tuning
 

when i will be tuning my 03 gt, i will have long tube headers, h-pipe, high flow cats, 75 mm TB, mac fenderwell intake, upper intake plenum and 3.73 gears. is this enough mods for the chip to make a big difference? or should i wait til more mods come? i have researched diablo so far, but i want to explore all options

None of those mods require a chip. However, a chip could be used to calibrate for gears and eliminate the need for mil eliminators if you are removing the cats.

A chip would give you 10 - 15 hp with those mods or w/o those mods. A chip would become a must if you swapped cams or added a blower, for example.

If you plan additional mods down the road, I would suggest something like the diablo pred. or an SCT Programmer. These devices are used to flash your cars computer. I have the SCT and I can receive custom tunes via email and then download to my car. It is a very flexible device that can grow with my car.

so, all you need to do is buy the programmer, then email the company and tell them what mods you have and what you want (street performance, drag, etc..) and they will send you a tune?

I would say yes...anytime you modify air intake/exhaust it's wise tuning the air / fuel ratio throughout the RPM band to get the MOST out of your mods.

Depends on which one you get. With SCT, when your order the programmer you simply tell them how your car is setup and they will give you two custom tunes on the programmer. I have a high octane tune and a 87 octane tune for example that I can switch between.

If you need to have your tune changed or updated, you can either mail the programmer back to your dealer OR have them email the tune to you. To receive tunes via email you need a $75 cable and power pack. It is more convenient than mailing, is more immediate, and cheaper in the long run on freight if you plan on making a lot of changes.

I would recomend www.modulardepot.com as an SCT dealer. BUT, if you have a local dealer, use them. As they will most likely have a dyno as well.

Technically TRUE! However, on a near stock car, with mods that are proven and have been used for 100's of people AND when you add in the cost of a dyno tune, it's simply not worth it. There will only be minimal change.

There are some rally cool devices like an LM-1 that you can install to your car, drive it down the road and it will data log a/f vs. rpms yagainst your actuall a/f. They are considered more accurate than dynos by many as the car is under real load AND high speed air flow. This has always been my problem with dynos....they can't do this.

so what exactly are these LM-1's? how do you install them? how much?how exactly do they work

It is pretty simple actually. There is a tail pipe fitting that you mount. It is not a permanant installation.

Go to www.modulardepot.com. They sell them there and you can read up on them. Also, go to the thread section on general tech and do a search on the LM-1 and a bunch of info should pop up. Expect to pay something like $450 by the time you have everything you need.