external wastegate question

[dsmless]

I have a 38mm wastegate (turbonetics), it have a 15psi spring, my problem is that I cant get any higher boost, even witht he manual boost controller screwed in all the way, I took the vacumn line off the wastegate and still only goes to like 17 psi, I can hear the wastegate opening under full throttle, so is my diapraghm torn or was going on, should i change springs, or just get another wastegate (I have a tial knock off I could try maybe) well, let me know guys

 

[Jesh]

hmmm... i'm not a pro or anything here, but i think your on the right track with the torn boot, cuz if you take the vacuum line off and it still only goes to 17psi somethings wrong. it should just keep making boost till it can't make anymore, or your car blows up, whichever comes first

 

[TylerAdamson]

Quoting dsmless:
I have a 38mm wastegate (turbonetics), it have a 15psi spring, my problem is that I cant get any higher boost, even witht he manual boost controller screwed in all the way, I took the vacumn line off the wastegate and still only goes to like 17 psi, I can hear the wastegate opening under full throttle, so is my diapraghm torn or was going on, should i change springs, or just get another wastegate (I have a tial knock off I could try maybe) well, let me know guys



You have a 15lb spring in there and when you take a boost controller off of it you're running wastegate pressure, which is 15lbs. Are you sure you have your boost controller installed correctly?

 

[dsmless]

yes its installed correctly also installed it straight manifold pressure and it was dead on 15 lbs open, but the thing that throws me off is why it opens without vacumn to it, so I will swap the wastegae and see what happens, in any case were can i get a new diaphram or what material is it made of?

 

[TylerAdamson]

It opens because that's all that particular spring can handle. You're simply blowing the wastegate open.

As for repair, I'm not sure how serviceable those wastegates are. I know you can buy TiAL parts at any TiAL dealer.

 

[turbowop]

Um, no. My Tial44 has a 15lb spring in it yet I'm able to run 30psi using a boost controller. It would be even higher without vacuum connected. 15lb means that's what it opens at when the vacuum nipple sees 15lbs, not when the wastegate itself sees 15lbs.

 

[Jesh]

if you go from a internal wg to external wg you eliminate boost creep right?

 

[prove_it]

^Yes, unless your running a huge turbo and a small wastegate.

Turbowop is right about the opening pressure on the spring rating. It takes 15lbs of boost at the nipple to open the wastegate, not 15 lbs of exhaust pressure. Springs are rated basically as a guide to the minimum amount of boost you could ever run on a properly running set-up. Disconnecting a wastegate should run boost up until the turbo maxs out. If you disconnected the wastegate and still only see 17 lbs then I would bet you have a crack, hole, poorly seated wastegate valve, or some kind of leak around the wastegate, or possibly a dead turbo.

Pull the WG off and do an inspection. I'm sure you'll see a problem.

 

[dsmless]

Well I swaped the wastegate out with one I have laying around, and tore into the one I took off, well no tore diaphramn and all parts look good, so took 96 for a spin and its the same probem, I have a good buddy that just opened up his shop, pretty cool to see 2 evos one on the lift and the vr4 in there, did a leak check and the BOV is toast, leaks a 5 psi, and even more at 10, not good, looks like its off to a synapse, he gets the homie hookup price so its okay, well thanks let you know what happens.....

 

[Boostdtalon]

Im actually about to order there 40mm for my car. I did some R&D for them on my Talon and the Evo. Got a couple of there products on the Evo.

 

[dsmless]

yeah really good product, he gave me a ride in a built customers 2 gsx and the sound is very loud and its setup for recirc, so I will be splurgin on this will post a pick of the install

 

[Boostdtalon]

I had there BOV's recirced on both the evo and the talon. couldn't hear it with my stock setup, but with hard piping it was very noticible.

 

I was gonna mention boost leak check. first thing to check always. pain in the arse