Ok lets see who can help me or give me a good idea. My truck is a turd off the line, it will not take off if it's life depended on it. My mods are full bolt ons w/3:73's, and my best e.t is 14.45 @98 mph with a 2.2 60ft. Before I finished all the bolt ons my 60ft was 2.1. I noticed I lost a lot of power on the bottom end when I did the lt headers and removed the cats. I don't mean a little power loss I mean a huge power loss. The only thing I can come up with is, that I think I might not have enough back pressure. My exhaust is all 3'' going into a single 3'' in magnaflow and dual 3'' out. Do you guys think this might be the problem? If this is the problem I'm thinking about doing single in single out but what I don't know is if I should step it down to 2.5'' in and 2.5'' out or keep it 3'' in 3'' out but single, single instead of single, dual? Sorry for the book but any help would be greatly appreciated. All opinions welcome.

p.s the truck has some topend from hell...

 

what stall? is it street tuned or just a hand held tune. are you stalling it up?

 

it's tuned with HP Tuners and it has the stock stall.

 

a stall will help a lot. do a 3000 stall. im doing a 3200 and if i dont like that im going up to a 3400-3600.
whats your shift point? i lost low end also...but gears and a stall will help that. have you ever thought about picking up some narrow cats and try that?

 

what size is the motor? muffler your running?

 

you will lose bottom end when running lt's. I dont see a problem with the back pressure. IIRC, my truck has 2.5" y-pipe running into a single 3" intermediate pipe. My muffler is a 3" inlet and 2.5" out. I was mad when found this out after I broke a hanger and had to sawzall that **** off. I'm going a different route.

Gears will really help you tho. I say 4.11's and be done with it. Get a cam too....

 

I think backpressure is a myth. Get yourself a tune and converter, and that truck will come to life.

 

i find that straight exhaust makes you lose low end tq. i went to a little longer muffler and it helped a bit. i think if id put high flow cats on itd help with the low end tq but not restrict my higher rpms

 

I agree with this man. Dragsters and Funny Cars dont have nothin but straight headers. The less resistance, the better. Ask any real racer.

 

I'm still not convinced that it's a myth.