# vr6 head spacers... difference between 8:5:1 and 9:1



## doobsta (Aug 25, 2003)

Obviously one is lower come then the other, but what exactly is the difference perfromace wise?
Only thing I can think of is 8:5:1 is good for 20psi and 9:1 is good for 15psi?
what are the parameters for boost of each spacer?


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## hubbell (Oct 30, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*

it would depend if its turbo or SC since turbo will see full bost at 3500RPMS whereas a SC wont see full boost until 6500RPMS+ so 15 psi with a 9.0:1 wouldnt be recommended for turbo but it would for a SC....you might be better off asking a recommendatio pending what setup you want to run....


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (hubbell)*

cool,
i was talking in general, but for turbo instance 9:1 is enough to push 20psi?


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## hubbell (Oct 30, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*

turbo and 20 psi you should be going for the 8.5:1


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## puebla (Sep 9, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (hubbell)*

8.5:1 for a turbo, and 9.0:1 for a supercharger.


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (hazw8st)*

thank you








im guessing the 8:5:1 turbo cause you can push more psi right?
can a Sc run a 8:5:1 also?


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## puebla (Sep 9, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*


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## I am Jack's VR6 (Sep 18, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*

I went 8.5:1 and I regret it. You can run more boost than most people think here on 9:1. I think people tend to be overly conservative.
Read this and make up your own mind -
http://www.motorsportsdigest.com/forced2.htm


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (I am Jack's VR6)*

Why would you regret it tho?
Does the car run worse or something?
Please elaborate, thanks


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## puebla (Sep 9, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*

8.5:1 c/r is way harder to tune correctly on a daily driver....


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## oettingerst (Mar 2, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (hazw8st)*

9:1 ratio running 15psi with 91 octane, pushiing 18psi with 100 octane so far so good. dynoed at 340hp at the wheel with 15psi.

OT


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## -:VW:- (Jan 27, 2006)

_Quote »_You can run more boost than most people think here on 9:1.

Yup, it's also all in the tuning. Choosing a compression ratio by basing it off of HOW your making the boost (S/C or T) is a little retarded IMO. Mole made over 400Whp on 9:1. Most of the newer factory turbo'd vehicles have a compression ration of 9:1, EVO, MKV GTI, etc. etc. Tunning.....


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## Vdubsolo (Apr 11, 2004)

*Re: (-:VW*


_Quote, originally posted by *-:VW:-* »_
Yup, it's also all in the tuning. Choosing a compression ratio by basing it off of HOW your making the boost (S/C or T) is a little retarded IMO. Mole made over 400Whp on 9:1. Most of the newer factory turbo'd vehicles have a compression ration of 9:1, EVO, MKV GTI, etc. etc. Tunning.....

Mole also has a fully built turbo ported head on his car..


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## -:VW:- (Jan 27, 2006)

*Re: (Vdubsolo)*

That doesn't change it from being 9:1.


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## I am Jack's VR6 (Sep 18, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*


_Quote, originally posted by *doobsta* »_Why would you regret it tho?
Does the car run worse or something?
Please elaborate, thanks









I regret it because I didn't research it enough before I made my decision. You will make more power with less boost if you go 9:1. Your car will be more responsive off boost and you will get better fuel efficiency to boot.
I don't think you will hit the limit of 9:1 compression on a VR with the chip management options out there now. I just don't see any reason to go 8.5:1.


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## Vdubsolo (Apr 11, 2004)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (I am Jack's VR6)*


_Quote, originally posted by *I am Jack’s VR6* »_
I regret it because I didn't research it enough before I made my decision. You will make more power with less boost if you go 9:1. Your car will be more responsive off boost and you will get better fuel efficiency to boot.
I don't think you will hit the limit of 9:1 compression on a VR with the chip management options out there now. I just don't see any reason to go 8.5:1.


How much boost were you running?? I went with the 8.5.1 spacer and plan on boosting 20psi...not to worried about low end power because i wont be hooking up in 1st or 2nd..I agree if you are running no more than 15 psi range then 8.5.1 might be overkill but if you are running 18-22psi..the 8.5.1 is where its at IMO..


