hey guys im a new member but I read the forums every night any help with the beast would be great, I have a 1996 corvette lt-4 6 spd I just upgraded to

tpis long tubes, high flow cats, 3inch magnaflow exhaust all the way with x pipe, 3.73 Yukon rear end and a ram air box with the bigmouth,

I would need corrections for air/fuel, rear end, check engine light for rear o2s

I called a few performance shops in my area today for tuning ( Hamilton Ontario Canada) and one tuner said that the 96 has to get the computer sent in (5 days) and could not do it all on the dyno. Another shop today said hey could do it all on the dyno no problem in one afternoon.

what do you guys recommend, can all those things be done at one place on the dyno or is there something I don't no about the 96-lt-4,
and with all the chitt chatt im starting to lean towards pcm for less, can they fix all those things 2?? but how the hell do you no if its hurting the motor or not. any help would be great, im all done my mods and just need the tune( most important part) any info would be great thanks guys.

 

Tuning on a dyno is the way to go, because pcm is set to the car. Sending pcm is ok, but there can be hick ups due to variations in componets, so it's a little trial and error, meaning you might sent pcm more than once. If your mods are part of an established "Hot Rodding Plan or Kit" there would be less trial and error. Programmer would already have a working calibration for application.

 

Hey man, if you dont mind driving down from Hamilton to Elma NY, there's a speed shop called J&J SpeedShop... the only one in this area that will touch an L98 or ltx. I'm actually taking my l98 there next summer after the winter blows over... maybe we can go together

Give them a call, I forget the owners name but he does most of the dyno tuning. $500 for as many pulls as it takes to get it right
(716) 830-0506

 

Use the dyno tune, the LT4 can be tuned on the dyno with Jet Dynamic tuning software (tunercat) , maybe others.

 

Actually on second thought, there is a speed shop in rochester that will tune LTx cars, but thats probably more of a hike for you... and plus then we couldn't go in for a tune together

 

I am watching this thread to see the outcome. But I have a question.
I would think that the stock computer has enough flexibility to adjust for the increased airflow through the engine (headers and cold air). MAF sensor should sense the extra airflow so shouldn't the fuel maps try and keep everything close to 14.7? At wide open throttle the fuel maps could probably use some tweaking (maybe more fuel enrichment?).
If I am wrong please let me know. I am doing similar mods as LT-4PWR.
From everything I have read about the LTx engines it seems the factory runs them a bit rich at WOT. So wouldn't a cold air system and headers cause the engine to go leaner at WOT? This should increase the power if factory stock is on the rich side.
ARH told me to get a tune by PCM4LESS to get the most from the headers. What does PCM4LESS do to the fuel and spark map? Does any one really know?

 

This^^^

 

Not sure about your speedometer problem, but when I did 3.75s in my car I had to get a speedometer calibrator, it was very simple and pretty quick to install. I had the option of put drive and driven gears in but I had to pull the overdrive unit and I didn't want to mess with that.

When I had my mustang, I had intended on installed long tube headers an x pipe and a cat delete, I didn't get a chance to because it developed a wrist pin knock so I sold it.

But I had purchased what are called MIL eliminators, which stands for malfunction indicator light, or more commonly referred to as check engine light. These plugged into the rear o2 sensors and sent a false signal to the computer making it think everything was okay. They were only $70. Not sure if someone makes something like these for this car but you can probably buy the mustang ones and cut the wires and wire them into your o2 sensor wires with no problem.

I was not aware that you can get this feature removed in the tune though, can you?

I know on my car, they said that most bolt ons didn't require a tune, only if you changed the heads or cam. Might be the same situation on yours. If you have a friend that is into modifying cars, maybe they can let you borrow a wideband o2 sensor and AFR gauge if they have one, and then you can post the readings here and we could let you know how you're doing.

Best of luck, after you start modding, you will continue modding!