Test Pipes vs Mid pipe vs Rear Section HP gains

[momo3605]

Hey guys, so I don't really understand how many different parts to this exhaust there are. And there are like 3 cats as well? Not sure...

All I know is it's way more complicated than my old car's axle back and cat back. So hopefully someone can help me out!

What are the hp gains to be had from modifying these 3 parts and what combination of the 3 would give the biggest gains? Keeping the price to a minimum.

Also, under consideration, which would keep the sound levels low? I've seen a few people change out the midpipe in videos with the stock exhaust and it sounds like a bee's nest!

Thanks!

[SflBimmer8484]

Some exhausts might not give this much but it should be close enough.

Full exhaust around +28 whp
Tune + full exhaust from +40-45 depending on the octane you have available.

[STi_traitor]

There are a total of 4 cats, 2 (400cells) near the front section just after the headers, 2 (200 cells) just before the X-pipe portion and (2 resonators) just after the x-pipe section. Andrew@Active covered the rest. Here is a picture, the exhaust system starts on the right side of the picture. VVVVV



Your cheapest route would to replace the 400 cells with test pipes and install a tune. Here is a picture with the test pipes (left side). VVVVV

[Superfly_M3]

/\/\ whats before the "tuning" in the last picture?

[momo3605]

Thanks STI_traitor (nice name)

So how much less power would you get from just doing test pipes and tune? Compared with full exhaust and tune?

[325rider]

Originally Posted by momo3605

Thanks STI_traitor (nice name)

So how much less power would you get from just doing test pipes and tune? Compared with full exhaust and tune?

From what Ive gathered test pipes + tune is about 30whp. Full exhaust + tune is about 35-40whp.

[Paul@Evolve]

Sounds about right, probably a bit more with the full exhaust.

Full exhaust sound for max power sounds a bit like this (only video we have at the moment of the F1 race exhaust)... loud but, wow, ...

[u2b]_0tQ0lCvObY#![/u2b]

We also do packages of Evolve ECU tune and Supersprint exhaust so let me know if you are interested and we can see if there is a specific dyno run we've done with that setup.

[Sandye90m3]

THREAD JACK: REVIVED
Hey guys quick question. This Mid-August I'm planning on getting a rear section exhaust, gintani race to be exact. However I'm not planning on changing the mid-pipe.

Also from my understanding there are two alternatives for the mid pipe; convert stock into test pipes or purchase an after market mid-pipe. What are the differences? I'm assuming these are similar to the suspension where springs are the cheaper alternative (test pipes) and coilovers are the more expensive quality (after market mid-pipe)

The reason I don't want to change the mid pipe is because I do not want to pollute the air anymore than it already is, and secondly I don't want any trouble from the 5-0.

So my question is, is it worth even upgrading the rear section exhaust to a after market one without changing the mid pipe?

[lsmkr01]

Originally Posted by Sandye90m3

THREAD JACK: REVIVED
Hey guys quick question. This Mid-August I'm planning on getting a rear section exhaust, gintani race to be exact. However I'm not planning on changing the mid-pipe.

Also from my understanding there are two alternatives for the mid pipe; convert stock into test pipes or purchase an after market mid-pipe. What are the differences? I'm assuming these are similar to the suspension where springs are the cheaper alternative (test pipes) and coilovers are the more expensive quality (after market mid-pipe)

The reason I don't want to change the mid pipe is because I do not want to pollute the air anymore than it already is, and secondly I don't want any trouble from the 5-0.

So my question is, is it worth even upgrading the rear section exhaust to a after market one without changing the mid pipe?

For sound...absolutely worth it. For power boost... you will see little to none with a stock mid section. The restriction is not the rear section but all the cats (4) the stock midsection has.

Sounds like you should just get a rear section and call it a day. The dramatic sound improvement will have you believeing your car is now faster

[CSanto]

Mild Exhaust+Stock Xpipe = Some Sound Increase, but no Power increase
Mild Exhaust+Test pipes (Or primary delete Xpipe) = Some sound Increase, Some Power Increase
Mild Exhaust+Sport Xpipe(HFC) = A Tad more Sound Increase, Some Power Increase

Mild Exhaust+Catless Xpipe = Most Sound increase for that Exhaust, Most Power Increase

Replace Mild exhaust with the Axle back of your choosing to get desired sound level.

[momo3605]

Yea, depends on what you want. Just for sound, do the rear section. Test pipes will get you about 80% of the possible power, and catless Xpipe will get you all the way (but with way too much sound if you ask me haha)

[BMW Fanatic]

Originally Posted by CSanto

Mild Exhaust+Stock Xpipe = Some Sound Increase, but no Power increase
Mild Exhaust+Test pipes (Or primary delete Xpipe) = Some sound Increase, Some Power Increase
Mild Exhaust+Sport Xpipe(HFC) = A Tad more Sound Increase, Some Power Increase

Mild Exhaust+Catless Xpipe = Most Sound increase for that Exhaust, Most Power Increase

Replace Mild exhaust with the Axle back of your choosing to get desired sound level.

