# Peoples opinion on the 8 valve and ITB's...



## Waagenz (May 29, 2003)

Like the question states, whats your opinion on them. I have heard about ppl useing them and I was wondering. Will they add anything in terms of performance? What are the advantages and disadvantages of ITB's. What are some manufacturers that produce them and provide the best performance results. Thanks in advance...
Btw: I have a 80' Scirocco S with the original 8v motor. I believe its a 1.6L or 1.7Liter.


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## Slow1.8 (Oct 9, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (Waagenz)*









As you can see every runner has a throttle bodie, so there's no "log" that all the cylinders have to eat from, no restrictions. 
I haven't driven or even seen a car with ITBs but I assume you get.

Mega response.
NO air restriction=Mega intake
An even amount of air in each cyl.








Those are my assumptions and opinions.














http://****************.com/smile/emgift.gif







http://****************.com/smile/emthup.gif 


_Modified by Slow1.8 at 6:31 AM 12-19-2003_


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## DjSuperChink (Sep 29, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (Slow1.8)*

who makes that beautiful piece of of engine madness...?...I would really want to know mroe about this topic as well.


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## ENJOI (Nov 24, 2002)

*Re: Peoples opinion on the 8 valve and ITB's... (DjSuperChink)*

i want those
where


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## Slow1.8 (Oct 9, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (ENJOI)*









I just skimed through the page but that bike got a turbo kit installed and the itbs came with the kit.
Here's the link to the page:
Click ME


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## Waagenz (May 29, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (Slow1.8)*

go they have kit for scirocco's?







need more info. bump!!! http://****************.com/smile/emthup.gif


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## 2L Bunny (Aug 15, 2000)

*Re: Peoples opinion on the 8 valve and ITB's... (Waagenz)*

ITB's are a great way of making very good HP, but they're also a very good way to kill all drivability. I ran my Rabbit with a 2L and 45mm ITB's for about a year on the street, it can be done, but it was a jumpy pain. Great Hp tho. Looking back, I'd kinda leave them for a weekend/play car.
hth,


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## Slow1.8 (Oct 9, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (2L Bunny)*

Why were they Unstreetable for you?
Alot of cars come with ITBs stock...


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## 2L Bunny (Aug 15, 2000)

*Re: Peoples opinion on the 8 valve and ITB's... (Slow1.8)*

I know some cars come with ITB's stock, but they're also de-tuned to make more civilized with MAF, or computer tricks. They were too jumpy. You touch the gas and it doesn what it should, rev...made driving down slow streets ~25 an excersize in bucking. Not saying I didn't like them. But for 95% of the people that's not acceptable. And I wouldn't want it again on a street daily driven car.


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## Capt.Dreadz (Jun 4, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (2L Bunny)*

I had http://www.twminduction.com make me a custom piece for my VR6T project. I highly recommend them. http://****************.com/smile/emthup.gif


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## grayfox (May 13, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (2L Bunny)*

i want ITB's for my 8v, where can i find them exactly?t


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## 8ac1v1c (Oct 28, 2002)

Isnt a CL an ITB


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## adidas_mc (Apr 26, 2003)

*Re: (8ac1v1c)*

would the ninja zx-11 throttles work on a 16v? how would you setup the fuel injection? price$$?


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## PolyToXiC (Dec 6, 2001)

*Re: (adidas_mc)*

The zx11 never came with ITB's from the factory, they came carberated. That zx11 has ITB because it has a Mr. turbo, turbo kit which uses fuel injection instead of the stock carbs.
Most new large displacement sport bikes have fuel injection and ITB's. My pick would be the ITB from a suzuki gsxr 750 or 1000. The 750 ones would be good for a mildly tuned motor and the 1000's for a motor with more porting and intake mods. All the GSXR 1000 have fuel injection, and from 1997 and up the 750 had fuel injection.
As far as driveability problems at low speed cruising, motorcycles have a similar problem and yamaha came up with their version of a solution. The 2003 yamaha R1 comes with ITB that are a combo of a cv carb and a ITB. They have a diaphram attached to slides that raise and lower in ratio to the throttle and engine load instead of mechanically actuated butterflies. This makes it so that there is a very slight delay from the time you give it more throttle to the time the slides open fully, making it more drivable without sacrifising the awesome throttle response you get with ITB.

I guess all the motorcycle knowledge I have aquired from working as a motorcycle mechanic has paid off in the vw world now that everyone is in a ITB frenzy.


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## nweurosport (Jan 16, 2003)

*Re: (PolyToXiC)*

I'm just curious if anyone has even mounted ITB's on a non-crossflow engine... It would seem a little tricky to me and suck up a ton of hot air if you didn't make a custom air box. 
I would think with enough work on the engine management that you could make it driveable on the street, especially if you had switchable programming (race/street).
Andy


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## sloppychicken (Jan 28, 2001)

*Re: (8ac1v1c)*


_Quote, originally posted by *8ac1v1c* »_Isnt a CL an ITB

It does, but its one throttle body feeding 4 cylinders, still run into the manifold restriction and limited size of the one throttle body.


