the same..exept ignition timing (and 2.0 ABA block of coarse). I am sure I will go to a cam with more duration and corresponding increased overlap...which will help. I do have cold air induction also.


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## ny_fam (Apr 3, 2004)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

YOu could cut a few grooves .. you knew I'd chime in..








This would lower the CR a bit and take care of the detonation.
BTW - whats the squish zone clearance ?



_Modified by ny_fam at 12:44 AM 1-27-2007_


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (ny_fam)*

Thats fine, I knew you were watching........I do actually want to use the grooves...but I need to evaluate the block swap first to get baseline results. That would be great if the grooves did "take care of" the pinging sure to come. We will see.
What do you mean by the squish zone clearance? 
The stock ABA piston (1997) has a smooth top with a rounded slight dish. No squish/quench pads as the JH 1.8 pistons or the later 2.0L tall blocks. There is a 0.009 inch gap at the top of the cylinder when the piston is at TDC. The compressed head gasket is about 0.060 inch thick, which is a round hole...so 0.069 inch clearance.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

*SNOWFOX* 
You said you had a ABA block with counterflow head hybrid at 10:1 cr. This combo should be 10.3:1 if unchanged. Or did you just assume 10.0:1 because that is what the ABA engine had? 
The large valve counterflow head has a smaller chamber volume of 29.5 cc verses the crossflow head volume of 31.3 cc. The smaller head chamber raises the compression ratio from 10.0:1 to 10.3:1, a noticeable increase and correspondingly more potential for pinging and detonation.


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## chickenfriend (Jan 31, 2005)

*Re: ABA block and JH head- compression ratio and ping control (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_
Thanks! that's the first plausible explanation for the idle switch that I've heard. 

You are welcome. Just passing on information. I believe I read that in the 16v swap thread in the mk1 forum, or maybe it was in one of the links in it.
If true, then the idle switch should be very easy to do without: take the manifold-to--knockbox vacuum off-line when doing idle timing.
From what I have read, the idle switch, off-or-on, did not affect the idle speed (I think the ISV would be for regulating that anyway). So, I think that rules-out any electronic idle stabilizing effect via timing signal.
Regarding the WOT switch, I had been thinking, how could it have anything to do with the ignition? Perhaps the knock box simply passes on the signal-- without actually using it--to the fuel brain to enrich for maximum power? 
But why would Bosch bother to pass the WOT signal to the knock box if the WOT switch were only to do about fuel? Wouldn't they just send the switch wire straight to the fuel brain? 
I'd speculated the WOT switch does _two_ things: 1) signal a swap to a different timing map in the knock box (the idea you mentioned), coordinated with 2) a signal to the fuel brain for greater enrichment, like a 12.5:1 A/F ratio.
My reasoning is that a richer mixture would need less time to burn and so should have less advance, e.g., WOT = 12.5:1 Air /Fuel ratio + retarded ignition timing map= maximum power.
If this were the case, then the WOT switch contributes only when the fuel brain _and_ the knock box are both getting a signal: a "one-two punch" for maximum power.


_Modified by chickenfriend at 5:28 AM 5-26-2007_


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (chickenfriend)*

I thought the idle switch was one of the signals to the computer for the ISV. Or..... does the tach tell the computer that the engine is at idle. Later cars could use the throttle position sensor at the throttle body.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

I did notice on digifant cars that the idle switch on the throttle body had more effect for off idle response. The cars were either at idle (950 rpm) or at 2,000 rpm nowhere in between. I think it advances the timing quickly when you change from idle.


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## 4thScirocco (Feb 27, 2001)

*Re: ABA block and JH head- compression ratio and ping control (chickenfriend)*

I'm running without the switches. Works just fine. I was having all sorts of pinging issues and no power until I had the knock sensor ignition system retrofitted on my CIS Basic ABA/JH motor. Now I can hit the gas pedal as hard as like when i like and it never pings. I still use 94oct gas tho.
To the original poster:
10.3:1 is not so bad. Personally, I wouldn't go with the stacked gaskets altho lots of people have no problems. Just another potential point of failure. Mine is about 11:1 with a shaved head and compression tests are over 200psi. 
Somebody mentioned a less aggressive ignition advance curve. This was my main problem at the start. With the original low compression EN 1.7L distributor, the ramp up was too much for my motor to handle. With the KS ignition, my motor gets as much timing as it can take and will dial it back as soon as it hears ping.
Long story cut short: To realize the full potential of your motor get the KS system. It's been super reliable for me. No damn pinging!


