Mattkovitch

So I want to buy the slp loudmouth muffler from hawks and build my own exhaust system from the cat back. I'll probably leave the original over Axel pipe and cut the old system off from there and build my own system. I also want to replace the factory cat with something that will flow better. So my question is, do I know what I'm getting myself into? It seems almost simple, is it? Any advice would be helpful! Thanks!

Thirdgen89GTA

iTrader: (5)

It sounds to me that what you want is definitely not custom enough to justify the cost of having a shop fab it up.

Just buy the SLP LM exhaust, it will be cheaper.

Unless you want some custom dual exhaust or otherwise setup its easiest to just go with a pre-existing setup. You can probably find a used setup if you are patient.

I have a SLP 2otL and I will NEVER give up that exhaust.

Twin_Turbo

iTrader: (25)

He wants to do it himself, not have a shop do it.

It's not that hard, just make sure you use all factory hangers or at least plenty of them so it won't hammer against any parts.

Mattkovitch

True, but I want the original slp loudmouth system muffler and the only way to get it is to buy it seperately and then the slp loudmouth II system and use the original loudmouth muffler. Also I've seen people cut the entire system out before the cat and put the muffler where the cat is then just pipe it out the side. But then you don't have cats, but it seems simple. Idk I just need ideas at this point.

Mattkovitch

Yeah I wanted basically keep the old system as much as possible for simplicity and just basically replace the muffler and anything that will have to go along with it, and eventually the factory cat. Also the slp muffler I need is 3 inch inlet and put let will I need a pipe that transitions from the factory 2.25 inch (I believe that's the right size) pipe to like a 2.5 or 2.75 in. pipe so it will slide on better or will the factory pipes work okay?

Twin_Turbo

iTrader: (25)

factory is more like 2.75 or thereabout. Just get a 2.5 to 3" reducer and cut the small end to size.

I recently did what you are planning to, quicky spintech install. Fabbed some slip in reducers and mated a 3" system to the N10 dual cats (not factory and they will go next time I redo it)

It's a 4" in out muffler, hence the reducers


it's got a 3 bolt flange reducer in the middle for easy taking apart

sofakingdom

iTrader: (1)

I would advise STRONGLY against any sort of "custom" exhaust.

A better plan would be, to buy a cat such as http://www.summitracing.com/parts/wlk-15043/overview and a cat-back system of your choice such as http://www.summitracing.com/parts/hok-16820hkr/overview, and do however little you have to do to adapt the other muffler to it.

BrutalGTA

iTrader: (2)

I concur! No need to reinvent the wheel. Buy complete system, muffler of choice then swap muffs and sell unused to recoup costs or trade for needed parts. NO MUFF TOO TUFF!

Twin_Turbo

iTrader: (25)

The hotrodding spirit sure is dead isn't it. The bought not built club. I'll keep fabbing my own instead of buying junk with 10 sections and clamps

sofakingdom

iTrader: (1)

No, it's not.

What IS dead is the days when you COULDN'T GET anything good when you needed stuff like ... exhaust, and you HAD TO build it because there simply wasn't any choice.

Nowadays for stuff that isn't worth the kind of effort of "build it yourself" like ... exhaust, there's boxed solutions; thereby allowing the SENSIBLE enthusiast to spend his time money and effort on stuff that DOES matter by just buying the commodity-type stuff that doesn't benefit from extra personal attention like .... exhaust.

There's a time and a place for "build"; exhaust for the most part, just isn't it.

Personally I'll take a pre-packaged system any day of the week over something poseur but overdone, like a 2½" I-pipe adapted with a buildup of a bunch of melted metal to a 4" muffler, and a 3-piece welded up 4" tailpipe welded to the muffler. That's A LONG WAY from my idea of how to "build" something. That looks to me like it was "built" just for the sake of "building" without any regard for ... much of anything, least of all function, efficiency, or effectiveness.

skinny z

I'll wade in on the hot rodding issue.
Yes, there used to be a time when you had build everything yourself. And a lot of what we do here at thirdgen still has that spirit.
The exhaust is a little tricky though. Up until Holley released the true dual kit (under their Black Heart brand), anything you wanted to do, HAD to be built because there were no other options. But, anything from the cat back IS available these days and it's much more cost effective (for those with limited tools and/or fabrication skills) to buy the part rather than pay a shop to make it.
Case in point: Torque arms. Before the 1st iteration of the tubular torque arm was released, we built them. Today, even for the guy who has all of the necessary ingredients, it's impossible to build one (taking your own labour units into account) as cheaply as it is to buy one.
The OP would probably be further ahead following the advice of the "buy it" crowd.

Twin_Turbo

iTrader: (25)

Are you referring to my exhaust above? Sure sounds like it with the 4" tailpipe and muffler. There's no transition made from a bunch of melted metal. It's a tig welded stainless section that I did fabricate, it's just mig stiched to the muffler over a short length to keep it all from sliding. The rear section was built with future mods in mind, the stockish 350 is coming out. It's not a poseur exhaust at all.