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Vdubsolo)*

anyone running 18-22 psi with a 9:1 spacer?


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## puebla (Sep 9, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*


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## I am Jack's VR6 (Sep 18, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Vdubsolo)*


_Quote, originally posted by *Vdubsolo* »_How much boost were you running?? I went with the 8.5.1 spacer and plan on boosting 20psi...not to worried about low end power because i wont be hooking up in 1st or 2nd..I agree if you are running no more than 15 psi range then 8.5.1 might be overkill but if you are running 18-22psi..the 8.5.1 is where its at IMO..

I was running about 1 bar on 91 octane.
Why do you say you need 8.5:1 for 18-22 pounds? Where are you getting this information? I hope it's not just from this site...


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## Vdubsolo (Apr 11, 2004)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (I am Jack's VR6)*


_Quote, originally posted by *I am Jack’s VR6* »_
I was running about 1 bar on 91 octane.
Why do you say you need 8.5:1 for 18-22 pounds? Where are you getting this information? I hope it's not just from this site...

its safer with the lower compression imo..I got thiss info from the fella who is tunning my car...thats why i went with 8.5.1


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## Ohio Brian (Aug 13, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (I am Jack's VR6)*


_Quote, originally posted by *I am Jack’s VR6* »_ Your car will be more responsive off boost and you will get better fuel efficiency to boot.


I tuned my car with an 8.5:1 HG and I hardly notice any difference now off boost. 
Like someone said, it's all in the tuning.


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Ohio Brian)*

sure, but what is your setup and software?


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## Ohio Brian (Aug 13, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (doobsta)*

Stock motor, head spacer, 42#'ers, and Jeff-based tuning. More or less.


_Modified by Ohio Brian at 10:44 PM 5-11-2006_


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## JDriver1.8t (May 20, 2005)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Ohio Brian)*

It seems mildly related so:
What would be considered 'safe' boost on a 10:1 motor? Less than 10 lbs?


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## bstdvr (Jun 11, 2004)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (JDriver1.8t)*

no more then 10 to be safe on a daily driver with software......standalone and a good tune you have capabilities to run more boost safely


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## Ohio Brian (Aug 13, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (bstdvr)*

The last 4-5 months I had my stock headgasket on I was running 12-13 psi on pump gas. 
I really think (and so do a few others) that with the right tune, a stock headgasket can take 15 psi.


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## fastslc (Sep 14, 1999)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Ohio Brian)*

^^ Wow.. for real ? 
That's impressive.. Stock everything too ? ie pistons, rods, cams ?
nice


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## I am Jack's VR6 (Sep 18, 2001)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Ohio Brian)*


_Quote, originally posted by *Ohio Brian* »_I tuned my car with an 8.5:1 HG and I hardly notice any difference now off boost. 
Like someone said, it's all in the tuning.









Just because you don't notice it, doesn't mean it isn't there. It's a proven fact that higher compression motors are more responsive and more fuel efficient with higher compression.
You should read that link I posted above if you haven't already. It's got some good info.


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## doobsta (Aug 25, 2003)

*Re: vr6 head spacers... difference between 8:5:1 and 9:1 (Ohio Brian)*


_Quote, originally posted by *Ohio Brian* »_The last 4-5 months I had my stock headgasket on I was running 12-13 psi on pump gas. 
I really think (and so do a few others) that with the right tune, a stock headgasket can take 15 psi. 

I would agree, the part that is missing in all our equations is "the right tune"
What would be the right tune?
Not everyone is in proximity or able to have someone custom tune their car or even go standalone. So what options are left plug n play ala ex: c2 software wise to make this work at 15 psi?


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## black97GTI (Oct 22, 2004)

ok im going to be using the 034 motorsports standalone setup with a t04 probaly going to be at around 20psi. i was going to use a 8.5:1 spacer but after reading this im not sure if i should get the 8.5:1 or the 9:1


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## doobsta (Aug 25, 2003)

*Re: (black97GTI)*

good thread doobs, now we are creating controversy!