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## fast84gti (Mar 2, 2003)

I ran 286 cam, and euro 16v basic fueling with vacuum advance stock gti dizzy . No problems.







I also had external oil cooler. Now going MS, though







.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (fast84gti)*

Thanks for all the info guys.
I am going to run the ABA block with counterflow JH head....with one metal layered head gasket (10.3:1 cr). 
I will also recurve the ignition distributer somewhat to compensate for the extra cylinder pressure. As the weather warms I will use the other methods listed at the start of this page to deal with the extra heat from outside sources (the sun). 
(203 cc increase from 1781 to 1984 cc and from 8.6:1 cr up to 10.3:1)
All info appreciated........


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (fast84gti)*

What is MS ???? Multiple spark (MSD) or other brand?
Did you drive the car in the hot summer in stop and go traffic?


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## ABA Scirocco (May 30, 2001)

*Re: (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_What is MS ???? 

I'm pretty sure he's refering to MegaSquirt.


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## Fox-N-It (Jul 23, 2003)

Speaking of which....I've been running my ABA counterflow with no knock for about 3 years now in the Fox. Megasquirt lets me run a much better timing curve with out ping than CIS-E did. With stock timing on CIS-e I had no problems on 93oct in 90+deg heat.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (Fox-N-It)*

Thanks for the input....I am going to have to check into this megasquirt system...I've heard so much about.....


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## chickenfriend (Jan 31, 2005)

*Re: (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_I thought the idle switch was one of the signals to the computer for the ISV. Or..... does the tach tell the computer that the engine is at idle.

If a Motronic system, the idle switch does both. 
The following information comes out of the Bosch Automotive Electric/Electronic Sytstems Handbook, so the coverage is general in nature, not specific to models. I don't have the Bentley that covers the models in these systems, so I can't double-check anything.
In KE-Jetronic, it appears that the IDLE and WOT throttle body switches have *four* functions: two related for fuel and two for ignition.
Since ABA/JH head swappers typically strip-out the fuel management part of this harness, to keep their CIS lamda or basic systems, the two fuel functions become pointless right away. Moreover, of the two remaining ignition functions, the WOT function might be pointless as well or even counter-productive in promoting engine optimization.
---
In Motronic systems, (knock box now integrated into the ECU), the idle speed control circuit *needs* those two signals: 1) an idle signal from the throttle valve, and 2) an rpm signal. 
Here, engine temperature is also an idle speed adjustment input factor, as well as signals from automatic transmission or air conditioners, when present. 
Motronic idle speed is adjusted by controlling airflow, two ways: 1) by bypassing air around the throttle or 2) by moving the throttle plate directly with an actuator. Another Motronic technique is timing advance at idle to boost torque. 
At this point, I am not clear how electronic timing idle control is coordinated with the air flow system, if it is. My Bosch manual infers that not all Motronics use electronic timing control. 
In summary, idle control in Motronic needs several legs to stand on. 
---
For KE-Jetronic, my Bosch handbook indicates the idle air controller actuator is only controlled by engine speed and engine temperature: nothing mentioned about the idle switch: however, the idle switch apparently does affect idle insomuch as it enables DIS in the ignition system. I don't have a Bentley manual for the cis-e cars, so I can't double-check this.

