I am doing a swap on my truck and the truck already has a custom tune that I do not want to mess with. Can I use a hypertech unit I have, for the truck, to modify the rear end ratio ONLY. And not mess with the tune that is already in the pcm?

 

You should be able to unless the tuner locked the computer where you can't change anything. It shouldnt mess with the tune at all. Which ratio are you going with and what are you ditching?

 

373s for 456s

 

Nice!! Not for fuel mileage though lol. Must be doing some serious pulling.

 

nope, gonna have some fun! haha, I will be turning 2450 at 75 with my 33' tires. I figured 410s would put it back to stock (what the stock tires would have been) and if I'm gonna pay the money, might as well have some fun with it

 

on hold, Camaro took a dump at 5k on dyno, spark issues, being looked at today

 

Uh oh!! Keep us updated!

 

i took it to a pro, i fixed a few minor issues, made 290ish wheel at 5k which wasn't too far off, but then the spark went to crap and was basically like it hit a wall. New plugs, wires were garbage I did some resistance checks. This place can tun OBD1s so I'm gonna see what they can do, in prime condition, she should be flirting with 360 wheel. The most frustrating part, and reason I sought a pro was, she was running perfectly, and making power all the way up to 5k, then nothing, just falls on its face. But as a DD, running perfectly

 

Well...earmuff the kids, there is no clean way to state this, he used the dirty word, Opti...

 

Yuck!!

 

got 16 years and 40k out of the last OPTI

 

Not bad at all.

 

Now it is being converted to the vented Opti

 

It helps but doesn't take the sting away from owning an opti lol. If I still had an lt1 car the only way I would go is 24x. Yeah its pricey but you get away from the opti and have better tuning software to go with it lol.

 

one day..., right now, get it running

 

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DOH!!!!

 

this is a DD that starts every day and passes smog without any modifications. #ad


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i should note it was about 98 degrees when this was done and the car had done multiple runs, I'm sure that would have had some affect on the numbers?

 

Yeah it will skew them some. Cooler air means more HP