I have had my car dyno tuned before and had the rear o2 sensors disabled, but am thinking of getting heads and a cam for the car. Are there any tuners near chattanooga,TN preferably with a dyno? The place I went to before had a great deal... $350 for the first tune, any supplemental re-tunes would require labor hours only. Unfortunately they've gone out of business or changed names. A little out of my way to drive out and see if they've opened under another name lol. Thus is the way the cookie crumbles I guess haha

 

Dynos let the people tune wide open throttle quickly, but do not give the same A/F ratios as the street. The best tune is on the street, for both part and full load. Most tuners don't want the ticket. Besides there is alot bad things that can happen on a dyno.

 

Can you explain why A/F would be different on the street? I haven't seen this happen.

Of all the "bad things" that I've seen happen on a dyno, not one of them resulted in someone getting killed

OP: The best tune will come from a competent tuner who uses a combination of a load bearing dyno and street tuning. It is tough to re-create low RPM part throttle "bucking" (which is common with a larger cam) on the dyno. The street is the best place to get that sorted out.

A load bearing dyno is not a tool that is only useful for WOT tuning. It can be used to cover the vast majority of the driving conditions that you will see.

Sorry I can't help with finding a tuner for you. I just wanted to offer up a different perspective. Good luck!

 

My tuner spent 4 hours with my car... 1 hour dyno time, 3 hours on and off the street cruising for low and mid range tuning, thus why I'm a bit upset they are gone lol. They had a dynojet, not sure if it was load bearing or not I'm guessing not due to the street time used for the tune. the numbers he got out of my stock engine with exhaust are in my sig, I was happy lol.

Thanks for that info though, things like that are why I really want someone in my area to do it. More time/ability to sort out issues.

 

I am not sure why the a/f ratio changes. My friend likes to brag about his HP numbers. He goes to the dyno alot. He has a dyno tune that gets the A/f ratio correct on the dyno. Then he puts the correct tune in the run on the street. I have seen this lots of times. It could be the temps in the dyno change compared to the street. I have got to agree I have never seen someone killed on a dyno, but sure hurt lots of cars. I read on here about a trans that shifted down two gears. This was an auto, broke the the engine. I think it was a new Camaro.

 

If the same WBO2 sensor was used in the same location (O2 bung. Not tailpipe sniffer) on the dyno as on the street, my guess is that your friends car was tuned on an inertia dyno and it didn't load the motor effectively. This is just a guess. Logging IATs during both runs would tell you if it's that could've made any difference.

Dynos don't hurt cars. Incompetent mechanics, engine builders, tuners, and dyno OPERATORS hurt cars. Not to mention plain old bad luck and honest mistakes.

It's clear that you aren't a fan of dynos. Believe me when I say they are a great tool when used properly.