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do mandrel bends really matter

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Old Dec 29, 2005 | 11:05 AM
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Default do mandrel bends really matter

I am debating on either buying the mandrel bend tsp dual set up or just having a local guy custom make it himself. The only thing is he cant do mandrel bends. Id save some money having him do it but for the few bends that the dual setup has is it an issue with power gains and exhaust velocity if they arent mandrel?
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Old Dec 29, 2005 | 11:32 AM
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Mandrel bends are more efficient than crush bends, yes.
Are they going to make a noticeable seat of the pants difference? Probably not to your average joe.

I went with TSP's setup not only because it's Mandrel bent - I chose them because I'd seen users on here run them and I knew what to expect. I chose them because I'd seen the dyno gains, I'd seen the install processes and I'd heard sound clips of how they'd sound. Most importantly, I chose TSP's system because I didn't want to be upset when a local exhaust shop completely FUBAR'd the job. To be quite honest, there is not a shop in my area that I'd trust to run even a half-decent exhaust system on my car.
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Old Dec 29, 2005 | 12:16 PM
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Don't waste your money running crush bent TD's. There are threads on here where people lost hp going from a single exhaust to crush bent TD's. Crush bends are not for performance, and cause a significant reduction in the diameter of the pipe. Not to mention the turbulance that's caused. I wouldn't spend money just to lose performance.
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Old Dec 29, 2005 | 02:37 PM
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i didn't use a mandrel bender to do my true duals. I just ordered a bunch of straights, and 90 degree bends, and but and welded them.

do a search for my exhaust set up
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Old Dec 29, 2005 | 02:44 PM
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I Was thinking of doing the same thing. i ordered magnaflows 2.5" inlet/outlet 4in round mufflers. and was gonna have my guy do a 2.5 true dual with crush bends

is it really gonna hurt the performance that bad? is buying the TSP kit then having him extend it over the axle gonna be better?

edit - i just called TSP and John said a 2.5" crush bent True dual system is not gonna hurt performance untill you are pushing a lot of power. above 500hp.

i thought of it like this, even if a 2.5" crushed dropped the flow down to a 2" tube, you still have one on each bank. making it a 4" total compared to one 3" y pipe setup.

Last edited by SSRZ28; Dec 29, 2005 at 03:07 PM.
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Old Dec 29, 2005 | 03:24 PM
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[QUOTE=SSRZ28]I Was thinking of doing the same thing. i ordered magnaflows 2.5" inlet/outlet 4in round mufflers. and was gonna have my guy do a 2.5 true dual with crush bends

is it really gonna hurt the performance that bad? is buying the TSP kit then having him extend it over the axle gonna be better?

edit - i just called TSP and John said a 2.5" crush bent True dual system is not gonna hurt performance untill you are pushing a lot of power. above 500hp.

i thought of it like this, even if a 2.5" crushed dropped the flow down to a 2" tube, you still have one on each bank. making it a 4" total compared to one 3" y pipe setup.[/QUOTE]


That is true, but you aren't taking into account the energy loss caused by turbulance at all of the crush bends. Do a search on here. I know I've seen dyno's of lost hp going from a single exhaust to crush bent TD's. One of the dyno's I've seen was on a car with less than 400hp. If you are doing it for sound only, and aren't looking for hp gains or don't even mind a small loss, then go for it. I'd never do it on my car, but that's just me.
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Old Dec 29, 2005 | 03:31 PM
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i thought of it like this, even if a 2.5" crushed dropped the flow down to a 2" tube, you still have one on each bank. making it a 4" total compared to one 3" y pipe setup.[/QUOTE]


The area of 2 2.5" pipes is more than a single 3". The area of 2 2" pipes is less than a single 3". I would go for the mandrel bends if at all possible.
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Old Dec 29, 2005 | 03:32 PM
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2 2" pipes are not equal to a single 4" pipe, since your talking about overall area, not diamater.

Ryan
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Old Dec 29, 2005 | 03:35 PM
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on summitracing.com they sell a flowmaster kit PN#FLO-15933 of different bent pipes that are mandrel bent do you think I could use this to make the true duals.
the x pipe I i know I could use but i dont want to buy the whole kit for just that piece.
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Old Dec 29, 2005 | 05:14 PM
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seriously guys, why don't you just buy pre-bent mandrel bends. They come usually in 45 and 90*, and you use a chopsaw to cut them to whatever angle you want. Then add some straight pipe and you'll have a mandrel bent y-pipe that's better than most pre-fabbed ones out there.

That's what I did at least.
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Old Dec 29, 2005 | 08:53 PM
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^^^ that's what i'm goin to be doin, do it right the first time instead of doing it again when you could have done it right the first time.
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Old Dec 30, 2005 | 05:54 AM
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seriously guys, why don't you just buy pre-bent mandrel bends. They come usually in 45 and 90*, and you use a chopsaw to cut them to whatever angle you want. Then add some straight pipe and you'll have a mandrel bent y-pipe that's better than most pre-fabbed ones out there.
I saw the summit flowmaster pipe kit. couple of guys have said it worked nice so im gonna do that.
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