Interest in MX3 downpipes (y-pipes)

[Gro Harlem]

This is my basica assessement of the header situations for our cars:

Pacesetter: very inexpensive, doesn't fit well, will need modification to fit a mx3, rusts out quickly, makes most power (~13whp gain on KLZE), makes engine sounds crappier.

Hot Shot: very expensive, flexpipe, still needs modification to fit mx3, quality is so-so, engine sound retained, makes a bit less power than pacesetter (~11whp gain on KLZE)

Engine sound is important to me. I don't want a pacesetter, modifying it to holy hell to fit, only for it to make my car sound like a$$.

I'd rahter just get a nice downpipe made SPECIFICALLY for our car. Seeing how pipe locations are the same on both K8, and KL motors, this would work for any V6 MX3, engine swap or not.

I've talked to a few guys who know how to properly design headers, and they said that 2" piping for a downpipe would be the best.

The downpipe I'm thihnking of getting made will be made of 2" SS steel, mandrel bends welded together w/the O2 sensor bungs, and flanges.

Not sure how much this would cost in all, but I got a buddy who owns a machine shop who said he'd use my car for a test subject, next time I visit him, and make me a downpipe of my own.

Anyone interested in this idea?

[mightym0use5]

sounds pretty good, but you have to dyno before and after -so you know how much you gained, and see what kind of price you can get.

[Zoso124]

Dyno's have showed very minimal gains on any type of designed header. Why? because Mazda did a good job of designing our exhaust manifolds and Y pipe. Back when Interprep was building engines for 2 MX-6 race teams they tried various designs and really couldn't come up with anything much better then the stock setup. The only way headers might be an advantage is if you were running a highly aggressive cam, exhaust work, Intake, and a P&P. But who really wants to spend money on the thing that actually makes hp, the cams! My opinion is the only reason people want headers is to be able to say "Hey, I got headers on my car" and performance really isn't a goal, its astetics.

Sorry I don't mean to high jack your post, I would just hate for you to put alot of time and energy into something that doesn't have a lot benefit.

If you could get someone to cut some cams for us for a reasonable price we would be on the right track.

[Gro Harlem]

I know they are well designed, hence why i'd rather spend my money on a downpipe.

There is no way you can say the stock downpipe is "well designed" Mine has bends that are almost 90 degree angles, and it uses about 1.675" tubing. A 2" downpipe would definitely free up some power for sure.

Anyways, i'm just trying to get interest. I"m doing this regardless, so if people want in on it, lemme know. BTW: this won't happen until winter break. I"m going to drive up to MI to meet up with my buddy, and we are going to do the exhaust w/downpipe, and paint my car since he owns a machine and body shop.

[curtklze]

if it makes power on a ZE mx-3 then im interested.

and yes the main thing holding back the power is the cams.

[Mnemonic]

add the kfze cams to your ze then get your headers you will see big number change

[papa roached]

and where can i get KF-ZE cams?

[MazdaManiacMx3]

I would like a downpipe . Stainless you said ?
Also I would like some KFZE cams , where can I get these besides a KFZE motor itself .

[mitmaks]

id be interested in headers for ze, keep us updated whatever you do.

[curve]

I would be interested in the downpipes and also is the kfze and klo3 the same engine if so I have a set of cams I will sell someone.

[mxer4eva]

Gro,
I know that right now you are interested in making some Y-pipes for our cars, but is there any chance that your friend would be interested in possible producing some piping for a turbo kit? I know its a stretch but I figured i'd ask, I mean I wont be ready to boost until next june anyways, but you said that development wouldnt begin until the winter anyways.

Also will these Y-pipes be equal length or is that just not going to be a possiblity due to the space restriction of the mx-3. Also will these include a flex pipe.

<small>[ October 08, 2003, 09:40 PM: Message edited by: mxer4eva ]</small>

[tatsu]

For what it's worth, Interprep claims to have dyno'ed an otherwise stock KL-03 at 170.2 hp with a straight pipe exhaust and custom 1.75" downpipes.

If you figure that Corksport found that they gained about 5 hp with a straight pipe, the peak gains would appear to be virtually nil with the downpipes IF their dyno numbers are crank or flywheel HP. Since the picture of the engine on the dyno on their website suggests that they are using an engine dyno, I would assume this to be the case.

Now, bear in mind that their dyno test was done with stock exhaust manifolds, so they weren't really taking full advantage of the extra flow in the downpipes. If the manifolds were Extrude-Honed, a couple hp gain might be found.

If their dyno numbers are WHEEL hp, however, then the downpipes would appear to make significant horsepower - on the order of at least 10 hp peak.

I would venture to guess that they found larger diameter downpipes lost too much exhaust gas velocity at lower RPM, hurting low to mid-range power and torque.

All that being said, I was thinking of doing the same thing to our MX-3 down the road. When you have some idea on pricing, let us know!