Ok, i'm sure all of you are tired of wastegate questions all the time, but its hard to find some product specific info on wastegates, and what exactly i'm looking for and if I should even be doing it. Now i'm still contemplating either going with the 2.5" Bonez DP and high flow cat, or an RB DP and presilencer. Taking out everything and putting back in all the stock parts for emissions testing next year is probably going to be too much of a huge pain in the ***, so even though I really want to go with the straight through, i'm going to have to probably do the high flow cat for the purpose of not having to deal with such a huge pain in the *** process.

Anyways, I have a few questions, some regaurding wastegates, and some not, so bear with me here. For starters, I have an A'pexi intake, boost gauge, and FCD for now. If I do go with the Bonez system, is porting the wastegate a must? Also, will porting it up to the stock flapper sides be good enough for this setup? Another thing, would porting the wastegate BEFORE putting any of the exhaust stuff on really effect anything? The reasoning behind this question is that I heard its a pretty cheap and standard practice of turbo shops to port wastegates, so if I got it ported so I didn't have to deal with the whole process, I would have it done before installing the exhaust stuff. Which brings me to my next question which is how much do they usually charge at a turbo or exhaust shop for a ported wastegate?

Lastly, i'm still a bit unsure about the whole fuel pump deal. Will I need an upgraded fuel pump after an A'pexi intake, 2.5" DP and high flow cat? If so, from what i'm hearing I will run rich. If at this point it was necessary to get a new fuel pump, would it be neccessary to get a fuel controller to manage it? I'm asking all of this because I want to be installing parts as the money comes in, so I want to know what parts NEED to go together, like one can't be installed safely without the other one being done, so if anyone could give me tips regaurding that, it would be nice. Thanks again for all the help you guys have been giving this n00b, lol.

- Brian

 

with those mods you will definatly need to port the wastegate, especially if its an S4. you might be able to get away with just rewiring the stock pump, but walbros are cheap, and a good insurance policy

 

S5, but I figured i'd have to do it eventually. My main concerns are what order I can install the stuff in safely, like fuel pump with no fuel controller, new exhaust without fuel pump, and so on.

 

Port PAST the flapper. You will need it. If you port *just* to the flapper it might get stuck and that wouldn't be good.

 

Are you sure you will still build boost properly? If you are to make it bigger then weld a bigger flapper on it and port away...

 

Well, if I have a turbo shop do it for me, i'll talk to them about size and all because they would probably know best, but would it be bad in any way to port it before doing most of the upgrading?

 

No... it shouldn't affect it alot. You are creeping though, so I would imagine not creeping would be more important than a tiny bit of extra lag.

EDIT: okay, ok let me put it this way. I ported mine out a little past the flapper and I was STILL creeping some with full exhaust(not intake) in 2nd sometimes and in 3rd.

 

Only porting to the edge of the stock flap will not eliminate boost creep, and porting past it will result in slower boost response (i.e. more turbo lag). A turbo shop would probably charge US$50-100 to port the wastegate and add a bigger flap. Worth every penny.

 

For my setup, how big of a port are we talking about? I'm going to assume that the turbo shop would know the best config for my setup, but just a general idea. BTW - this is an S5 TII

 

I don't think you'll need to weld a bigger flap on an s5 unless it's a hybrid turbo. You can still port the wastegate holes larger, but that should be plenty flow for your application.

 

i have ported the s4 wastegate to 22mm which is bigger than the door with no problems. i cant tell the difference. and i can still get my blowoff valve to work while idling in neutral.

 

I don't think you would surge enough boost to make the BOV go off in neutral.

 

I had the same question as you did and after much searching & researching I've come to a semi-solid conclusion:

S5 Turbo + 3" turbo back + stock airbox = hints of boost creep
S5 Turbo + 3" turbo back + turbo inlet duct = blown motor

it seems like the turbo inlet duct is a major deciding factor in whether boost creep happens or not

 

I have a s5 TII with rebuilt stock turbo and check my mods in my sig, stock intake by the way. In 3rd 4th and 5th gear pulls I can hit .7 bar = a little over 10psi at WOT. I only do this just until boost builds up to that level and let off immediately. I think it would creep higher if I keep on the throttle. I will be porting my wastegate soon and have my fuel pump on the way. Just keep a light foot.

IMHO if you are going through the trouble to port your wastegate do it once and do it right. Port it as much as you can and have a larger flapper welded on. Porting too much doesnt have a negative effect on boost. You just need to add a boost controller to raise it.

EDIT: I should mention it sucks not being able to go WOT.

 

If you add weld a larger flapper, do you need to add a lip so that the wasegate will sit at the normal hieght?

 

any one have a How-to write up on porting??? I've been looking for one.
thanks

 

Do a search for wastegate porting, then put my member name on the right side and search. I made a few threads all of which have good links and stuff that people gave me.

 

coo, thanks