# Question for experts.....cam timing affect on turbo spool .........



## Salsa GTI (Aug 29, 2000)

SO that is the Question how does cam timing affect turbo spool.....??
does advancing the cam make the turbo spool earlier or later?
I know more cam over-lap will delay spool.......what are the effects or advancing the cam on spool?
PS this is an ABA turbo currently running 22psi...dyno to be done at h20










_Modified by Salsa GTI at 10:01 PM 9-24-2007_


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## dub101 (Jul 19, 2002)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*

I have heard that 3 or so degrees retard on a 2.0T is good for 30 or so hp up top because it increases the time for fuel burn at tdc in higher rpms. However I have messed with mine 3 degrees advance and retard and in the butt dyno advance feels better however it might just be that it pulls harder off the bottom making the transition into boost feel quicker. Does that make sense? Note I am also experimenting with a AEG 2.0L cam. However I would probably bet that a little retard will make more power however it will feel sloggish on the street.
Hope this helps
Stan


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## VDUBIN (Jun 28, 2001)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*

as far as I know cam timing doesn't affect spool up time, if it did it would only be by 1-200 rpm. But advancing does give you more bottom end torque and retarding it will give you more high rpm hp.
So, chose do you want butt puckering hole launch or higher top speed?


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## Salsa GTI (Aug 29, 2000)

*Re: Question for experts.....cam timing affect on turbo spool ......... (VDUBIN)*


_Quote, originally posted by *VDUBIN* »_as far as I know cam timing doesn't affect spool up time, if it did it would only be by 1-200 rpm. But advancing does give you more bottom end torque and retarding it will give you more high rpm hp.
So, chose do you want butt puckering hole launch or higher top speed?

Cam timing and power band Iv'e known for decades.....and i lent out my copy of maximum boost and cant locate it at the moment








so if there is no affect on spool I'll just tune for power curve.
Thanks for the input


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## mikemcnair (Mar 28, 2003)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*


_Quote, originally posted by *Salsa GTI* »_
Cam timing and power band Iv'e known for decades.....and i lent out my copy of maximum boost and cant locate it at the moment








so if there is no affect on spool I'll just tune for power curve.
Thanks for the input









the only thing you can do now is put a VRT in there and make some REAL hp.........
noob.


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## Salsa GTI (Aug 29, 2000)

*Re: Question for experts.....cam timing affect on turbo spool ......... (mikemcnair)*

perhaps if it was a 24 valve model.........but the head flow on the 12 valve is close to the 8v engine....so who cares.....next step is obd1 aba and multi valve head on megasquirt.....I need a vr like a hole in the wallet.....
your just lucky i was loading beer into my car....or i would have shown you how slow your vr realy is


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## mikemcnair (Mar 28, 2003)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*


_Quote, originally posted by *Salsa GTI* »_or i would have shown you how slow your vr realy is









only vah gi nahs race on the internet. fu ck off.


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## Salsa GTI (Aug 29, 2000)

*Re: Question for experts.....cam timing affect on turbo spool ......... (mikemcnair)*


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## GTijoejoe (Oct 6, 2001)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*

I would assume (advancing), only because it brings your power sooner in the power band, that therefore there would be more exhaust energy equating to quicker spool up.
I have no evidence of such a thing.... i'm just talking


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## kimosullivan (Aug 12, 2002)

*Re: Question for experts.....cam timing affect on turbo spool ......... (Salsa GTI)*

I figure advancing the cam causes the exhaust to open early, and therefore dump more energy into the exhaust manifold and turbine, so it should spool faster. Are you having problems with lag to begin with?


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## SELFMADE (Mar 30, 2006)

When I dyno`d 309whp I was running the cam timing 1 full tooth retarded on a stock cam gear. 
Vehicle wouldnt spool til 4k-ish and pulled to the 7k rev limiter. Anybody know how many degrees one tooth is?


_Modified by SELFMADE at 2:16 AM 10-3-2007_


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## Salsa GTI (Aug 29, 2000)

*Re: (SELFMADE)*


_Quote, originally posted by *SELFMADE* »_When I dyno`d 309whp I was running the cam timing 1 full tooth retarded on a stock cam gear. 
Vehicle wouldnt spool til 4k-ish and pulled to the 7k rev limiter. Anybody know how many degrees one tooth is?

_Modified by SELFMADE at 2:16 AM 10-3-2007_

No but I will find out what the exact degree is....I'm going to pull mine back as soon as i degree the damn thing to see how far spacing the head advances the whole mess......


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## sxracer001 (Jun 27, 2005)

i believe a whole tooth = about 8 degrees, but dont quote me on that


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