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Exhaust on a i5? Worth it or not?

razortray

Well-Known Member
Messages
91
Location
Arkansas
Anyone have any type of aftermarket exhaust on their h3 i5. The last thing I want is for it to sound like a Honda Civic but if I could find something to make it sound beefier I'd be happy. May not be worth the hassle just wanted to get some opinions. Thanks


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scoreh3

Well-Known Member
Messages
1,024
Location
SoCal
I have a cat back Magnaflow and it sounds great . The cat back MF and the Air Doc made it sound and feel a lot better .
 

Chook

Well-Known Member
Messages
706
Location
Brisbane (Australia)
I have done both Cat Back & Extractors/Headers.

Both together is unbearable but either/or is fine

The extractors give a better performance gain
 

4speedfunk

Well-Known Member
Messages
4,250
Location
Tardville
Big Red had the "GM Performance Exhaust", and it is the nicest sounding 5-cly. I've ever driven. (I've driven a lot of them).
The biggest issue I've noticed is that most aftermarket systems have an unbearable "drone" around 2000rpms...right where you spend most of your time. The five cylinder is not a motor that you want to hear....nothing will ever take the "fart" sound out of it.
As far as gains?....well I think that is mostly psychological. A header (extractor) will certainly add some power but I really think any improvement in power would be in the 4000-6000 rpm range, and the motor just doesn't operate in that range very often. Unless you're Rod Hall and you"re bombing across the desert at 90 mph...I don't see the point.
 

rsc

Well-Known Member
Messages
1,087
Location
Tulsa
From the few 355Nation and H3 (the Broken's) dyno pulls I've found, the power gains seem to mirror the stock power curves. Maybe a bigger gain in the upper mid-range. Not miracle numbers, but then it's coming through a 4WD system and adding another 10% of drag into the system. About 18-22 hp at the wheels from exhaust work depending on the particulars of your setup. (Edit- header, exhaust and a PCM tune for the changes)

Chook, good to know about the noise from header pipe AND a cat-back, thanks.
 
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jphh20

Well-Known Member
Messages
173
Location
CT
I have a cat back billy boat system that deletes the resonator and leaves a deeper sound that does not sound like a coffee can system that you see in Honda's. I have had it on for 8 years without issue other than the normal dragging of the tips off-road.


Joe
 

RazorbackH3

Wooo Pig Sooie
Messages
528
Location
Tecumseh, Mi
I've been running a Gibson Dual Exhaust ran straight out the back for 2 years now... Start up and around 1750 rpm range I love it... Extremely low and deep rumble... around 2000 I get the annoying drone... If I had to do it again, to be honest I probably wouldn't have done it... As much as I love scaring old ladies on startup, the trade off of having every big truck owner, jeep owner, and muscle car owner getting their panties in a wad because of a big, loud Hummer just isn't worth it... (I already get enough hate before I even start my H3) I think it's more of a personal taste thing with the exhaust sound, for me, I could have spent the money that I didn't use on the exhaust for some other mod on my H3 (UCP/belly armor, etc...)
 

digglesworth

Well-Known Member
Messages
1,789
Location
illinois
i thought about cutting my resonator off and welding a flowmaster series10 or series40 in its place to ditch the ginormous stock muffler across the back. but i havent done it yet in fear of the fart in a coffee can sound.
 

cbetts

NERD!!!
Messages
3,188
Location
Rancho Palos Verdes, CA
I am running a Gibson cat-back system. No significant gains on the highway but I did get better low-end power for climbing. Has a mellow sound but deletes the resonator which causes dome droning on the highway.
 
D

Dennis

Guest
I put on the Gibson Dual Cat back exhaust, from almost the first day I had the H3 back in 2006..Never regretted it..sounds and looks great IMO....

The performance can be appreciated more if you have he PCM tuned for it...Mine at cruising altitudes on the Interstate is mellow and hardly noticeable....BTW, that's also why they put stereo's in these rigs.
 
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Woodtick

Well-Known Member
Messages
801
Location
Ilanoid, UP MI
I've been running a MF cat back with a air hog cold air intake since 06. 4speed is spot on. Bad drone at 60 mph aprox 2100 rpm. I pull a snowmobile trailer sometimes. The power gain is very noticeable passing and merging on the highway. You won't notice anything around town.
 

humvee

Well-Known Member
Messages
507
Location
Doha, Qatar
I had the GM performance exhaust, it sounded great on the i5. They're made by Borla.. and are out of stock.

If you can score a used one from someone, go for it.
 
S

SedonaBound

Guest
I had the GM performance exhaust, it sounded great on the i5. They're made by Borla.. and are out of stock.

If you can score a used one from someone, go for it.
Last year Borla had a H3T Alpha performance exhaust listed on their close-out page for 1/3 of list price and I got my hopes up only to have them dashed when I tried to place an order and they said "oops..all gone!".
 

Bigunit

Hammer Down!
Staff member
Messages
6,561
Location
Arizona
I have a GM Borla performance exhaust on my I5 H3T that I could remove and sell and put the OEM exhaust back on but shipping it would probably be pretty high. If interested, shoot me a PM.
 

Bigunit

Hammer Down!
Staff member
Messages
6,561
Location
Arizona
...also have a H3T Gobi rack if anyone is interested......Sedonabound? I will be in Prescott in 2_weeks! [emoji12]
 
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