New LT/Shorty Debate

[musclemerc]

I know everyone claims the LT's are making more HP over Shorty's. This has been the story here for years. I don't doubt it, they should. Not everyone with LT's are getting these 30hp's. We know the shorty's make about 18~22HP with a dyno tune. This has been well documented over the years. The guy's that have LT's and did the full exhaust (in either 2.5" or 3") and a tune are definately seeing these 30hp but i'm starting to doubt the guy's that went with either the Kook's or SW's kit that have the LT's and cat's and kept the stock H pipe are getting these HP gains. How are the LT's giving you any benefits when your reusing the stock 1-7/8" H pipe? When we install shorty's the entire mid section has to be removed (H pipe included). There is now way around it. I'm willing to bet the HP number's on a shorty install and a LT-w/cat install are'nt that far off. Im attatching a poll to this thread please select your setup and vote. If you have a LT install and reused the stock H pipe please post your dyno number's

[ImpalaSlayer]

Hey Travis, i wouldnt doubt this either, like i told you in my other post i did it cuz its alli could afford at the time.

my setup is kooks to 2 custom mid pipes that meet the stock h pipe flanges with 2 non high flow cats. i made 306/295 with full bolt ons, pretty *****y IMO. how ever i think a few things contributed.

1. being exactly what you just described
2. leaking naz intake
3. a 90mm maf with the 80mm cartridge in it. we did the math to figure it out but i dont think it was quite right.

i never got any of that squared away to go back for a retune. that was all dont in july and i went FI in september.

[kmastl]

Here are my numbers

294 hp and 307 tq

Stainless Works Maucat "includes headers, two high flow cats and lead pipes that connect to the factory H-pipe flange"
Setup with factory H-Pipe and back

K&N cold air
Steeda underdrive pulleys
Jmod
Dyno tune

I know LeoVampire has the same exhaust setup as me, I am unaware if he has had it on the dyno.

I am making no claim to weather or not these LT's make more power than shorties.. I have no idea, but I am more than happy with the way my setup turned out.

[MercOut]

I wish i could help you in this debate but I didn't/don't have the money to get a dyno tune. If this helps any, my butt-o-meter is off the charts when i smash the gas

[FordNut]

The stock H pipe tubes are 2", the crossover is 1-7/8".

[ImpalaSlayer]

The stock H pipe tubes are 2", the crossover is 1-7/8".

they are 2"? i thought they were 2.25

[FordNut]

oops, you're right.

The 2" section is at the cats.

[kmastl]

For the record when I was under my car I measured the inside diameter of the factory H-pipe where it connects after the cats and it was 1 7/8"

[musclemerc]

Brian you are right. The pipe is 2", the bend's are 1-7/8", the crossover is 1-7/8"

[LeoVampire]

Here are my numbers

294 hp and 307 tq

Stainless Works Maucat "includes headers, two high flow cats and lead pipes that connect to the factory H-pipe flange"
Setup with factory H-Pipe and back

K&N cold air
Steeda underdrive pulleys
Jmod
Dyno tune

I know LeoVampire has the same exhaust setup as me, I am unaware if he has had it on the dyno.

I am making no claim to weather or not these LT's make more power than shorties.. I have no idea, but I am more than happy with the way my setup turned out.

Yep I have the Maucat set up on but I have done so much work on the engine and added so much that the dyno numbers do not count to say how much of a difference they actualy made other than sound and what I FEEL they did to the way the Marauder run's.

To me they were worth it all the way around especialy after all the porting work I did to the head's and intake manifold.

[Spectragod]

Stock H pipe, with long tubes and high flow cats, 472RWHP.

[DOOM]

Dont get Glen started!

[babbage]

cougar1950 has great n/a numbers, and has long tubes with larger midpipes.


With regard to factory mid pipes - they are 1 7/8 inches at the bends so that's the smallest area. I think factory mufflers are even smaller than that inside.

[DOOM]

LOL at merc!

[LANDY]

LOL at merc!

Tell me about it. BTW where is Glenn?