Borla vs HKS Hi power for ms3

[09TRMS3]

I have listened to alot of hks sound clips and like them but i havent heard to many good borla clips. I want one of these exhausts . which one do you guys think sound better?

 

[mazdaspeedster3]

Sound or performance? isnt the HKS a 3" exhaust where the Borla is a 2.5"? You will lose some back pressure with the 3" causing a loss in low end torque but will match up to most TP's and DP's. Have to choose wisely based on what you might do down the road.

 

[dandan2]

u dont need back pressure in a turbo car

 

[mazdaspeedster3]

Not necesarily no. But guys running 3" exhausts will tell you that they have lost low end grunt with the stock 2.5" tp dp

 

[Silver Ecstasy]

Having done an obnoxious amount of reading on exhausts, backpressure, turbos, yata yata, here's what i've found:

3" exhaust is definitely a good idea on our cars, that is, if you're going to commit entirely. Downpipe all the way back to catback will have to be 3" to make an improvement. When I installed my MSCBE, 3" didn't really do much with stock downpipe. Infact, I lost low end, but gained in the higher rpms (which is proven, larger exhaust is always better on turbo cars in higher rpms, our ms3's are not high rpm cars).

Anything less than 300hp and you should maintain the stock 2.5" exhaust diameter. Borla and I believe also AutoExe is 2.5" exhaust. That size was picked by Mazda to maintain proper exhaust velocity and torque throughout our car's particular power band. For light mods, stay at stock or stock sized piping.

Then again, if all you're looking for is sound, start cutting out exhaust resonators..it's much cheaper.

If you're looking for good sound and don't really care much about the performance aspect, then go MSCBE! I like the sound a lot. It's very subi STI-esque.

 

[dandan2]

i dont think he is lookin for cheaper if he is lookin at hks exhaust! hks is the way to go though!

 

[dandydaniel]

I'm running a stock downpipe with a ********** test pipe and the hks hi power. i love the sound of it.. it isn't obnoxious at all at rpms below 3500 (really useful for me in california with cops pulling people over based off of how loud your exhaust is :/) but damn.. when you do get on it, the thing just opens up and you really appreciate the sound you paid for. after getting JUST the exhaust by itself installed with stock tp, i felt a minimal gain in the high end and nothing else really changed... threw in the test pipe and thats when alot of power got opened up throughout the power band for me. car has been screaming these days in 55-60* fall weather here..

let me know if you want a sound clip

 

[Silver Ecstasy]

Well in his signature, it says Future Mod Cobb DP. The Cobb DP necks down to 2.5" so it would fit the Borla fine but its kinda pointless opening up the DP to close it down to 2.5" near exit.

And besides, exhaust note changes completely with a downpipe.

HKS is the least expensive exhaust next to Corksport.

 

[MSMS3]

Well in his signature, it says Future Mod Cobb DP. The Cobb DP necks down to 2.5" so it would fit the Borla fine but its kinda pointless opening up the DP to close it down to 2.5" near exit.

And besides, exhaust note changes completely with a downpipe.

HKS is the least expensive exhaust next to Corksport.

Good observation. I run the TurboXS dp/rp (catless but you can put a cat in the rp if you need to). It is 3 inches and solves the flow issue.

I disagree with the poster who thinks that a 3 inch CBE makes a flip of difference in power. Unless and until you get north of 300 whp, which you really can't safely do with the stock K04 turbo, the stock CBE flows better than the maximum exhaust flow rate out of the turbo. It make sense to go with a 3 inch CBE only if you plan to mod to the point of exceeding 300 whp.

Otherwise, you are just modding for the sound you want, which is perfectly fine. Personally, I don't "pay for" sound. I pay for power. But for those who want to pay for their sound, they should know that going with an aftermarket dp/rp is going to make the system a lot louder to begin with. Someone tuning for sound might want to do the dp/rp first and see how it sounds before spending big bucks on the CBE, as that sound will change when you uncork the restrictions, which are all upstream.

Just one opinion.

BTW: As to quality, both the HKS and the Borla systems are absolutely top notch in quality and should fit perfectly to the stock system. There could be issues when connecting to an aftermarket RP. On that issue, an aftermarket RP alone will help a little bit, only a little bit with power. The biggest restriction, and it is huge, is still in the DP. In combo with a DP, they compliment each other and things really come alive.

 

[coololddude]

I pay for sound and power. In fact I seem to never stop paying for power. I also pay for........Whoops, wrong forum!!

 

[09TRMS3]

Hey thanks alot gents. From what I have read in your replies I should probably go with the HKS atleast for the power and team it up with some Turbo XS gadgets lol. I wanted to go for cobb on all the parts until they decided to yank there cbe and there front mount which im really upset about. I really wanted that fmic. Well looks like i will have to change my plans up then, Probably hks cbe with turbo xs rp/dp combo followed by the turbo xs fmic which is too big in my opinion but still efficient.

 

[09TRMS3]

I just hope that i will still be able to pass emissions every year with the turbo xs set up if i go that route.

 

[MSMS3]

I just hope that i will still be able to pass emissions every year with the turbo xs set up if i go that route.

Turbo XS DP/RP is catless. I hope I made that clear. If not, please understand that with this you will not pass an emission test. You will need to add a cat in the system. This can be done cheaply with a single high flow mini-cat in the RP section. Any good performance exhaust shop should be able to do this for you.

I run this catless and love it, but I'm in a state that does not test emissions.

 

[Speedkid]

The hks sounds pretty good.