# 12v VR6 CR:? / Head Spacers



## gtimagic (Feb 13, 2002)

Compression Ratios- Whats available? What can you make?

For 12v VR6/AAA engines
From C2
8.5:1
9:1
OEM metal= 10:1 
or 10.5:1 from MK4
Stock AAA Cor/MK3
10:1
OEM MK4 Metal
10.5:1 on Cor//MK3
What is the final CR if stacking 2 OEM HG on a MK3?
What is the final CR if stacking 2 OEM MK4 HG on a MK3?
Are there any HG's that yield 9.5:1 CR? 



_Modified by gtimagic at 9:27 AM 12-13-2007_


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## SilverTrek12v (Dec 28, 2005)

You can use 8.5/1 spacer with 2 mk4 HG,one on each side to get 8:1CR


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## Noobercorn (Aug 17, 2007)

*Re: (SilverTrek12v)*

i thought the MK4 gasket actually raised the compression of a MK3/rado motor? 
~.5:1 as far as i know. i may be wrong tho....
from schimmels site............

*Steel gasket that will raise compression to 10.5:1 on 1992-1998 VR6
$55.00*

Steel gasket and reusable spacer stock compression - 12v
$195.00

Steel gasket and reusable spacer to lower compression to 9:1 - 12v
$195.00

Steel gasket and reusable spacer to lower compression to 9:1 - 24v
$265.00

Steel gasket and reusable spacer lower compression to 9:1 24v-R32
$265.00

Steel gasket and reusable spacer lower compression to 8.5:1 - 12v
$195.00




_Modified by Noobercorn at 8:29 PM 12-7-2007_


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## C2Motorsports (Nov 25, 2003)

*Re: 12v VR6 CR:? / Head Spacers (gtimagic)*

Out of curiosity "why" the target of 9.5?


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## gtimagic (Feb 13, 2002)

*Re: 12v VR6 CR:? / Head Spacers (C2Motorsports)*


_Quote, originally posted by *C2Motorsports* »_
Out of curiosity "why" the target of 9.5?

not too low, not quite stock (10:1)


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## redled_ (Sep 21, 2004)

*Re: 12v VR6 CR:? / Head Spacers (gtimagic)*

Too low for what?


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## Noobercorn (Aug 17, 2007)

*Re: 12v VR6 CR:? / Head Spacers (redled_)*

keith, if you are going turbo, just go to 8.5:1


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## gtimagic (Feb 13, 2002)

too low for daily driver SC'er making around 12psi. I dont want a dog if I aint boostin at WOT/6K
Stickly SC mike, no turbo for me, no IC for me. I'll sell it & go NA b4 that happens.


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## Noobercorn (Aug 17, 2007)

*Re: (gtimagic)*

werd.


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## CDJetta (May 11, 2004)

*Re: (Noobercorn)*

Are you serious? I was running 11/12 psi with no intercooler/meth on my turbo setup which holds that boost level longer than your SC setup does. I wouldn't worry about "dogging" it with that kind of boost level on a SC.
I'm not up to 16psi on a stock compression with my turbo setup and now have methanol. The levels of boost to run that you hear on the vortex are very conservative in my view.


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## websaabn (May 23, 2003)

*Re: (CDJetta)*

i am running 12-13 psi on my vr sc with stock comp spraying meth/h2o, i was thinking about going to a mk4 to get 10.5 to 1, don't worry about lowering the comp


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## Noobercorn (Aug 17, 2007)

*Re: (websaabn)*

there is "possible" and "safe". i was 15 psi turboed on stock compression, non intercooled. i also had LOTS of meth spraying. 
SC systems don't hold the boost at that level like a turbo will, so i agree with the "go for it" approach. 
however, as mentioned, keith needs a big turbo on that ride of his!!!!


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## gtimagic (Feb 13, 2002)

well, I have an MK4HG w. 262's and the SC capable of 13psi. 
I have a custom made cogged pulley setup that yields consistent boost w/o slip. 
When running a 7 rib set up I could near redline and timing would be pulled do to knock/higher compression. 
With the cogged set up, it basically starts pulling timing around 4700rpms & the engine hits a wall by 5500.
If I part 1/5 throttle it will still climb to near redline, but @ WOT (full boost) 47-5500 is where it stops. 
I need to lower the CR to avoid this massive retard of timing. 
How much is the question?
a few tuners have told me that the MK4 HG has even caused knocking issues in stock cars(where originally a 10:1, not 10.5:1) ...
Will the 'kits' called for stock 10:1 be enough? ...not sure
Will going to 9:1 be a safer better as far as knock/tuning issues? ...yeah, def.
Will 9:1 make it a dead dog down low & while out of boost? .. I'm not sure and def. dont want this. Yet HG swapping is an expensive & timely ordeal that I am not looking to 'experiment' with.
..hence my hopes of finding a 9.5:1 combination that may yield compromised results. 
Currently working w/ a tuner & Vagcom data logging to see whats possible cause/best fix,solution, etc.. 
custom tune/lower CR, ????