[Sandye90m3]

Originally Posted by CSanto

Mild Exhaust+Stock Xpipe = Some Sound Increase, but no Power increase
Mild Exhaust+Test pipes (Or primary delete Xpipe) = Some sound Increase, Some Power Increase
Mild Exhaust+Sport Xpipe(HFC) = A Tad more Sound Increase, Some Power Increase

Mild Exhaust+Catless Xpipe = Most Sound increase for that Exhaust, Most Power Increase

Replace Mild exhaust with the Axle back of your choosing to get desired sound level.

Originally Posted by momo3605

Yea, depends on what you want. Just for sound, do the rear section. Test pipes will get you about 80% of the possible power, and catless Xpipe will get you all the way (but with way too much sound if you ask me haha)

Thanks for the info, now does deleting the primary cats pass emissions of California? And does it carry that smell?

Because right now I'm debating whether I should get the Gintani Race or Sport rear section. I want to be able to hear it in the cabin, so that's why I'm leaning over towards the race side

[pkimM3r]

Originally Posted by Sandye90m3

Thanks for the info, now does deleting the primary cats pass emissions of California? And does it carry that smell?

Because right now I'm debating whether I should get the Gintani Race or Sport rear section. I want to be able to hear it in the cabin, so that's why I'm leaning over towards the race side

from what I've read and the reason I am getting them is that the smell won't be too bad with just the primary cats deleted. As for passing, I think not. But I've never read any posts on anyone getting a REF ticket on here - plenty from evo forums.

[Jive]

Originally Posted by Sandye90m3

Thanks for the info, now does deleting the primary cats pass emissions of California? And does it carry that smell?

Because right now I'm debating whether I should get the Gintani Race or Sport rear section. I want to be able to hear it in the cabin, so that's why I'm leaning over towards the race side

Deleting your cats does not pass emissions in California. Even high flow high quality cats in a mid pipe like in the Akra Evo would not pass California's emissions.

Also, I was told the other day that it is a $2500 fine if you run catless in CA.

[momo3605]

Originally Posted by Jive

Deleting your cats does not pass emissions in California. Even high flow high quality cats in a mid pipe like in the Akra Evo would not pass California's emissions.

Also, I was told the other day that it is a $2500 fine if you run catless in CA.

Originally Posted by Sandye90m3

Thanks for the info, now does deleting the primary cats pass emissions of California? And does it carry that smell?

Because right now I'm debating whether I should get the Gintani Race or Sport rear section. I want to be able to hear it in the cabin, so that's why I'm leaning over towards the race side

Yea, you won't pass smog, but you have 6 years from buying the car to worrying about that . And cops aren't going to check for cats on a high end luxury car. Also, there is hardly any smell with just test pipes.

[SilentAttack]

Thinking about a rear section with test pipes.

[Sandye90m3]

Originally Posted by Jive

Deleting your cats does not pass emissions in California. Even high flow high quality cats in a mid pipe like in the Akra Evo would not pass California's emissions.

Also, I was told the other day that it is a $2500 fine if you run catless in CA.

Originally Posted by momo3605

Yea, you won't pass smog, but you have 6 years from buying the car to worrying about that . And cops aren't going to check for cats on a high end luxury car. Also, there is hardly any smell with just test pipes.

Originally Posted by SilentAttack

Thinking about a rear section with test pipes.

And if I were to convert my stock midpipe to test pipes I would get a CEL error correct which I would need to get coded for?

[SlashM3]

Originally Posted by Sandye90m3

Thanks for the info, now does deleting the primary cats pass emissions of California? And does it carry that smell?

Because right now I'm debating whether I should get the Gintani Race or Sport rear section. I want to be able to hear it in the cabin, so that's why I'm leaning over towards the race side

So why can't u get. Test pipes. And cut. The cats. And gain full power?

[momo3605]

Originally Posted by SlashM3

So why can't u get. Test pipes. And cut. The cats. And gain full power?

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

[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

[KmndntKlink]

Originally Posted by Sandye90m3

And if I were to convert my stock midpipe to test pipes I would get a CEL error correct which I would need to get coded for?

That's my understanding. Also think you won't pass emissions with testpipes as from what I understand, it deletes all the cats rather than high flow. It's also harder to go back to stock, if say you want to swap it out to pass the test then go back.
thnx for this thread btw, I'm having a very hard time choosing as well.