Sluggish car with low CR
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From: Tranås, Sweden
Sluggish car with low CR I have a question for you 
If i lower my CR to 9:1 how sluggish will the car feel compared to a stock LS1 if i start from stop... What are youre experiences with boost and a lower CR. I know this depends on a lot of factors but i´m only looking for some info
Thanks.
I´m going to have a Inconkit on my car with two GT3776R.
If i lower my CR to 9:1 how sluggish will the car feel compared to a stock LS1 if i start from stop... What are youre experiences with boost and a lower CR. I know this depends on a lot of factors but i´m only looking for some info
Thanks.
I´m going to have a Inconkit on my car with two GT3776R.
my car with forged 347 was really sluggish till I figured out how to take off. I have to rev to 4500 rpm and dump the clutch and then I would imediatley have boost. the CR was 9.1
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From: Somewhere I Belong
Not 346ci but my buddy's Y2K C5 M6 equipped with 408ci the CR dropped down to 8.7:1 for 300+shot moves damn well & ya can say better than full bolt-ons LS1 esp. from low roll or dig so i don't think that considered to be sluggish,Btw he has 3.42's & he spinning thru 1st 'n 2nd on street tires damn hard 
Anyway keep us updated with progress
peace
Anyway keep us updated with progress
peace
Last edited by bad95killer; Jan 21, 2007 at 03:36 PM.
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On The Tree
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Originally Posted by mdhmi
My CR is in the high 8's and don't have any problems with partial throttle umph. Properly sized torque convertor is priceless.
346 with T76MPS turbo. I am going to run my vig 3200
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From: Tranås, Sweden
Originally Posted by Pro Stock John
Figure a 3% decrease in power from 10:1, that's nothing to worry about. It's the bigger cams that make forged engines feel like they lack low end.
Originally Posted by Pro Stock John
Figure a 3% decrease in power from 10:1, that's nothing to worry about. It's the bigger cams that make forged engines feel like they lack low end.
on this. My 408 sucks coming out of the hole. I'm 9.5:1 SCR, about 7.0:1 DCR with the cam I'm running. Built the motor for boost, but running it N/A for now. Best I could pull at the track was a 14.89 @ 97 with a 2.4 60'. I had a stock 6.0 with a Radix at 7 psi before and ran a 13.66 @ 104, 2.05 60'. I was hoping to be close with the N/A 408 but it's just a dog down low. 
I think the key to low compression is having a good set of heads on the top end to make up for it. My next combo is going to have 8.0:1 CR but topped with some bad boy ET LS7 heads flowing over 350cfm.
Phil
Phil
We just put together a 8.25:1 355 Ltx motor for my buddy's turbo project. We installed the motor without the turbo to do break-in. On a stock tune, AFR 195's, stock injectors, LT4 intake - extrude honed, and a baby turbo cam, the car pulls waaayyyy harder than the stock full bolt-on Lt1 did.
Im sure its not making as much N/A power as it could if we had left the compression alone, but its still not sluggish by any means. Once the turbo gets here it'll be on!
Im sure its not making as much N/A power as it could if we had left the compression alone, but its still not sluggish by any means. Once the turbo gets here it'll be on!
I ran my car for awhile with the wastegates setup so no boost would come on. (engine break-in) 8:5-1 compression ratio. Not sluggish like you would think. Car drove like it did before I put everything on it. Now that it's in boost it's awhole different story!!!