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## Ohio Brian (Aug 13, 2001)

*Re: (doobsta)*

When I say "hardly notice a difference off boost" I mean that the car is by no means a dog. I can tell it's a little less efficient because I have to use the pedal more to keep speed while cruising. But that's about it. 
And I did run stock EVERYTHING on 12-13 psi. I think my stock headgasket tune is better than my 8.5:1 tune so far. I was kinda bummed I had to "start" again. 
People can read the internet all day long and say this is better than that and so forth. I spent that time tweaking my car to make it drive nice and pull hard. I think just now after 5 years of boost my bottom end might be getting tired (120-130psi compression), but it feels faster than ever.


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## bstdvr (Jun 11, 2004)

*Re: (Ohio Brian)*

i second the 12psi on stock headgasket!!!! done it for about 3 years before i got the spacer. I have 8.5:1 gasket and have hit 22psi without any problems on c2 software for about 2 years. Little slugish down low but nothing DTA cant solve.


_Modified by bstdvr at 8:55 PM 5-14-2006_


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## D Wiz (Jun 20, 2003)

*Re: (bstdvr)*

how about no spacer headgasket and work on tuning:
roel models of cars
the old schimmel stock block jetta, turbo dub 2.0, TONS of peopel on stock upopened blocks 10:1. tuning is the key


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## doobsta (Aug 25, 2003)

the only thing I can think of whe you guys say work on tuning is standalone....
alot of people fear going that route for the time and $$$


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## bstdvr (Jun 11, 2004)

*Re: (doobsta)*

its worth it when your car runs perfectly


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## VRQUICK (Sep 20, 2000)

*Re: (D Wiz)*


_Quote, originally posted by *D Wiz* »_how about no spacer headgasket and work on tuning:
roel models of cars
the old schimmel stock block jetta, turbo dub 2.0, TONS of peopel on stock upopened blocks 10:1. tuning is the key

When Brians jetta had the stock block it still had a eurospec 8.5:1 head gasket. Pointless to run a VR6 on high boost with stock compression cause you will have no timing.


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## black97GTI (Oct 22, 2004)

my block is bored out to a 3.0L if i went with a 8.5:1 spacer what would my actual compression be?
thanks


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## -:VW:- (Jan 27, 2006)

*Re: (black97GTI)*

8ish


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## puebla (Sep 9, 2003)

*Re: (VRQUICK)*


_Quote, originally posted by *VRQUICK* »_When Brians jetta had the stock block it still had a eurospec 8.5:1 head gasket. Pointless to run a VR6 on high boost with stock compression cause you will have no timing. 
 http://****************.com/smile/emthup.gif


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## I am Jack's VR6 (Sep 18, 2001)

*Re: (VRQUICK)*


_Quote, originally posted by *VRQUICK* »_When Brians jetta had the stock block it still had a eurospec 8.5:1 head gasket. Pointless to run a VR6 on high boost with stock compression cause you will have no timing. 

No, it's pointless to run a VR6 on high boost, period.
You trap at 117 so you know what I'm getting at. How's traction under 70 mph on street tires? How's traction under 40 mph with radials?
To the guys making the decision: You may be able to make a lot of power with lower compression, but you can't put it down. What's the use? If these are daily drivers, don't waste your time with 8.5:1. It's overkill for a car that is driven off boost most of the time.


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## doobsta (Aug 25, 2003)

*Re: (I am Jack's VR6)*

what about fun factor?


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## I am Jack's VR6 (Sep 18, 2001)

*Re: (doobsta)*


_Quote, originally posted by *doobsta* »_what about fun factor?

Sounds like a waste to me. 


_Modified by I am Jack's VR6 at 7:21 AM 5-19-2006_


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## burtonguy567 (Apr 24, 2005)

*Re: (I am Jack's VR6)*


_Quote, originally posted by *I am Jack’s VR6* »_
Sounds like a waste to me. 

