Why no gains after head install?
09-12-2011, 04:43 PM
#21
No, no, and no. No yesterday, no today, no tomorrow. Absolutely not.
They do not make much difference in the autos, especially since he only back-tracked to a 3.23.
OP, something is wrong. Your 60 should be better, you ET should be better, and your mph should be better.
They do not make much difference in the autos, especially since he only back-tracked to a 3.23.
OP, something is wrong. Your 60 should be better, you ET should be better, and your mph should be better.
09-12-2011, 05:20 PM
#23
Ok I have uploaded my tune in its current state. I have attached two logs, one from the track and one from some tuning yesterday. The night at the track the car was getting pretty fat at the top end (LTFTs were adding fuel) and not much timing pull, but when I lean it out closer to what AFR I want to run (12.5:1) it starts to pull timing. Is this were I am losing the power?
09-12-2011, 08:18 PM
#26
Okay, I have read all the stickies on stalls, etc. But help me understand this: If you have two identical automatic cars, one with a 3.73 rear gear and the other with a 3.23 rear gear, it seems to me that the only difference at the automatic transmission output is that one car (the 3.73) will have a driveshaft that requires less torque to turn - So why doesn't that help?
09-12-2011, 10:24 PM
#33
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Do you think it would be mechanical or tune related? Car seems to run fine. Idles well, doesnt spit and sputter or anything like that. Could my PRs be too short? Would that even make much of a difference? I am running a 7.325? I measured with the comp adjustable pr checker. Installed ls7 lifters during head swap and am running .045 head gaskets, stock rockers.
Okay, I have read all the stickies on stalls, etc. But help me understand this: If you have two identical automatic cars, one with a 3.73 rear gear and the other with a 3.23 rear gear, it seems to me that the only difference at the automatic transmission output is that one car (the 3.73) will have a driveshaft that requires less torque to turn - So why doesn't that help?
09-12-2011, 11:39 PM
#36
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The gear change i assure you has dropped your mph in the 1/4. Ive done many combinations and i am a veteran street/strip racer. A car with your acceleration you have cost yourself atleast 1.5 mph. Maybe .07-.08 in et.
09-13-2011, 12:06 AM
#39
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Just my opinion,you put on the heads and gained 30-50hp.Went down on gear size and your wondering why your not running a better time.The HP you got with the heads you lost on the gears.Put 3:73 gears back in and you'll pick up 5-7 tenth's of a second in the 1/4 mile.Are you using a stock torque converter.
09-13-2011, 12:07 AM
#40
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Not to throw a "wrench in the works", but everything that I've been reading/learning about tuning always states that the only way to CORRECTLY tune for VE involves a steady state on a dyno as a starting point. I'm obviously no expert with regards to tuning, but am left thinking that no matter how good he thinks his tuning ability is, he's still leaving a significant amount of power "on the table" through not being able to correctly CALIBRATE for VE.
He changed to a set of worked over heads....
Am I missing something here?
He changed to a set of worked over heads....
Am I missing something here?