More about the WOT and Idle switches on the CIS-e harnesses:
Regarding KE-Jetronic (the same thing as CIS-e +knock sensing, I believe), I have two sets of information on it in my Bosch handbook. The first set pertains to fuel management for KE-Jetronic. In this section, I found this out about the WOT switch:
"At full load... the KE-Jetronic enriches the air-fuel mixture. The full-load signal is delivered by a full-load switch on the throttle valve, or by a microswitch on the accelerator-lever linkage. The information on engine speed is taken from the ignition. From this data, the ECU calculates the additional fuel quantity needed, and this is put into effect by the pressure actuator...the throttle valve switch communicates the "idle" and "full load" throttle positions to the ECU."
Here is information on the IDLE switch which is used to control overrun fuel cutoff: "the the driver takes his foot off the petal while driving, the throttle valve returns to the zero position. The throttle-valve switch reports the "throttle-valve closed" condition to the ECU, which, at the same time, receives from the ignition the data concerning engine speed." The engine speed data is then used to tell the differential control pressure regulator to cut the fuel flow. This saves gas and reduces emissions, according to the handbook.
When the CIS-e harness is separated from the ECU harness as commonly done for ABA/JH head hybrid engine swap, one question is, are the two throttle body switches in that harness still of any benefit for the swap? 
By discarding the fuel brain from the harness, the harness throttle body switches not longer serve two purposes related to fuel 1) overrunning fuel cutoff signal and 2) full load enrichment signal. They can only serve what is left of the stripped harness, which are functions related to the ignition system; the identity of those functions appear to be revealed in the "Semiconductor Ignition" (SI) chapter. 
SI is one step evolved more than the Bosch "Transistorized Ignition" that came in later year mk1 cars. SI uses a rotational speed sensor that is either mounted off the crank or cam, or at the distributor with a "Hall ignition vane switch". 
Cis-e +k uses the latter with the single window wheel passing though the Hall sensor gap--which is like waving to your Mom, God love her, as she stands still to the side of the merry-go-round, only once, as you ride around.
According to Bosch, under SI, "When the throttle valve is closed, the special idle/overrun characteristic curve is selected. The ignition point can be "advanced" for engine speeds below the nominal engine idle speed in order to achieve idle stabilization by increasing the torque... At full load, the full-load curve is selected. This curve contains the best programmed ignition parameters allowing for the knock limit."
One point of huge puzzlement here, is that my handbook says that SI uses DIS; however, in the KE-Jetronic chapter, it mentions idle speed control by the fuel ECU using an air actuator that bypass the throttle vane. So, are air-bypass and DIS both at work in this system? That's what it sounds like.
I have come up with a few summary points:

1. Given that CIS-e is a Bosch SI system, the idle switch enables digital idle stabilization (DIS).
2. DIS is conducted by timing advance or retard adjustments, freedom given by a special map programmed in the knock box. The knock box must also possess the capability of using the engine speed signal to modify the timing signals to get a stable idle.
3. No idle switch=no DIS! 
(That some have noticed no effect at idle between the switch being on or off I can't explain, but maybe they should test further by monitoring idle while adding loads to the engine, such as turning on the A/c or radiator fan, to see if it recovers. The idle air stabilization system would need to be disconnected for this test.
4. The SI idle map is unique compared to other timing maps, because it permits timing adjustments to roam freely independent of any manifold vacuum signal.
5. No idle switch means the timing map jumps to one of the others that are *all* influenced by manifold vacuum. 
Interestingly, this explains the suggestion I read to take the manifold vacuum signal "off-line" when adjusting initial timing; I don't think this causes the knock box to revert to the idle map, but rather gives enough stability to one of the other maps, so initial timing is not jumping around all over the place.
If the idle switch is present, then there is no need to take the vacuum off-line for initial timing, it follows.
6. The WOT switch signals a special timing map. However, without accompaning fuel enrichmment, I wouldn't think there would be any benefit there, since the map would likely be retarding timing for a richer mixture that doesn't exist anymore. If it retards when it doesn't need to, that would be a loss of combustion efficiency, wouldn't it?
7. The WOT switch might be a benefit if accompanied by fuel enrichment. I believe the 83-84 GTI's had a system for this, triggered by a microswitch on the throttle body.


_Modified by chickenfriend at 5:37 AM 5-26-2007_


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (chickenfriend)*

Thanks Chickenfriend, 
It looks like you have spent substantial time and thought on these issues....I lot of good info, all together in one post...nice


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## Fox-N-It (Jul 23, 2003)

Makes sense since the fox's never had an ISV on the CIS-e cars and never had throttle switches. I always wondered that.


