RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Single Turbo RX-7's (https://www.rx7club.com/single-turbo-rx-7s-23/)
-   -   Wastegate issues. (https://www.rx7club.com/single-turbo-rx-7s-23/wastegate-issues-883955/)

FDrifting7 01-24-10 12:24 AM

Wastegate issues.
 
I have a 44mm tial wastegate, and I cant get it to hold spring pressure.

I have the pressure source coming straight out of the compressor housing, directly to the side port of the WG. The top port i just left open.

The boost isnt even near spring pressure... it skyrockets up into 17-20 area. I checked my spring and it's the green 11lb one.

The WG is brand new from a-spec. Could it be stuck? Could the diaphram be bad?

I can't come up with any conclusions. Suggestions would be nice. thanks

7passu 01-24-10 12:52 AM

You can use a air blower hooked to that vacume line running to the gate to see if it opens under pressure. Turn it down to like 50 psi if you can ans just bump the blower a lil and see/listen for air leaks or to hear if it clicks open or not....

NoPistons! 01-24-10 04:34 AM

Take the wastegate apart and put some high temp anti seize on the valve shaft and see if that makes a difference. It could very well be sticking.
Definately pressure test it OFF the car. It should open at 11 psi if you have an 11psi spring.

The only other thing i can think of is poor wastegate routing on your manifold causing it to creep up like that OR the spring is marked incorrectly which is unlikely but should be looked into regardless.

rxspeed7 01-24-10 10:00 AM

yeah sucker i told you to come over yesterday so we could get it off and look at it

zeaone 01-24-10 10:25 AM

I would hook up vac from upper intake after tb

BigTurbo74 01-24-10 11:12 AM


Originally Posted by zeaone (Post 9758454)
I would hook up vac from upper intake after tb

That will make it worse. It is best to come straight off the compressor housing.

What is your turbo setup? If you have a heavily ported engine and a big turbo the w/g must be placed correctly. Its just happening in the higher rpms right?

rxspeed7 01-24-10 04:39 PM

its basically a 500r setup with the short runner a spec manifold. the source is right from the comp housing as it should be. its a stock port rew motor with the a spec kit on it. when we get it off we'll let you know the findings.i believe its just jammed, so when we get it apart im going to lube the valve with antiseize and make sure theres no obvious issues

rx72c 01-24-10 04:57 PM

Is the manifold designed with such a small gate in mind?

FDrifting7 01-24-10 05:30 PM

i bought it from a spec and I'm guessing the 44mm wg should be big enough for my setup. Its overboosting as soon as the turbo can make boost from like 3500-4000 and up.

Zack, we need to get a pressure tester and hook it up. Ill be over asap though.

Could a brand new wg just stick if it sat around for a while?

rxspeed7 01-24-10 08:34 PM

yep but the only way to tell if it opens with that is to take it off. it should only take like 20 mins to do

psiturbo 01-24-10 09:07 PM

Use like a bike pump and connect it to the line to see if it opens up. It could be defective.

rxspeed7 01-24-10 09:13 PM

thats the plan

FDrifting7 01-25-10 05:37 PM

okay... so I took the WG off and pressure tested it with an air tank.

the valve SLIGHTLY opens at 17 psi.

and when i put it down to 15psi, it didnt move at all. But i could hear some air seeping around where the piston shaft goes into the upper part of the WG. Is that normal?

So I'm guessing I need a new spring. Although the spring is green and should be .8 bar, or around 11 psi.

Maybe if i go with a 5lb spring i can actually hold steady boost pressure. Where can i get a tial 44mm 5lb spring for a decent price?

Has anyone ran into this before?

FDrifting7 01-25-10 06:11 PM

I just ordered the small red spring that should open at 4.35 psi.

I got it second day air shipped... so i will let you know what happens when it get here!

Carpenter 01-25-10 09:16 PM

At what point (PSI), did it open up? 18?

FDrifting7 01-26-10 01:43 PM

yes. It started to slightly open around 17. and when I gave it 20 it open decently quick. but i want it to slightly open at 10! lol

PandazRx-7 01-27-10 05:11 PM

If I'm not mistaken, you need pressure both on the diaphragm and the valve (exhaust) to open correctly. I also had creep issues with my long runner 500R kit...ended up going down to a 10psi spring to hold minimum 13psi.

Pressure tested the Tial and was told the slight leak around the shaft is normal and would be minimal after expanding from the heat. Let us know what happens.

DriftDreamzSS 01-27-10 05:21 PM

ive seen the same problems with a tial v44. Im now running a 7psi spring to hold 10-11 psi on a 35r/hks tubular manifold with a high flow cat, straight pipe its worse.

moehler 01-27-10 05:35 PM


Originally Posted by FDrifting7 (Post 9761481)
But i could hear some air seeping around where the piston shaft goes into the upper part of the WG. Is that normal?

As long as the air is coming out the inside of that shaft (around the valve stem) then it's normal. If the air is coming out from outside the shaft (where the spring housing meets the WG body) then its not normal. Mine did that - turned out to be a bad O-ring under the nut that holds the body to the housing. I bought a replacement from McCaster Carr. I also used a copper silicon sealent just to make sure it wasn't ever going to leak again. If you remove the nut make sure to use a high temp threadlock sealent.

FDrifting7 01-27-10 11:21 PM

Yah it just slightly leaked around the valve shaft.

WaachBack 01-28-10 11:19 AM


Originally Posted by DriftDreamzSS (Post 9766041)
ive seen the same problems with a tial v44. Im now running a 7psi spring to hold 10-11 psi on a 35r/hks tubular manifold with a high flow cat, straight pipe its worse.

Same here, I have a 13lb spring and it holds about 16-17psi.

FDrifting7 02-01-10 06:51 PM

okay so i installed the 5 lb spring today, and the car now holds around 8lbs steady.

I finally have controllable boost!:nod:


All times are GMT -5. The time now is 02:14 PM.


© 2024 MH Sub I, LLC dba Internet Brands