Automatic Trans Shift Delay [Archive] - GrandAmGT.com Forum

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romanticarmyguy
07-13-2006, 05:49 PM
I have a 99 Grand Am Se. Its an automatic. I know they r electronic transmissions. Im gonna b racing it @ the Fontana Dragway this Sunday. When i shift it manually it has a shift delay. I also noticed that when i shift from 1st to 2nd manually it wants to take it to 5500 rpms. Is there a shift delay, and if there is how many rpms is the delay, or is it supposed to go to 5500 rpms @ full throttle regardless if its manually or shifted on its own? I want it to shift in @ bout 4800 rpms, which is the top of the powerband for that motor.

SikMindz
07-13-2006, 05:55 PM
Good luck in Fontana this weekend. Wish I could make it out as usual but I'm back up in the Bay Area now.

As for shifting, your best bet is to leave it in 3rd. Power brake on the line, feather it then go WOT once youre tires catch. Currently I'm on top there with my N-Body running a 15.6.

AaronGTR
07-13-2006, 06:23 PM
I have a 99 Grand Am Se. Its an automatic. I know they r electronic transmissions. Im gonna b racing it @ the Fontana Dragway this Sunday. When i shift it manually it has a shift delay. I also noticed that when i shift from 1st to 2nd manually it wants to take it to 5500 rpms. Is there a shift delay, and if there is how many rpms is the delay, or is it supposed to go to 5500 rpms @ full throttle regardless if its manually or shifted on its own? I want it to shift in @ bout 4800 rpms, which is the top of the powerband for that motor.


Actually the stock redline should be 5900-6000rpm. That is the point where the pcm will shut off the injectors to keep from over revving. If you are trying to shift manually from 1st to 2nd etc it is probably hitting the rev limiter first and then taking a second after you move the gear selector before it recognizes the gear change and upshifts. This will only slow you down. Leave it in 3 or D, that is the fastest way to run these cars. If you are running at full throttle it's going to shift at redline. There's no way to lower the shift point unless you re-program the pcm, but you don't want to do that anyway.

Thats because the power peak is higher than 4800. It's definitely over 5000 and doesn't really fall off until 5800 (reason for the factory redline at 5900). You have to remember one other thing... the third gear ratio sucks! 1st and 2nd are much better for acceleration so the longer you leave it in those gears the better. Many people gain 1-2 tenths by raising the redline, and a basic intake exhaust combo and especially headers will raise the powerband and help even more. Follows these tips and good luck!

romanticarmyguy
07-13-2006, 06:34 PM
I tried shifting @ 3200, 3500, 4000 and everytime it takes it all the way to bout 56-5700.

xxbackhillxx
07-13-2006, 06:47 PM
Don't manually shift it ... leave it in 3rd and just go

AaronGTR
07-14-2006, 05:12 PM
I tried shifting @ 3200, 3500, 4000 and everytime it takes it all the way to bout 56-5700.


Yeah. Heeelllooooo.... what did I say? If you have it at full throttle it doesn't matter when you shift it, it's going to go all the way to redline. Shift rpm is dependent on throttle position and the only way to change it is by reprogramming the computer.

i_ammetal
05-27-2008, 01:20 AM
Don't manually shift it ... leave it in 3rd and just go

Wouldnt that damage the tranny though???

Dont get me wrong racing is racing and wear and tear is expected but overall isnt leaving it in 3rd gear effect the torque as well?

SikMindz
05-27-2008, 01:35 AM
Holy thread revival, JHC! In 3rd it prevents the tranny from entering into overdrive; not that it is actually IN 3rd gear the entire time.

i_ammetal
05-27-2008, 01:45 AM
yea im actually digging for more info on gear ratios.....need help.

bad!

ok so it prevents overdrive....but what about 1st and 2nd?

My buddie went against a civic and while doing so shifted to 2nd in his auto. grand am se and left it there until he got to about 60ish/i.e. end of the little race......im not too sure about what the acutal speed was but there had to be something bad with that...

hass
05-28-2008, 06:08 PM
Actually the stock redline should be 5900-6000rpm.

stock redline is @ 5800 RPM.

If you get a DHP PCM or something like that, it raises it right to 6000 on the dot.

It's all posted on the PCM tech info.
Says it raises the shift point from 5800 to 6000

gectek
05-28-2008, 06:25 PM
manually shifting an older auto trans isnt going to gain you anything...period. m putting it in 3rd manual it will go through 1st 2nd and into 3rd reaching the max rpm that gm has programmed, usually like aaron said 58-6000(on the tach). just leave it in 3rd or even drive for suburban combat. if the trans were meant to be manually shifted, it would have a clutch instead of a converter

and FYI^^^ my DHP PCM raised my shifting to 6300 at WOT

lone_wolf025
05-28-2008, 07:56 PM
I know about this lag. That's normal for stock, even if you leave it in third. Redline is there not just for power cutoff reasons but as its very near the upper limit of what the engine can handle mechanically without falling apart. Pushing past redline is bad juju on stock internals.

i_ammetal
05-28-2008, 09:19 PM
manually shifting an older auto trans isnt going to gain you anything...period. m putting it in 3rd manual it will go through 1st 2nd and into 3rd reaching the max rpm that gm has programmed, usually like aaron said 58-6000(on the tach). just leave it in 3rd or even drive for suburban combat. if the trans were meant to be manually shifted, it would have a clutch instead of a converter

and FYI^^^ my DHP PCM raised my shifting to 6300 at WOT

Thats actually what i tried last night.............
200? Nissan Max..... lol they wouldnt go a second light.

Ok but i still want more juice out of my tranny i think i have the MN5 trans
and i know i touched on this in another thread ( :( ) but still need more information... isnt the gt's stock ratio 3.29?

mfuller
05-28-2008, 09:43 PM
Yes, GTs get the 3.29 diff(erential) and 35/35 tooth drive/driven sprokets to yield a 3.29 Final Drive Ratio. Your SE has a 3.05 diff and a 3.05 FDR (assuming you have a V6). 4-cylinder cars got a different drive/driven sproket ratio (33/37) to yield a 3.42 FDR with the 3.05 diff.

i_ammetal
05-28-2008, 09:48 PM
yeah i got the 6 just want more power...... with the 3.05 is hard to spin the wheels

gectek
05-29-2008, 10:00 AM
there has been alot of debate on whether the mn5 came with both diffs in it, i think it did, that is why you need to source your gear ratio code from ur RPO sticker(its on the underside of the spare tire cover)

i_ammetal
05-30-2008, 08:16 PM
will look into it tomorrow

buddy knows a guy that manages a tranny shop i think im going to go there tomorrow and get my gears set, depending on what i really have

plus need to get it adjusted with new CAI and chip, car jerks hard between 1st and 3rd

nickofcourse
05-31-2008, 01:38 AM
:doh: hope you dont mean a perofrmance chip loll

williamGT
05-31-2008, 02:51 AM
Yes, GTs get the 3.29 diff(erential) and 35/35 tooth drive/driven sprokets to yield a 3.29 Final Drive Ratio. Your SE has a 3.05 diff and a 3.05 FDR (assuming you have a V6). 4-cylinder cars got a different drive/driven sproket ratio (33/37) to yield a 3.42 FDR with the 3.05 diff.
Man, I thought V6 and the GT's had the same gear ratio.

gectek
05-31-2008, 10:09 PM
yah they sometimes dont have the same stall on the converter either. and yah I think he was talking about potatoe chip maybe, thats the only chip my car has in it. just find out what gear you have first. it is really more of a mess to change the gear ratio than u would think