[Iceberg3232]

Thought I'd throw a question out to the forum in hopes of getting a better idea of what RPM range I should be looking to launch my car. In essence, I'm looking to avoid treading the line between perfectly launching and breaking my damn transfer case.

The Proceed rev limiter sets the stage for the launch and a recent Spec 2+ clutch install in ensuring that all the power can be fully used, not like I've really had this problem considering the car is an XI. To make matters a little more complicated, I've yet to change the non-staggered 19 X9 wheels the previous owner put on the car. The car has KWV1 coils and new Kumo Ecsta SPT tires (not my first choice but the price was right) 235X35X19 fronts & 265X30X19 rears.

Per the user guidelines on the Proceed, it's recommended that I launch at about 2500, however, doing so in an XI, the car literally throws up before taking off as it has too much traction at that RPM. I've stepped it up to 3200 with similar non-thrilling experiences. The question to the forum is this:

With a FBO setup running e85, putting down approx 440 to wheels, where should I be trying to launch this car and where do I draw the line setting the rev limiter? 3750 ish sounds where I would guess next - thoughts? Is 4K too much?

[Sean335i]

4K sounds like too much to me, I would say 3K, but i dont have an XI

[Carl Morris]

Nobody is going to be able to answer you, I don't think. I haven't heard of anybody pushing the limit and breaking a transfer case due to power. I've pushed hard enough without a two step to spin the fronts at the track and I'm not sure what you're going to do that's any worse than that as long as you don't wheelhop. If you get any wheelhop try something else. Other than that just keep raising the rpm until you stop bogging. A little wheelspin is fine. I was flooring it at the first yellow and dropping the clutch on the third yellow at just under 5k according to the logger to get that result.

[Jeff@TopGearSolutions]

Since your manual the launch is heavily waited on your driving style. You would need to dial it in according to your driving style and how it works with the car. If it 3200 is enough you likely need some more.

Shiv was launching at nearly 6000 RPM if I recall at the track on slicks.

Keep in mind this is hardly recommended from me but if you want to launch your car it will take some abuse.

[akotten]

With those tires, I would assume you will break traction far before you cause any damage to the transfer case.