LT1-LT4 Modifications - Is this normal?




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Speedmonster185
03-28-2009, 11:44 AM
I was thinking about taking my stock catback off and just sticking a flowmaster single chamber on the end of the Y pipe... so I get under there to look...

From the back of the cat all the way to the muffler it is just one single pipe. That isn't the way my LS1 was... It's welded to the cat, then bends towards the center of the car, gets near the driveshaft and turns straight back and goes up and over the axle to the catback. Were LT1's like that, or is something weird here?

I'm not really sure what to do now because one of the main things I liked about that plan was I wouldn't have to destroy anything.


TABBED 5.3
03-28-2009, 11:52 AM
yes that is right for LT1 cars to have the pipe run next to the drive shaft. About the only muffler you can "stick" on the end of the y-pipe is a bullet type muffler. You can put a flowmaster in there but it will require some fabrication of the exhaust

Speedmonster185
03-28-2009, 12:05 PM
Is it normal for it to be one single pipe right off the end of the cat (welded to it) all the way to the catback?


bombebomb
03-28-2009, 12:27 PM
Is it normal for it to be one single pipe right off the end of the cat (welded to it) all the way to the catback?Yup. Then two exits off the muffler, I thought this is how LS1's were also.

Formula350
03-28-2009, 12:37 PM
Is it normal for it to be one single pipe right off the end of the cat (welded to it) all the way to the catback?

All the 98+ exhaust I'm seeing, even most aftermarket stuff, single pipe just like the 93-97. I've not seen what the setup on the 98+ looks like though, and I'm not at work to look at the exhaust book to check. Either way, your LT1's is normal.

myltwon
03-28-2009, 12:44 PM
if your z28 is a 93-95 it will have a single cat setup, all 96-02 fbodies have dual cat like you're used to

jarretthise
03-28-2009, 02:18 PM
what your talking about though with the cat being welded to it i dont think it is normal...somebody didnt clamp like it should have been done and they welded it...come out and i have a bunch of lt1 stuff..i could hook you up...i know exactly what your wanting to do...i live in crawfordsville so

Formula350
03-28-2009, 06:43 PM
what your talking about though with the cat being welded to it i dont think it is normal...somebody didnt clamp like it should have been done and they welded it...come out and i have a bunch of lt1 stuff..i could hook you up...i know exactly what your wanting to do...i live in crawfordsville so

Unless it's a band clamp, I'd rather have it welded (unless it's a shitty weld lol). I wouldn't say that clamping it is the "proper" way to go about it. If it is factory flanged, then either adapting the intermediate pipe with flanges or welding it off of the vehicle and bolting it up, would be what one should do. Then band clamp before crush clamp.

Speedmonster185
03-29-2009, 02:23 AM
what your talking about though with the cat being welded to it i dont think it is normal...somebody didnt clamp like it should have been done and they welded it...come out and i have a bunch of lt1 stuff..i could hook you up...i know exactly what your wanting to do...i live in crawfordsville so

Yeah, that's what I was talking about basically. haha, what could you be "hooking me up" with?

Unless it's a band clamp, I'd rather have it welded (unless it's a shitty weld lol).

It is. Lol. I JB Welded around the seam too because it had some nasty leaks. Didn't smell so nice for a little while because of it, but now it's just fine and no more leaks :P

impaled
03-29-2009, 09:41 AM
add the short dynomax Shotgun resonator. it will sound something like this. here is a vid of my iroc, which has LT's, 4" of crossover pipe, the shotgun resonator, dumped to the ground 90* right under the passanger seat...

http://www.youtube.com/watch?v=-CMXVUpqoNs

93TAJ.C.
03-29-2009, 11:35 AM
what your talking about though with the cat being welded to it i dont think it is normal...somebody didnt clamp like it should have been done and they welded it...come out and i have a bunch of lt1 stuff..i could hook you up...i know exactly what your wanting to do...i live in crawfordsville so

That is correct. Theyr welded to the collector. Kinda weird though, but it is stock.