Test Pipes vs Mid pipe vs Rear Section HP gains

[SlashM3]

Originally Posted by momo3605

Well then you have a catless x pipe

Haha, but yea, I guess that would just be cutting all the cats out of the stock x pipe. I dunno how that would fare power-wise

How would a aftermarket catless xpipe. Be power wise ? Lol

[MTrezzz]

Active Autowerks High Flow Cats X-pipe?
Or
ACM Test pipes/OEM x-pipe?
Or
Gintani High Flow X-pipe?

Power & weight??? which one would you use? is test pipes louder then high flow?

[pbonsalb]

No cats are louder than high flow cats. Cats have some sound muffling effect.

No cats flow better than high flow cats.

No cats are lighter than cats.

Just about anything is lighter than the stock x-pipe.

I would guesstimate the power gains from a catless aftermarket x-pipe at up to 25 rwhp. I would guesstimate the gains from just removing the front cats on a stock x-pipe at up to 15 rwhp. I would guesstimate the gains from an aftermarket x-pipe with one set of high flow cats at up to 15 rwhp. There are my guesstimates. I understand there are reports of stock x-pipes with test pipes and the second cats left in place adding 20 rwhp, and reports of aftermarket x-pipes with high flow cats adding 20 rwhp. The only way to be sure is to do a before and after dyno on your car, preferably on the same day.

[IB M]

Is the extra 25 hp noticeable in daily driving? I am considering the Akra Evo full system but it is a boat load of cash. I like the idea of extra HP, less weight and a better sound plus Titanium will never rust.

[pbonsalb]

Just buy a supercharger if you are prepared to spend that kind of money. Leave the exhaust stock.

[W///]

Originally Posted by KmndntKlink

What's the difference between test pipes & xpipes in terms of cats, power, smell & sound?
Are test pipes headers back (ie deletes all the cats?) From what I understand HFC gets you most of the power with no smell, which I think is great for daily drivers

I'd like to get the extra power but I don't want it to smell or drone or be race loud, so I was thinking a challenge xpipe and a dinan or OEM mod rear. It also has to be bolt-on & easy to go back to stock.
I hear test pipes require cutting stuff & so does the challenge street xpipe.

any experts care to chime in? TIYA

It depends on the X-pipe, there's so many options. For example, Challenge:
Sport = high flow cats + resonators
Race = Resonators
Race + = absolutely nothing.

I think that's how it goes. Test pipes only delete the primaries (which is where you'll gain the most HP). I had test pipes + OEM secondaries & resonators = no smell.

The most important part in terms of sound will be what axle back you go with. Don't do test pipes + oem mod. Very loud, raspy and it drones.

Out of those combos, I'd recommend going test pipes + Dinan for sure, trust me. I've gone through like 8 exhaust combos before I found my perfect one.

[KmndntKlink]

Originally Posted by W///

It depends on the X-pipe, there's so many options. For example, Challenge:
Sport = high flow cats + resonators
Race = Resonators
Race + = absolutely nothing.

I think that's how it goes. Test pipes only delete the primaries (which is where you'll gain the most HP). I had test pipes + OEM secondaries & resonators = no smell.

The most important part in terms of sound will be what axle back you go with. Don't do test pipes + oem mod. Very loud, raspy and it drones.

Out of those combos, I'd recommend going test pipes + Dinan for sure, trust me. I've gone through like 8 exhaust combos before I found my perfect one.

Thanks so much! I was actually considering oem mod + xpipe or test pipe, I'll avoid that. Was also thinking dinan rear. Test pipes are cheap, may very well just go with that & spend the saved $ on a nice rear. Only thing I'd be losing is the weight savings, which I'm fine with. So hard to justify $2k+ for some steel piping!

Thanks again

[momo3605]

Originally Posted by KmndntKlink

Thanks so much! I was actually considering oem mod + xpipe or test pipe, I'll avoid that. Was also thinking dinan rear. Test pipes are cheap, may very well just go with that & spend the saved $ on a nice rear. Only thing I'd be losing is the weight savings, which I'm fine with. So hard to justify $2k+ for some steel piping!

Thanks again

I also have dinan rear + test pipes. Absolutely phenomenal sound. I'm really sensitive to drone and rasp and it's just perfect. Loud when you get on the gas, and almost silent when cruising.

