hey guys sorry to bother you again but my 8100 is getting boring and annoying
it has 70k on it and is mated to a zf6 in a reg cab 4x4 here for about a year it just doesnt cut it anymore no service lights are on fuel pressure at idle is 60lbs and never drops goes up to like 65 at wot
when you are takin off and you get the clutch all the way out and start to accel it stalls for a bit just enough to push you forward in seat then it takes off when you got defrost on and your goin down the road and it kicks in you can really feel it load the truck it wont even hardly spin my 285s unless its wet it has new ac delco plugs 185 stat it has dual 3 inch magna flows with stock tail pipe i had a straight pipe but everyone on here said it was bad but it sure felt better to me than these magnaflows is it hard on the engine with straight pipes with the factory y pipe and tail

It is said gas engines need back pressure to have good mpg. i have read without back pressure it can fall on its face.

Brian

Cats should give it plunty back pressure. If you haven't done tuning, that make a big difference. Sounds like your experiencing torque management. It's purdy aggressive on 8.1l. I'm sure you would like 40hp gain.

It is said gas engines need back pressure to have good mpg. i have read without back pressure it can fall on its face.

Brian
i had heard that too
but when i put the muffs on it felt worse

TM is in trans too but you wouldnt have that prob. Cats clogged? They rattle when you hit em?

That thing should be roaring with a 6sp.

Yea that thing should be strong.Def. something wrong

Still have the old plugs. Put them in and see if it helps. If they not gapped right they can cause issues but mostly on Idle. Just my own experience with 8100 in a 2500 Avalanche.

Brian

It is said gas engines need back pressure to have good mpg. i have read without back pressure it can fall on its face.

Brian

I keep hearing how the 8.1 is picky about its exhaust. I found a dyno from corsa exhaust and was shocked at how a perfomance exhaust kills the motor at any RPM less than 3200. Around 65 ft/lbs LESS torque. I have no idea what your setup has done with the power of your motor.

Here is the other exhaust thread:
http://www.dieselplace.com/forum/showthread.php?t=335472&page=2

i may try my straights again not sure on the torque management with it being a six speed manual maybe its the ethanol gas you hafta buy these days plugs are the ac delco not sure on number its what several people on here recommended the truck is mostly stock except the stat and plugs it has a new wix heavy duty air filter new fuel filter too

Alot of TM in engine as far as hard take offs. Its all Knock Retard and retarded timing.

maybe its the ethanol gas you hafta buy these days

If your only running 10% like everyone else, then that's not your problem.

DEWFPO

That thing should be roaring with a 6sp.

I was thinking the same thing! A reg cab 6 speed shoud be an animal,esp with tuning.

ya, i to would think it would be mean as hell with the 6spd, wish mine had one.

on the exhaust thing running straight pipes shouldnt damage anything except maybe your eardrums. i'm running duals with no mufflers on my truck dumped at the rear axel with no issues. it was the only way i could get any sound out of mine where its a Cali emission truck with 2 extra "pre"-cats in the exhaust. however like someone mentioned earlier opening up the exhaust will help on the topend but it can hurt bottom end. i know with all the stuff i've done on my truck i've gained a pretty good amount of pull on the topend in the seat of the pants o meter but may have lost a bit on the bottom.

on the back pressure thing, no gassers dont need back pressure. when going to a big free flowing exhaust you dont lose the power do to the lack of back pressure its cause to big of exhaust can actually slow down the exhaust flow. its like a nozzle on a hose, you decrease the diameter and it will increase the speed the water travels out the hose. you take the nozzle off and it slows down. so to big of exhaust will slow down the flow but on the other end of the spectrum, to small of exhaust will cause back pressure which will also effect the flow so for the best performance you want to run as small of exhaust as you can with as close to zero back pressure as you can. does that make sense?

keep us posted if you get the problem figured out, there is something definately wrong though, mine wears out my 35's way too fast!

^^^^^^^
is your truck tuned