So I bought a 1994 Camaro Z28 with a 4L60E transmission but the previous owner had the rear gears switched to 4.10's. So to make sure he was telling me the truth, I did the test where you turn the drive shaft and count the rotations for one tire rotation. It turns out the rear gear ratio is 3.73, if I counted correctly. My problem is that the car hasn't been tuned for the new gears. I think this is causing the transmission to shift late because when I lightly accelerate it gears up at about 3200-3700rpm and when I open the throttle fully, the engine redlines and doesn't shift until I let off the gas. Also the speedometer is off, I was going about 63mph (according to speedometer) but one of those traffic speedometers said I was going about 55mpg. So my questions are 1.)will a retuning of the PCM fix these problems and 2.)is Trifecta a good company to use for this?

 

Number 1 yes. Number 2 I have no clue.

 

I used Madz28 personally. Did a decent job on my tune I can't complain. Think his website is http://www.madtuner.com

 

I am personally, very happy with my Trifecta tune. I have only a bolt on car and had a crappy hypertech tune, so yeah it made a very significant difference. Vince - Trifecta is on here a lot and is great to deal with.

 

You double posted (a no-no) https://www.camaroz28.com/forums/sho...d.php?t=599810 .

Maybe a moderator will merge the threads for you.

Trifecta does give you the option of not having to send your PCM anywhere for those that don't have the tools to load a tune themselves.

 

So a tune should fix all of my problems?

 

yes, and get it tuned for 93 octane fuel. They will advance spark timing and get you more power as well.

 

Forgot to add that the car has longtube headers and no cats, and the SES light is on.

 

what kind of codesn are you throwing, get the car scanned so people here can help you out. you may need to get more than the gears done in your tune to help eliminate your codes depending on what other mods you have so you dont have to tune your pcm more than once

 

I just went to autozone to get the codes pulled, and the SES light went off and didn't come back on like it is suppose to he said.

 

#1 yes, #2 I delt with them and had no problems, plus you dont have to send your pcm to them, they send you a little hand held with everything you need wires etc. Then you just follow the on screen instructions, tap the screen a few times and your done in minutes. I thought it was very nice.

 

You've got three different posts going... two about the tranny problem, and this version one is turning into a code scan issue, which is already being discussed in your third thread. Generally not a good idea to cover the same topic in multiple posts, because people trying to help you in one thread might not be aware of info you posted in the other thread, or suggestions others have made to help you.

We request that you post drivetrain problems only in the "Drivetrain" forum, since "LT1/LT4 Engine Tech" is only for engine related questions. We also discourage multiple posting of the same question on multiple forums. I'll merge this thread with the one you have in the "Drivetrain" forum.