With a built bottom end and a goal of reaching around 500whp, will a 2.5" dual exhaust be suffice? At what point will a 2.5" dual be the bottleneck of power?

 

You could do it on a 2.5" exhaust, but why not make it easier on your motor/help spool and go 3"? You have an APS TT or Greddy twins? AAM makes an awesome TD 3" exhaust fyi...

 

With APS 2.5 TD and some test pipes 6xxrwhp has been achieved on an APS TT.

 

3' is an overkill. It'll help spooling but will also be fawkin loud. A great mix between the two is the new evoTT exahust by Greddy. Its TD 2.75', its also quieter than most 3' exhausts.
I also like the SVRTech exhaust..but its fawkin loud. I have it

 

Yeah 3" will make it easier, but as mentioned it will be loud, I have a custom 3" we did at the shop and it gets boomy in the car but man it sounds great at WOT.

 

I know that I don't have the TT, but this is my point of view. Most likely a 500+whp machine will not be a daily driver, and even if it were, I would opt to get the meanest, loudest exhaust out there, if for nothing else but to scare the neighborhood's dogs, cats, children or whatever else that has annoyed me on or off the road. There are reasons that a car has 500+ whp, and I would argue that power and SOUND are two of the biggest reasons!!!

 

The new Greddy Evo TT exhaust has full 2.75" piping. From what I understand it flows really well and has a more subdued sound than the 3" TD's on the market. It might be worth checking out.

 

+1 if you are making a mean scarey car you might as well scare the poop out of little children and small animals

 

3" true duals plus wastegate dumps on the greddy kit is what I would recommend. Mine is louder than most because the duals are custom and the mufflers are cheap, but others don't seem to be quite as loud as people make them out to be...just kinda boomy at cruising speeds.

 

Thanks for all the feedback guys, this is great information.

Here is my idea, maybe this will help clarify a little.

Planning on going with the APS TT setup (boost level an unknown at this point). In addition to the twin turbo setup, I will be planning on doing some lower end work on the block (specifically targeting the "upgraded shortblock" offered through SGP Racing with sleeving).

So, I'm torn between APS' 2.5" and APS' 3.0" true dual exhausts. Knowing these facts, does it change any opinions?

Thanks in advance!

 

I agree plus it is fun setting off car alarms as you drive by

 

I have AAM 3inch duel and it is not loud at all! The dump is what makes it loud but that makes it sound mean! I posted a crappy cell phone vid in the video section of a 30 kick. Alot of tire spin sound but still can hear the dumps and some of the exhaust. Go 3inch cuz as soon as you get 500 and get used to it you will want more lol

 

I think that if you are sleeving your block, you will be able to go past 500whp. Also, APS makes a 3.5" downpipe for the turbos, and mating a 3 inch dual from there would obviously make it flow better and helps with spool (especially at high boost). At this HP range, the difference between a 2.5" and 3" dual will be much more apparant. You will be making a bit more power at same boost.

 

+1 for the EVO TT

 

The APS 3 inch is arguably the most subdued of the 3 inchers. At idle and cruise, its not bad at all. WOT is pretty nasty, but they all are...I love the sound.

For 500whp+, and plans for more....a 3 inch true dual would be your best option. Zero backpressure reduces thermal load on the engine, and the subsequent heat....safety and more power and reason enough to go 3 inch.

 

Good advice, thats the route I've gone. Wanted more noise, and less load on the engine is always a bonus.

 

just curious, but if someone was shooting for 500whp on an inline 6 cylinder engine like a supra or skyline or something, wouldn't a single 3 inch exhaust be big enough?

I was under the impression it is, but then why would a V6 engine be so much different to need more flow?

is it just a turbo thing with getting faster spool up times?

 

I would steer clear of the APS 3" exhaust.

 

SVRtech FTW. (or EVO TT)

 

your opinions are greatly appreciated, but i would also like to know why? If you can give a more detailed explanation, it would help me understand. For example, sharif's comment.