Compression Ratio

[SYCK SS]

So as you all know i am in the process of rebuilding my motor.

One of the many decisions that needs to be made is what compression ratio to set the motor up with. So i thought i would get some opinions on what you all think about what CR to run.

What are your thoughts on the differences between HIGH CR / LOWER BOOST or LOW CR / HIGHER BOOST.

To also give a little aid i will use my motor for example. I will basically daily drive my car (except in winter) and occasionally take a trip out to the track. I will have my car setup for 3 stages... 10psi - 16psi - 20psi(track only)+

So what do you guys/gals think?

[Crime2]

So as you all know i am in the process of rebuilding my motor.

One of the many decisions that needs to be made is what compression ratio to set the motor up with. So i thought i would get some opinions on what you all think about what CR to run.

What are your thoughts on the differences between HIGH CR / LOWER BOOST or LOW CR / HIGHER BOOST.

To also give a little aid i will use my motor for example. I will basically daily drive my car (except in winter) and occasionally take a trip out to the track. I will have my car setup for 3 stages... 10psi - 16psi - 20psi(track only)+

So what do you guys/gals think?

I'm running 9:4:1 on my setup. Don't mind it because if a ever get some bum gas should still be safe when in boost.


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[SYCK SS]

I'm running 9:4:1 on my setup. Don't mind it because if a ever get some bum gas should still be safe when in boost.


Sent from my iPhone using Tapatalk. If it is spelllled wrong, deal with it.

Hows down low power before spool up?

sent from my galaxy s3. that would explain the errors.

[Crime2]

Hows down low power before spool up?

sent from my galaxy s3. that would explain the errors.

Not bad but not good. It likes to be in boost.


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[SYCK SS]

Not bad but not good. It likes to be in boost.


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Wish you didn't move down south lol. But that's kinda what I was thinking it would be like.

sent from my galaxy s3. that would explain the errors.

[Crime2]

Wish you didn't move down south lol. But that's kinda what I was thinking it would be like.

sent from my galaxy s3. that would explain the errors.

Do a cam that makes some nice power down low and that will make up for it.


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[SYCK SS]

What I need is to move down by you and Matt lol

sent from my galaxy s3. that would explain the errors.

[Crime2]

What I need is to move down by you and Matt lol

sent from my galaxy s3. that would explain the errors.

Now that's a good idea!! Just had him do a handful of work including a full retune. It's like a new car!


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[SYCK SS]

Now that's a good idea!! Just had him do a handful of work including a full retune. It's like a new car!


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i was thinking about shipping the car down after the work for help tuning her. but its probably a good thing i am so far away, saves me money... kinda lol

[SYCK SS]

I'm running 9:4:1 on my setup. Don't mind it because if a ever get some bum gas should still be safe when in boost.


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did you do a -11cc piston with a .051 headgasket? stock heads?

[Crime2]

did you do a -11cc piston with a .051 headgasket? stock heads?

Stock heads worked over some. They are Diamond pistons but don't remember the size or head gasket.


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[litle88]

It's all in the timing and the gas you'll be using bud. So you can go 10.-1 BUT timing will have to be retarded and get it right on the sweet spot for ALL boost levels. Your kinda going to need 3 tunes. 20lbs and at that level you'll be needing that sweet smelling gogo juice and that's a tune all by itself.

Hope it's all going good so far bud.

[SYCK SS]

It's all in the timing and the gas you'll be using bud. So you can go 10.-1 BUT timing will have to be retarded and get it right on the sweet spot for ALL boost levels. Your kinda going to need 3 tunes. 20lbs and at that level you'll be needing that sweet smelling gogo juice and that's a tune all by itself.

Hope it's all going good so far bud.

Totally agreed. I learned the hard way how important tuning and fuel is. I like the idea of higher compression to aid turbo spool and daily drivability. But also like Crime2 said, like the lower compression for the what if moments.

Plus another thing it seems like i am faced with, to get anything over a 9.6 CR, i have to lose the dished piston and go with a flat top. Unless i go custom piston that is.

I was thinking i could pull off 20psi with the aid of my meth. Spraying 2 -550cc nozzles that is.

[Crime2]

Totally agreed. I learned the hard way how important tuning and fuel is. I like the idea of higher compression to aid turbo spool and daily drivability. But also like Crime2 said, like the lower compression for the what if moments.

Plus another thing it seems like i am faced with, to get anything over a 9.6 CR, i have to lose the dished piston and go with a flat top. Unless i go custom piston that is.

I was thinking i could pull off 20psi with the aid of my meth. Spraying 2 -550cc nozzles that is.

Be careful with the AEM pump, it's JUNK. Was out this morning toying around and my pump took a s@!t at WOT. Thankfully my tune is setup correct and it yanked all the timing and the car fell flat on its face. Going to pull all the AEM stuff and get the Allky Control setup real soon. Matt at FSP warned me about the AEM and sure enough it failed.


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[SYCK SS]

Be careful with the AEM pump, it's JUNK. Was out this morning toying around and my pump took a s@!t at WOT. Thankfully my tune is setup correct and it yanked all the timing and the car fell flat on its face. Going to pull all the AEM stuff and get the Allky Control setup real soon. Matt at FSP warned me about the AEM and sure enough it failed.


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dont scare me like that! lol how long did it last you before crappping out?