Rotal

I got my RB exhaust today and I already fell in love with it looks so nice and has rotor symbol on each muffler. This exhaust supposedly can push the boost to 11 psi or even 13 psi. Also my intake is upgraded to mushroom intake so intake should be able to keep up with it. I haven't put it on yet and I have a question. My plans right now are not to put it on till I get FCD then rewire the Fuel pump wiring and get Walboro fuel pump, port the waste gate is this enough to keep my engine safe from detonation?. Do I have to reprogram the ECU? The FC-pro site saying that stock fuel system is good up until 14 psi as long as it is with in factory specs. Is this true? Any suggestions ?

HeffBoost

Here's my two cents. I would say definitely port your WG if it's an S4 turbo, if S5 it's not as big an issue. Although porting the WG is never really a bad thing.

The fuel issue definitely needs to be addressed before you run that exhaust. BTW I'm jealous, people seem to really dig that exhaust.

Just the way I do things, but check the voltage your fuel pump is getting now & rewire only if it needs it. The Walbro should be on the short list for sure.

Not a bad idea to have your injectors serviced for safety unless you know they're good. If I were you I would add some way to control them like an S-AFC or whatnot. You'll need an FCD, but I would be damn careful running even 10# w/o proficient tuning. They say that the stock fuel system can support around 300HP while keeping injector duty-cycles in the saftey zone, under the right fuel pressure conditions.

It's all kind of a crapshoot w/o a way to accurately monitor your air/fuel ratios when modding. You need a wideband (expensive) or dyno tuning (expensive).

Oh, a good, ball & spring manual boost controller is a good cost-effective way to set boost.

Cheers

Rotal

I was planning to service my injectors just forgot to put it on the list. I'm planning to put fuel management on but I just don't have enough money right now (I will get it with in next 6 mos). But still you weren't clear do I have to reprogram ECU or not? (If I will get big tax return I will definitely get FMS)

And about that ball spring manual boost controller(I’m not that good with boost controllers I thought that they actually do something with how turbo works to increase the boost) does it go on the intake and will release excess of boost? I don’t what to go above 8# for start.

Scott 89t2

the only ways to lower boost are to restrict the air going in and out of the engine. (putting stock intake back on, or not putting exhuast on..) or porting the wastegate.

puting the stock airbox back on *might* keep you below 10. but certainly not 8.

boost controllers are for raising only.

Rotal

Thanks again but anyway do i have to reprogram ECU?

gsracer

with full exhuast and intake you are going to be creep close to 1bar on the stock s4 turbo. If you did the TID mod then you could creep up to 11 pounds in...first in really cold weather. lmao it happened to me. That's when I knew it was time to do something. Port the absolute **** out of the wastegate, and then some. I would advise going bigger than the stock flap. Rule of thumb is to have the flap cover at least 75 percent of the hole.

My advice for the mods is to first put on your stock intake. Then when you get the walbro do the re wire, put on fcd, and exhuast. Then see what kind of boost you are getting. If you are happy with it then try putting on the intake and seeing where it takes you too.

I have full intake and exhuast now and only have walbro/fcd for fuel. The most boost I get is about .8bar in third and fourth. A couple pounds of that is simply creep. Keep in mind it's like 40 degrees outside, so if it gets a lot colder than that where you are you might get different results...

dr0x

Make the wastegate hole about 30mm and get an exhaust valve that fits almost perfectly over it. Then weld that onto the wastegate arm.

Ryde _Or_Die

I'd say get a walbro before full exhaust and intake definitely. Its the weakest part of the fuel system. Port the hell out of the wastegate too. Oh, do you have a good boost gauge?

gsracer

Ultimately the best solution for the s4 wastegate woes...but not always neccesary. Yet if you have the time and ability to get this done it's an awesome set up.

nonameo

I need to do this to mine once I get the turbo out. Maybe over spring break.