Slightly modded KB MM-S results from 3-19-04

[89lxbill]

Well, took my friends slightly altered KB Marauder (9psi) to Virginia Motorsports Park Friday night and it ran a best of 12.39 @ 112. No more modding he said unless the bottom end grenades. Right now, it is a very safe tune. I told him though if it blows, Kar Kraft has Cobra long blocks cheap, then he can run the boost up.

[Zack]

Would you mind sharing the 'slightly modded' secret?
What exhaust, pulley size, gear ratio?
Thanks and awesome time.

[89lxbill]

4.10 gears, stock exhaust, except flowmasters, and I believe it was a 3.23 pulley on the blower. All I remember was is the tuner said it was a regular Cobra app 12lb pulley, but with the intercooler restriction, it runs abt 9-9.5 psi on the dyno. So, really the 7lb pulley on the stock KB setup is a 10lb on the Cobra setup. I have tried to talk him into some real exhaust, but he is tired of spending money. I told him, welcome to the world of drag racing. :D

[Zack]

I believe I provided you this info when you first had this car in your shop.
A 3.61 pulley yields 8lbs of boost
A 3.48(Which Kenny Brown Uses) yields 10lbs of boost.
A 3.23 pulley would get you 12lbs, even with the intercooler.
I couldnt figure out how the car went that fast with the stock exhaust, but the small pulley explains it now.

I havent found one Vorteched Marauder that lost the advertised boost because of the intercooler.
My 8lb pulley puts out closer to 9lbs at 6200rpm.
Ive seen other Kenny Brown cars make close to 11lbs at the same rpm.
If he loses the crappy exhaust, he will run 12.0's with that level of boost.

[89lxbill]

The boost has been verified on the dyno. It also has a new Pro-M blow through style MAF. The car is shifting at 6200rpm by the chip. Possibly turning it harder may get more boost, I dunno. Again, I may be a little off on the pulley size also. I can say, though that it never made 10lbs of boost when he got it back from KB. 6.5lbs was the most we ever saw on the dyno or the guage. I'll be honest with you, not to bash KB, but when he got it back, it was quite sub-par from the rest of the people we talked to with the KB cars. It only ran a 13.42 @ 102 mph out of the box. 4 chip burns from Ford Chip later, it finally ran a 12.8. The trans still shifted bad and the tune was real lean (13:1) in the upper RPM range. We installed Cobra pumps and a larger fuel filter with strait fittings and then a local guy named Ed Clark tuned the car using the Superchips Tuner software. It came out of the box with a 12.71 @ 108 with a 25mph headwind. Then he ran the 12.39 last weekend. But this is all on a verified 9.5lbs boost. I am like you though, ditch the stock pipes, and he may gain some more on the big end.

[89lxbill]

Officially, it is a 3.33 pulley. I looked at it this morning.