I will make the story as short as I can,my brother a few weeks ago was valeting his 430 italian when he bumped into a new lambo gallardo parked behind.The guy does custom work,so my bro felt bad for him and offered to give some business to him by getting the 410s and kooks headers with off road xpipe,and lower it,red calipers,and lingenfelter hood painted and installed on my car since the guy works with vettes.He basically outsources the work.I was hesitant about letting someone I dont know work on my car but when Im not paying,hell ya Im going to do it.The hood came out great.The headers sound great with the bullets,but when I get on it just a little (breaking in the gears),the car starts pulling and then has some hesitation briefly around 2600 to 2900 rpm and the exhaust seems backed up or something(sputtering).I also got the check engine after about 20 minutes of driving,but I was kind of expecting it.The car idles normal and I dont hear gear whine,but the hesitation and backfire is killing me.The car has not been tuned yet with the headers and gears,but was tuned a year earlier.Do you guys think tuning will get rid of this or does it sound more like a leak?Any guys in south florida who know a lot,I could meet and take a ride.The guy offered to tune it because he said that was the problem,but I want to take it to a good tuner that I know.I will try and post a new pic in my profile.The hood with the powdercoated rims and dark tint really have this black beast looking nasty.VERY LOUD now but more so when you open it up at 3k.I havent had a chance to hit the throttle hard since I want to go a few hundred miles easy with the gears,but I can tell its a whole new beast.I might be heading up to the tower shops around 6 or 7 if anyone is going.

 

I'm no expert but I think it does need a tune. 410's are pretty steep gears and the Vette has computers that monitor everything so the car is likely getting messed up because it's reving alot more than it should at any given speed. I also think this would be especially true if it's an automatic? Good luck with it.

 

The cars a 6spd.I think the 410s are perfect,its still low rpm on the highway and the headers,off road x and bullets are doable for me on the highway.Im hoping tuning will be the cure.Im guessing the lingenfelter hood is actually good for a tenth in the quarter,as its ramming air right into my stinger intake and keeping the engine cooler.I can tell the kooks make some nice power over 4k.The car smells like its running super rich if that could cause any of the hesitation.

 

I wonder if he got the front O2 sensors plugged in backwards. Kind of sounds like it. It's pretty easy to reverse them and try it.

if that's not it, or for your tune, go see Roger at Horsepower Sales in Pompano, he can help you for sure.

There is a table you need to adjust with gears or you will have a false rev limiter at 5800 or so in 2nd. I made a post about a couple of weeks ago. I'll try to post a link later.

 

first thing you need to do is know what codes your are getting from your CEL then go from there.

 

if you were not tuned for the gears that's the problem

 

 

You don't NEED to tune a manual car when you get gears, except if you get the false 2nd gear rev limiter. But a tune will give you benefits on top of the gears so I recommend getting one. Mike Norris comes to Horsepower Sales in Pompano every other Friday, he can take care of you.

Here's a link to the thread where the high rpm miss with gears and a basically stock engine is discussed:

http://forums.corvetteforum.com/show....php?t=1525166

Here's the table discussed in that thread that you need to adjust when you put gears in a basically stock LS2. Worked like a charm for me. Change the one cell from 500 to 0 and it makes all the difference:

 

Joe G, are you sure you dont' need to input the gear ratio and that accel threshold table value? It may actually have 2 enablers for the revlimiter. I'd love to take a look at your tune if you want to email it to me @ dougnosser@hotmail.com

By not inputting the gearing in a genIII car you are actually in the wrong cell timing wise. sometimes too far advanced causing detonation. Just curious, maybe the genIV cars work differently but I'd still be concerned if I'm in the right cell or not. It would be intresting to do 2-3 pulls in 3rd gear to get a average timing value via rpm and export that to excel and then change the gear value in hptuners and make the 2-3 pulls again to see if the car is seeing the same timing values based on rpm.

dougie

 

I also am getting a check engine light after having gears installes...Been back to the Vette Doctors a few times.they say it'd got something to do with the trans speed.they are trying to correct it.I also had a tune done after the gears and converter installed.check engine light seems to come on when the trans is winding down.Hope they can find the problem......in the tune...............NastyC6

 

happening with my c6 auto now...........engine light...has no effect on the performance though......the dealer may not agree.but that,s for down the road....NastyC6....(.3;73's and a 3K converter..)....

 

Hey Dougie, I'm certainly no expert but I was told by reputable tuners (Roger and Mike) that you don't need to adjust the gearing for a MANUAL car. You absolutely do for an AUTOMATIC car or it won't shift correctly. So I understand why NastyC6 is having trouble.

That said, I see where you can adjust the gear ratio on a manual car's tune, I wonder if it would make a difference. I'm tied up with family activities this weekend but I'll give it a try and let you know.