Built APS TT runing though Y-Pipe & 2.75" exhaust? Your thought's please.
 

As stated im building my block and running APS TT kit (old BB turbo's not Knock-off new ones).

At the moment i have a 5zigen exhaust and Y-pipe. I love the tone of the exhaust and dont really want to change it. I know that will FI the less back pressure after the turbo the better, but do you think running this exhaust set up will hold me back alot? Im looking to run APS 3.5 inch DP. The down pipe diameter has the biggest effect on backpressure as its where the exhuast gases are at there hottest so do you think i could hit my 500RWHP (DD) with that APS down pipe and small(ish) 2.75 inch exhaust?

APS's web site states that you MUST run a 2.5 inch true dual exhaust with there kit but im not sure why this is??

WILL IT DAMAGE MY MOTOR ???

Thanks for the help guys.

I think you can hit the 500whp goal, but Id at least run 2.5" TD personally. The 3" is REALLY loud.

Some on here run 3" singles and hit over 600whp Id imagine the 2.75" would be sufficient for your goals.

BACK IN THE DAY Julian from MRC was running a 2" TD and making 450ish whp and trapping 120's....

i dont think you'll damage anything. But there's probably a good reason why the manufacturers specify n/a and rubo exhausts. i think if you want optimum performance out of your tt kit you should go with a boost specific exhause system. just find a buyer for the exhaust you have now and it'll cut down the price of your new shiny one.

I think with that exhaust your EGT's will be much higher than running a dual

I would advise moving up to at least their 2.5" exhaust. Especially if you are running a built block and your goal of 500hp (more than 8-9 psi). You do realize that the exhaust note you have now will change considerably with the addition of the turbos?

Thanks for the replys, Zivman yes i understand the note will change due to the muffeling effect of the turbos.

Glex that is what im worried about. I dont want excessive EGT's due to the smaller exhaust dia.

I may have the y-pipe, center section removed and a custom 60mm TD made to fit the 5zigen rear cans?

Hi Tim,


you know why APS put that statement on their website? Because of Giles' issues (and blown engine) and the many engine failures that the old G-Force here in UK had to deal with. At the time G-Force was the UK authorised APS distributor, obviously before going bust, and the reputation of APS suffered through their failures.

Personally for the sake of a true dual exhaust, I wouldn't think twice about swapping (I did, loved my Milltek sound but went HKS which I'm not really digging sound wise, but at least it does its job!)

Or just go to Blueflame and get them to custom make you a nice TD exhaust!

Hi Val, I was thinking about Giles's car when i wrote this.

Im thinking the bule flame custom center section is the way to go. Ill keep my rear cans and get them to fab up the center to mate up with them. Ill be running testpipes 2.5 inch/3.5inch APS DP's if i can get hold of them and a 2.5 inch TD then.

how do 3.5" test pipes mate with a 2.5" exhaust? I didnt even think 3" DP mated with 2.5" exhausts..

The bolt up just fine. On my setup, I just reamed the opening on the 2.5" a bit to give it a little taper

good choice mate!

I run 3in DP's into a custom Y that is 4in diameter....4in diameter pipe into stock muffler that has been moddified (and slightly gutted) to accept the large pipe.

Tom