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## the tech 71 (Dec 20, 2005)

i just made a post about fuel in higher compression engines. then i found this one, just wanted to mention that this post has been EXTREMELY helpful! my higher compression dreams now live on
my one question
if i run the KS system in the diagram above do i switch to a non vacuum advance distributer? i believe the answer will be a yes, but just want to be sure.










_Modified by the tech 71 at 9:35 AM 1-29-2007_


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_*SNOWFOX* 
You said you had a ABA block with counterflow head hybrid at 10:1 cr. This combo should be 10.3:1 if unchanged. 

Ooops! My bad.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*

Cool....Just checking to make sure you did't change pistons, or had something machined to lower the compression.
Funny.....I also played with Legos as a child (but I won't tell what I did with the Barbi dolls!


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_Cool....Just checking to make sure you did't change pistons, or had something machined to lower the compression.
Funny.....I also played with Legos as a child (but I won't tell what I did with the Barbi dolls!

Nope- just a knucklehead, I reckon.
Some things are better left unsaid.


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## ny_fam (Apr 3, 2004)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

Ben,
Have any advice on how to polish the piston tops?
Like - how smooth ?
round or not to round the edges around the dish?
Mirror finish on the whole top ? or just parts
Cheers


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (ny_fam)*

Great news guys, 
I just got my 86 Scirocco II running after the ABA block swap....awesome. Very smooth and powerfull and no ping. The gas tank had 87 octane in it but was almost empty. So I drove down and filled with 89 (plus) due to the cold weather (30 degrees F at night and 45 in the day). 
I set the ign. timing to 6 degrees BTDC with the old distributor and 2.0L lower gear (11 degrees before with the 1.8 JH, 8.6:1 cr).
Current set-up is:
89 octane
6 degrees BTDC ign timing (stock distributor)
2.25 inch Techtonics exhaust with resonator, Walker dyno max muffler
Techtonics dual down pipe (SS with flex,A3 cast iron exhaust manifold)
2-1/8 inch ID cat (standard type)
Audi 4000 intake ported polished and matched
Big Throttle body (A2 golf)
K & N air filter with cold air inlet tube (2-1/4 inch ID)
Stock JH head, G cam, polished head combustion chambers
polished piston tops
new metal layered head gasket (head was milled 0.003 inch for a flat surface, new stretch bolts
new clutch, PP, machined flywheel (not lightened)
10.3:1 comppression ratio
thermal heat tape on all fuel lines in the engine compartment
Polishing:
I used 180 grit wet type sandpaper to start the polishing after everything was clean (piston tops and head combustion chambers), then used 400 grit, then a purple fine scuff pad (lightly), then polishing paste......very smooth. Not a mirror, but very shiny.
The head chambers were also de-edged...every edge was ground, then sanded, scuffed ....smooth. Even around the spark plug holes, chamfered, smoothed. I will send pictures, of the car, engine, head (next week) and performance tests (before and after).


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

Congrats. http://****************.com/smile/emthup.gif My ABA set-up was very similar to yours, I remember well the first time I took it out for a test drive. It's amazing what that extra 20+ hp will do for an 8v Scirocco isn't it?


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (ABA Scirocco)*

I am not sure of the hp increase, but will check next week. It definitely feels better. I can also tell the stock head needs to be opened up for high rpm power...great mid range.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

IN-GEAR PERFORMANCE TESTS
Presision stopwatch used, average number out of 4 runs.....
*BEFORE (1.8L JH (8.6:1 cr)* (other mods listed above)
20-70 mph (2nd,3rd) = 9.38 sec
50-70 mph (4th) = 6.12 sec
70-90 mph (5th) = 10.58 sec 
0-70 = 11.23 sec
*AFTER* (2.0 ABA block, 10.3:1)(all other components the same)
20-70 mph (2nd,3rd) = 7.94 sec
50-70 mph (4th) = 4.95 sec
70-90 mph (5th) = 7.65 sec 
0-70 = 10.38 sec
These numbers were taken from the same road, same direction, and two weeks apart due to block swap time (outside temp 40 degrees F)(dry)(same amount of fuel in tank)
Only differences besides blocks was: gaskets, belts and ign timing adjustments (8 degrees (2.0L) vs 11 degrees (1.8L), and fuel 89 octane (2.0, 10.3:1 cr) vs 87 octane (1.8, 8.6:1 cr)
1/4 mile, 0-60, groung hp...#s coming........