_Modified by gtimagic at 11:52 AM 12-16-2007_


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## Noobercorn (Aug 17, 2007)

*Re: (gtimagic)*


_Quote, originally posted by *gtimagic* »_
a few tuners have told me that the MK4 HG has even caused knocking issues in stock cars(where originally a 10:1, not 10.5:1) ...

what i'm saying is that if you have a stock MK4 gasket in your car, you are running 10.5:1 compression. which could be why you are seeing the timing retard. 
http://****************.com/smile/emthup.gif 
go with stock, or 9.5 and yer set. but, if you are gonna do it, i would go all out, and plan for more power down the road. i mean, i know you are saying you don;t want any more, but we all said that at once


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## gtimagic (Feb 13, 2002)

*Re: (Noobercorn)*

I know its 10.5:1 now, and is def a cause of the retard.
a 9.5:1 doesnt exist to my knowledge, thats why I started this thread. To see if it could be achieved from a combination of stacked spacers/gaskets. 
so now its either stock 10:1 or 9:1. As I am on a charger seeing max impeller speed @ 7000 & yielding aprox 15psi there, I'm done. Honestly thats fine for me.


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## redled_ (Sep 21, 2004)

*Re: (gtimagic)*

You should be able to get an 8.5:1 spacer milled down or even have one made by giving a gasket to a machine shop.


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## doobsta (Aug 25, 2003)

*Re: (redled_)*

thickness required for 8:5:1?


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## Noobercorn (Aug 17, 2007)

*Re: (doobsta)*


_Quote, originally posted by *doobsta* »_thickness required for 8:5:1?

C2 doesn't release that, and i know schimmel won't either. 
kinda a "trade" secret i guess. makes sense.


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## doobsta (Aug 25, 2003)

*Re: (Noobercorn)*


_Quote, originally posted by *Noobercorn* »_
C2 doesn't release that, and i know schimmel won't either. 
kinda a "trade" secret i guess. makes sense. 

doubtfull lol...
I hjave a 9:1 here, I can just take a micrometer and measure it.
as for 8:5:1 need to find someone else who can do the same.
I am wondering if having one cut out from a machinist would work as well as the c2 or SP ones.


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## Noobercorn (Aug 17, 2007)

*Re: (doobsta)*


_Quote, originally posted by *doobsta* »_
doubtfull lol....

ask them. i know the answer because i have already asked the question. http://****************.com/smile/emthup.gif


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## C2Motorsports (Nov 25, 2003)

*Re: (Noobercorn)*


_Quote, originally posted by *Noobercorn* »_
C2 doesn't release that, and i know schimmel won't either. 
kinda a "trade" secret i guess. makes sense. 


C2: 8.5:1 12v VR6 ~.120"


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## Noobercorn (Aug 17, 2007)

*Re: (C2Motorsports)*


_Quote, originally posted by *C2Motorsports* »_

C2: 8.5:1 12v VR6 ~.120"

um, why wouldn't you guys tell me that A YEAR ago.


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## C2Motorsports (Nov 25, 2003)

*Re: (doobsta)*


_Quote, originally posted by *doobsta* »_

I am wondering if having one cut out from a machinist would work as well as the c2 or SP ones.

They are ONLY $199 and that INCLUDES the metal crush gaskets....I think you will pay more having a machinist make you one, and then purchase the metal gaskets.
OH YEAH...and we have a stack of them in stock...so there is no waiting on aisle 4


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## doobsta (Aug 25, 2003)

*Re: (C2Motorsports)*


_Quote, originally posted by *C2Motorsports* »_

C2: 8.5:1 12v VR6 ~.120"

nice no secret in that.
Altho I would probably just buy one its always fun to know.
http://****************.com/smile/emthup.gif


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## CDJetta (May 11, 2004)

*Re: (doobsta)*

I'm thinking about running a stock compression gasket with 16-20psi of boost.







I'm crazy like that though.
Edit... a copper one that is with LOTS of cooling.


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## Dubbed_Monk (Feb 18, 2004)

*Re: (gtimagic)*


_Quote, originally posted by *gtimagic* »_well, I have an MK4HG w. 262's and the SC capable of 13psi. 
I have a custom made cogged pulley setup that yields consistent boost w/o slip. 
_Modified by gtimagic at 11:52 AM 12-16-2007_


This is a little of topic, but where did u get a cogged pulley set-up made?


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## gtimagic (Feb 13, 2002)

*Re: (Dubbed_Monk)*


_Quote, originally posted by *Dubbed_Monk* »_

This is a little of topic, but where did u get a cogged pulley set-up made?

the kits are still on the 'custom' side right now but should be available through Verdict MotorSports and http://www.TheDubNutz.com.
Currently there is a kit available for the VF based kits and mine is the developer kit for the C2/eurotech V1/V2 based kits. 
My kit is capable of 13-15psi depending on your redline & works w/ AC cars. 
IM for any additional details as I'd like to keep this thread on topic.


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