93camaroLT1

Coming to the realization that open headers won't allow for enough backpressure I bought the summit X pipe kit, which is many say bolts right up to hooker LTs. It doesn't quite bolt up to my Groty LTs. If I just weld flanges to the first 2 peices of pipes of the X pipe kit and just bolt that up to my headers will that be enough back pressure for my car to run good? I know people just bolt up bullets and that is ussaully enough (i can't imagine that being much longer than the piping from the first part of the x pipe). The car is a heads/cam/nitrous car, and I beleive the 2 pipes that connect to the X are about a foot and a half long, is that enough backpressure? (Right now I just have a couple glass packs on, reasoning for wanting to do this is because I want the car as loud as it was with open headers)

valter

Why do you need "enough" backpressure?

BlackScreaminMachine

This site seems slow, it needs more backpressue

2000GTP

I've heard of backpressure becoming an issue with the LS1 engines, but I dont know if there is any fact to back that up. As for the LT-1s, I know of many people in my area just running long tubes to an x-pipe and then to dumps. They aren't complaining of any power loss due to lack of backpressure. When I did my LT install, I just bolted up the y-pipe to keep the O2s protected and drove it for a couple of days and it felt like it had the same amount of power as now with a pair of catalytic converters and cat-back installed.

93camaroLT1

i've been reading on here a bit, and from what I gathered, no one runs open LT headers without running into problems with backpressure and power loss due to that (which is what I was originally going to do.) Then as you said I was going to run the LTs to a X pipe kit and dump it after the x pipe, but that kit won't fit. So... essentially what i'm asking here is would I be straight to run open long tubes headers plus a foot and a half of exhaust piping after the collectors without backpressure issues?

93camaroLT1

I realize this isn't much better than just running open headers but it is a little piping after the collectors (about a foot and a half).. If it's not going to be enough piping, I can take it to a exhaust shop and have them extend the pipes, If its not enough piping, how much should I extend it?

1racerdude

If backpressure was the "thing" then Pro Stock would be running mufflers.
Ya need to tune for open header's 'cause the intake works better.

mrr23

here do some reading up on 'back pressure' http://web.camaross.com/forums/showt...t=backpressure

can't believe that notion still exists in the 21st century.

93camaroLT1

I actually posted about running open headers a while back
click here: http://web.camaross.com/forums/showt...9&page=1&pp=15
Anyway, regardless of what people said on that thread, my car sounded great with open headers during the 30 min cam break in, and was so loud that it pissed off 6 neighbors and set off 2 car alarms

It seems that the only problem with running open headers is that (like the post http://web.camaross.com/forums/show...ht=backpressure) shows is that on a car running a mild cam and some some head work it would actually decrease HP. Obviously its not the case on a forced induction car or even my car when spraying the 150 shot. The reason for this post is becuase I don't know how much piping past the headers would be ideal to prevent from losing HP, and I figure someone on here has already experimented and found this out. I don't really want to experiment cuz it is expensive and I am sure someone has already done so. One benifit to not running a lot of piping is just that is would be simpiliar to switch from headers to a couple of short pipes (for really loud) to headers to glasspacks (to quite it down once in a while). Right now the collectors on the headers are 3" and the piping after it will be 3 inches. How much piping do I need if any, to prevent HP loss, I do plan on dynotuning the car, so it will be tuned.

93camaroLT1

stock cars/ race cars are also running much, much, much higher compression than I am and nitro-methane. I am only running 10.7:1 compression, i'm sure open headers will be awesome for power with the nitrous, but I question if the car will make as it could N/A with open headers, but then again I don't know since I havent experimented, which is why I ask.

mrr23

it depends on your exhaust system. if it's too restrictive (hence back pressure) then going open headers will pick up. i've seen cars pick up 15 rwhp removing the exhaust system they have.

93camaroLT1

The car has no exhaust system at all right now. I just wonder if running about a foot and a half of 3 in piping would be ideal, where it wouldn't lose power due to not enough velocity, but also where it wouldn't cause backpressure losing power that way.

mrr23

collector extensions is what it's called that you are wanting to do. this helps to promote more midrange power. the pipe will be the same size as your collector diameter. how long will be a guessing game. make a long piece. spray a paint line on them. make a run. look for the point where it burned the paint off. cut there.

JS_CZ28

Oh your posting in lt1 tech tonight robert ya must be a lil bored

mrr23

you know me. i see the word back pressure and i try to kill it quicker than a blakc widow kills it's mate. :P