lose horsepower with h-pipe

[pjdellenger80]

Someone told me that you can actually lose horsepower from taking out your cats and putting in a off-road h or x pipe Is this true?

 

[DavidCroft]

As far as Im aware you dont lose power at all. I actually felt the power in every off road H I have installed. I have one on order for my 1997 Pacific Green Cobra. So far on my old 96 GT and Bullitt, it helps. I'd say they are a 15-20 hp increase. How would you lose power taking out restrictive cats?

 

[cmb91LX]

I will say that at one time I had an o/r Xpipe on the 99 and when I put the factory converters back on I did notice a significant difference in the performance of the car. The 4 converters really stopped the car up big time. The information you have been given may be accurate in some situations BUT I doubt it is true in your situation.

 

[jrc_03_gt]

You will have less torque down in the low end. I noticed it too. To fix it I have 4.10 gears being installed. That should make up for the loss and then some. The sound is awesome with a off road pipe!

 

[GTvert01]

By freeing up the exhaust, you are gaining more top end hp, while you may be losing some low end tq from lack of backpressure.The 4.10s more than make up for the difference.I have an o/r x-pipe and I love it.

 

[Ryan02Stang]

You will lose some low end torque from the loss of backpressure. But the gains up high are worth it. Trust me, you will benefit from an off road pipe.

 

[ProCharger GT]

Plus it's a good excuse to get gears

 

[jrc_03_gt]

Got the call gears are in have to go pick up car! YAHOOOOOOOOOOOOOOO!

 

[pjdellenger80]

You will have less torque down in the low end. I noticed it too. To fix it I have 4.10 gears being installed. That should make up for the loss and then some. The sound is awesome with a off road pipe!

how do you like the 4.10's? are they what you expected in performance?

 

[pjdellenger80]

an older buddy of mine mentioned this, but he didnnt know if in was a problem with the newer cars. I felt power gains with the install and it sounds great with the flowmaster. I might go with magnaflow later on down the road though! have heard good things about magnaflow

 

[jrc_03_gt]

I love them ! I have not roasted the tires yet, they told me to take it easy for about 100 miles or so.

 

[WRXracer]

ok

dont listen to these guys my xpipe on my car gained power.. I felt nothing down low and a lot up top..

 

[hotmustang331]

Will that X pipe cause the engine light to come on in our cars?Also what does one sound like with the stock mufflers?Anyone tried it?I also heard good about magnaflow, is their cat back with their OFF road X or H too loud for normal driving and will it attract cops?I love how noone can hear me right now with the stock exhaust, keeps people from call the fuzz...or the fuzz from hearing me LOL.

 

[just some guy]

Will that X pipe cause the engine light to come on in our cars?Also what does one sound like with the stock mufflers?Anyone tried it?I also heard good about magnaflow, is their cat back with their OFF road X or H too loud for normal driving and will it attract cops?I love how noone can hear me right now with the stock exhaust, keeps people from call the fuzz...or the fuzz from hearing me LOL.

i had a BBK off road h pipe on my 98 and loved the sound with stock mufflers. it sounded mean as hell. i also trapped 96 or so with just that pulleys and timing adjuster. you cant tell me you lose power with it.

 

[03trubluGT]

Ok, I have seen some posts saying that you "might" or "will" lose some low end torque with an exhaust upgrade.

YOU WILL NOT LOSE ANY LOW END TORQUE! PERIOD!

I have seen several combinations dynod, and I have NEVER seen anything but a substantial gain.

See sig.

Any questions?

Matt

 

[03trubluGT]

I have my dyno of before/after my exhaust upgrade on my computer at work.

I'll post it up on Monday.

In the meantime, if anyone has a dyno showing a loss, please post it up and the details of the swap...


Matt

 

[jrc_03_gt]

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.

 

[jrc_03_gt]

dont listen to these guys my xpipe on my car gained power.. I felt nothing down low and a lot up top..

There will be a noticeable TORQUE loss down low if there are no other mods to the car. Just reaserch it. I have felt it on 2 different 4.6 mustangs that I have owned.

 

[SonicB]

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.

 

[merc123]

It would make sense that you would lose some low end torque.

For example: I removed the exhaust behind the factory H-pipe and could feel a significant lack in power. As soon as I hit 70 MPH though it felt like a bullet and 70-100 was faster than before.

Less restriction = Less backpressure = Loss in low end power

O/R H/X = Less Restriction = Less backpressure = Loss in low end power?