I talked to a gentleman last night that mentioned his wastegate that came with his t-78 kit has stuck both open and closed on his fd. He mentioned he had the piece disassembled and a friend fixed the tolerances. From what I understand he doesn't drive the car on the street.
Is this a common problem and should I go with a more reliable wastegate? My car will see some track time but mostly be a street driven vehicle. What is the wastegate that comes with the kit anyway?

 

I've had the same trouble with the A'PEXi wastegate in my RX6 kit. I need a rebuild now because it stuck shut and I got a huge boost spike. It seems like it would be smart to install a pop-off valve to protect against this failure.

The net wisdom seems to indicate that the HKS Racing wastegate (available for a great price from the RX-7 Store) and the TiAL 46mm wastegate (available from http://www.xtecheng.com/) are the most reliable.

I am not sure which wastegate comes with the T78. I do know that gmonsen is running a TiAL wastegate with his T78 (at least according to the SCC article), but I am not sure what led to that setup for him. Gordon, care to comment?

Rotaries are hard on wastegates because of the extreme exhaust heat. It seems like some wastegates are not designed to deal with this heat.

-Max

 

it'll be a turbonetics wastegate

they are known for sticking open or closed on a rotary

i think it's too much heat for them

 

Are their any fitment issues with using the Tial wastegate along with the T-78 kit? Does it bolt up without modification?
Also, what is the difference between the Tial 46mm and the Tial 46mm high pressure?
Thanks for all the info thus far guys!

 

I concur.&nbsp HKS and Tial seems to be the top brand at this point.

The 46 high-pressure is probably just the (regular) 4 with a higher pressure spring for higher boost pressures.



-Ted

 

another vote for the TIAL, no problems whatosever w/ it, in sharp contrast to the Apex unit i had before..

 

Tial is the best, don't even bother with anything else.

except maybe that 60mm band clamp HKS honey....

woohoo.

Tial will have a 60mm band clamp wastgate soon also.

 

Hey, that's good to hear. I just finished my AVC-R install this weekend, and the TiAL WG will be going in during the rebuild. Thanks for the tips on what works, Gordon.

-Max

 

I'm just doubling my post here since no one has responded yet:
Are their any fitment issues with using the Tial wastegate along with the T-78 kit? Does it bolt up without modification?
Also, what is the difference between the Tial 46mm and the Tial 46mm high pressure?
Thanks for all the info thus far guys!

 

Thanks for the clarification on the regular and high pressure Tial wastegates. Let me add yet another question.......

Should I go with the 46mm or wait on the 60mm band clamp version Magnus mentioned? Would the 60mm be overkill? I'm not too familiar with wastegates so guidance is appreciated.
I'm still curious if the Tial wastegates (both 46 and 60mm) can be swapped in place of the T-78 kit wastegate (whatever wastegate that is) with no modifications?

 

I wouldn't wait on Tial, they're a bit rammed with work

If it comes this year we'll be lucky. you can just change the springs to change the base pressure on the tial gates

 

I got my TiAL in about two weeks, but I am still waiting on a flange.

I don't know for sure, but I would guess that you will need to get the TiAL flanges welded on to your manifold and dump tube. The v-band setup would cetainly need some fitment unless it has v-band adapters that bolt to the manifold, but that seems like it would take up a lot of room.

-Max

 

Yeah I've been having some trouble with my apex unit lately. With my old turbo set-up I had a T-70 with a tial and no problems at all. The apex one is a little flaky. With the tial I never looked at the boost gauge, with the apex one eye is always glued to the gauge.