[David Gordon]

They are back in stock and I was wondering if going witht the Mid pipe to stock system is worthy?

[ALMN]

Nope, not worth it unless you are going to switch to a full catback in the future. Stock exhaust also has an x pipe so just switching to another x pipe will have no effect on the noise or exhaust flow. That’s my opinion. Now if you do H pipe though, then your exhaust note would be more deeper but won’t flow freely as the X pipe.

[FlukeSS]

Originally Posted by ALMN

Nope, not worth it unless you are going to switch to a full catback in the future. Stock exhaust also has an x pipe so just switching to another x pipe will have no effect on the noise or exhaust flow. That’s my opinion. Now if you do H pipe though, then your exhaust note would be more deeper but won’t flow freely as the X pipe.

This is false.

An aftermarket X-Pipe on average will net you 7-12 HP over stock with a tune.

If you don't plan on getting a tune right now, then I'd wait for when a tune is needed to put the X-Pipe on

[David Gordon]

It doesnt remove the back set of cats?

[FlukeSS]

Originally Posted by David Gordon

It doesnt remove the back set of cats?

Well I'm running 3" Speed Engineering X-Pipe. I do not recall if those back cats are removed, but I know my LT headers deleted the cat on my car. And my X-Pipe goes into the stock axle back.

I will defer to someone else with more knowledge to answer your question.

[6spdhyperblue]

Originally Posted by FlukeSS

This is false.

An aftermarket X-Pipe on average will net you 7-12 HP over stock with a tune.

If you don't plan on getting a tune right now, then I'd wait for when a tune is needed to put the X-Pipe on

Where did you get this number?

You will get some gains on a auto but very minimal on a m6

[Jeb114]

BS on the 7-12 HP, maybe 1.

[ALMN]

Originally Posted by FlukeSS

This is false.

An aftermarket X-Pipe on average will net you 7-12 HP over stock with a tune.

If you don't plan on getting a tune right now, then I'd wait for when a tune is needed to put the X-Pipe on

Nope trust me on this. I am a professional engineer in manufacturing. An x pipe is not going to give you any horsepower unless you remove the remaining constraints in the exhaust system. Main constraints are the primary and secondary cats. I am not sure the restrictions on the airfoil suitcase mufflers. The stock system already has an x pipe so going with just an aftermarket x pipe and leaving the remaining exhaust system the same will net you $800+ out of your pocket with 0 horsepower gains.

[ALMN]

The other myth i would like to bust here is the back pressure on the exhaust system. Yo do not want back pressure, back pressure is the build up pressure in the exhaust system due to pressure drops resulted in restrictions. Think of it as a person being constipated. You do not want that and flow freely as possible. Your best bet to gain power is long tube headers with either no cats or highflow cats.

[FlukeSS]

Originally Posted by ALMN

Nope trust me on this. I am a professional engineer in manufacturing. An x pipe is not going to give you any horsepower unless you remove the remaining constraints in the exhaust system. Main constraints are the primary and secondary cats. I am not sure the restrictions on the airfoil suitcase mufflers. The stock system already has an x pipe so going with just an aftermarket x pipe and leaving the remaining exhaust system the same will net you $800+ out of your pocket with 0 horsepower gains.

Which I believe was done to my car.

My dyno showed an ~85 hp gain at the crank with the mods I have. Sadly though I don't have a baseline, but most of these cars baseline between 390-400 with a few outliers. So I assumed my car baselined for 400 which nets me about 59 rwhp gain which accounts for a 15% parasitic loss.

The only way to come up with 85 hp gain over stock at the crank is if you use the following numbers which I came up with through a lot of research and modesty to down play those numbers to be more reasonable.

25hp from headers
30hp from E85
1-9hp from CAI
7-12 hp from X-Pipe

Add them together you get my exact expected gains. 76 hp at the wheels. Add 15% to that and you get 87.4 at the crank. Obviously some margin of error but we are talking about: 2.75% margin of error. And I chose to assume my car baselined at 400 rwhp, if that 76 at the wheels is correct, then that means my car baselined closer to 383 at the wheels. Or you are right and the X-Pipe does nothing, and my car then would have baselined at 400. Which is more likely?

Either way, its very hard to come up with an 85 hp gain to the crank if the X-Pipe does nothing. My dyno showed an approximate crank power of 540 hp. Or if you use the formula 545hp.


I did all the number crunching before I did my mods, and I got the near exact numbers I was looking for.

[ALMN]

Originally Posted by FlukeSS

Which I believe was done to my car.

