Is there a way to know if wastegate leaks?

[KFT0001]

I've just finished installing my new turbo setup, but it seems to lag awfully bad. I have a 60trim t3/t4 and it won't build boost in any gear unless I have it near WOT. Once the boost builds up, there's no problem holding the boost steady. The manifold I used was a turbonetics T3 manifold with a TiAL wastegate on it. My wastegate is vented back into the exhaust. My question is, is there a way I can find out if my wastegate is leaking exhaust?

 

[pneumo]

When does the turbo reach full boost? Maybe you're just not used to a laggy turbo.

Tial wastegates are high quality, it's rare for them to leak. Maybe look for soot around the exhaust manifold, turbo, wastegate, and O2 housing area to see if exhaust is leaking out somewhere.

You should be able to tell if the Tial is good just by looking at where the wastegate valve touches the seat. There shouldn't be any gaps. Also push in on the valve to see if the spring is strong enough.

 

[Groomz]

Originally posted by KFT0001
I've just finished installing my new turbo setup, but it seems to lag awfully bad. I have a 60trim t3/t4 and it won't build boost in any gear unless I have it near WOT. Once the boost builds up, there's no problem holding the boost steady. The manifold I used was a turbonetics T3 manifold with a TiAL wastegate on it. My wastegate is vented back into the exhaust. My question is, is there a way I can find out if my wastegate is leaking exhaust?

Do the usual stuff. Check vacuum lines for kinks, boost leaks and maybe the throttle cable linkage. Normally they should spool just below 4K, of course depending on setup.

 

[DSMJim]

I have much the same setup as you (50Trim Tial routed back in and turbonetics manifold) and I achieve full boost by 3800-4000 which is perfectably acceptable to me. If your not getting boost until after 5000 then you have a problem.

When you installed your tial gate you put the ring around the valve and it sat on the manifold sort of away with pressure. When you screwed the gate down on the manifold it compressed that ring into the valve inside the gate right? If you forgot that ring then that would be your problem.

Also take some time and port our your turbonetics manifold. They are pretty crappy from the factory and need lots of attention. Here are some pics just to show you. If you didn't port out (and a lot) then that could be a whole lot of your problem as well.

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Before

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After

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Runners.

 

[KFT0001]

My turbo doesn't build full boost until about 5000 rpm. I can hear the leak loudest around the downpipe, but I've doublechecked that the bolts are indeed tight and I still hear the little sputter of exhaust coming out somewhere. I'm fairly certain that there are no vacuum leaks. Most of the hoses were untouched during the install and the ones that were are in good shape. All connections have clamps on them and all the lines have long radiused bends. As for the wastegate, the install went just as you described Jim - the wastegate spring compressed as I tightened down the wg onto the manifold with the valve ring in place. Anyway, I think I need to pull the turbo off again anyway because I've found that my oil feed line fitting is leaking a bit on the turbo side and I'll need to clock the turbo to be able to tighten it down. When I have it off I'll go ahead and make sure everything is sealing up before I put it back on. Would you guys recommend using anything else on the exhaust flanges to seal other than a gasket? I've seen the copper make a gasket in a tube that they sell at auto parts stores. Should I go ahead and put some of that on my flanges as well?

One other thing though, I didn't port my manifold. It'll probably hurt the spool compared to Jim's car but it shouldn't cause a 1k rpm increase in lag I think. Thanks for all the input everybody.