boost creep - external w/g on stock manifold?
 

I have boost creep, I've had it in the past when I was a n00b. It cost me 1 motor. and I dont want it to cost me another. I just rebuilt this one and Its gotten me a good 6k miles so far.

My car is a 10th AE, my mods are 3in full exhaust, FMIC stock injectors, stock everything else. Now, I'm already putting money together and I'm going to get the Rtek 2.1, and a fuel pump + fpr. But I still want to bring the boost back down to stock. Its creeping up to 13 -/+ psi. I have already swapped out my manifold and hot side of the turbo with the s5 to see if I can control it better. Well, I was wrong, didnt work. Apparently with my setup I'm just putting out too much. So, now I'm trying to retain as much of the stock setup as I can. I dont want to get an aftermarket manifold, then I need to get an after market turbo etc etc. SO, I'm going to add a waste gate to the stock s4 manifold, I already have it going but I really am curious how big of a wastegate I should need for sorta stock application? I was thinking like a 38mm but I started to search and found that people still had creep issues with smaller external wastegates, but thay ALL had many more modifications than I do. I mean I just want to bring it to stock boost and tune it (hence all the good fuel modd stuff I mentioned earlier.)


I'm not going really going for a power maker, more of an efficient runner. I know I have the FMIC and the exhaust but I'm just trying to make these mods help and not hurt me.

Doing this is actually ridiculously cheap since, I have everything I need at the shop I work for. the only thing I have to pay for really the the w/g so I'm thinking of going cheap to test it, that way I have little to lose if it doesnt work. ebay w/g like 50$?

Try not to flame me too much, as I'm sure plenty of guys frown of this.

I have done your exact same setup with a Tial 38mm, worked flawlessly. Never tested in ambient temperatures below 100 F however...

Thanks man I guess thats really what I needed to hear. I'm still considerign the cheap-o w/g to make sure I have good calculations on the fitments. If you have any pictures on what you did post them please.

Anyone have pics? I'd like to see how a WG flange would fit on to the stock manifold, that thing looks like a brick, lol. And the only bad thing about the ebay wastegates is the diaphragm often goes bad resulting in little or no boost (not bad). You might want to do some research on them before you make your decision.

Search for Blue TII's setup. He has a BNR stage 4 with an external WG setup.

just in case you haven't seen, aaroncake has a write-up on how to port the stock waste gate to 38mm?. I'm interested in how to do the external one though, it might be easier.

I tried the ported waste gate before and it didnt help me at all. If this cost me more than the cost of the waste gate I'd consider doing somthing else. I'll post up some pictures when I can. I actually have the hole already in the manifold, its 35mm now. I just need to get the pipe welded on and the flange.

You should definitely get some pictures up on this, I would like to see how well this all fits on the stock manifold.

here's some from friday, this is just the hole. its currently 35mm. but I'm gonna add the pipe about 3-4 inches in length and the the w/g flange. As you can see its pretty lean. But no worries its only been about 1500 miles.. soThis is why I want to fix it now.

http://i488.photobucket.com/albums/r...kid/wgs4_2.jpg
http://i488.photobucket.com/albums/r...zykid/wgs4.jpg

are you going to braze a pipe on to that?

do you have an aftermarket TID? the stock one helps keep the boost down some.

you could always put some sort of restrictor in your exhaust...like a smaller gasket.

yeah, a pretty short one and I might put a small angle on it.


No, I dont. I actually used some parts from a cobalt SS turbo intake and from the equipment I work on. I can take some pictures if you guys want to see it. I didnt think the intake would do that.

I'll have more work done to it if monday is a slow day at work.

But do you guys think that 38mm is big enough for this? I had one plus on that.

enjoy

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if your car is still up and running, try putting the stock TID back on and go for a drive.

I would but I hacked it up to do my buddy a favor and get him home one night when he was in a bind and ripped a 90 coupler off his intercooler pipe.

Thats really nice, how well does it work? I'm gonna finish up mine before I do that much. I like it tho.

https://www.rx7club.com/single-turbo-rx-7s-23/fds-s5-turbos-760865/

Post#8

well, so far so good, I have a dump tube and the pipe to weld, and a spare downpipe to give me an idea where this needs to be and the clearance.. I'l just waiting on the w/g to arrive. for sure it should be done next week. ill post more as I go.

This looks pretty well done. I hope it can control boost for you. What size spring are you going to use? I'd go with a 7psi. And do you have an EBC?

Yep, 7 psi spring. No boost controller. I'm gonna keep stock boost till I get fuel upgrades and Rtek2.1!! :D But here are a few more pics I took with my iphone ta work after I got it welded in place. I ground out the rest of the pipe inside the manifold and I will have some more pics tomorrow of the finished product. I'm excited about it, everything fits perfect and clear's like it was ment to be there lol. I've seen majority of the people putting it on teh turbo. But never like this.

So please give me som feedback! GRAND TOTAL COST SO FAR $75 pipe and w/g.

http://i488.photobucket.com/albums/r...kid/photo7.jpg
http://i488.photobucket.com/albums/r...kid/photo6.jpg
http://i488.photobucket.com/albums/r...kid/photo3.jpg
http://i488.photobucket.com/albums/r...kid/photo2.jpg
http://i488.photobucket.com/albums/r...kid/photo5.jpg
http://i488.photobucket.com/albums/r...kid/photo4.jpg

wait..you're using a cheapo wastegate? :[

I like that. Staying tuned...

.9 bar (13psi) bar the it falls to 6psi after 6k Rpms.

No

Who gives a shit if its an ebay wastegate, if it works it works. Its up to him to decide whether he wants to take the risk or not. Try and provide some productive remarks instead of talking shit.

The setup looks good, be sure to report back with the results.