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## ny_fam (Apr 3, 2004)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*

Ben,
that must be a blast to drive on the highway, you can pass anyone with just a blip on the gas pedal
Here is a test I'd like to see you run:
Take the A2 big bore throttle body off and put the A1 back on and rerun your tests. I hav'nt seen any test results with that swap.
Also do you have any pictures of the polished combustion chambers and pistons ? I'me very interested in them as I'm about at that stage with my engine work.

Cheers
ny_fam


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## ABA Scirocco (May 30, 2001)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_[*BEFORE (1.8L JH (8.6:1 cr)* (other mods listed above)
20-70 mph (2nd,3rd) = 9.38 sec
50-70 mph (4th) = 6.12 sec
70-90 mph (5th) = 10.58 sec 
0-70 = 11.23 sec
*AFTER* (2.0 ABA block, 10.3:1)(all other components the same)
20-70 mph (2nd,3rd) = 7.94 sec
50-70 mph (4th) = 4.95 sec
70-90 mph (5th) = 7.65 sec 
0-70 = 10.38 sec
........

That's what I'm talking about. Good results http://****************.com/smile/emthup.gif


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## scirocco gt2.0 (Oct 29, 2004)

*Re: ABA block and JH head- compression ratio and ping control (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_IN-GEAR PERFORMANCE TESTS
Presision stopwatch used, average number out of 4 runs.....
*BEFORE (1.8L JH (8.6:1 cr)* (other mods listed above)
20-70 mph (2nd,3rd) = 9.38 sec
50-70 mph (4th) = 6.12 sec
70-90 mph (5th) = 10.58 sec 
0-70 = 11.23 sec
*AFTER* (2.0 ABA block, 10.3:1)(all other components the same)
20-70 mph (2nd,3rd) = 7.94 sec
50-70 mph (4th) = 4.95 sec
70-90 mph (5th) = 7.65 sec 
0-70 = 10.38 sec


Nice numbers.







http://****************.com/smile/emthup.gif 
How much does your car weigh? Which gearbox do you use?
Generally, I'm quite sceptical with stopwatch timing (no offense!), even if it is a precision stopwatch. The speedo is pretty much inaccurate (especially during hard acceleration), as well as the triggering. An accurate accelerometer would be a better way to prove results.
Of course, it is obvious that the improvement in performance is huge, the ABA pulls much harder than the JH, but the acceleration times with 1/100 seconds resolution contain no real information.
Again, not to start a flame, just to express my oppinion.








Greets


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (scirocco gt2.0)*


_Quote, originally posted by *scirocco gt2.0* »_
Nice numbers.







http://****************.com/smile/emthup.gif 
The speedo is pretty much inaccurate (especially during hard acceleration), 

It's proabaly too late to develop baseline info again, but the pulls in a single gear might be better reported referenced to RPM as the tachs tend to be more consistent. (Not necessarily more accurate, just more consistent.) Then the MPH can be calculated back out with your wheel and trans numbers.
Indeed nice numbers. I've got a little G-Tech thingy that I've never used. You (OP) are inspiring me to dust it off and get some baseline numbers on my c-flow/ ABA set up before I dink with the cam and some mild port/polish work...


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## scirocco gt2.0 (Oct 29, 2004)

*Re: ABA block and JH head- compression ratio and ping control (snowfox)*


_Quote, originally posted by *snowfox* »_
It's proabaly too late to develop baseline info again, but the pulls in a single gear might be better reported referenced to RPM as the tachs tend to be more consistent. (Not necessarily more accurate, just more consistent.) Then the MPH can be calculated back out with your wheel and trans numbers.

