Here's my first log after, after custom 3 in exhaust. The shop cuts the exhaust in sections to avoid crushed bends, they actually did a pretty good job. I paid $380 for 3 in piping with 2 resonators and 4 in tips. I'll post pics later, along with old logs that are saved to my work computer.

The car definitely feels faster, boost is a few psi higher and holds longer, the only thing that doesn’t make sense is that my g/s seems a bit lower! But to be fair I haven't logged in this kinda heat in awhile.
Also, I can boost 13psi and 270 g/s while in neutral, when before I would only see 3psi.

The stock rear section of the pu exhaust is rediculously restrictive. I think all that is necessary is aftermarket axle back

I like seeing threads like this, i'm learning so much :)

I know I'm paying a lot for it, but I really like the sound of the cpe cbe.
Should be getting it sometime mid-April. Rallysport had it backordered during their 10% off sale and won't be getting it in til then.

Just got a quote from a shop... 300 installed.. Stainless steel 3" cat back and flow masters mufflers.. And resonators according to the loudness; I might go in to get it tomorrow

crush bent? I'd stay away from crush bends.

I guess one of my questions...are our resonators restrictive at all? What type of resonators are they?

This would help us determine if just an axleback vs a catback would have very similar performance on the Pu

Took a peek inside mine. Looks like its the same diameter pipe, just baffled inside of the resonator core. So as far as flow goes, theres no bottle necking.

You heard it here first!! Now we just need a test to confirm. I will perform this test when my vehicle is out.

With and without Axleback.
With resonator delete stock pipe. :usa2:

Just talked to him over the phone and asked him what method do you use to bend your piping crush or mandrel? his exact response was: I dont crush anything so I guess I mandrel bent...

Not so sure I want to do it there anymore

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Its just piping. I think theres also a OBX CBE on Mazdas247 for 300 bucks.

I used my speed daddy 3" piping and a used a greddy rs ricer special muffler. Total was around $500. Sounds aggressive as hell. Less weight also.

But I can never leave anything alone.
So I'll be going back to dual tips soon. Using the same speed daddy piping.

My stock rear muffler was leaking massively with only 10,000 miles on the car.. I was wondering why it was so loud

Ollie replied to my PM - to paraphrase, he's working on Ferrari and BMW exhausts now, and we're not going to make him the kind of coin he's making doing that, so no - he's not going to be making any more axle backs for MS3's.

I have someone local working on a reasonably priced axle back for the rest of Nator AL Pu's. That might turn into something worth talking about, I'll share pics n stuff once progress is made.

I was very pleased with my OBX turboback exhaust, no cats, 1 muffler, 2 resonators, 3" piping, 4" tips, $507 shipped to my door.

The OBX CBE is also a slightly different design than the full TBE (1 stock size muffler on the TBE, 2 mini mufflers on the CBE, don't know why that is)

I think for $510 basically, you really can't beat the price for what you get. Spending over $1000 on an exhaust is insane to me.

Lets not forget that if you're running a 3 inch downpipe, the stock midpipe will neck it down. There may not be a huge amount of power to be had with a replacement midpipe but there will be gains.

IMO, the best buy right now is the ebay special CBE's for the gen2, just make sure you get the one that has the Y split evenly instead of the one that tends to flow more to the passanger muffler.

That sounds like a lot of mufflars lol; just go straight pipes get full performance, loud as fawk!

Ha, it's only 1 muffler on mine, but yeah that's another reason I went with the OBX, it's barely louder than stock idle, but opens up and sounds really nice when you get on it. Didn't want it sounding crazy loud and obnoxious when just cruising around town.

If I ever make this a track only car, definitely just going with a straight 3" pipe.

Hmmm time for me to make it a full turbo back! I having a xrappy weld in the rear


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So finally here are some real logs.

The first log was all mods in sig minus the customs catback, only resonator delete.

I went to a local shop and had them make me a 3in catback with 2 resonators, 1 10" and 1 14"

Second log I find very interesting, I went back to the exhaust shop and had them cut out the large 14" resonator that was right after the tp. Ive never seen anything over 300g/s until now.

