High Compression Woes - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Bildo · 03-09-2015, 02:33 PM

So I recently added a set of PRC 255 heads to my car, along with Nitrous. I ordered the heads w/ 65cc chambers making my compression 11.4:1, I have decided to throw on a procharger, even with meth I suppose I will have to go back to my factory heads as the compression ratio is rather high for FI?

blake-b · 03-09-2015, 03:17 PM

No, if you have a good tuner it can be done. A high CR will narrow down your tuning window.

Unreal · 03-09-2015, 03:39 PM

11.4 isn't that bad. Just like Blake said, tuning window will be smaller, and it will take less timing, but totally doable.

Hell C7s are 11.5 and loving the boost.

Bo White · 03-09-2015, 05:39 PM

Exactly. I'm stock LS3 compression pushing 12psi

Bildo · 03-09-2015, 07:49 PM

Yeah I might just send the stock heads in to be ported and polished, and throw them back on and sell the PRC heads. I just ordered a D1SC stage II tuner kit....

stevieturbo · 03-10-2015, 03:24 PM

Stick a big cam on it

Unreal · 03-10-2015, 04:39 PM

Per Stevies point, static compression is just one thing, dynamic is another. You can have a cam that bleeds off compression, or one that makes it higher than you want.

Slowhawk · 03-10-2015, 04:42 PM

Depends on the cam. My personal car runs 11.5-1 on stock pistons. Planning 16lbs on it but I will have meth injection.

sr71bb · 03-10-2015, 04:45 PM

I run 11.3 with 21 pounds of boost and 18 degrees of timing on a F1R setup that makes over 1000 RWHP. Running E85 and progressive METH injection

H-E · 03-10-2015, 05:09 PM

You will be fine with a d1 and a good tuner

Todd in Vancouver · 03-10-2015, 05:12 PM

Interestsing comments. I'm biulding another cat and it has a Stealth Ram with 10.8:1 compression and I'd like to add twin turbos and was wondering if my compression was to high.

jrpxxii · 03-10-2015, 05:38 PM

You could get thicker head gaskets but you will be fine with that blower

03-09-2015, 02:33 PM	#1
Bildo Drives: 2012 2SS/RS LS3 Join Date: Dec 2011 Location: Omaha, Nebraska Posts: 1,677	High Compression Woes So I recently added a set of PRC 255 heads to my car, along with Nitrous. I ordered the heads w/ 65cc chambers making my compression 11.4:1, I have decided to throw on a procharger, even with meth I suppose I will have to go back to my factory heads as the compression ratio is rather high for FI?

03-09-2015, 03:39 PM	#3
Unreal Drives: 2006 Z06 Join Date: Oct 2010 Location: Gilbert, AZ Posts: 5,712	11.4 isn't that bad. Just like Blake said, tuning window will be smaller, and it will take less timing, but totally doable. Hell C7s are 11.5 and loving the boost. __________________ Nick Corvette Z06 -1200ish rwhp

03-09-2015, 05:39 PM	#4
Bo White Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012 Location: Vance Alabama Posts: 8,090	Exactly. I'm stock LS3 compression pushing 12psi __________________ Retired wanna be cylinder head porter 2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter, stage 4 cam and Wilkes 11° 65cc heads Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X

03-10-2015, 04:39 PM	#7
Unreal Drives: 2006 Z06 Join Date: Oct 2010 Location: Gilbert, AZ Posts: 5,712	Per Stevies point, static compression is just one thing, dynamic is another. You can have a cam that bleeds off compression, or one that makes it higher than you want. __________________ Nick Corvette Z06 -1200ish rwhp

03-10-2015, 04:45 PM	#9
sr71bb Drives: 2019 Camaro Z-28 Join Date: Jul 2010 Location: Dallas Posts: 1,486	high compression I run 11.3 with 21 pounds of boost and 18 degrees of timing on a F1R setup that makes over 1000 RWHP. Running E85 and progressive METH injection __________________ __________________________________________ 2019 SS 1LE BIG NA A10 Eagles Canyon Raceway 2.7 CCW Below https://youtu.be/c9M5UHDftcA 4-15-23 at SCCA TT U1 Class MEGA Thread on THIS car: https://www.camaro6.com/forums/showthread.php?t=602092 Retired Cars BELOW: 1973 Camaro, 1969 Camaro, 1969 Camaro SS RS 2010 Camaro SS with 1000HP F1R, 2019 ZL1 1LE A10

03-09-2015, 03:17 PM	#2
blake-b Drives: 2009 ZR1 Join Date: May 2010 Location: KCMO Posts: 3,205	No, if you have a good tuner it can be done. A high CR will narrow down your tuning window.

03-09-2015, 07:49 PM	#5
Bildo Drives: 2012 2SS/RS LS3 Join Date: Dec 2011 Location: Omaha, Nebraska Posts: 1,677	Yeah I might just send the stock heads in to be ported and polished, and throw them back on and sell the PRC heads. I just ordered a D1SC stage II tuner kit....

03-10-2015, 03:24 PM	#6
stevieturbo Drives: it changes Join Date: Nov 2010 Location: Norn Iron Posts: 1,128	Stick a big cam on it

03-10-2015, 04:42 PM	#8
Slowhawk Drives: 1999 Trans Am Join Date: Jul 2009 Location: Bridgewater,Ma Posts: 2,018	Depends on the cam. My personal car runs 11.5-1 on stock pistons. Planning 16lbs on it but I will have meth injection.

03-10-2015, 05:09 PM	#10
H-E Account Suspended Drives: 2010 zr1 Camaro 2011 vert Join Date: Apr 2013 Location: everywhere Posts: 1,121	You will be fine with a d1 and a good tuner

03-10-2015, 05:12 PM	#11
Todd in Vancouver Drives: 2014 ZL1 Join Date: Oct 2013 Location: Vancouver, BC Posts: 1,538 View My Garage	Interestsing comments. I'm biulding another cat and it has a Stealth Ram with 10.8:1 compression and I'd like to add twin turbos and was wondering if my compression was to high. __________________ Todd in Vancouver '14 ZL1 Camaro '67 Camaro SS Pro-tour in process How hard can it be... Check out my other build http://www.pro-touring.com/threads/9...ject-Obsession

03-10-2015, 05:38 PM	#12
jrpxxii Drives: 2010 Camaro SS/RS 427ci Join Date: Jul 2009 Location: Bowling Green, Ky Posts: 3,355	You could get thicker head gaskets but you will be fine with that blower __________________