I decided that I am going to get a custom cat-back done rather than go the expensive $500 route. People are so quick to say go to a shop that does mendral bends, BUT I have NEVER found a shop that does this. I've called several shops when I was in Orlando and the shops here in Savannah. NONE!

Does anyone know what kind of loss you get when using crushed piping?

Are we talking 1-2hp loss?

I've seen how crushed piping looks and it's not that bad. Yeah, mendral is better, but is crushed really that bad?

Thanks for any input on this!

 

You are probably right; the difference is probably pretty small. I think the diameter of the pipe, and the radius of the bend is more important overall than the smoothness of the bends. I suspect that on a 250whp car, the difference is less than 10whp, and probablly only on the top end.

 

I was thinking of maybe going with 2.5" piping instead of 2.25" with crushed piping and the GSR motor.....

I hope it's not 10, because that is actually a good bit (to me at least). ....especially if I am running someone who also has a GSR motor.

 

just get the 2.5 crush bent. and as for hp loss, i would think its like 5 horses lost in a 220 whp monster. But for mild buildup, it should be more like 1-2 horses. if i am wrong please enlighten us. And someone should really do a damn dyno comparison....lates
manny

 

I would never use crush bent pipe. Jegs, Summit and JCWhitney all have mandrel bent pieces. Just think of smooth flow.

 

hey get a hold of me
i can do a exhaust system mandrel bent.. you dont have to order a muffler you can get just the piping if you wish.. my setups for just piping run 200-250 just piping..

 

If the exhaust shop you go to does not have mandrel benders, you can get a hold of mandrel bent elbows, I have those in my car, just weld them anywhere you would need bends. It's as good as getting the whole pipe mandrel bent

 

that's what i would do. just buy the bends and take them to a muffler shop to weld in place.

 

the muffler shops dont have to have the mandrel bending machine. you can ask if they can do Mandrel weld piping. which uses U bends welded and cut to size to create a smooth flowing piping. any muffler shop can do it if they are willing to.

 

If the shop doesn't have a mandrel bender, I think you're
in the wrong shop...

 

lol...thats funny

 

Miami muffler works does mandrel bend custom exhaust piping. look them up on the net and call them. they ship to your door as well. thats where i got my exhaust from

 

although welding in bends would be a great idea if you were going to do this yourself. the labor on havin a shop do this for you would totally negate any savings.

the if the don't mandrel your in the wrong shop comment is about right.

TRUST ME there is someone doing it on a regular basis right under your nose just look harder call around. You'll find a place.

I thought the same thing then i thought there was one place in my area. I've come to find out there are 3-4 shops that do it in a 30 mi radius and probobly more than that.

GOOD LUCK

Also ignore what everyone is saying: mandrel bent pipe makes a big difference. If you plus size it like you said the difference will not be big at all.
all these dudes yabbering on and on about mandrel bent pipes have there heads up there own tailpipes.


[Modified by NonovUrbizniz, 4:31 PM 11/7/2002]

 

Also ignore what everyone is saying crush-bent pipe doesn't make that big a difference if you plus size it like you said the difference will not be big at all.
all these dudes yabbering on and on about mandrel bent pipes have there heads up there own tailpipes. [/QUOTE]
wtf?? what the hell are u tring to say??

 

all I am saying is that any gain is good

 

Geeshhh!! Mendrel bend piping at "www.burnsstainless.com"
and yes it does make a difference, not 5 whp more like 5% - 10% maybe even 15%! lets say your making 200 to the wheels no piping: 5% off = 10whp, 10% = 20whp, 15% = 30whp!!! but id say more between 5 and 10 percent.
one more thing, anything under 2.0 liters, is suppose to be under 2 inch piping (NA)- but id go with 2.25 inch just for the hell of it. but then again, i have a 2.0, and you got a 1.8....

oh yeah, you DONT need the GOOD stainless steel, just get the lower grade - if you go to a regular muffer shop there just gonna use mild steel - and if half of it is mild steel why would you wanna put the expensive stainless steel on the other half....

 

lol@30 whp .......sure buddy. u must think we are talking about domestices. we are talking about imports.... dumbasss

 

ur dumb....20 or 30 whp???? wtf? stick to dumbestics fool

 

I'm probably just going to get the crushed piping done.
Everyone seems to have their own opinion on this. I was kind of hoping for some dyno slips, but I guess that is not happening.

If I go with 2.25" piping I think the larger diameter should make up for the few crushes....

I could do like some of the ricers do around here and just clamp a muffler onto the OEM piping

I have crushed piping on my 98 LX cat-back and I'm going to measure the diameter of the crushes to see how much smaller they are than the 2.25" piping used.

 

..............smooth flow......................

 

like i said, between 5 and 10 percent, plus none of you guys are making 200whp so even if you losing 10% your not losing 20whp because you NOT make 200whp!!

 

I am not sure how big the difference is. But I can tell you that it is not just 'all on top'. The big advantage of mandrel bent tubing is that a smaller diameter tubing which is mandrel bent has the same flow as a larger crush bent tubing. This means that you have increased gas velocity without increasing backpressure in the smaller mandrel bent tubing (vs the larger crush bent tubing). This improves cylinder scavenging while not choking flow, which makes for a wider powerband.

 

I can feel the difference between oil changes, if that doesn't say enough.. GET MANDREL BENDING. minimal gains CAN be felt.

 

Surprisingly, not that many shops actually have a mandrel bender. The cost of a mandrel bender is prohibitive. For a maching that could bend up to 2.5", you could end up dishing out close and over $15k. I don't think that's very cheap at all.

Jay Kim

 

wtf??? u can feel the diffrence between an oil change??? lol.....danm.,my but dyno needs to be recalibrated then...because i dont feel a damn thing.