jturbo

I recently installed a Tial 46mm wastegate on my '87 944 Turbo. I have the wastegate set-up in "single port" mode allowing the Cycling Valve to manage boost level and the KLR to control overboost. I believe that I have all of the hoses set-up correctly, but when I test drove the car my Autometer boost guage read 30+ psi at full throttle???

I have 2 springs (1 small diameter Green Spring, 1 larger diameter Red Spring) inside the wastegate housing. Both of these The combined tension of the two springs are rated to hold 1.1 bar of boost before opening the valve and releasing boost pressure. However, I think the springs are binding inside the wastegate housing and creating a higher spring tension than the actual spring rating. But I am not sure if this is the problem?

Has anyone experienced a similar problem with massive overboost when setting up their wastegate? :cryin

jturbo

Help!!!!

TRACKIN951

umm, the cycling valve is obviously not working properly. Something cant be hooked up properly is my guess. Try searching on here for a diagram of the routing.

reno808

How did you connect the WG? you might of installed it backwards

jturbo

I did notice that when I installed the wastegate springs (One fits inside of the other for a net effect of 1.1bar) that seemed to be binding? Do you think this is possible?

jturbo

Reno,

I have the boost hose, which was installed on the top barb of the factory wastegate, installed on the side barb of the TIAL46mm wastegate. The TIAL46mm side barb is vented to the atmosphere. All other boost and vaccum lines are set-up identical to factory?

Please advise.

reno808

Sorry for the late response. The side of the wastegate is boost that one should go to the CV. Just how the stock wastegate would go. The top is vac that one your leave alone since your using the CV however i strongly recommend that you upgrade to a MBC. My question was referring to which way did you physically install the wastegate? You might of installed it backwards.

Porschefile

+1 That's the correct way to hook it up, side port to the boost source and top vented. Also, even if you don't want to run a boost controller, you can simply eliminate the cycling valve and run the wastegate spring pressure alone. Ouch, 30psi? Did your motor sound like it was grinding up rocks? Bye bye ring lands! j/k

Oh, just FYI because I think some people might get a bit confused about this (sorry if it's re-stating the obvious). It is physically impossible to run less boost than the wg spring pressure (under WOT). There really isn't any point at all in keeping the cycling valve in the system as it can no longer physically default to the stock .2bar safety mode. Even if your KLR senses knock, the cycling valve will try to react but, the wg is going to continue to push 1.1bar assuming a WOT condition. The only way the stock setup is able to accomplish this is because the stock wg has a .2bar spring. If you were to run a lighter spring, theoretically it should be able to perform the same type of boost protection like stock, though I don't think anyone ever really does that. Also, the springs binding is not a problem I've ever heard of from user of Tial's, and I've never had that problem myself. I'd say it's about 99% unlikely that that would ever happen. Sounds like your wg isn't receiving the proper boost signal and is remaining shut because of it.

jturbo

Reno,

That is a good point about the wastegate setup being installed incorrectly. I believe the valve opens to the exhaust dump pipe and the opening on the side of the wastegate is connected indirecly to the exhuast manifold.



This is really frustrating. This install should not be this hard?

jturbo

Should the bottom (valve) of the wastegate be installed on the "J" pipe and the side installed on the exhaust "dump pipe"?

reno808

correct. When installed it should like it was installed backwards. There are some pics here. do a search. I think this should help

jturbo

Thanks for the help. This problem was driving me crazy.

Do you think that there was any internal engine damage realized from the increased boost spikes? (30psi) I believe I only experienced these boost spiklevels 4 or 5 times before I looked at the Autometer boost guage and realized that something was seriously wrong.

ibkevin

Ahhh, the old Danno pic.

I just went through the Tial spring debate myself and learned a lot thanks to listers and the data logger.

Mechanical boost control is fine, but has NO over boost protection, and at 1.1bar what is your A/F ratio doing?

jturbo

Kevin,

I do not have a Air / Fuel Guage, but I believe my Autothority MAF sensor / Chips and Banjo Bolt - Jetted for 1.1bar are set up to fuel at 1.1bar boost pressure (According to David at Powerhaus - Where I purchased the set-up)

Do you think that I may run lean under this set-up?

I have not gotten a chance to check the spark plugs to see what they look like. ie: burnt / chalky white usually is a good sign that the engine is running lean.

How else might I be able to check the air / fuel mixture? Aside from an air / fuel guage.

ibkevin

Wideband is the only way, seems expensive, but now I know at exactly at what conditions I overdrive my A/F ratio.

It's life in the boooost lane!