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I don't know of anyone who drove post-swap for any length of time on the stock exhaust.

Nd4SpdSe wrote:I did my ZE swap, was running the stock intake and exhaust system at first...

Few months later, the exhaust blew out, needed to be done, so I did a 2.5" cat back

That's from the previous page of this thread... There are others as well, that made mention of the power dropping off at ~5-5.2K instead of the 6,700 advertized for the J-spec MX6.

If you would like to see more examples, there should be some in the worklogs... It'll be a lengthy search, but believe me when I say not everybody upgrades their exhaust at the same time as they swap.

It's a good idea to do both together, but finances rarely line up with our wants in life, unfortunately! If only...

mikeetown wrote:thx for the pictures man. i appreciate it. i ordered the headers in the link above. i guess ill be swallowing the cost Haha.



did everyone get a noticeable in power after the exhaust being done?? i bet you all did.

Depending on diameter and chosen components(i.e. resonator(s), catalytic converter, muffler), the difference should be fairly noticeable.
With a KL swap and bone stock K8 exhaust, your power will cut off a little above 5,000 RPMs. With a freer flowing exhaust, preferably not being choked down by the K8 muffler(sounds amazing, but that sound comes at a price of ~5-6 WHP BEFORE a KL swap), you should see power up until the 6,200-6,700 depending on other mods... This assumes a relatively stock KL with KL01/KL31 cams and no power adders.

I'll tell you this though, the low end torque with a KL and 2" exhaust is a kick in the pants.

Allow me to rephrase. I have not personally had a discussion, or given advice to a single person who chose to run their stock exhaust post swap and I've never heard anyone who had to for any length of time suggest that it was doing anything but absolutely crushing the performance of their swap.

I did drive my own car from my house to the muffler shop with the stock exhaust...about 10km, but it was literally the first drive so I was going very easy with her. I didn't open it up at all until I had a good 1000km on the swap so I can't really say.

Fair enough, and I believe most people would benefit from doing exactly as you did... I imagine most people are eager to romp on their newly swapped engines, and abuse that extra power.

It's tempting, but easing into it won't cause you any harm, that's for sure!

I can personally attest to the "choked" feeling that stock K8 exhaust gives after a KL swap, as my '93 has a nearly mint K8 exhaust bolted onto it to this day. The low end feels amazing, but you definitely feel something missing up high... Definitely helps to remind me to drive economically though.

I ran stock exhaust for awhile, now I run a very open 2.5" setup and there was a noticeable difference up high.

No dyno charts though, just the butt dyno, which is oh-so-sensitive to those $500 modifications...

MrMazda92 wrote:
I'll tell you this though, the low end torque with a KL and 2" exhaust is a kick in the pants.

I ran a 2.25 inch cat back exhaust with stock k8 headers for over a year. Went much faster with ebay headers.

I'm currently up on the rigs surveying and I can't help but twiddle my thumbs because.......My Headers, downpipe and muffler I ordered could be at my house any day now then

wish i was on here a week ago. i just scapped my first mx3 and i had a fairly new 2.25" catback exhaust sitting inside the car i couldnt sell. i was also in kelowna for work last week and could have delivered it .

MrMazda92 wrote:

Nd4SpdSe wrote:I did my ZE swap, was running the stock intake and exhaust system at first...

Few months later, the exhaust blew out, needed to be done, so I did a 2.5" cat back

That's from the previous page of this thread... There are others as well, that made mention of the power dropping off at ~5-5.2K instead of the 6,700 advertized for the J-spec MX6.

If you would like to see more examples, there should be some in the worklogs... It'll be a lengthy search, but believe me when I say not everybody upgrades their exhaust at the same time as they swap.

It's a good idea to do both together, but finances rarely line up with our wants in life, unfortunately! If only...

yes that is the truth.

mikeinaus wrote:wish i was on here a week ago. i just scapped my first mx3 and i had a fairly new 2.25" catback exhaust sitting inside the car i couldnt sell. i was also in kelowna for work last week and could have delivered it .

WELL GOSH DARN ITTTT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! YOU OWE ME brew for that one haha. I woulda paid

That header system has been sold for at least 6 years now. I bought one and it's still rocking far as I know so 5 years now. It comes with a plug for EGR delete but you need to leave the EGR connected so your ECM won't throw a code. I found the fitment to be ok. I bolted the down pipes on first then kinda hand bent the cross over pipe to get it to align between the front and back down pipes. No biggy. One thing I will say is go to a muffler shop and buy 2 - 3 bolt spacer/flanges. The cross over is really tight to the oil pan so by using the spacer/flanges between the down pipes and the cross over they will give the cross over a little more clearance from the oil pan. Last but not least that header system is made for the MX6 and Ford Probe so expect to cut about 8-9 inches off the first pipe on a stock MX3 exhaust (I think cut the 8-9" off the resonator pipe). Bon Chance.

http://www.ebay.ca/itm/MX6-Probe-93-94- ... 5659fc4d9e

Are these the same headers? that old ebay link doesn't work anymore.

Yes those headers should work. If you are installing in an MX3 you will probably need to do some customization of the Y-pipe or down pipe. On mine the Y-pipe needed to be shortened in 2 spots:
1. One leg of the Y had to be shortened so the flanges would mate to the exhaust manifold
2. The overall length of the Y-pipe after the flex pipe was shortened to mate with the cat back portion of the system