Ideal compression for longevity
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12 Second Club
Joined: Dec 2001
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From: Santa Clarita, CA
Ideal compression for longevity I don't plan on going forced induction, but have always been curious about the inherent hassles with boosting the LS1 or LT1. I had a 89 TTA and the car was designed for boost, but I've always thought it interesting how many Turbo Regals/TTAs were in the 10s and power those v6s can make. My highly speculative speculation (from someone with absolutely no wrenching experience), is that LS1 guys are running to high a compression, too much timing, and too large a cam in an effort to maximize performance. What would be the problem of using a 7:1 compression ratio, 18 deg timing, and a say a 218-218 cam with .5 lift, and running 20 lbs of boost on 100 octane. I would guess, and its far fetched, but I'd say the car would make 450-500 RWHP, and move a 3400lb car in the high 10s. I guess the nice part is that with a 3000 or less stall, the car might be nicely streetable. I am I just crazy or? Like I said I don't any experience in such matters.
Regards,
Regards,
LC2 stuff (Turbo 3.8 GN) is 8:1 compression FYI.
I would imagine that GN'ers run 10's with 104-110 gas. I've heard of GN's going 9's with C16 (117 octane).
We work with what we got.
I've never heard of anyone running less than 8.5:1 with a stock cube LS1 but it would be interesting.
I think SupraTT's are 7:1 stock but I'm not sure.
I would imagine that GN'ers run 10's with 104-110 gas. I've heard of GN's going 9's with C16 (117 octane).
We work with what we got.
I've never heard of anyone running less than 8.5:1 with a stock cube LS1 but it would be interesting.
I think SupraTT's are 7:1 stock but I'm not sure.
Thread Starter
12 Second Club
Joined: Dec 2001
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From: Santa Clarita, CA
Believe the TTA was 8.5:1 as well, but anyway just thinking about a detuned LS1motor running high boost. Keep the gas 100 unleaded, so as not to fry those expensive oxygen sensors for the FAST system (which I think would be essential), and maybe the 18 degrees of timing I mention before is foolish, how about 22. For some reason I think the V8 is going to live better with less than 8:1 compression. Hell I don't know. It seems the only way to see these upper teen/twenties boost levels is with a turbo. For some reason I think the simplicity of a single, fairly small but extremely efficient turbo is the way to go. Will a TE-60 or 60-1 (if they are the same thing) support those power levels (say 600 bhp)? Maybe one day I will win the lottery and give it shot 
.
Regards,
.Regards,
TECH Resident
Joined: Aug 2003
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From: orlando, florida
I don`t think the 60-1hifi will support 500hp at least not on a ls1 425-450 is about pushing it to the max. but the T60 which flows 20% more air then the 60-1 should get you 500hp but not to far above that. Also when i redo my pistons and heads I`m gonna shoot for 8.5:1comp.
TECH Senior Member
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The headbolt design of the LS1 block is a real limitation.
I think a great engine combo is a 409 iron block (4.035 x 4 inch stroke) with big headstuds and mainstuds, good gaskets and around ~9:1 comp. T76 or T88 single turbo with custom exhaust manifolds and huge intercooler, 6L 330cfm heads and custom intake (LSx or sheetmetal).
Fairly mild cam (say 240/240 on 114LSA) and you would make some serious power and torque and be perfectly drivable with 94 octane to boot.
Of course, FAST, huge injectors and fuel system and good dyno tuning would be a must
I think a great engine combo is a 409 iron block (4.035 x 4 inch stroke) with big headstuds and mainstuds, good gaskets and around ~9:1 comp. T76 or T88 single turbo with custom exhaust manifolds and huge intercooler, 6L 330cfm heads and custom intake (LSx or sheetmetal).
Fairly mild cam (say 240/240 on 114LSA) and you would make some serious power and torque and be perfectly drivable with 94 octane to boot.
Of course, FAST, huge injectors and fuel system and good dyno tuning would be a must
