dath

Here we go again, I'm about to flog a dead horse here, but I thought maybe some of you who have already went through this could give me some advice . . . I'm getting ready to fab up a 2.5" exhaust system and wanted to know which assortment of bends I should buy. . . The price can really add up pretty quickly, so I am trying to not buy more than what I need. I'm thinking this may be a good source for the bends:

http://www.jcwhitney.com/webapp/wcs/...atalogId=10101

I was also thinking of putting a couple of ball flanges just behind the cross member so I could drop either the front or rear half of the exhaust easily. I'll be using these collectors for my Dynomax headers (they have preinstalled O2 bungs for less than what it would cost to buy the parts):

http://store.summitracing.com/defaul...D88314&FROM=MG

I am not planning on running mufflers, but I may change my mind once I'm there. I'm thinking 3 10' sections of pipe will be enough, but I'll have to measure to make sure.

Is there anything I'm forgetting? How would you cut the pipe up (especially the bends)? I was thinking of using my chop saw, but that may get a little hairy, so maybe I should be patient and use my trusty (well not that trusty) old chain cutter?

For a ~450HP 383 do you think the 2.5" pipe is enough? I thought of going to 3", but tshort (a looooong time ago) suggested that it would be a lot more annoying to get it to line up well enough to go through the cross member . . .

Oh yeah, one last stupid question, anyone know where to get a set of 2.5" ball flanges for less than $45/pr? I was thinking of going to a junk yard with a hack saw, but I wasn't sure if I'd find any ball flanges in the right size?

Regards,
-dath

P.S. Yeah, as you can tell I'm on a budget here. My new welding habit is driving me bankrupt

dath

Anyone?

427V8

If you think you welding habit is expensive, try paying someone to fab the new exhaust!

I can't remember where I found cheap U Bends but there was a recent thread about a good place to find them.

Why do you want ball flanges? I use flat flanges and they seal excellent and are easy to find, any speed shop has them allong with gaskets. Just bolt them together before you tack weld them ;-)

3" is pretty big, I'd bet unless you are making serious HP and running at WOT a lot you won't notice the diff

dath

Oh, I know all too well about the fab costs, that is one of the major reasons I bought my welder. I figured with the exhaust work and one or two other small jobs I'd pay for the welder. On top of that, I hate taking my cars anywhere, I prefer to do everything myself.

I'll search around for the thread. Someone from the forum also offered to sell me their stockpile from their last job. . . Problem I have is that I don't know how many I need. Should I just go with U bends and forget everything else? That's kind of what I was starting to believe . . .

I was thinking ball flanges as they don't require any gaskets and I get tired of sealing issues with the flat flanges. I guess the aluminum gaskets work better, but I think I'd be into more or at least the same money for flat flanges and the gaskets. Just trying to save the last bit of hair I have

Yeah, I was thinking 3" is big as well. What I didn't mention in my original post is that I plan to make about 450HP NA, I'll be spraying another 150-175 HP with nitrous oxide. . . I prefer to tune for the normally aspirated number though since that's where I'll be the majority of the time.

Regards,
-dath

1BAD80

I recently cleaned up my exhaust system,for 3" mandrels at cost was $200. You get what you pay for, go cheap and you will be doing it again next year.
LOL

Budman68

I'm using Speedwaymotors.com. Not sure about exhaust pipe though.

dath

1BAD80 - I doubt I'd be doing it again next year, even if I used the crappiest parts I could find. At the rate I'm going, I average about 200 miles a year on a "driver" I really don't see the difference, aluminized pipe is alumized pipe, no? I would consider going stainless, but I'm not sure I want to go the whole trimix gas route in which case I'd just be welding with mild steel, so the seams would loose the stainless properties.

Also, $200 for parts isn't that much. I'm not even putting on mufflers and I'll be close to that for 2.5" I think. I just don't want to spend more than it is worth, ya know? If you have anything bad in particular to say about some place that sells pipe, I'm all ears. I don't want to do anything sub-par, I just want to get my money's worth here.

I'd love to be able to make my own mandrel bends, but nobody has ever come up with a mandrel TUBING bender for a reasonable cost that I've seen . . . If I could make the bends I could do the whole thing for very little money.

