New LS1 Owners - Newbie Tech - shifting prob?
brady346
02-21-2006, 12:19 PM
I just bought an ALL stock '01 nhra formula with and auto. It has 80K and was driven all highway miles by a woman to work a long distance away daily. I know the history on the car so i gave a premium price. However, as soon as i got it i had to do some full throttle launches. Is there a problem? Here are the symptoms. If I take off from a dead stop, wheelspin is inevitable and every time it hits the rev limiter 2 or 3 times before shifting and then it seems like it is about to die. Could the dying be from hitting second at about 15 mph? Any help or preventative maintenance tips would be appreciated.
When it hits rev limiter, the fuel is cutoff to prevent any damage to the engine from over-revving, hence, engine appears to be cutting off.
FrozenMonkey
02-21-2006, 12:56 PM
Well you are bouncing off the rev limiter. Not to sound like an ass, but it seems to me like you don't know how to launch your car. If you are shifting into second at 15mph to keep it from spinning you need to relax on the 5k rpm clutch dumps.
brady346
02-21-2006, 02:36 PM
The car is an A4 so it does the shiftin all its own. But the help is appreciated. Also, is there any way to lower the rev limiter, it sounds kinda tough on the motor at 6300. But what i was sayin is that it hits the rev limiter between the 1-2 shift. Any input on that would help a lot bc that seems abnormal.
camaromarc
02-21-2006, 02:42 PM
Sounds like the shift point in the ECM needs to be changed.
brady346
02-21-2006, 02:52 PM
Do you have to have an expensive tune done to get the shift point reprogrammed? Will it hurt anything just continuing to drive the piss out of it?
camaromarc
02-21-2006, 03:19 PM
You could buy a simple hypertech handheld tuner to change shift points and the rev limiter. If you'r just going to drive the piss out of it shift it manuelly.
brady346
02-21-2006, 04:35 PM
can the hypertech make the car shift at a point lower than it was stock?
black00TA
02-21-2006, 04:43 PM
yes, hypertech will let you do shift firmness, shift point and set rev limiter.
Sgt. Spuds
02-21-2006, 04:56 PM
Auto's can hit the rev limiter??
It seems as if the whole advantage to haveing a auto would be not having to shift, and if the fuckin thing doesn't actually 'shift' before the rev limiter, it seems like of pointless.
Swang
02-21-2006, 05:32 PM
Auto's can hit the rev limiter??
It seems as if the whole advantage to haveing a auto would be not having to shift, and if the fuckin thing doesn't actually 'shift' before the rev limiter, it seems like of pointless.
:bash: dumbass...if you punch it, from a 15 mph roll...it will hit the rev limiter even in an auto if it cant get traction...
black00TA
02-21-2006, 07:10 PM
i dont own an A4 but ive drivin a few ls1 fbody's with A4's
and what ive noticed is that it wont do it most of the time. but if your beatin on it repeatedlypretty good then it will start to do it more, like the warmer the tranny gets.
Sgt. Spuds
02-21-2006, 07:11 PM
So in a A4 you cant punch it and burn through first and second? Im not even going to comment on that.... I Thought the shifting was based on teh RPM's of the motor, not the rate at which the tires are spinning...
Lucas'02SS
02-23-2006, 12:29 AM
So in a A4 you cant punch it and burn through first and second? Im not even going to comment on that.... I Thought the shifting was based on teh RPM's of the motor, not the rate at which the tires are spinning...
Dude, do you even know what you are talking about, or asking for that matter? You can burn through 1st and 2nd in an auto, and it does shift based on the rpms. What are you talking about?
Back to the question of the thread, my friend had this problem with his auto for a long time. His wheels would spin a lot faster than his car could shift, and consequently he hit the rev limiter a lot. Good tires and a tune fixed it, and we haven't had problems with it since.
I wouldn't drive the piss out of it and let it just hit the limiter though. It doesn't happen a lot, but hitting the limiter in an auto can bend pushrods. If you want to get on it, I would suggest feathering the gas a bit until it grabs. So good luck with it man. For us it was as simple as tires and a tune.
black00TA
02-23-2006, 04:42 PM
i may infact be crazy.
but a rear-gear change tends to screw the A4 a bit into shifting odd. that being based on MPH vs. throttle position rather than RPM.
'Trust'
02-23-2006, 06:28 PM
Back to the question of the thread, my friend had this problem with his auto for a long time. His wheels would spin a lot faster than his car could shift, and consequently he hit the rev limiter a lot. Good tires and a tune fixed it, and we haven't had problems with it since.
I wouldn't drive the piss out of it and let it just hit the limiter though. It doesn't happen a lot, but hitting the limiter in an auto can bend pushrods. If you want to get on it, I would suggest feathering the gas a bit until it grabs. So good luck with it man. For us it was as simple as tires and a tune.
Yup, exactly right.
As soon as I had the Nittos put on and the tune corrected, (the tranny tune wasnt exactly perfect before hand) I havent hit the limiter once going into 2nd. If it was third I'd be more worried about being low on ATF or the 2-3 clutch pack. The transmission will shift off of MPH and RPM at any given percent of throttle, for example there is a different table for 10% throttle opposed to 100%. So the best bet, dude get some tires and quit holding it down when you hit the limiter, the car will only take it so much, bouncing off of the limiter 3x until it shifts is a bad idea.
Lucas'02SS
02-23-2006, 07:22 PM
Haha, Reza I had no idea that was you for about 10 minutes. I guess they finally did your name.
If it was third I'd be more worried about being low on ATF or the 2-3 clutch pack.
Yeah if it hits the limiter from 2-3 you need to check your fluid and clutch packs. Trust is right. You don't want to rag on the limiter very much. But I think tires will help a ton.
'Trust'
02-23-2006, 07:29 PM
Could the dying be from hitting second at about 15 mph? Any help or preventative maintenance tips would be appreciated.
Check your speedo too if you ever decide to do that again, i bet you it wont say 15mph, BUT in the unlikely case it does, then my money is on the VSS (Vehicle Speed Sensor)