Which Compression Ratio?
Thread Starter
Registered User
Joined: Sep 2009
Posts: 420
Likes: 0
Which Compression Ratio?
I had my shortblock sent to laskey racing 2 days ago and should get there tomorrow. I am having him put in the CP 9.7 cr pistons but am starting to think that might be too much and should have picked 9 instead.
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?
Joined: Feb 2008
Posts: 3,964
Likes: 7
From: USA
I believe you may be pushing it on 9 or 9:7. 550WHP is a tall order even for a low compression motor.
Did you talk with Toan about a GT35R or GTX35R? The GT3076 is hard to get past 500WHP the X will help some but it sounds like the 35R would be a better choice for your goals and leave you pleanty of head room
Since you will be running a trubo setup now the 9:1 would be the prefered piston in my mind. Had you kept the supercharger I would have definatly suggested the 9:7.
Keep us up to date.
Did you talk with Toan about a GT35R or GTX35R? The GT3076 is hard to get past 500WHP the X will help some but it sounds like the 35R would be a better choice for your goals and leave you pleanty of head room
Since you will be running a trubo setup now the 9:1 would be the prefered piston in my mind. Had you kept the supercharger I would have definatly suggested the 9:7.
Keep us up to date.
Thread Starter
Registered User
Joined: Sep 2009
Posts: 420
Likes: 0
Well I figured there are quite a few people making those numbers with the 3mm HG trick but the downside of that is I read about too many people blowing thier HG.
The 3mm HG lowers the CR to what? 9.2? im not quite sure.
So currently my block is on its way to Mike Laskey and on the 15th my head is going to Combustion Contraption for the Max Flow package. I'm just trying to make the car as reliable as possible after I put it all together. Its not my DD but I don't want to have to constantly fix it.
next would be the diff and tranny of course
The 3mm HG lowers the CR to what? 9.2? im not quite sure.
So currently my block is on its way to Mike Laskey and on the 15th my head is going to Combustion Contraption for the Max Flow package. I'm just trying to make the car as reliable as possible after I put it all together. Its not my DD but I don't want to have to constantly fix it.
next would be the diff and tranny of course
Registered User
Joined: May 2008
Posts: 3,791
Likes: 1
From: Around
Originally Posted by Blucky87,Dec 8 2010, 06:22 AM
I had my shortblock sent to laskey racing 2 days ago and should get there tomorrow. I am having him put in the CP 9.7 cr pistons but am starting to think that might be too much and should have picked 9 instead.
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?
Even if they were 9.1, I'd still say that.
Simple setup.
30r
500whp
meth kit + pump gas.
Solid.
Thread Starter
Registered User
Joined: Sep 2009
Posts: 420
Likes: 0
Ok so I guess i can set my goals a little lower. 500 isn't that bad.
so if I choose the 500 goal just keep it 9.7? or spring for the 9?
I'm not sure about adding meth to make more power if 500 is doable without it.
so if I choose the 500 goal just keep it 9.7? or spring for the 9?
I'm not sure about adding meth to make more power if 500 is doable without it.
Trending Topics
Joined: Dec 2004
Posts: 1,108
Likes: 4
Originally Posted by dsddcd,Dec 8 2010, 10:41 AM
I was refereing to a GT35X I should have specified
I understand what you are saying but one needs to think about the entire picture here. I had heard rumors of this same thing so I made my owne map just to compair. You are correct that is in the case of the Compressor efficencies. The efficancy of the new GTX wheel at the same mass flow and pressure ratio's are as good or better than the GT35. However there is a LOT more to it than just compressor wheels here, their are a few things to think about.
1.) Turbine Wheel design, the turbine on the GT35 is larger which means greater exhaust flow potential
2.) Also note that the GT30R reqires higher MUCH higher wheel velocities to achive the same pressure level. So will it really spool much faster.
There are other questions to be asked here but which trubo will be best for the OP is something he needs to talk with PTunning and his tuner about.
I understand what you are saying but one needs to think about the entire picture here. I had heard rumors of this same thing so I made my owne map just to compair. You are correct that is in the case of the Compressor efficencies. The efficancy of the new GTX wheel at the same mass flow and pressure ratio's are as good or better than the GT35. However there is a LOT more to it than just compressor wheels here, their are a few things to think about.
1.) Turbine Wheel design, the turbine on the GT35 is larger which means greater exhaust flow potential
2.) Also note that the GT30R reqires higher MUCH higher wheel velocities to achive the same pressure level. So will it really spool much faster.
There are other questions to be asked here but which trubo will be best for the OP is something he needs to talk with PTunning and his tuner about.
And thaks for the graph. I like that over-lay you did.
GTX35R and this guy is in business though.
Its going to be a fun turbo year in 2011 with the new EFR series coming out from borg warner. I held one of there new titanium cast turbine wheels and it was so light that it blew my mind!
Oh its going to be fun for 2011 for us FI guys.
J. R.
Joined: Feb 2008
Posts: 3,964
Likes: 7
From: USA
Originally Posted by flexer,Dec 8 2010, 11:53 PM
tushay.....
And thaks for the graph. I like that over-lay you did.
GTX35R and this guy is in business though.
Its going to be a fun turbo year in 2011 with the new EFR series coming out from borg warner. I held one of there new titanium cast turbine wheels and it was so light that it blew my mind!
Oh its going to be fun for 2011 for us FI guys.
J. R.
And thaks for the graph. I like that over-lay you did.
GTX35R and this guy is in business though.
Its going to be a fun turbo year in 2011 with the new EFR series coming out from borg warner. I held one of there new titanium cast turbine wheels and it was so light that it blew my mind!
Oh its going to be fun for 2011 for us FI guys.
J. R.
Cant wait to see how the new Borg Warners do, I really like the internal wastegate and BOV. This should simplily the installs greatly
Registered User
Joined: Jul 2007
Posts: 502
Likes: 0
From: Tampa, Florida
Originally Posted by Blucky87,Dec 8 2010, 06:22 AM
I had my shortblock sent to laskey racing 2 days ago and should get there tomorrow. I am having him put in the CP 9.7 cr pistons but am starting to think that might be too much and should have picked 9 instead.
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?
My goal is a reliable ~550 whp with ptunings turbo kit and a gtx3076r (providing the new gtx can make that much) , should I have it lowered to 9 or is 9.7 fine?