View Full Version : Autoexe Stainless Catback Review (Part 1)


gfoo
05-16-2006, 09:38 PM
Just installed my spanking new Autoexe Stainless Muffler, and here's a short take of my initial impressions:

Looks:
The Autoexe catback is lovely - very unique 2 box design and the tips are the tapered kind (ie cut at an angle) each lasercut with the Autoexe logo. Very nicely polished midpipe which connects beautifully (and easily) with the exhaust outlet. Most importantly, the exhaust tips have a perfect visual alignment, unlike other exhausts i've seen where one tip protrudes out more than the other. The Autoexe definitely doesn't have this problem. Also, the 2 box design has a lower profile than stock. Previously, i used to scrape and even dent the exhaust box when clearing humps or even parking - not so with the Autoexe.

HP/torque increase:
Now I'm not really one of those 'wake up the neighbours' type of guys that go for loud exhausts, and would rather have a muffler that improves my ride's performance. Now this is about the 3rd AT car i've owned in the past 3 years ( a Honda Civic, and then a Mazda 3) and i've tried about everything from 'kui-tao' the muffler at Manz, getting Sebring catbacks, changing resonators, pipe sizes etc etc. In fact, for the 8, this is the first time i'm getting a jdm brand.

From my experience, and also that of my previous club buddies, ATs are really hard to 'tune' exhaust-wise. You'll either get no benefits other than sound, or even lose HP/torque. This is as a certain backpressure is needed to generate torque. In my Mazda 3, i once had a straight through setup with an increased pipe size, and it totally killed my low end torque.

The Autoexe performs really well, at least on my AT. There is a noticable increase in low end torque, and the car just feels substantially lighter. Revs are much more responsive, and the slight lag felt when launching the car seems to have melted away. Linear acceleration is also much faster (at least across 1st 3 gears), and i'm reaching 120-130kmh much faster on 2nd gear alone (NB mine is the 4spd AT). I'm very pleased with the low-torque gains on the Autoexe - finally i have that slight 'lurch' from start which the manuals seem to have, but the ATs don't.

Sound:
As mentioned earlier, if you want those really loud exhausts, look elsewhere. The Autoexe starts off idle with a really low, bassy growl. When first installed, it was barely audible, but sounds louder now. In time, the db will increase to an extent. On higher RPM revs, exhaust sounds deep and wet, and def not those shrilly Remus' we hear on the expressways from time to time. Think of a younger Pavarotti, low but not overtly bassy, and definitely not as high pitched as Jose Carreras.

Installation:
Installation was a breeze, and took under an hour at Monster Garage at Ubi, who's the only authorized dealer in Singapore, so these guys know their stuff. Now what i really like about the installation is the care and time they take to make sure stuff goes up properly, it's almost like they're installing on their own cars. Now if you've ever experienced the crap service at FK and other exhaust places, you know what i mean.

Overall impressions:
The torque/hp improvement was a shocker esp on low end, esp when mine's an AT. I've heard of bros installing Fujitsubos and HKSs that have either no or negative benefit. In this respect, I'm mighty pleased with the Autoexe. Sound is not loud, but a soft low bassy growl when idle, which develops into a mature wet sound at higher revs. The only other exhaust I know which works great with ATs is the RE Amemiya steel muffler, which is also available only at Monster Garage. The RE from what I heard has a very unique kind of sound.

I'll post a further review on the sound once it breaks in further, what happens at higher speeds and hopefully, dyno results.

Rating
Low-end torque: 4.5
HP gain: n/a
Sound: 2
Looks: 4
Installation: 4
OVERALL RATING: 3.5

Available in Singapore with JASMA Cert from Monster Garage

http://www.boomplustoys.net/images/autoexe/Autoexe_Muffler_for_RX8.jpg

theboy
07-29-2006, 05:44 AM
Autoexe gain how much HP???

Spin9k
07-29-2006, 06:26 AM
Looks nice, I love autoexe stuff. How does autoexe provide much HP (#) gain when no others do? Maybe the sound makes it 'feel' faster lol! My Corksport certainly does, even sitting still!!

How 'bout some pics of it on your car (#)? rear end, from back away, etc. Thanks.

