Forced Induction Superchargers | Turbochargers | Intercoolers

STS turbo boost What compression???

Thread Tools
 
Search this Thread
 
Old Nov 28, 2004 | 10:47 PM
  #1  
Lawnboy's Avatar
Thread Starter
Restricted User
iTrader: (54)
 
Joined: Jan 2002
Posts: 902
Likes: 1
Question STS turbo boost What compression???

Hi maybe you guys can help me out.

I have a 2001 M-6 SS that i am rebuilding my LS1 with forged internals for boost.

Parts:
eagle ESP H-beam (6.125) rods
diamond pistons -2cc or -8.6 cc dish ????????????
stock LS1 crank (cryno treated)
double LS1 timming chain
ARP main and head studs.
Cometic FI .074 head gaskets
King bearings


Ok i want to be able to run 12PSi of STS boost. I am going to install the OBX front mount intercooler.

My question is what would be the better compression ratio to run.
if i use the -2cc diamond flat top pistons with the cometic .074 head gaskets i will end up with 9.5 to 1 compression.

If i go with the -8.6cc dish diamond pistons i will end up with 8.8 to 1 compression.
But i am not sure if this low compression is good to have on a LS1 motor.

Can i get away with having 9.5 to 1 compression with boost,
How much boost can i squeez into a 9.5 to 1 LS1 motor without hurting it?

If everything is kept the same what motor would be better for me? the 9.5 motor with less boost or the 8.8 motor with a little more boost.

My car will be a street machine only car, it is a M-6 with stock 3.42 gears stage 3 spec-star clutch, and i want to build it to be also a everyday street car.

i would like to make 550RWHP, I have #50MSD injectors with the intank racetronic fuel pump.
Can a 9.5 compression handle enough STS Boost to make that kind of power(550)
I like the idea of keeping the motor at 9.5 to 1 because it is not too far from stock compression (10.1 to 1) the way the motor was designed to run.
Please hel me out
thank you for your advice
Reply
Old Nov 29, 2004 | 08:58 AM
  #2  
trtturbo's Avatar
TECH Fanatic
iTrader: (25)
 
Joined: Mar 2004
Posts: 1,810
Likes: 0
From: Newark, Tx.
Default

you shouldnt have to run 12psi to get to that power. You will need to run the GT-67 over the 60-1. I'm sure people will have different opinions, but if it never sees the track and mostly normal driving, I would want the 9.5. What cam are you going to run?
Reply
Old Nov 29, 2004 | 09:17 AM
  #3  
PurEvl's Avatar
TECH Senior Member
iTrader: (2)
 
Joined: Mar 2002
Posts: 5,469
Likes: 0
From: South of Heaven
Default

im around 9-4 and run the gt70 at 12-14 psi. At 8 psi I made 575hp 585 tq, just for reference.
Reply
Old Nov 29, 2004 | 11:33 AM
  #4  
F8L Z71's Avatar
12 Second Truck Club
 
Joined: Feb 2002
Posts: 5,574
Likes: 0
From: Sacramento, CA
Default

I am around 8.7:1 on my 5.3L right now but the new 6.0L we are building is going to be at 9.0:1. Enough to run some nasty boost yet be able to keep some part throttle driveability.
Reply
Old Nov 29, 2004 | 06:15 PM
  #5  
Lawnboy's Avatar
Thread Starter
Restricted User
iTrader: (54)
 
Joined: Jan 2002
Posts: 902
Likes: 1
Smile

Ok so the 9.5 to one compression will work fine?
realy only 8PSi made 575 to the wheels WOW thats great , So how much power can my motor and fuel system take????

Parts:
Eagle ESP H-beam rods
stock LS1 crank (cryo treated)
Diamond -2 cc pistons.
ARP main and head studs.
double roller timming chain set
Stock LS1 2001 block.
Cometic .074 FI head gaskets

Fuel system:
I have a set of #50MSD fuel injectors that are going in with the LS1 racetronix fuel pump. And the Bigger 85mm SLP mass air.

Thanks guys for your help
Reply
Old Nov 29, 2004 | 06:22 PM
  #6  
Lawnboy's Avatar
Thread Starter
Restricted User
iTrader: (54)
 
Joined: Jan 2002
Posts: 902
Likes: 1
Default

O
I have a Comp 214-224 560/570 115 + 3 degs (112cl) blower cam,
It was custom grind for me, i was going to go with the DS-1 Procharger set up befor the LS1 - STS turbo system came out.
I see that Turbo setups are using a reverse cam ,
My engine rebuilder said that this cam that i have now will work fine, but not optioum.
Any input, would be helpful.

If any one is interested in this cam let me know , or trade for a Turbo cam, My camshaft is Brand new still in the box ,never opened
I aslo have a set of SLP subfram connectors that i cant use because of the STS system.
Thanks again for your help
Reply
Old Nov 30, 2004 | 12:11 PM
  #7  
Smoov-E's Avatar
Teching In
 
Joined: Aug 2004
Posts: 35
Likes: 0
Default

I'd talk with the guys at LS1speed.com about it. I bought my diamond pistons from them, and placed the order after about a 10 minute conversation. We went over the math regarding compression ration, what kind of gasket to use, etc. They build quite a few FI ls1's, and really know their stuff.

I opted for a turbo piston that took me to about 9:1. I also bought my rods from them.

As for Billy's comment about part-throttle driveability....I don't know what part-throttle means....
Reply
Old Nov 30, 2004 | 06:03 PM
  #8  
Lawnboy's Avatar
Thread Starter
Restricted User
iTrader: (54)
 
Joined: Jan 2002
Posts: 902
Likes: 1
Lightbulb

IF i go with the Diamond -8.6cc blower pistons and my cometic .074 head gaskets i end up with 8.8 to 1 compression.
My Engine rebuilder Said at 8.8 to one compression the motor will be lazy until the boost comes on, but i could run 15PSi of boost and it will make more power and be faster at the track.

At the 9.5 to one compression the motor wont be affected that much at all to be noticed but boost would be limited to around 10PSi,

I am looking to make 550RWHP so i think i can make this type of power eazy, with 10 PSi and the front mount intercooler with 9.5 to 1 compression

what do you guys think???
thanks again for your help
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Dec 1, 2004 | 05:43 AM
  #9  
Slowhawk's Avatar
LS1Tech Sponsor
iTrader: (12)
 
Joined: Nov 2001
Posts: 14,865
Likes: 6
From: Bridgewater,Ma
Default

I would get the -8.6cc pistons and run GM MLS gaskets instead.That should put you around 9-1 compression and you could even mill the heads to raise it alittle more.A mild cam in the 224 range,ported heads with stock valves and a STS kit with a T67 or T70 (Front mount intercooler) will put you at 550 -650rwhp depending on boost level on pump gas.
Reply
Old Dec 4, 2004 | 07:32 PM
  #10  
TeeKay's Avatar
TECH Apprentice
 
Joined: Jan 2004
Posts: 337
Likes: 0
From: Frisco TX (Dallas Area)
Default

My 383 forged stroker is good to about 8 psi at 9.7:1, so they say. That should make about 680 crank at 6 psi, or about 540 at the wheels on 93 octane. IMHO, 9.5 is the way to go for the street. Just my 2¢. HTH
Reply




All times are GMT -5. The time now is 08:17 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE