horton72

I just had my new transmission from Triple Edge performance put in my 2007 Grand Prix GXP today but now going 65 mph my RPMs are over 2500 but before the new transmission at 65 it was running around 1700 RPMs and of course now my gas mileage used to be 27 MPG and now I'm getting 13 MPG any thoughts?

rottonj

iTrader: (4)

You got a gear change.

horton72

No gear change.same gears

rottonj

iTrader: (4)

I would check with Triple Edge to see what was done or check your paperwork because what you are describing is a gear change.Factory ratio is 2.93, my guess is they put in 3.29 or maybe even 3.69.

horton72

I talked to him and he said there was no gear change

rottonj

iTrader: (4)

Not by chance running 14 inch wheels up front then are you, because something changed the ratio

lVloses

iTrader: (1)

Sounds like the converter isn't engaging. Have you driven it enough yet? Dave told me 100 miles to break it in. Also your converter won't engage until the transmission is at a certain temp.

horton72

I have 18 inch rims. And I've only put on 20 miles since the new tranny was put in what sense the RPM's were so high my transmission temperature went over 220 degrees

spawne32

iTrader: (2)

i agree, sounds like 3.69 gears to me

Sint3k

A video of the rpm/speed gauge. Drive at different speeds with acceleration from 0 with some throttle blips at 60 will tell us whats going on

rottonj

iTrader: (4)

Post back your findings after you bring it back to Triple Edge to see whats going on. GM feels 220 degrees is normal lol. The car will probably need a transmission cooler as well ,if it already has one that's a problem.Good luck.

blkchevyz

sounds like converters not locking lock others have said.

i got the 329 or what ever gears and im right around 2k at 65-70

spawne32

iTrader: (2)

at 65mph the converter not locking still wouldnt put him over 2500rpm's with the stock gear set. Only other thing I could think of is possibly that hes not shifting into 4th?

horton72

Yes I already have a aftermarket tranny cooler on it.dave said everything with the transmission is electronic and I might have some kind of sensor gone bad.i have an appointment Wednesday with my local mechanic shop (same people that installed my transmission) to take it for a ride while hooked up to a computer to see what it's doing or not doing and hopefully they can figure it out.already sunk alot of money in this car so I have my fingers crossed.dave told me to keep him updated.

horton72

Besides the high RPMs which leads 2 overheating and bad gas mileage the new transmission shifts like it's brand new and by the looks of it, using my tap shift, it's shifting in all gears. There's not much of a change from 3rd to 4th but there is a change

rottonj

iTrader: (4)

Well driving something for 20 miles isn't much, you might want drive it a little more before getting others involved.

blkchevyz

i agree. i think he told me the first 500 its going to be a little different. harder shifts and what not.
it needs time to break in and the computer to learn

spawne32

iTrader: (2)

there is nothing that the trans computer has to learn to bring the car down from 2500rpms to 1700 when cruising. Something is clearly wrong.

horton72

Here's a little update Friday morning on the way to work the RPM's went to normal about 1700 at 65 but on my way home it went back to 2500 RPMs so I messed around a bit and stuffed the throttle to about 105 mph for about 10 seconds then used my tap shift from 3rd to 4th a few times got to a stop sign shut my car off then turned it back on and it went back to 1700 RPMs at 65 mph and it did the same thing this morning until I shut the car off and turned it back on and went to 1700 rpm.its got me stumped?

Sint3k

Rpms just don't change, so im guessing the tq converter is not locked up at the higher rpm vs the lower