I can guarantee you that my hand built exhausts outperform most anything out of the box, all tig welded and transistions with smooth joints and no leaking connections.

You can not buy stuff like this out of the box:

2015 E63 AMG dual 2.75"


87 trans am, dual 2.75 into 3.5


73 Formula 455, dual 2.75






63 stingray 327, dual x over 2.75s handbuilt mufflers









82 Corvette GTO LS1 T56, dual 2.74s borla mufflers. 10 year old system, still like new



As for other parts, I build my own torque arms, SFCs and stuff like that. It's sort of readily available but I enjoy building stuff. I built my own double a arm suspensions, front steering rack systems and coil over setups because I enjoy that a lot more than just buying stuff and seeing the same on everyone elses car.

The case is, this guy wants to build part of his exhaust system himself. So let him, applaud him for that and maybe encourage a little. Just saying, buy this or that...what good is that?

sofakingdom

iTrader: (1)

Hey all I do is call em like I see em. Which in the case above, all I could see was what was in the photo; which sure as hell looked ALOT LIKE what I described it as. Doesn't too much matter how many pics of how many other cars you post to try to make yourself look better and to make up for that utt bucking fugly POS up above; it's STILL utt bucking fugly.

The case is, the guy has a car, and wants to put an exhaust on it. He might THINK he wants to "build" an exhaust; he might even have ASKED ABOUT "building" an exhaust; but that doesn't change the basic facts at hand: he's at point A (no exhaust) and wants to get to point B (yes exhaust).

I'm giving him the shortest route to get from point A to point B, pure and simple.

I have no desire to "applaud" or "encourage" wasted effort and money that produces, in the end, NO tangible benefit, and in fact, is likely to be INFERIOR TO what can be obtained by simply opening a box. Now, when there IS NO SUCH BOX AVAILABLE, it's a different matter; but as Brutal so eloquently put it, no sense in reinventing the wheel, when there's nothing wrong with choosing and opening a wheel box and just using it.

[disclaimer] No I don't cast my own blocks, stamp my own floor pans, machine my own pistons from billet aluminum, slaughter my own cows and tan their hides to get the leather to cover my seats, turn my own valve cover hold-down screws on the lathe in my garage, or .... I just buy that stuff when I need it. [/disclaimer]

There's a time and a place for all that. Maybe all your torque arms and whatever else, is that time and place. This guy's program doesn't quite qualify.

Twin_Turbo

iTrader: (25)

I'm sorry, I wasn't aware I was in the presence of such greatness as you. Sorry we can't all rise to your level of excellence. Yes, my stuff is junk...thank you very much.

sofakingdom

iTrader: (1)

Any time.

Scuze me now, gotta go melt the rubber I'm working on for my next set of tires... I'm a hot-rodder, you know...

dmccain

iTrader: (2)

Hahaha! Man your stuff looks great! Very neat and well done and thought out. Don't let that old thorn bother u.

rb85TA

Twin_Turbo, I have a quick question ( not criticism, honest question ), on the 87... is there a reason why you didn't just route the pipe into a "Y"? You crossed over at the tail shaft & from the picture, it looks like it might have been cleaner, easier & tighter fitting if you would have just run it into the other pipe a few inches further back.
Again, not criticizing. ... just want to why, or what I'm not seeing?
Thanks, Rick

rb85TA

Here's a close up from your picture & the area i have questions about.

Twin_Turbo

iTrader: (25)

This way the 2 merge in a 3.5 inch bend so a much larger area. The s bend if the 3.5 is there so the rear section is straight gack and clears the driveshaft loop that ended up being installed crooked and I left the lower part off. Also this way it can run closer to the floor. Midway between the tires is where it scrapes first on speed bumps

Hard to see but where the 2 pipes meet the drivers side on curves under the talshaft and back up to clear that and the panhard mount. I also had to make it so a ford vss actually fits. It was left off before because of clearance issues so speedo was inoperative.

rb85TA

Ok, thanks

Twin_Turbo

iTrader: (25)

Here's a better view, not as restrictive as you might thing, it steps up to a much larger size

rb85TA

That's actually very clean! Thanks

shugart111

you can buy a cheap harbor freight welder, all piping, and mufflers for the same if not cheaper then even the cheapest prefabbed system. then once your done you now have a welder and a new skill. plus what happens if you don't absolutely love the sound of your $400-$600 prefabbed exhaust system? you still have to do custom work anyway to put in another muffler/ resonator.

rb85TA

Yeah, I have a friend that bought one... not crazy about the Flux core welders, just doesn't seem to give as clean or as strong of a weld ,as better "gas" welders provide.
Really want to get a tig welder & get familiar with it.

Twin_Turbo

iTrader: (25)

Sounds pretty good too for a junk exhaust built without efficiency effectiveness and function in mind. I'm sure some off the shelf system would have worked much better, had much better fitment and a lot better ground clearance... a waste of time indeed

rb85TA

It sounds better than most of the single out exhaust that I have heard!
I'd like to get my shop finished so I can get started on my ride....