_Modified by I am Jack's VR6 at 7:21 AM 5-19-2006_

well thats why u have ur DSM for ur traction, as seen in the side...many people on here could car less if you think its a waste or not to run high boost because for some on here their goal is to just get the most HP out of a VR6 reguardless if it has traction or not...others run high boost for drag racing, whether u think its a waste or not to run high boost on a VR is ur opinion...but this thread is all about running high boost because in order to u need to lower ur compression aka-pistons/headspacer...ur info that u gave on the actual topic for daily driving was good http://****************.com/smile/emthup.gif but i dont know if its just me, but this thread is almost all about running high boost and its a little wierd to come in and say running high boost is pointless


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## I am Jack's VR6 (Sep 18, 2001)

*Re: (burtonguy567)*


_Quote, originally posted by *burtonguy567* »_well thats why u have ur DSM for ur traction, as seen in the side...many people on here could car less if you think its a waste or not to run high boost because for some on here their goal is to just get the most HP out of a VR6 reguardless if it has traction or not...others run high boost for drag racing, whether u think its a waste or not to run high boost on a VR is ur opinion...but this thread is all about running high boost because in order to u need to lower ur compression aka-pistons/headspacer...ur info that u gave on the actual topic for daily driving was good http://****************.com/smile/emthup.gif but i dont know if its just me, but this thread is almost all about running high boost and its a little wierd to come in and say running high boost is pointless









That's my opinion and I am fully entitled to post it. Considering my experience, I'm suprised you are telling me that I _should'nt_ post my thoughts.
How much boost are you running and at what compression?


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## puebla (Sep 9, 2003)

*Re: (I am Jack's VR6)*

9.0:1 c/r is ideal....


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## burtonguy567 (Apr 24, 2005)

*Re: (I am Jack's VR6)*

i dont' have exsperience with higher boost...im at stock compression...i wasn't saying that the info u gave was bad, i just thought that it was stupid saying that high boost in a VR is pointless, when this whole thread is about high boost VR6's and what the best headgasket spacer would be for a certain PSI...


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## puebla (Sep 9, 2003)

*Re: (burtonguy567)*

Boost is easy to make, power is easy to make.... now, putting that power down to the wheels is another story....


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## I am Jack's VR6 (Sep 18, 2001)

*Re: (burtonguy567)*


_Quote, originally posted by *burtonguy567* »_i dont' have exsperience with higher boost...im at stock compression...i wasn't saying that the info u gave was bad, i just thought that it was stupid saying that high boost in a VR is pointless, when this whole thread is about high boost VR6's and what the best headgasket spacer would be for a certain PSI...

I think you are missing the point entirely.
It _is_ pointless to drop compression lower than needed.
It's already proven that you can run low 20 psi on 9:1 compression. What I am talking about is beyond that, which should be a serious consideration.


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## kyle319 (Nov 26, 2010)

so how much boost can i push on a dd with a 9 comp?


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## dub_slug (May 12, 2008)

8.5:1 for _safety_ and 9.5:1 on e85 for the win. 

Don't forget a higher compression ratio will yield more torque and spool your turbo faster :thumbup: I'm sure you could run 9:1 on 20+psi 

I'm currently running 8.5:1 and honestly I don't even notice a difference


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## dub_slug (May 12, 2008)

No one Knows for sure how much boost you can run. It all depends on your setup and how cool it runs. If your turbo makes more heat then power; keep the boost low. If you've got something like a gt40,boost away! Lol 

More Efficient your setup is, more boost/power you can make


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## marat_g60 (Mar 5, 2003)

Sure you can run high boost on a VRT and many other engines. If you use the right boost controller and the right setup, you can do anything you like. Im running 22-24psi on 8.5:1 HD and have no regrets, I also have very good traction in pretty much every gear.


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## Fast929 (Nov 13, 2004)

Not VR related but planning on running 10:1 on pump with a Precision 5857 and some big'ish cams and shooting for 350-400whp with a heavily done 16v. I'll be running WI and might use a splash of 2-stroke oil in the fuel but I think I can do it on 15-18psi. 


I'll second tuning being key. We'll see what happens


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## dub_slug (May 12, 2008)

marat_g60 said:


> Sure you can run high boost on a VRT and many other engines. If you use the right boost controller and the right setup, you can do anything you like. Im running 22-24psi on 8.5:1 HD and have no regrets, I also have very good traction in pretty much every gear.


