# CIS modified 8v ignition timing



## salz2135 (Sep 18, 2006)

Just wondering what others are running for ignition timing on modified 8v CIS cars. I searched and didn't find any of the threads relevant.

My base ignition timing is currently at 10 degrees BTDC
CIS Lambda fueling
Integrated knock box from 86 GTI CIS-E
Autotech 270 camshaft
2.0L ABA bottom end/shaved G60 cylinder head


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## WaterWheels (Aug 14, 2005)

If using "regular" gas then that 10° should be about right. If you use mid-grade or better then maybe bumping to 12° will be better, but no one can really say as all engines can react different. The bets way to set it if you really want the bets is to take it to the track, use a base starting point and each run move it 2°. If it pings or runs slower back it back down the 2° or 1° and try again. Most will not do track testing and adjusting, or on a rolling road, so seat-of-the-pants testing and ping limits are what happens. A very slight ping is OK, in fact it makes its best power on the edge of pinging, so use a nice up-grade to cause the engine to work when testing.


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## Glegor (Mar 31, 2008)

salz2135 said:


> Just wondering what others are running for ignition timing on modified 8v CIS cars. I searched and didn't find any of the threads relevant.
> 
> My base ignition timing is currently at 10 degrees BTDC
> CIS Lambda fueling
> ...


i run my 8v GTIs at around 18* timing. thats just a guess since theres no marks past 6*.. 

my 86 gets a little more timing for now, its got a low compression engine, and it doesnt have the boost hooked up to it yet..


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## ziddey (Apr 16, 2006)

Can anyone describe how much the knock box retards? I figure you won't be noticing any knocking, if the box is able to detect and pull timing right away, perhaps leaving you far less than if you simply set your base timing back a degree or two. I'm wondering particularly since I'm planning on going forced induction with cis-e + knock box. I'd like to have a fairly aggressive baseline timing so I can optimize highway fuel economy, with hopes of the box pulling timing as needed under boost (1. assuming it won't pull too much and 2. assuming it can even pull it quick enough). I'm dreaming of being able to run 10:1 (or 9.6:1 or whatever a big valve 8v c-flow on an obd1 aba would bring) with a smaller turbo (junkyard route-- saab c900/9000 t3 most likely) pushing cis-e's limits of ~170whp.

And sorry for the threadjack. FWIW, on my fox, which has 9:1 and no knock box, I've been running 10*BTDC. I use 87oct. 12*btdc seems to ping sometimes under load on hot days. I do have a leaky head gasket too.

Which knock box did you get? 8v and 16v ones have different curves.


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## vwturbofox (Jul 31, 2010)

I use to run around 12 degrees on my old na with 10:1comp with 92 octane.Now i run 6 degrees and 20 psi with no ping but i run 92 octane and water/meth so my octane is above 100. so just bump the timing 1-2 degrees at a time and go do some hard pulls and find the sweet spot


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## salz2135 (Sep 18, 2006)

Thanks for the feedback, guys. 

I always run 92 octane fuel in the car. Unfortunately OR state law requires 10% ethanol to be added. 

I'll do some pulls and fine tune. Doubt I can get the car on the track.


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## EuroKid83 (Jan 26, 2005)

There's no need to run more than 32 to 34 degrees total timing which would be 8 to 10 degreed BTDC at idle. Too much timing can be bad.


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## Glegor (Mar 31, 2008)

salz2135 said:


> Thanks for the feedback, guys.
> 
> I always run 92 octane fuel in the car. Unfortunately OR state law requires 10% ethanol to be added.
> 
> I'll do some pulls and fine tune. Doubt I can get the car on the track.


 im pretty sure its a US federal law, not an oregon law. 

whoever thought of adding something that absorbs water, to gasoline, should be SHOT!! 

(just a side note) 

i recently bought a car, that had been sitting 10+ years, not even started once. had a half tank of fuel in it too. i figured the fuel would be scarry, and not burn at all. was expecting straight varnish. then i remembered back when this car got that tank of fuel, there was no ethanol in it. 

needless to say, i burnt every drop of that ancient fuel, no problem. 

if that car would have had ethanol blended fuel in it, i imagine there would be lots of problems, along with a half tank of sour gas.. another thing that happens now, when you let a car sit, the ethanol collects water, and kills your fuel pumps and fuel dizzys (on cars that have them) along with anything else sensitive to water in the fuel system.


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## ziddey (Apr 16, 2006)

not sure how legit this list is: http://pure-gas.org/index.jsp?stateprov=OR 
i do know that a lot of states in the midwest have e0 gas. i remember driving cross country and finding 87e0 to be a little more expensive than 89e10. 



> MW 50 is something of a misnomer, as it is actually a mixture of three fluids: 50% methanol acting primarily to achieve optimum anti-detonant effect, secondarily as an anti-freeze; 49.5% water; and 0.5% Schutzöl 39, an oil-based anti-corrosion additive.


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