So ive recently aquired a 2001 xkr, my question is, does anyone know of ways to get more power out of them? I have mina gallery intake and exhaust. Im looking to see if anyone knows a company for headers or has recommendations for pulleys and if theres a way to get into the computer and tune them differently.

 

The cheapest way to get more power per lb. Is to start ditching unneeded weight. Like the rear seat and spare tire. You can also ditch the under hood fabric mat with no worries of heat damage to the paint on top of the hood. I took mine off 3 years ago and have been driving cross-country in 115 F heat every summer with no ill effects. I took mine off because it was rubbing on the supercharger cooling hoses and degrading them. But it does weigh 20 + lbs that you don’t need.

without too much effort I get a person could
remove 400 lbs of sound deadener and rear upholstery, spare tire, etc and boost the acceleration accordingly. And at zero cost.

there are pulleys available for both the crank and supercharger that will increase the spin rpm.

I don’t think there are aftermarket ECU tuning devices for the 4.0 liter engines, only the 4.2’s. Someone please correct me if a have that wrong


Z

PS before doing anything make sure your #2 fuel pump is operating. If it doesn’t kick in you will not have crisp acceleration.

 

Another apparently neglected item is the dedicated intercooler water pump. It is located near/under the air box and can die silently. Reportedly, it runs with the ignition on, engine off, so quick to diagnose.

 

Something to consider: there are quite a few recent forum discussions concerning pros/cons of replacing the +/- 60 lb AGM (or standard wet cell battery) with an "antigravity" lithium battery that are worth searching/reading. Not a cheap replacement, but the weight savings is substantial; several owners have remarked that they save about 40 or more lbs, without any operational issues.

 

Have you considered installing a flux capacitor?

 

A few years ago, people were swapping the eaton roots supercharger with a Kenne Bell Twin Screw and achieving upwards of 600 rwhp. Unfortunately the kits are no longer being made.

 

Removing excess weight from a car is a good idea, but how about the driver? If I lost 50 lbs. I would look and feel better and my car would run faster!

 

it may be more realistic to rip out the back seat vs having the driver lose weight, unless of course the driver is willing to have surplus body parts surgically removed, like spare kidney, redundant ********, left leg ( no clutch, right?) , etc

Z

 

I did upgrade mine with a 18% bigger crank pulley a month ago. It will not give you a lot more peak power (because the supercharger reaches its max rpm) but a good deal of torque low and mid, and the best of all - a MUCH better throttle response.

 

It's amazing what a couple of Pulleys will do!

Billy Clyde

 

Bigger crank pulley and mina underaxle exhaust was quite noticable overall but adding a diff change from 3.06 to 3.27 was icing on the cake as far as acceleration is concerned.