Jcbarr25

Hey guys,

I understand that after headers, a tune is needed. Which one would be best, dyno or hand held tune? I would like to see some HP increase but I am aware that I need to return to stock manifolds every 2 years for smog. Here in CA, apparently they connect to the OB2 port and check for codes and other monitor readiness.

With that in mind, which tuner would be best for my case? I don't know if the dyno tune installer will be willing to give me the tune file and the OEM file so I can switch back and forth? And if we does, what program will I use to do that?

tblu92

LT headers are a VISUAL inspection in Calif---So even if you have all related codes deleted it doesn't matter---They will not pass any car with long tubes---PERIOD--
Typically most handheld tuners will not address enough tables to allow full HP potential of your LT headers---I wouldn't waste my time-- exception being the Diablo which has the most tables available for simple bolt ons like LT's
A mail order tune would be your next choice---They can address all of the approx. 450 tables in your tune to correct for things like LT's cams or heads
Drawback is you have to mail your ECM to them and if any issues arise you have to pull it out and do it again and have them make the changes
The best option but the most pricey is a full tune---A dyno tune only adjusts WOT fuel and timing to try and get the most HP at WOT ONLY---They do not address any drive ability issues like dying-surging--idle hunting--shift points (if an auto)
To me the best route is a street driven tune--It fixes all issues---If your car is a DD this would be your best choice---A street driven tune will also adjust WOT fuel and spark--but on a dyno they are able to take it to 130 MPH so WOT on 3rd gear---Which to me is not needed for a DD---Typically a street driven tuner will go to apprx 100 MPH where the load value is so close to a dyno tune that it is extremely accurate regardless--
Safety on the street sort of limits the speed --unless the tuner has access to a road where they can safely run it up to 130
Most handhelds now cost about $325
Diablo tuner about $375
mail order tunes as low as $150
Dyno tunes $450-500
Street driven tunes can range from $250 to $350

PDsVettes

The OP says he will return to stock manifolds every two years for the state emissions inspection.

Op, if you get a Diablosport inTune or Trinity handheld tuner, you do not have to send the ecm anywhere. All you do is update the tuner once you get it thru your computer and the internet, then install the canned tune that you want, 91 or 93 octane, plus a canned tcm tune. The best setup is to get a custom tune. You load one of the canned tunes, drive it for 150 miles, do a log run, and then email the log and tunes back to the tuner. He will then send a custom tune for the ecm and tcm, install them, drive another 50-75 miles, do a WOT log, send that to the tuner via email, get his custom tune back, install it, and VIOLA, you have a Corvette that runs like a Corvette should. With the Diablosport, you have the ability to reinstall your stock tune, which was saved when you put the first canned tune in you car. Then you can reinstall the custom tune when you want.

You get a little more horsepower for performance, but the throttle response is dramatically increased. The tranny, if you have an automatic, shifts a lot better, quicker and firmer.

Contact Lew @ http://www.diablewtune.com/. You can buy the Diablosport inTune and his custom tune for $495.00. You won't be sorry.

Jcbarr25

Would a custom tune after datalog be similar to a street driven tune? Meaning I data log what the car is doing and how its acting, send file to tuner, they adjust and send it back.

I rally wanted to do a dyno tune as I hear is th best. But its not very practical for me to be swapping.

the biggest question is, if I dyno tune with th LT, do I have to return to stock tune when swapping to oem manifolds? Or can I run OEM manifolds with the tune I got while having LT on? Will I still pass the OB2 Inspection? Visual will be taken care as I will return everything to stock.

I just don't want the car to be out of whack for having a tune made with the LT but running the OEM manifolds

PDsVettes

The answer to your first question I believe is a yes. For the Diablosport, you install the canned tune, datalog and send it to the tuner, he sends the custom tune back and you install, do another datalog for WOT, datalog and send it back, he does his thing and sends you your final tune. If you want changes, he'll do that. Just email him with what you want.

Once you have your final tune and your are satisfied, it's just a few minutes to put the stock tune back in. And it's just another few minutes to put you custom tune back in when you are ready.

If you left the custom tune in with stock manifolds, it might throw a code, I really don't know. You would have to ask the tuner. As I said, it's only minutes to change tunes back and forth. Then you for sure won't have a problem. After all, you probably spent a couple of hours, or more, changing your exhaust components, what's a few more minutes while sitting in the driver's seat.

Monday thru noon Friday, Lew usually answers your email within an hour or two.

Jcbarr25

Thanks for the reply ans the info. I might have to give this a try whenever I decide to tune. Still waiting on a few things but hoping soon.
Will try datalog show my AFR so that the tuner could adjust?? Or do I need wideband to do that?

Mike's LS3

However, a load bearing dyno will replicate street driven scenarios in a much safer environment. This followed by a street run will help the tuner make any further adjustments.