8.1L performance parts

BB2500HD · October 10, 2002

I have a 2500 HD with the 8.1L in it and am looking for any power mods that actually see results. I already have the otherguys headers, volant intake, and directhits ignition. I am looking for more. If anyone has any positive mods or things to stay away from let me know. Thanks

Pancho · October 11, 2002

How tough was the header install? Did you do it yourself and was it worth it? I have heard good things about TOG headers and am considering them.

gandolphxx · October 11, 2002

You have already done a great set - the TOGS are sure fire winners - you might want to open up that exhaust a bit - a nice Magnaflow 12590 would drop right in.

The other thing is to consider an HPP3 - will give it some get up.

BB2500HD · October 11, 2002

PANCHO

I think the headers were worth it. The headers were extremely easy to install. the only problems i had was with the EGR hook-up on the back of the passenger side header. The other problem was turndown pieces that you but up and weld to the stock exhaust. They were not close. However i called Duane at TOG's and he was very reseptive to the problem and because we are only about 40 miles away from eachother he came and pick my truck up on a trailer and took it to his shop, redesigned the turn down so it fits fine now. one of the problems is GM has a few different contractors that make the exhaust systems so there is a few type of systems out there. My truck is 2WD also. Duane said that usually people do not have a problem.

BB2500HD · October 11, 2002

GANDOLPHXX,

I forgot to mention that i cut the stock muffler off and was going to put 2 spintech mufflers on, but i started the truck up without the muffler and supridingly it wasn't that loud. So currently i have no muffler. That seems really stupid, i know, usually i don't do stuff like that, but it really is not that bad. The only time it starts to get a little loud is at wide open throttle and higher rpm. I don't think i am hurting the truck because the bigger the motor the less back pressure you need and when i had the exhaust off to do the headers i blew my air gun through the exhaust where one (there is 4 on my truck) cat was and i could not believe how restrictive they were.

I did want to ask you what you did to your AV to get it to run a 14.5

how well do you think the HPPIII really works?

Thanks

gandolphxx · October 12, 2002

I have a few intake mods, a K&N, Whipple supercharger and intercooler.

I also have the TOGS [great!] and a drivetrain that has been stiffened with Kevlar clutches and a 2600 torque converter and Trasgo kit.

I only use the HPP3 for gear and wheel settings and playing with the shift points - the Whipple overrides the "performance" stuff with their computer - I have had the PCM reprogrammed to minimize the dreaded torque management.

Thats how you get a 7000+ lb truck into the mid 14's - sheer size seems to scare some of the folks at the track

Brian1 · October 14, 2002

Hi gandolphxx, emailed you awhile back and now see you have the intercooler on now. Do you see an inprovement? The installation looks real nice on your site. Also did you ever get rid of Torque Managemant on the 8.1 and 4L85E Setup? And what did you use?

Nice talking with you.

Brian

gandolphxx · October 14, 2002

Love the intercooler, still working on some minor things. The key to the torque management is to get the chip fixed - no aftermarket fix is available - it really works.

I used a local shop MTI in Houston to do the deed. :thumb:

tbyrne · October 15, 2002

6-7# of boost on an 8.1 motor feels very good and can surprise alot of cars Torque management is more noticeable with the blower. With it the truck feels like it's losing power between shifts (it actually is), without it the RPMs climb quickly to the shift point and then the truck keeps on going.

gandolphxx: Have you had your truck on a scale yet? I weighed my Suburban with the car hauler and a car/equipment inside and came up with 16,100. I believe the truck alone will be in the 6600-6800 range.

Tom

gandolphxx · October 15, 2002

Tom, my truck, as a daily driver weighs in at 7010lbs - had it done at a Cat certified to check - the track scales went "tilt"

Actually, the 8.1L with s/c can surprise a lot of trucks :thumb:

CMNTMXR81 · October 15, 2002

Heck stock 8.1's can shock a lot of autombile's on the road! Just that dreaded Allison and TQM that hold it back. Can you imagine what a gorilla it must be with a 6spd?