MaczPayne

iTrader: (5)

I ported my wastegate on the s5 turbo today, ported as much as I can and left enough for the flapper to seal on. Put it all back together, and went WOT in 2nd, it hit 13-14 psi!!

There is no creep, but I'm just getting these psi's consistently. I have a ebc, but I made that run with just a vac line going from the compressor to the actuator to simulate stock boost.

Mods are:

Microtech lt8s
Racing Beat full exhaust
stock fuel system
tmic
stock turbo



This isn't the finished picture, I ported the left hole alot more than that, but the right hole was opened up considerably.

SureShot

You can file off the back side of the door, so it can open wider.
(Note the yellow line).




Also the outlet path after the the ports can be widened.

MaczPayne

iTrader: (5)

Great advice Bill, I'll get to that as soon as I get a better bit on the dremel. This is the 4th time I've taken that turbo out!!

When are you gonna get another T2?

scrip7

iTrader: (6)

Those are good tips SureShot......so does the actuator have enough travel to open the door that far after it's been filed?

EDIT: Nevermind, I forgot that with the cover plate bolted on, it won't open as far as your pic shows, but anything wider than stock should help with creep I would think.

SureShot

MaczPayne - I'm looking for a bargain RX-8

scrip7 - Yes the actuator has plenty of stroke.
The limitation is when the door lever on the outside hits the casting.
In the 2nd picture, I'm holding the door just about full open.

arghx

iTrader: (3)

See my thread: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/pics-my-vicious-s5-wastegate-port-job-638098/

MaczPayne

iTrader: (5)

I saw your thread, looks good, but it's not something that is within my abilites to do right now. This car is my daily driver. I think I'm gonna take some material off the back of the flapper so it can open more, like sureshot suggested. Hopefully this will be the end all of boost creep for me.

t-too

13-14 in 2nd gear on an s5??? I dont even get THAT bad of creep on my s4 that i ported to the edge of the flapper. maybe there's something wrong with your wastegate acutator...

nik

Since you have a microtech I would say just live with it. Make sure your AFRs are good and have fun

I had this same problem with almost identical setup and a haltech. I got up to 16 psi sometimes when it got cold. The stock fuel pump will handle quite a bit of power, I was running 1600 secondaries tho...

The boost curve should peak around 5000rpm, and then drop off to 7 psi or so by redline (unless you use your boost controller)

MaczPayne

iTrader: (5)

I'd imagine that the ports I got, which were huge, and look almost exactly the same as the ones on fc3spro, would solve my boost creep.

maybe it's the way I routed the wastegate vacuum lines? Is there any way I can correctly simulate the stock setup, using just the wastegate actuator for stock boost?

I know one thing for sure though:

Boost isn't going any higher than 13-14 psi.

Yeah, I've richened up the maps on the microtech, until I solve this problem.

MaczPayne

iTrader: (5)

EDIT: Boost is going up higher!

I don't think creep should be THIS bad with the porting I have done...
so I really think it's my wastegate actuator. What's the stock boost setup? Just run a line directly from the compressor housing to the actuator? If I still creep like this then I'll call the actuator dead.

88rxn/a

iTrader: (6)

what i would do is port the wastegate BELOW the flapper more and leave enough on the top so that it still seals....
in other words..... leave a "lip" on the surface for the door flapper and then port it in a angle as you go deeper in the hole...
hope you get what im trying to say?

nik

If you run a line directly from the compressor housing to the actuator that will get you stock wastegate boost if you don't have creep problems. The stock wastegate design is limited and cannot keep up with full open exhaust and full open intake. Like I said, when the weather got cold I was hitting up to 16 psi. Creep should be worse in the higher gears. It's possible that the actuator diaphragm is damaged or something like that.


For insurance you should always have an overboost fuel cut setup just in case your wastegate fails, say to 16 psi or something like that(that your car would normally never hit).

TehMonkay

iTrader: (-1)

Have you moved the actuator arm to make sure it isnt broken?

Ryu

[quote=SureShot;7076059]You can file off the back side of the door, so it can open wider.
(Note the yellow line).


[/quote=SureShot;7076059]

Where did you find this picture by chance?

This is my turbo and my port job on it from 3 years ago. lol

With the porting I did I never saw any creep/spikes. It held whatever boost I wanted out of it even on the coldest nights in 4th and 5th gears at WOT.

Here's some more shots of where else I ported....

Notice I enlarged the entrance to the WG ports from the inside of the runners as well

SureShot

[QUOTE=Ryu;7079527]I had saved it to add the cut line & reply to your original post.

dregg100

iTrader: (34)

if the actuators are the same (S4 vs S5) i have one that you can have if you just pay shipping. i know it worked just fine, stayed at 7psi and then would creep about .5 psi when it was cold. lmk

Wankel7

I know my turbo is a S4 but the port might be just about as big as yours in surface area...

With a missing flapper it still got 12-14 psi. These wastegates blow. Well for stock they worked just fine. But that isn't the point

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/boost-control-problem-found-melted-flapper-665592/

James

toplessFC3Sman

iTrader: (1)

if you spike to 16 psi, would you really want to cut fuel to control it? wouldnt an ignition retard or cut be safer?

MaczPayne

iTrader: (5)

S5 actuators have a slight bend in the metal line that goes to the wastegate arm.

scrip7

iTrader: (6)

Good point. Not an easy solution in my opinion. If you cut fuel, combustion temps spike, which isn't friendly to apex seals. If you cut or retard spark, exhaust temp spikes, not good for backfires and cats.

nik

I figured that might start an argument. Fuel cut works great on aftermarket EMS. If you cut fuel, combustion stops. Use it, it won't damage your motor unless you are bouncing off it constantly. It helps to set the recovery pressure much lower than the cut pressure so that you have time to react and know exactly what happened.

BTW Ign cut is very violent.

philyII

two questions, one i need a s5 91 turbo II jdm spec mass air flow sensor. and two who could port my waste gate? can i send it to racing beat or mazda trix? I need helpm this is my first turbo rx7

MaczPayne

iTrader: (5)

Well, until I get that actuator fixed, I'm grandma'ing it with extra fuel in the maps.

Oh the wonders of standalone.

7dust

iTrader: (14)

[quote=Ryu;7079527]Thats bullshit. The flapper will hit the backplate first. You want to mill THAT out first.