Budman - they look like they have good prices, but unfortunately their U bends are meant for headers and thus only go up to 2" . . . I think I need to find a friend who has access to a mandrel bender

So now my latest question based on what 1BAD80 implied (or I think he implied), should I forget about aluminized pipe and use stainless instead? I could probably spring for the trimix gas even, though I'd need to sell a few more oddball car parts That'll be cutting into my compressor budget, but that's a story for another post

-dath

1BAD80

Maybe I should have said get what you need for size.
Your motor may not like the 2 1/2" with the nitrous.
With my 350 I put on 2 1/2", then with the 427 small block I went with the 3" crushed bends and after I put on VP&B chassis package, I did not like the looks of the bends, plus it was hurting the flow, so for a nice fitting job plus a big difference in flow went with mandrel bends.
So I been there & done that.
If you go 3" you will have to cut the center brace for it to fit.
There was a posting on this site a while back with pictures.
Using aluminized pipe you will have to paint the welds and it will look odd with silver rings.
My friend owns a few muffler shops and gets quantity, that's where the price break came from. I used my same Warlock mufflers.
I used aluminized pipe and painted from the headers to the mufflers with header paint by Krylon 1500*.
IM not sure why you need 30 ft. of pipe.
Tommarow I will look under my car and see how many bends is has to give you some count on U bends that you may need.
My 80 does not have the same center support as yours, I can drop the complete system from the bottom without any problem.
My web page shows the old 3" crushed pipe.

norvalwilhelm

Guys I have unlimited 3 inch bends. We make them by the thousands at work for testing but nothing in 2 1/2 inch.
You don't need as many as you think because you can get a number of smaller bends from one 180 or even a 90. You are just taking pie slices.
A chop saw does a great job. It cuts easily and get a flat surface to piece an exhaust together.
I have done a number of them and it is not as bad as you think.
I really like reworking the crossmember so the exhuast passes through a crossmember with no bottom to the cutouts.
If the crossmember is removable it is not hard to modify it and then a straight pipe can be used most of the way back.

dath

Hey, thanks 1BAD80, sorry, I thought you were scoffing at my pipe choice, not the size. I don't mind stepping the size up, I wouldn't even mind stepping to stainless, but obviously that is going to add to the cost (mainly in the gas I need for the welds). I just called the place I'm getting my welding supplies from and they said filling a 80cf bottle with trimix will run $40 and the cylinder is $126. I could go with a 40cf for $82 and $24 for the fill, which may be a little more reasonable since I don't plan on doing a lot of stainless work, but it would be a shame if I decided I really like stainless and wanted to build lots of stainless stuff

Norval, as usual, you impress me my cross member is not removable (though I do have a stock automatic car, so I think my frame has been swapped). . . I was actually planning on making that crossmember removable after I finished the exhaust. Sounds like I should tackle that bad boy first. I like the idea of no bottoms on the cutouts, but did you consider making them bolt on instead? Seems it would be a little more sturdy that way, or do you think just cutting them off was enough? On second though, it looks like you did more than just cutting the bottoms off, didn't you?

So are you just teasing us with your unlimited supply of 3" bent pipe? Your system looks stainless, am I right?

New plans - Definitely going with 3" pipe, I was already thinking 2.5" was borderline, so I may as well pay the small amount extra and do it the way it should be from the start. Someone want to try to convince me one way or the other on the stainless pipe? Minimum it would be about $100 for the gas and I'd need to learn to weld stainless (probably not that big a deal). Then I'm looking at a few extra bucks for the pieces of pipe, header couplers, and bends. Remember, no mufflers, who needs 'em anyhow?

-dath

dath

Ttt

1BAD80

Looks like 2 U bends will do the job.

norvalwilhelm..... nice job.
Didn't you post this picture before on this site?

dath

Hmm, two huh? Looks like the stainless U bends in 3" are *NOT* cheap. Summit only seems to have Borla and the price is $81.99 per bend Maybe aluminized is the way to go, I didn't expect that large a difference, I think it is really the combination of 3" and stainless that pushes the price so high. Either by itself isn't too much more. . .

So Norval, those bends you can get in 3" stainless? Want to sell a couple?

-dath

comp

cheap bend's where

stickboy

I have been looking into doing my own stainless exhaust too. From the research I have done you can weld stainless with a MIG if the heat range is adjustible. Also you need the trimix gas and stainless wire. Once you find the proper heat range it's just like welding mild steel. I haven't found anywhere cheap to buy the pipe though.

Twin_Turbo

Can you fill up a box for me? 3" bends are fine BTW, do you have the car on the ramp now? I need a measurement from the trans crossmember through bolts to the center of the trans mount (halfway between the 2 bolts),....I lost my measurement and now I can't finish my crossmember.

comp

i'll take a few

Twin_Turbo

I was 1st...I was 1st.. the picket line starts behind me LOL

comp

True 2nd is just fine with me on this one

Maymyvetteliveforevr

norvalwilhelm, what material is your exhaust made of?


Frank