Yes, at least a bit better than the speedometer. Anyway, the bottleneck in any cases is the manual triggering. You might try to catch 1/100 seconds, when your reaction time is in the range of 1/10th. Triggering is also affected by psyhical stuff ("it's almost 60"







) I know guys who try to make "accurate" measurements by taking a video of the dashboard and measure the time with a video editor program, but the results are still way off compared to accelerometer measurements. And, of course, always in the optimistic direction.


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## snowfox (Apr 4, 2002)

*Re: ABA block and JH head- compression ratio and ping control (scirocco gt2.0)*

Yeah, I understand the error involved in manually timing. I'm just saying that despite that limitation, better data might be obtained by using RPM/gear info. Not perfect, but maybe a bit better...


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## vwpoorboy (Jul 11, 2005)

*Re: (the tech 71)*

"if i run the KS system in the diagram above do i switch to a non vacuum advance distributer? i believe the answer will be a yes, but just want to be sure."

Yes you will need to swap to the non-vacuum advance distributor(to a CIS-E ignition distributor). Oh and if you're running an ABA/JH, swap the guts into the distributor, it's pretty easy.


_Modified by vwpoorboy at 10:48 PM 2-6-2007_


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (vwpoorboy)*

All good points. 
Rpm based runs would be more consistant...except for one problem, when the car gets this quick it is hard to even get close with a stopwatch because the tach is swinging faster than the speedo and the tach has some lag (old analog factory tach).
I do have a accelerometer G-tech...but "G" force info is a topic few would understand or know how to relate to .
Also with a stopwatch there is two times you have reaction time. When I do a 0-60 mph run with the G-tech accelerometer, the time is around 7.0-7.2 sec. (with controlled slight wheel spin). When I do the same test with the stopwatch it is usually about 1 full second longer (8.0-8.2 sec) due to 0.5 sec reaction when pushing the stopwatch to start and then to end. I have tested this many times. That is why NHRA drag strips have a 0.5 sec reaction at the start as the default (if your faster then this it is usually because your drastically anticipating the green light. (pro stock is 0.4 sec because of their experience).
*The key point here is...the difference between each test *(how many seconds reduction for accelerating-look at the 70-90mph in overdrive)(keep in mind in the 1/4 mile each 0.1 sec is a car length at about 90+ mph), since they were tested the same way the difference is accurate...and repeatable. All runs were within 0.25 sec of eachother several times (which is good enough)
Look at the improvement. 
I just weighed the car today at a C.A.T. certified scale (+ or - 20 lbs).
current weight is *2060 lbs *(with 35 lbs of extra stuff...yes I weighed it). Originally the car weighed 2180 lbs (without extras books, clothes, tools, etc). I have lightened it by euro bumpers frames (-45), lawn and garden battery(425 ca) (-18), lighter wheels (-20), lightened rear seat (-13), cut springs (-6), no econo spare (-24), lighter exhaust (-10) etc. Also added weight (stress bars) sound deadening, etc.
9A trans (3.67 final)
(3.45 1st)
2.11 2nd)
(1.37 3rd)
(1.13 4th)
(0.89 5th) 
...... if memory serves


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## snowfox (Apr 4, 2002)

*Re: (Ben B (Bengineer))*


_Quote, originally posted by *Ben B (Bengineer)* »_
*The key point here is...the difference between each test *

I'm with you, on that. I didn't mean to sound like I was bashing your methodology.


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## scirocco gt2.0 (Oct 29, 2004)

*Re: (Ben B (Bengineer))*

"I do have a accelerometer G-tech...but "G" force info is a topic few would understand or know how to relate to ."
I meant timings made with G-tech or so... But if you wrote your car accelerates from 60 at 0,3 G, I'd also say "wow".








So, the improvement is clearly visible (and huge). It is maybe my fault that I wanted to compare the numbers to the ones I've measured (for myself and for others).
Oh my god, your car is real lightweight.







Mine weighs with empty(!) fuel tank and 15" summer wheels 2226 lbs. In addition, I have an ATH gearbox, which adds some seconds to the in-gear acceleration times. On the other hand, it makes longer freeway trips comfortabel and economic.








greets
Just forgot to ask: we are talking about weight without driver, aren't we?


