mandrel or non mandrel bent y pipe?

differnces in power? etc - thanks guys

 

when you typically bend a pipe, lets say at home, around the bend the pipe will constrict and wind up with a slightly smaller diameter thant he rest of the pipe, so you go from 2.5 to 2.25 and back to 2.5, which obviously causes a bottleneck for airflow, nonmandrel will bend it so that the diameter is uniform throughout the entire pipe, the power will be greater in the mandrel if the initial diameters are teh same as the nonmandrel bent pipe

 

get mandrel bent

 

you will (eventually) be very bummed if you waste your money on a non mandrel exhaust component

 

I looked at the difference between the mandrel and non-mandrel pipes whne I was at Warpspeed. There was almost no difference at all. I don't know how they do their non-mandrel bends, but they looked great. I've seen some that looked horrible and would obviously cause more restriction but not these. I've got a Cattman Y right now. I would have no problem going to a Warpspeed non-mandrel 2.5" (which I'll be doing when I get the money).

 

Most of the time, unless it is just very poorly bent, you don't even lose all of that .25" that you are talking about. It is a little less than that.

With the y-pipe, I would say go with mandrel bent.

With all other exhaust back from there, I would just get non-mandrel bent 2.5" piping. It is not enough of a trade off for you to pay an extra $150 for a b-pipe, when it only costs like $50 to get a custom made one that is non-mandrel bent.

 

Mandrel Bent, then you know it was done profesionaly.

http://www.oceanmachinery.com/exhaust-pipe-benders.htm

 

I have the non-mandrel WSP Y-pipe and it performs much better than my Stillen Y-pipe did (I have dyno proof of that). I've also witnessed the same car (GuidoSST's 1995 GLE) dyno on the same machine with the non-mandrel and then the mandrel Y-pipe. The difference was about 1-2hp above 5400rpms. IMO, that difference is simply dyno error. Dallas at WSP even admits there should be minimal difference in performance between the mandrel and non-mandrel pipes. I've gone 99mph in the 1/4 mile with the non-mandrel pipe so I'm pretty certain it's not hampering my VQ


Dave

 

nice sig, icefishing. I don't know how long you looked for that machine, but you found one. That one looks like it might not be too expensive, but most of them up until now have been really expensive. There is nobody in the whole state of Mississippi that has a mandrel bending machine. I think it is that way a lot of places.

 

Really?!

Like how much better numbers wise would you say?

I learned something in this thread- I figured mandrel bends were super important because they keep the inside surfaces smooth besides eliminating the crimping that closes the actual width of the pipe. I guess its not that important?!

Tough one to accept but I guess the numbers dont lie..

 

My car dynoed 176fwhp/192fwtq with the Stillen Y-pipe, HKS intake, and B-pipe. A few months later I dynoed with the hacked airbox instead of the HKS intake and made 175fwhp/192fwtq. A couple months later my Stillen's flex section blew so I sold the pipe and bought the WSP non-mandrel y-pipe. I also added an UDP. My car then dynoed 183fwhp/193fwtq. I know the UDP didn't gain me anything like 8fwhp and about 10-11fwhp/fwtq over the midrange. I'd say the UDP might have accounted for a couple hp/tq, but the majority of it came from the WSP y-pipe. The day I installed it I immediately noticed more power above 3000rpms. I believe the gains came from the much larger and more direct piping of the WSP pipe. Stillen uses 2.1" ID downtubes whereas WSP uses close to 2.4" ID downtubes. Non-mandrel doesn't mean "crimped". The pipe is slightly oval shaped on the bends, but the overall ID of the pipe is unchanged and uncrimped.


Dave

 

BS

non mandrel sucks *****

Mandrel bent pipes are the same diameter throughout to give you up to 25% more flow than compression bent pipes

 

Oh, that's right. I remember seeing YOU at the dyno the day we dynoed GuidoSST's mandrel vs non-mandrel y-pipe and saw a whopping 1-2hp gain above 5400rpms. Same car, same dyno, same correction factors, etc


Dave

 

It's true. I was there.

 

OK, How is a car going to get a bigger gain because of MORE air restriction in their y-pipe?

Maybe he got a better dyno but it has to be because of other factors.

If two pipes are identical except the bends the one that is mandrel bent is better.

Why wouldn't it be?

 

Maybe bacause the car isn't pushing out enough exhaust for the bends to make a difference.

 

Yepper Thanks.


Dave

 

can you pass emissions wiht the warpspeed y-pipe?

 

lookin at those pix, I could see how the more gradual bend would work better, mandrel or not