Ls1 LOW mph troubleshoot
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Teching In
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Ls1 LOW mph troubleshoot Hey guys so I have a 99 z28 with cam and basic bolt ons. It is a 4l80 car with a 3200 converter. All tuned by a reputable shop made 399 to the back tire. Going to the track, the car would only do 13.2 barely getting 102, car wasn't spinning but only getting a 1.9 60ft probably due to the small converter. But with the extremely low mph, I know something is wrong. So I am gonna do a log tonight to start. What are some things I should check, replace, or look into?
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Verdad Gallardo it'll be hard to launch much better without gear. Something else -- your dyno curve was still going up, so I'm wondering --what is your shift point? you might simply need to raise your shift points. If you're peaking at 6300, you should be shifting around 6800.
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Teching In
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Not even sure if it’s that high. Will definitely check that out was actually thinking the same thing. Are stock ls1s with springs and push rods are good to rev to 6800?
Originally Posted by Brendyn G
Not even sure if it’s that high. Will definitely check that out was actually thinking the same thing. Are stock ls1s with springs and push rods are good to rev to 6800?
I wasn't sure on the phrasing which way you meant it.
Thread Starter
Teching In
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Sorry for the confusion, I put the springs and push rods in the car that came with my Texas speed cam kit, so they are not stock .
If there is anything in your tune, it would be raising the transmission shift points. if it's a manual, I would go with 6800. The bottom end can do that just fine. I have little direct experience with an auto, and have only built one hotrod with an auto, but you definitely need to be shifting at least 6500 just to get past peak power.
Hardware-wise, you do not mention converter. A 3600 stall converter will wake the car up if not already done. Coupled with 3.73 gears, your car will come to life.
Bottom line, i do not think the motor is the issue. Just have to work on the rest of the car some.
Thread Starter
Teching In
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Awesome, thank you for the good info. I’m gonna mess with the shift points this weekend for sure . Also the car has a 3200 converter . A bit small but I’m not huge into racing just want a number to make sure it’s all working good .
There must be something going on here. The dyno numbers and trap speed don't seem to match. My 01 SS ran 13.6 @ 102 bone stock. With current mods it did 12.6 @ 108. OP's should be trapping significantly higher.
What converter is it?
What converter is it?
Thread Starter
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I agree . It’s a summit branded 3200 believe it’s made by Hughes ? The car still runs good also, was pretty even with a 2019 coyote last night on the highway from 60. The track is slightly uphill that I ran at, might take a few mph off but not a ton.
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i could definitely see this. I’m thinking it’s not a real “problem” as it is just a bad setup considering the converter is brand new.