saw a post where LS guys replied but i'm looking for LT1 specific experience please

for those of us that want every last mph at the track, what have you guys seen through an X vs opening cutouts or pulling catback? thank you.

 

Pretty sure open headers lose low end torque but make it back up higher.

And if you run it out the back it should be like the opposite or something?

True duals will always outflow a Y-pipe system, even with a cutout - or so they say.

I don't have any numbers, but I DEFINITELY noticed a difference from going open headers to a true dual X-pipe setup, even with cats and bullet mufflers.

 

Open headers, well open headers with header extensions to be exact.

 

X pipe- equalizes the banks and helps accelerate gases thought the exhaust system.
Open headers- will not have equalization and while they will make more power than stock manifolds you are not maximizing the potential of a long tube headers design.
Cut out- A cut out after an X or Y is the best place for them so you get the benefit of equalization and free flow.

 

It completely depends on what the headers are bolted to.

 

sounds like regurgitated internet hearsay to me. I don't see ANY race cars running any sort of x pipe or "equilization" device. Exhaust design is very complicated, and needs to compliment the camshaft, intake design, valve sizes, displacement, rpm window, etc. I'd run it with 24" collector extensions, cut off 4 inches on each pass until you lose mph. Obviously recording DA at the time of the passes will help determine the gains or losses if you're not making passes within a few minutes of eachother.

 

I have read in magazines and on the net about the equalization effects of an x-pipe. However, I agree with you, every time I have been to the track most everyone is running open headers or headers with collector extensions. I know they don't run lt1s, lol, but you don't see top fuel dragsters with equalization devices on them. And they are trying to squeeze every last bit of power.

 

my goal is a lightweight, MAX effort track exhaust that is, or can somehow be a Little street friendly(ie not chopping, open LTs next to police).

so far i have LTs and 3" dynomax bullets(if they hurt power, atleast they'll quiet it down for the street while sounding nice). just trying to decide if i should even bother with an X or go straight to dumped bullets? and if i should rethink cutouts for track? if so, before or after X? ugh my head hurts.

i imagine Wicked may be onto something with the tuning lengths

 

this is one of the few that inspired my dynomax bullet purchase.. note in the comments, he later put on an X ??
http://www.youtube.com/watch?v=NlBHf...ext=1&index=22

Also the impressive SR Ai 355, who opted for just an open X pipe off the headers for track days?
http://www.youtube.com/watch?v=vWMmD...eature=related

ugh

 

I would do an X-pipe with Dynomax Bullets dumped at the axle, that way you can drive on the street, I had mine with aftermarket cats and 2.5" piping and it was VERY tolerable and sounded great.

I couldn't imagine a Dynomax Bullet being restrictive, have you seen the inside of them?

 

OMG that 355 sounds amazing, thats my vote if you don't care about being loud as ****.

 

yeah it does sound sweet, wish there was more people sharing experience/results

 

what are the specs on your engine?

displacement?
heads?
cam?
compression?

what did it dyno? or what does it run and what's the car weight?

 

I'm going to be running 3" X and true duals over the axle (one on each side) and Dynomax Stainless mufflers on mine once I get my new engine outta the machince shop and in the car.

 

answered above.

 

bringing this back from the dead.

still wondering if an X pipe will help me in any way at the track, trap is all i really care about.

any proof out there?

 

375rwhp through a hooker catback, 369rwhp with true duals run out the back and another 30+ lbs.

And there's no reason you need lt1 specific results for this. It's not some magical motor that defies physics.

 

I'm seeing around 66" from end of primary to the X to be the optimum length. Or ~16.5" collector length for open headers. Or the same ~16.5" to an H pipe if you wanted to try that. Total exhaust length from the end of the primary to the tail pipes would be 132. I'm going off a 230/238 on a 108+2. I think open headers will benefit you the most on this combo.

 

when i ran open Y-pipe, after a month it started backfiring like a shot gun with every shift

 

open headers will be the fastest as it is the lightest option and flows the best. idc what anyone says