lose horsepower with h-pipe

jrc_03_gt said:
I dont need a dyno! If you know how your car drives you can tell if you lost a noticeable amount of torque down low. I know for a fact I did. I did on my 98 gt too! I must say the gears helped bring it back though. I love the way an off road pipe sounds. If you dont like the performance after the install of a off road pipe just get the gears.

I was amazed at the gain after my exhaust mod. I dyno-d about 23 rwhp gain and 20 rwtq gain (peak). At nowhere did I lose torque. The torque curve was about 10-20 lb-ft above the stock dyno the whole rpm range.

My 03 must be different than your 98.

I don't know why this myth continues. I've only seen about 15 'Stangs dyno exhausts, (not "millions", but keep in mind these are average Mustang buyers not wanting to sell a product) but each one is consistant with my gains and NO torque loss.

Has anyone but me noticed that there are no dynos to prove what I've claimed?

Matt
 
we dont need one ! The proof is in the way the car performs. I have owned a 98 and now I have a 03 . Both lost low end TORQUE after exhaust mods. I did not say anything about horsepower. Just TORQUE.
 
jrc_03_gt said:
we dont need one ! The proof is in the way the car performs. I have owned a 98 and now I have a 03 . Both lost low end TORQUE after exhaust mods. I did not say anything about horsepower. Just TORQUE.

You can't show me one because you can't post something that doesn't exist.
(unless someone photochops one).

I just don't want this myth to continue.


Matt
 
SOTP feel means a lot. My 2000 GT lost a little down low when I installed
MAC H-pipe w/cats. You could feel it wasn't as mean down low. Not a major
loss, but a loss none the less. The trade off is the beautiful music to your ears that the less restrictive H-pipe makes. :banana: Like everyone else said,
just get some gears. :p
 
I'm gonna try to attach my before/after dyno...

Matt
 

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I don't see any power loss and I don't feel like i lost anything, but gained. I love the h pipe, but kind of wish i would have went with a different brand. The mac h pipe was a little bit of a pain in the ass to fit up with the manifold and i still think their might be a small leak in the drivers side, but cant tell. Gears are a must and will soon be getting some installed.
 
SonicB said:
http://www.alternativeauto.com/techtips/techtips_46.html

http://www.flowmastermufflers.com/cgi-bin/flowmaster/faq.html?id=RRH4AQnZ

http://www.magnaflow.com/07techtips/faq/question10.htm

http://www.dynomax.com/techsupport.stm

flowmaster, dynomax and magnaflow have installed performance exhaust on millions and millions of cars over the last half century. two pipes 2.25" each is 4.5" worth of pipe. can you picture a 4.5" exhaust pipe sticking out the back of your mustang? now your have 5" worth of pipe and according to performance exhaust makers at your power level your did lose low end torque and perhaps gained 5hp somewhere above 4k rpm. which may not have been a good trade.

twin 2.25" pipe = single 3" pipe

you're measuring area of a circle with diameters of 2.25 and 3 ", not straight lines.

just my .002
- Kons
 
I have owned 2 stangs 1st was a 98 gt and now a 2003 U will feel a loss down low when u open up the exhaust. It comes back and then some with 4.10 gears. I do not need a dyno . It is noticeable from sotp driving. I will say that the loss is small but the sound is well worth the little bit of loss in torque. I feel the off road h pipe is the better choice over the off road x pipe.
 
jrc_03_gt said:
I have owned 2 stangs 1st was a 98 gt and now a 2003 U will feel a loss down low when u open up the exhaust. It comes back and then some with 4.10 gears. I do not need a dyno . It is noticeable from sotp driving. I will say that the loss is small but the sound is well worth the little bit of loss in torque. I feel the off road h pipe is the better choice over the off road x pipe.

SOTP feel is based on perception, right? Maybe you just think you lost low end because the High end is higher than it was before. Just a thought. :shrug:

I doubt that 03trubluGT was making up his dyno run, and if he says that is just exhaust, I tend to believe him. I saw a similar result on the dyno that used to be (still is?) posted for the older version of the MRT H-pipe. It showed another brands X, their own H, and the stock, and the two after market pipes showed no loss of low end. They did show proportionally greater high end gain, tho. They only gained 9HP, tho. He gains 22 in his. Maybe because of other mods, unless that is a dyno for improvement with full exhaust.