I have an S4 TII with a mild streetport (Pineapple template) and a custom intake. The wastegate is ported just below the diameter of the stock flapper door.

Question 1: I'm assuming that I can still expect some boost creep since I didn't weld a larger flapper on the wastegate arm and port the hole larger, but approximately how much creep can I expect?

Question 2: If I were to port the wastegate larger with a larger flapper door, is it possible to achieve stock or near-stock boost levels with the RB exhaust?

Thanks.

 

I have an S5, intake, stock ports, stock turbo, corksport downpipe + test pipe to dual apexi N1. I hit 17 psi once. Then I peed myself + tried not to do that again. Usually I will hit 15 tops then it will crawl down to around 12.

 

I would port your wastegate now. 35mm, no less.

 

with my boost controlle,r stock ports and a revii exhaust.

I get spikes up to ~12-13psi at 5000rpm.

Not looking at the gauge during WOT redline :P

 

Yeah, you will likely get unsafe boost levels with the RB exhaust and a better intake. Port the wastegate, but be careful what metal you use for enlarging the flapper. There are posts on this forum showing erosion of the enlarged flappers over time according to what metal was used. Try a search to see what I mean. You might be better off to pick up an S5 turbocharger, port that and you should be OK. You would not need to enlarge the flapper on an S5.

Don't forget to add a fuel cut defencer no matter what you do with the turbocharger or the wastegate.

 

+1

I've got the same exhaust as well as a custom TID. I upgraded my fuel pump and secondaries but hadn't gotten to adding any kind of boost or fuel control. I have a bad front rotor that is possibly from detonation. I'll know more when I start my rebuild.

 

With your current setup I recommend you run a cat to maintain some restriction in the exhaust.

 

Hey, if you need a fuel cut defender, I have two. PM me.

Also, get some gaskets too. Whenever I've gotten exhaust, if there were gaskets with it they were always toast.

 

If I were to get an S5 turbo and port the wastegate holes, would I be able to hold stock S5 boost with a 3 inch turbo back? or would it still spike a bit?

 

for what it's worth I have small street port, full 3" RB exhaust, JSPEC (unported) S5 turbo, cone filter with stock TID, and I never see past 9psi.

 

Get a rtek to control your fuel so the boost creep wont make it run lean. Also it eliminates the need for a fuel cut defender.

Also, if you get the RB kit new it comes with all the gaskets except the turbo to down pipe.