My Vdyno doesn't seem to want to open up, can someone post these for me please.
Both runs were done in the same location, tire size 235 40 18, I weigh about 345

Here ya go.

Same weight and tire size on both? Im seeing something different but I can't post it for whatever reason.

redone for you. I'm glad when my logs reported similar that it appears not to be a fluke.

http://www.mazdaspeedforums.org/foru...1&d=1396549309

I installed CS axle back exhaust last night. I'll try to get some logs tonight and post them up so we can see the difference between stock exhaust w/ racepipe and stock exhaust w/ racepipe & axle back.

It's certainly having an easier time holding boost and hitting the load targets. The CBE log is taken in cooler temperatures but car is running well overall and making great power. We could squeeze a bit more out at this time due to the ability to run more midrange boost it seems.

OK. Here's what I ended up with. Logs labeled "-pre" are pre ABE and... well... you can figure it out...

Both are taken on the same road. pre 1 and abe 1 are one direction and pre 2 and abe 2 are the opposite direction.

@atvfreek; let me know what you think.

Heres another log i did today on the same stretch of road, since I didnt like what seemed to be a bump in the road on the first log, let off a little early though.

Wow thats impressive for a ko4. Tuned by Lex?

So I've been following this thread and decided that I was in disagreement with those saying that a catback system does nothing but add sound. So much so that I ordered an ultimate racing catback exhaust. The Vdyno's are two days apart on same tank of gas and same E85 map by @Lex; . The Maps labeled Post exhaust are obviously after putting exhaust on and the other two are with all my other mods in signature with CPE downpipe (catted) and stock catback. In the logs I saw MAF g's go about 8-10 higher than in any other previous log or map. Boost seemed to be a tad higher for that RPM in the other maps.

You mind posting the actual pre & post logs?

Ya no problem, not sure if my tune is complete but this is the latest stratified map im running...

Got another data point to add to this. Just installed the CS single-exit CBE last week and ran a log yesterday. Plenty of asterisks here available for the doubters to poke holes in the results (and I doubt the increase is actually as big as VD says it is), so I'll just go ahead and list them. Logs weren't done on the same day, weren't done on the same tires, BATs were 10 degrees higher in the stock logs, blah blah blah. Logs show that I'm moving 20 g/s more air. Datalogs 1 and 2 are the stock exhaust, datalog 8 is with the CBE. These were all done with the same OTS stage 1 map, 91 octane, and I still haven't run a new MAF cal since installing the exhaust. Only other power mod is an SRI/TIP. Stock logs were done on the stock wheels/tires. After CBE log was done on 245/40/17s.

http://i797.photobucket.com/albums/y...pseae74b31.jpg

looks like i was able to get about 15-20whp from installing my UR cbe, cleaning the valves, and installing TIGs. i'll take it.

For what I can see most ppl are running different size than oem tires because oem is 25.08... Changing that number will inflate you hp numbers...

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I would assume that VD has a calculation to take tire size into account, hence why you can change the value. I don't think the numbers would be inflated if you put the correct number in. Sure, if you change the tire size from the tires that are actually installed on your car the numbers will be off.

I'm going to assume you're referring to my plots, and the fact that my highest hp run was on smaller-than-stock diameter tires. Changing the tires to a smaller rolling diameter actually lowers the reported hp. But let's not let facts get in the way of accusations.

According to VDYNO 225/40/18 = 25.09, If you have stock tires/wheels and aren't using this number, then is not an accurate reading. go on settings and put this tire size manually and see how VD changes it to 25.09 and watch your power drop like 10 to 15 WHP

Exactly what I said. Insert the correct tire size that you are using and you'll be fine.

My charts are with aftermarket size tires but both my graphs are with that size so there is no change in consistency, so the increase is not from changing tire size

Nitto Tire - Fueled by Enthusiasts

25.47 for 235/40/18 Neo Gen. My speedo is also off 1.5mph at 100. If Vdyno calculations aren't accurate for changing out the stock dunflops, I can't help that.

Removing the Pu muffler is a good thing, that I will attest to. I was trapping ~109 on most passes at ENM on par with the other 330whp speeds that weren't running slicks with a TMIC as a handicap.