 8.5:1 in my opinion is a great compression ratio to run if your car is mainly going to be on pump gas. I've run 28psi on 93octane with no water/meth and didn't experience any problems. With water meth I'm sure a healthy 30psi would have been possible and relatively safe lol @28psi I start to lose traction in 4th/5th gear, anything below that forget about it. 





Fast929 said:


> Not VR related but planning on running 10:1 on pump with a Precision 5857 and some big'ish cams and shooting for 350-400whp with a heavily done 16v. I'll be running WI and might use a splash of 2-stroke oil in the fuel but I think I can do it on 15-18psi.
> I'll second tuning being key. We'll see what happens


 That sounds like alot of fun! Not much talk of e-85 in here, I'm sure that's the key to higher compression boost motors. I think the O34 A4 VR is running 9.5:1 on e85 making something over 700hp iirc


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## dub_slug (May 12, 2008)

dub_slug said:


> 8.5:1 in my opinion is a great compression ratio to run if your car is mainly going to be on pump gas.


 If you know your gonna get trigger happy with the boost, go 8.5:1. If you have extremely good self control, leave it at 10:1. It's already been stated that guys are running lots of boost on stock compression 

Lower the compression=more boost on pump gas


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## PjS860ct (Dec 22, 2002)

Ive been running stock engine with 9:1 spacer for 3years now at 24~25 psi on my pt-61 on Lugtronics with no problems except broken gears this past year. Lol 

my friends vrt runs 10:1 has forge pistons and runs about 15-18psi on obd1 c2 and beats the crap out of it with no problems...


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## JoHnsVrT (Feb 1, 2007)

My buddies 42r vr he runs 28 psi on a 9:1 spacer with just valves retainers and springs and its reliable.


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## vergessen wir es (May 12, 2010)

I just came across this topic while reading Corky Bell's maximum boost. 

He said 
"It is certainly reasonable to assume that low-speed driveablity is superior if the vehicle is fitted with an intercooler and the compression ratio is kept above 8:1." 

I ran my mk3 VR NA at 8.5:1 for a while before putting the turbo on. I thought the engine had plenty of pep down low before the turbo. The sluggishness in the low rpms came with the additional back-pressure from the turbo. Hoping to get some low end pep back with 3" exhaust and maybe a more open hot side.


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## Capt.Dreadz (Jun 4, 2003)

Until someone does back to back test in the same conditions using the same setup, no one has a definitive answer. It's like we all know women love sex yet we're arguing on how properly please them. :facepalm: 

70 different answers to 1 question...opcorn:


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## gongshowguy (Jul 21, 2010)

i just bought a 30r and debating on my headspacer as well also debatin on the injectors/tuning software i want 25 psi and my buddy said to run 420 or 630


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## PjS860ct (Dec 22, 2002)

^ whats ur power goal? I know u said 25 psi but what whp?... 30r is a good turbo for the street on a vr6... what exhaust housing do u hav on it?...


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## Love2Spool (Sep 10, 2010)

i think if your going for anything over 17psi a 8.5:1 should be your primary choice for a daily driver. IMO i think its safer. if you want responsiveness down low get a twin scroll DBB turbo and port the inlets, or get a smaller turbo, or get low grind cams. or bigger valves, or somehow screw around with your cam timing, or call your tuning company and get them to give you some more advance, or spray it, get a different intake manifold, or a different better flowing equal length exhaust manifold, or bigger TB, i can go on for a long time. there are tons of things to do to offset the half a point in compression. once you start dancing with alot of boost, IMO its better to have a lower comp ratio if your going to daily it. just my 2 cents


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## TBT-Syncro (Apr 28, 2001)

gongshowguy said:


> i just bought a 30r and debating on my headspacer as well also debatin on the injectors/tuning software i want 25 psi and my buddy said to run 420 or 630


 on a vr? you bought the wrong turbo. its going to start falling on it's face around 20 psi-ish. 

3076 is a great turbo on a 1.8T, but 35R is a much much better turbo on a VR. They spool almost the same on a Vr, but the 35R has way more top end. 

42lb setup is more than enough fueling for it.


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