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## 2L Bunny (Aug 15, 2000)

*Re: (nweurosport)*


_Quote, originally posted by *nweurosport* »_
I'm just curious if anyone has even mounted ITB's on a non-crossflow engine... It would seem a little tricky to me and suck up a ton of hot air if you didn't make a custom air box. 
I would think with enough work on the engine management that you could make it driveable on the street, especially if you had switchable programming (race/street).
Andy

I was runnintg Puma 45mm ITB's on my counterflow 2L motor in a Rabbit. As far as tuning, it's not a funtion of tuning that makes them drivable, it all related to what was mentioned about CV type ITB's on bikes. No matter how your fueling is, if you tip the throttle in and get a huge amount of air, it's going to be hard to drive at slow speeds no matter what. You pretty much end up with an on and off switch for a gas pedal. For a race car it's just fine, for a fast road/street car it can be a pain at times.
hth,


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## ABA Scirocco (May 30, 2001)

*Re: (nweurosport)*


_Quote, originally posted by *nweurosport* »_
I'm just curious if anyone has even mounted ITB's on a non-crossflow engine... It would seem a little tricky to me and suck up a ton of hot air if you didn't make a custom air box. 
I would think with enough work on the engine management that you could make it driveable on the street, especially if you had switchable programming (race/street).
Andy

Have you seen  CdnDubs ITB's thread? It's 7 pages long so far.


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## Yellow Snow (Mar 20, 2003)

*Re: (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_
Have you seen  CdnDubs ITB's thread? It's 7 pages long so far.


Great thread http://****************.com/smile/emthup.gif


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## Andrew Stauffer (Oct 2, 2000)

*Re: (Veedub4me)*

I'm running a set of ITBs on my non cross flow 2.0 8v, they were originally 2LBunnies(Tim's).
At first, the driveability was HORRIBLE. Barely crack the throttle and you were going somewhere in a hurry, regardless if it was the open road or the bumper in front of you. Energetic but difficult to drive slowly under real world conditions. 
However, I've spent the last two months developing/tweaking the fuel management(MegaSquirt) and timing. I spent all this time working on cold starts, low rpm driving, and driveability in general. Why? Because there is no doubt these parts will make a powerful motor- BUT- can they make a powerful motor with factory levels of driveability? Keep in mind that with this set up ( ITBs and programmable efi) it's a waste of time and effort if it doesn't offer better all around driveability than DCOEs. Top end powerwise, I expect similar performance btw the two, but the advent of programmable management should allow for smooth low end, fuel efficient cruising, easy cold starts and then DCOE performance when needed. 
IE, the challenge with this set up isn't going fast, it was built to do it. The challenge is making it go *slow* as well as it goes fast. Have your cake and eat it too...... 
At any rate, even with my somewhat grabby 6 puck clutch disc, my car is nearly factory smooth. Very driveable in town, traffic, etc. It's taken alot of focus, effort and tuning to get it there. I'm still not done, but the priorities will soon change back to tuning for max performance as the low end is just about daily driving smooth. 
You ought to hear 4 ITBs pointing right at you, screaming at 7000rpms. You can't even hear the exhaust at that point in time











_Modified by Andrew Stauffer at 6:04 AM 12-24-2003_


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## angusmf (Jun 14, 2002)

*Re: Peoples opinion on the 8 valve and ITB's... (2L Bunny)*

Even according to the Jenvey (check out their size recommendations, then compare that with what they sell







), 45mm bodies are too large for a street VW motor. That's what causes the drivabilitiy problems. This happens anytime you use a throttle butterfly that's too large, wether ITBs or a plenum setup. The area of a circle (the throttle plate) increases exponentially (as opposed to linearly) with increase in diameter. So a relatively small increase in throttle bore makes a relatively large change in the amount of open area you get with the same amount of throttle input. Smaller bodies or a clever progressive throttle linkage would help. An 8v doesn't flow that much to begin with, so going huge on the intake doesn't make sense. If you have programmable EFI, it may be possible to make it feel smoother by underfueling at high vaccuum (nearly closed throttles) and eliminating accel enrichment, but hopefully there are better solutions.
When my 16v Rabbit is finished, I'm going to do back-to-back tests with 38mm and 42mm ITBs and see what the difference is in drivability and output.


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## nweurosport (Jan 16, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (angusmf)*

So basically the first person to machine a throttle linkage that incorporates a ramping wheel at the TB end will have a nice, driveable car?
Andy


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## angusmf (Jun 14, 2002)

*Re: Peoples opinion on the 8 valve and ITB's... (nweurosport)*

My point was that you should use TBs that are sized properly for your engine (easy, since there are so many different sizes of motorbike TBs out there.) But try it and let us know. I do think it will help, but I doubt it's a cure. Remember, the other problem with overly large ports, intake runners, or throttle bodies is that air velocity will be poor at low RPMs. 8v ports (and 16v ports to a lesser degree) have significantly less cross-sectional area than a 45mm bore does.


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## civcklr (Jun 10, 2002)

*Re: Peoples opinion on the 8 valve and ITB's... (Slow1.8)*


_Quote, originally posted by *Slow1.8* »_Why were they Unstreetable for you?
Alot of cars come with ITBs stock...

Name three cars(non exotic)that come with ITBs.
Do you know what "ITBs" are?
Usually if someone is asking questions about tunning on here, they probably dont need ITBs, or carbs.
You may also think the fuel distributer is called a "Fuel dizzy" Its not.


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## theuean (May 11, 2000)

Go back to Tucson, dimwit. And maybe read the rest of the thread before replying to stuff like that.


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## Slow1.8 (Oct 9, 2003)

*Re: Peoples opinion on the 8 valve and ITB's... (civcklr)*


_Quote, originally posted by *civcklr* »_
Name three cars(non exotic)that come with ITBs.
Do you know what "ITBs" are?
Usually if someone is asking questions about tuning on here, they probably don't need ITBs, or carbs.
You may also think the fuel distributer is called a "Fuel dizzy" Its not.

lol,You are a complete moron!
Sure, I can name ONE car of the top of my head. BMW... 
I guess I would have to look into other makes, but I KNOW that BMW isn't the ONLY "non-exotic"







car that comes with ITBs.
Again, you a moron










_Modified by Slow1.8 at 11:00 AM 12-31-2003_


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