_Modified by scirocco gt2.0 at 9:00 AM 2-7-2007_


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (scirocco gt2.0)*

Yes the car is actually 2,025 lbs once cleaned out (2,060 with misc floor mats, tools, jack, lug wrench, glove box contents, extra parts, etc.). With me as driver the weight is 2,200 (+175)(and without crap).
When racing this coming spring I will replace the wheels with others I have (-6 lbs each = -24 lbs), remove the lightened rear seat (-13), remove the pass. front seat (-36 lb), remove the rear hatch sound pads and carpet (-8 lbs), washer bottle (-2), etc....1,940 lbs








Weight removed is as good or better than extra hp because your braking works better and handling is improved...along with acceleration. Another trick is to use the solid front rotors (instead of vented), which saves a couple lbs on each side...once you have lightened the car (unless your road racing and constantly on the brakes you don't need the vented rotors, which only stop quicker if overheated compared to solid rotors (then drill and balance the solid rotors).


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## scirocco gt2.0 (Oct 29, 2004)

*Re: (Ben B (Bengineer))*

O.K., with me in the car, some (even minimal) fuel, usual tools, etc., mine is almost 2500 lbs.
I am not willing to throw anything out, that is needed for daily comfortable driving. So when I do some measurements, I tend to do it with less than 1/4 tank of fuel, no toolbox, but all other stuff are in, so "race weight" is around 2400 lbs.
I agree, non-existent weight is better than extra hp. Being a street car, I beleive sparing weight on the brakes is not the way for me. It has the 256mm 16V front brakes, and rear disks too. Much more effective (and feels much better) than the 8V system. Even the summer wheels are a bit heavy, around 7 lbs heavier each, than the 14" ones. The grip is much better (which is welcome), but the increased rotating mass shows its negative effect once the tyres stop spinning. 
If I'll have the time, the '77 Mk. I. will get an at least this powerful engine. It also has a 9A gearbox, and 1800 lbs of dry weight.








And since it will not have to be daily driver, I will have more freedom when building it up.








greets


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## PoVolks (Oct 2, 2003)

*Re: (scirocco gt2.0)*

lots of great info here, BUMP.


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## Ben B (Bengineer) (Dec 20, 2006)

*UPDATE - 0-60, 1/4 mile, HP ground, Comparison to 2002 Golf 2.0 L*

*UPDATED*
2.0L ABA block, stock counterflow head...as above in string (except new high flow catalytic converter, slightly larger induction tubing, timing 7 degrees BTDC)(weight with driver 2,200 lbs)
STOPWATCH
20-70 *7.95 sec*
0-70 *9.95 sec*
70-90 *7.67 sec*
G-Tech accelerometer
1/4 mile *15.58 @ 93.4mph *
0-60 *7.25 sec*
HP ground *111 hp*
Note: High flow cat made a noticable improvement, worth every penny
Best 1/4 mile with standard, old, replacement cat was... 
15.98 @ 89.7 mph - same road, temp, gas, etc. 106 hp
DEQ - Emission test - passed all 4 checks.... easily

*2002 VW Golf GL 2.0L 5 spd* (My Brother's, 28K miles)
Stopwatch
20-70 11.45 sec
0-60 10.03 sec
70-90 11.3 sec
*G-Tech*
0-60  9.19 sec
1/4 mile 16.24 @ 91.9 mph


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## fast84gti (Mar 2, 2003)

how much do you weigh, and what was removed from vehicle?


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## 84_GLI_coupe (Apr 3, 2001)

*Re: (the tech 71)*


_Quote, originally posted by *the tech 71* »_if i run the KS system in the diagram above do i switch to a non vacuum advance distributer? i believe the answer will be a yes, but just want to be sure.









_Modified by the tech 71 at 9:35 AM 1-29-2007_

You need to swap, yes. The knock controller will dictate your ignition map (with base settings done via distributor clocking still), not a vacuum canister.


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## Ben B (Bengineer) (Dec 20, 2006)

*Re: (fast84gti)*

I weigh 175 lbs, the car now weighs 2,025 lbs, so together 2,200 lbs total with driver. The only thing I removed was the econo spare and 
1-1/2 coils from each susp. spring, some mods listed above in string.


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