My dyno showed an ~85 hp gain at the crank with the mods I have. Sadly though I don't have a baseline, but most of these cars baseline between 390-400 with a few outliers. So I assumed my car baselined for 400 which nets me about 59 rwhp gain which accounts for a 15% parasitic loss.

The only way to come up with 85 hp gain over stock at the crank is if you use the following numbers which I came up with through a lot of research and modesty to down play those numbers to be more reasonable.

25hp from headers
30hp from E85
1-9hp from CAI
7-12 hp from X-Pipe

Add them together you get my exact expected gains. 76 hp at the wheels. Add 15% to that and you get 87.4 at the crank. Obviously some margin of error but we are talking about: 2.75% margin of error. And I chose to assume my car baselined at 400 rwhp, if that 76 at the wheels is correct, then that means my car baselined closer to 383 at the wheels. Or you are right and the X-Pipe does nothing, and my car then would have baselined at 400. Which is more likely?

Either way, its very hard to come up with an 85 hp gain to the crank if the X-Pipe does nothing. My dyno showed an approximate crank power of 540 hp. Or if you use the formula 545hp.


I did all the number crunching before I did my mods, and I got the near exact numbers I was looking for.

An X pipe swap over a stock x pipe is not going to give you any gains, there is no magic behind it. If that was the case Chevy would have done it and rated these cars 465 hp instead of 455. Trust me on this.

[enzia35]

Speed Engineering x-pipe deletes the rear cats. Looks like the Corsa keeps the cats. I have the Borla mid-pipe and they used to sell one that keeps and one that deletes the cats, until the EPA got up in their business.

[FlukeSS]

Originally Posted by ALMN

An X pipe swap over a stock x pipe is not going to give you any gains, there is no magic behind it. If that was the case Chevy would have done it and rated these cars 465 hp instead of 455. Trust me on this.

Then as an engineer you need to explain how I gained 85hp at the crank.

Because the numbers don't add up without the X-Pipe.

Or do you think I have a Unicorn that would have baselined at 420 rwhp stock?

You may be an engineer but numbers don't lie.

Where did I pick up the extra hp from stock if the X-Pipe did nothing?

Perhaps E85 added 50 rwhp instead of just the normal 30-35?

Or would you care to explain to Motortrend they are wrong?

https://www.motortrend.com/how-to/x-...inder%20faster.

The X-pipe will usually make anywhere from two to four more horsepower than an H-pipe. The slight horsepower difference comes from the way the X-pipe creates a venturi effect, which helps pull the exhaust gases out of the cylinder faster.

That said, I have stated previous you need to get a tune, and it does matter what other mods you have. When you consider LT headers cat delete and the X-Pipe with a tune, the numbers do add up showing the X-Pipe does in fact add power. And its not just mototrend that agrees with me but many other sites.

Even if we consider probability, statistically the odds are not in your favor of you being right. There are too many other sources that contradict what you have stated.

Further consideration:

For much of the system, the exhaust gases leaving the LT1 remain separate. Two sets of 2.75” diameter piping and emissions equipment run in parallel to evacuate exhaust from both the left and right banks of the engine.

https://www.mishimoto.com/engineerin...system-review/

I have a 3" X-Pipe so wider diameter = more exhaust flow. And the stock exhaust is not an X-Pipe.

It really is basic physics. Why do you think I'm so against the LT2 intake manifold which caps out at 95mm. Where as the Atomic Airforce caps out at 103mm. Combine that with a NW 103mm TB and you will see higher gains at the finish line, than the LT2 can provide. Especially considering the 2" Headers I have installed as opposed to 1 7/8ths even though I don't have a supercharger yet. Yes the LT2 is cheaper, but sometimes you do in fact get what you pay for.

My intention with my build is to possibly eliminate bottlenecking with the intake and exhaust to allow the engine to breath properly. Everyone knows a proper breathing engine produces power.

[Chrome383Z]

Originally Posted by FlukeSS

Then as an engineer you need to explain how I gained 85hp at the crank.

Because the numbers don't add up without the X-Pipe.

Or do you think I have a Unicorn that would have baselined at 420 rwhp stock?
.

Xpipe doesn’t do anything on a stock or bolt on car. The only instance where you could see 10hp or so is on a high power FI car with an automatic as the AFM valve does neck down a little.

My 19 A10 pulled 423 on a mustang dyno with an A10 stock. Did have a rotofab but unless tuned you don’t get much from it. So yes you could have hit 420 depending on dyno. They are a tuning tool without a baseline it’s all speculation and guessing. Some are happy, some are not. It’s the delta you need to watch.