Mazdaspeed RX8 ver2
07-29-2006, 06:28 AM
some pics would be good and maybe a sound clip as well.

theboy
07-29-2006, 06:38 AM
the design is almost the same as greddy one, but this design will increase power lose due to distance from muffler in pipe to muffler our pipe. even the size of greddy and autoexe is the same. how come greddy one can gain 19HP?

mysql101
07-29-2006, 07:58 AM
you'll be lucky to get even 5 hp. 19 is out of the question.

sqflyer
07-29-2006, 09:01 AM
how come greddy one can gain 19HP?Maybe because there is a Greddy turbo attached upstream of it's exhaust... ha ha ha. :mdrmed:

theboy
07-29-2006, 11:30 AM
i got these from rx7.com, it says 19HP

http://www.rx7.com/RPGReddyRX8exhaust/images.html

http://www.rx7.com/RPGReddyRX8exhaust/dynocharts.html

INXS
07-29-2006, 11:43 AM
MOre details

Mazda RX8 2003-UP Dual Muffler

Features:

Polished 304 Stainless Steel Mandrel Bent Piping
SUS304 Stainless Steel Construction
Lightweight, Flared and Stamped Stainless Steel Flanges
60mm Piping 115mm x 110mm x2 Outer Curled Oval Exhaust Tip
Minimal Number of Bends for Maximum Efficiency
State-Of-The-Art Robotic Seam Welding

gfoo
07-29-2006, 11:53 AM
No matter what exhaust, no way u can get 19hp esp not an auto. Dun mean to be a spoilsport but let's not have pipedreams here.

expo1
07-29-2006, 12:02 PM
i got these from rx7.com, it says 19HP

http://www.rx7.com/RPGReddyRX8exhaust/images.html

http://www.rx7.com/RPGReddyRX8exhaust/dynocharts.html
Those numbers look like there are with a midpipe ( no cat ).

http://www.rx7.com/store/rx8/images/rx8supercat_factory.jpg

Is a dyno run with a RP supercat AND Greddy SP2 and claim only 9 HP.

theboy
07-29-2006, 01:26 PM
Finally someone gave me the figure. Mazdaspeed cold air intake 7psi. how much HP is 7 psi?

sqflyer
07-29-2006, 01:39 PM
PSI is pounds per square inch... used to measure air pressure and not horsepower, well not directly at least.

Spin9k
07-29-2006, 02:05 PM
Finally someone gave me the figure. Mazdaspeed cold air intake 7psi. how much HP is 7 psi?
If the MS CAI pumped 7psi into the 8, it'd be the cheapest "free air supercharger" ever produced lol. A good CAI might relieve perhaps .5 psi (~14in H2O) of restriction from a bad OEM intake, give or take a few inchess, but the chance of true pressurization of the intake charge above atmospheric is slim to none.

theboy
07-29-2006, 02:20 PM
spin9k
so u saying that the mazdaspeed intake encourage atmospheric pressure suck into the intake better than oem one and gain oxygen burnt like a super charge force air into the engine?

Genesis
07-29-2006, 02:57 PM
There's no friggin HP gain....don't get swept up in that bs, however the sound is very cool :)

sqflyer
07-29-2006, 03:00 PM
theboy, I think maybe you have selective hearing/reading. What Spin9k said can be summed up in his last statement, quote "the chance of true pressurization of the intake charge above atmospheric is slim to none" unquote.

theboy
07-29-2006, 03:13 PM
i dun get what he meant in technically, cause i am a noob. hahaha well since u quoted the sentense, i think i understand now. is it air filter no matter how much the ps, the atmospheric pressure will not allow much air into it?

Spin9k
07-29-2006, 08:11 PM
I'll try again. Cold air intakes do NOT pressurize air coming into the intake more than a very very very very small tiny amount at normal car speeds (less than 100 mph). No 7psi, no 3 psi, no 1 psi even. A CAI may REDUCE the restriction a poorly designed intake system makes however. So instead of a NEGATIVE pressure at the throttle body, say like -.5psi, a CAI may lesson the loss to -.4psi or even (just) atmospheric at 0 psi. And air filters, like the 8s, have almost NO restriction to the air passing through. They are very efficient.

theboy
07-29-2006, 08:44 PM
Oh ic~! Thanks man. point taken.