Exhausting Thoughts

[LGAFF]

Heart throb exhaust out of MN did a system for the new DOHC Mustang....interesting to note, they found an X Pipe actually hurt HP significantly...H pipe made significantly more HP. Better Torque too

Also interesting to note they used 3" on a 5.0 motor....maybe bigger is better. I think I will call them and get their thoughts on the LT-5.

H Pipe: http://www.heartthrobexhaust.com/1029050dyno.pdf

X Pipe: http://www.heartthrobexhaust.com/1029045dyno.pdf

http://www.youtube.com/watch?v=_MGRvx5RRDw

[LGAFF]

Just sent them a note:

I just watched your video on the new 2011 Mustang with the DOHC engine. Two things of interest 1) Exhaust size and 2)The H pipe made more power and even torque over the X pipe.

I have 2 90s Corvette ZR-1s...They too use a DOHC motor, but are 5.7ltr vs the mustangs 5.0..... as with the Mustang they make peak HP at 6500-7500RPM. I was wondering if ZR-1 would benefit from a 3" exhaust vs most AM exhaust that are 2.5 to 2.75 and secondly if the H pipe selection was in any way related to the high RPM application. I am currently runs X Pipes in my car and Tradiational thought is that 3" exhaust is too large for most applications. My cars make 390rwhp with ported intakes and header applications.

Thanks for your time,

Lee

[VetteMed]

Interesting - please post their reply when you get it!

[jrtoffroad]

I love the 3" system I recently built for my Z, but am curious about the performance difference between an H & X pipe (I'm running a magnaflow X)

It'd be pretty easy for me to fab up an H pipe to swap in, and I've been wanting to hit the dyno anyways...maybe I should do a quick comparison test.

-Jordan

[LGAFF]

Response:

Hi Lee,

Traditionally I would agree that on a small block, dual 3? is too big. But on these later model engines (5.0L 4V Mustang, 6.1L SRT8 Challenger), we are getting very good dyno numbers with dual 3? and an H pipe. Would you car benefit from the H and dual 3?? Possibly, and I would think so. The only true way to be sure is to dyno it. So far, on all late model vehicles, with everything the same, and similarly designed systems, we have been getting better numbers with the H over the X. But that doesn?t mean that your applications, which we have not tested, would not yield different results. I had a 1990 Mustang LX, had both an x and an h on it (this was before we had a dyno to test), I noticed better off the line grunt with the H, but better high end highway passing power with the X. This contradicts what we find on the new 00+ dyno testing. So really, to be sure, the only true way to know is to test both. Your modified ZR1?s may benefit from a 3? dual and an H.

Thanks,

Mike Forbes

Heartthrob Exhaust
60819 U.S. Hwy. 12 W
Litchfield, MN 55355
P: 320-693-0222
F: 320-693-8964
website: www.heartthrobexhaust.com

[A26B]

That's actually good news for me. With the custom 3" straight tnrough system with X-pipe, it seemed to do well. due to the noise with no mufflers, I had some custom, 4" cherry-bomb style glass packs made, as long as possible to try & quieten it down. Consequently, the X-pipe was eliminated. I did not notice a reduction in noise, but did notice a difference in sound & a seat-of-the-pants drop in power, both not to my liking. I have planned to put in an H crossover. Your posts give me some reason for optimistic results.

Thanks Lee!

[mike100]

My old 5 liter tpi Z-28 had a single 2-5/8's " pipe. I would love to try an exhaust system with dual 2-5/8 pipes. They seem to resonate at a different freq than 3", but are plenty bigger than 2.5".

Another thought I have is my 6.2 LS3 walks on C4 with 2.5 inch pipes. Seems like you can easily make 450 hp with 2.5". And again, reminding myself that fat pipes aren't alsways the most driveable solution, I just had a look at a new Lambo Murcialago and the merged twin outlet pipes on that were quite small for a 6xx hp supercar.

I have an X-piped 3" B&B that I would love to trade for a stock pipe with better muffs.

[Pete]

Originally Posted by mike100

My old 5 liter tpi Z-28 had a single 2-5/8's " pipe. I would love to try an exhaust system with dual 2-5/8 pipes. They seem to resonate at a different freq than 3", but are plenty bigger than 2.5".

Another thought I have is my 6.2 LS3 walks on C4 with 2.5 inch pipes. Seems like you can easily make 450 hp with 2.5". And again, reminding myself that fat pipes aren't alsways the most driveable solution, I just had a look at a new Lambo Murcialago and the merged twin outlet pipes on that were quite small for a 6xx hp supercar.

I have an X-piped 3" B&B that I would love to trade for a stock pipe with better muffs.

I have stock pipe exhaust with H-pipe and Flowmaster muffler fits early 1990-1991 ZR-1's

Pete

[mike100]

Originally Posted by Pete

I have stock pipe exhaust with H-pipe and Flowmaster muffler fits early 1990-1991 ZR-1's

Pete

I think I made a promise to myself to never buy flowmasters again, but I'm still interested in a stock-ish pipe setup- would probably prefer a resonator.

I honestly think it might be easier to have the guy down the street make me one from scratch- Although for that money I could buy the Corsa...is the Corsa loud? (I want quiet-just a bit louder than stock is ok).

[Pete]

Originally Posted by mike100

I have an X-piped 3" B&B that I would love to trade for a stock pipe with better muffs.

Mike,would you sell your B&B outright? how much?

Pete