[ashtaron14]

So Test Pipes (Such that of Turner), OEM everything else, Tune, and no one should notice right? (GF/Wife, etc)

[W///]

Originally Posted by ashtaron14

So Test Pipes (Such that of Turner), OEM everything else, Tune, and no one should notice right? (GF/Wife, etc)

Oh they'll notice I think. It won't be obnoxiously loud, but the volume will definitely go up with test pipes.

[ashtaron14]

Originally Posted by W///

Oh they'll notice I think. It won't be obnoxiously loud, but the volume will definitely go up with test pipes.

Thanks

[rjd598]

This helped me out big time when I wanted to understand the e9x m3 exhaust layout
http://www.m3post.com/forums/showthread.php?t=548959

[momo3605]

Originally Posted by ashtaron14

Thanks

nononooo, don't get test pipes with the stock rear. It's going to sound like a bumble bee's nest!

[KmndntKlink]

Originally Posted by momo3605

nononooo, don't get test pipes with the stock rear. It's going to sound like a bumble bee's nest!

I've heard the same, gotta pair test pipes with an exhaust, avoid oem mod.

Has anyone done, say, turner test pipes+ challenge xpipe + rear? Comment on noise,smell,drone, emissions test?
That should net something like 40+whp which should be way noticeable and way $$$. I wonder if there's a way to get a full bolt on using this approach. I'd really like to avoid cutting/welding. Just in case!

[ridin135]

Originally Posted by IB M

Is the extra 25 hp noticeable in daily driving? I am considering the Akra Evo full system but it is a boat load of cash. I like the idea of extra HP, less weight and a better sound plus Titanium will never rust.

Total waste of money and to top it off that system loses hp unless you have a tune for it. If you don't want too spend much just get test pipes, it sounds fine with the stock exhaust. I ran all four cats gone with the stock exhaust and it was a nice sound but wasn't deep enough for me. If you want a rear end I can't recommend any exhaust more then the Megan exhaust. For the price it can't be beat and the quality & fitment were perfect.

[momo3605]

Originally Posted by KmndntKlink

I've heard the same, gotta pair test pipes with an exhaust, avoid oem mod.

Has anyone done, say, turner test pipes+ challenge xpipe + rear? Comment on noise,smell,drone, emissions test?
That should net something like 40+whp which should be way noticeable and way $$$. I wonder if there's a way to get a full bolt on using this approach. I'd really like to avoid cutting/welding. Just in case!

If you get challenge X pipe, then you don't need test pipes i believe. You use test pipes when you want to use the stock mid pipe. I have test pipes and the smell isn't that bad. Catless xpipe will smell pretty bad. With test pipes, there is no welding, only cutting and clamping.

But if you want no cutting, then your best bet is xpipe + rear. Xpipe runs somewhere around $1500-$2000 and same with rear. Test pipes cost $400 which is why a lot of people do it, since it gives you at least 80% of the power gain of a catless x pipe.

[KmndntKlink]

Originally Posted by momo3605

If you get challenge X pipe, then you don't need test pipes i believe. You use test pipes when you want to use the stock mid pipe. I have test pipes and the smell isn't that bad. Catless xpipe will smell pretty bad. With test pipes, there is no welding, only cutting and clamping.

But if you want no cutting, then your best bet is xpipe + rear. Xpipe runs somewhere around $1500-$2000 and same with rear. Test pipes cost $400 which is why a lot of people do it, since it gives you at least 80% of the power gain of a catless x pipe.

Thanks for the pro tip! It's really hard to argue with the value test pipes give. IT's like 20$/hp. I only worry about emissions testing doing any of these options.

[ashtaron14]

Originally Posted by momo3605

nononooo, don't get test pipes with the stock rear. It's going to sound like a bumble bee's nest!

Aye Aye!

[Billj747]

Originally Posted by momo3605

nononooo, don't get test pipes with the stock rear. It's going to sound like a bumble bee's nest!

Is it really that bad? I don't want a loud exhaust and especially don't want highway droning.

[tom @ eas]

Originally Posted by Billj747

Is it really that bad? I don't want a loud exhaust and especially don't want highway droning.

Stock muffler + Bypass Track Pipes sound fine.

However, OEM Exhaust Mod and Bypass Track Pipes are not recommended. Simply too loud/raspy.

[momo3605]

I dunno...if this sounds fine to you, then go ahead. Not my cup of tea though

[8k3]

Originally Posted by tom @ eas

Stock muffler + Bypass Track Pipes sound fine.

However, OEM Exhaust Mod and Bypass Track Pipes are not recommended. Simply too loud/raspy.

x2. test-pipes with stock rear actually sounds darn good