2JZ - shutting off the second turbo (reverse TTC)

[Draven]

Well, seeing as it appears my second turbo is not working, I'm looking for ways to make my car work better until the gt35/40 goes on.

Currently my car loses boost when I hit 4000rpm, as the second turbo is not spooling.

Is it a good thing (ie: will I break my #1 turbo) if I do the TTC, but instead of wiring both gates open I wire them both closed.

I don't know enough about the 2j sequential system to be sure, so I'm wondering if the wastegate will still happily limit the #1 turbo to boosting to its usual 7psi, or will it end up overboosting and killing itself?

[supra1]

There is only one wastegate on the stock setup (on the #2 turbo) so I would think if you wired things shut in the TTC mod rather than open you would have no way to control boost.

[Norbie]

He didn't say anything about wiring the wastegate shut. I think it's fair to say he wouldn't be that stupid.

As for the question, the answer is yes it would work but you run the risk of overspeeding and/or overheating the turbo. If it was me I'd leave it in TTC mode and just accept the car is effectively NA for a while.

[supra1]

I know he didn't say he was going to wire the wastegate shut and yes that would be stupid. Also (and correct me if I am wrong) but the TTC mod does not touch the wastegate. Maybe my understanding is wrong but if you in effect did a reverse TTC and wired both actuators shut wouldn't that mean that no exhaust gas will flow through the second turbo therefore you would not be able to regulate the boost?

This is the question Draven was asking as he is trying to have all the exhaust gas going to the first turbo only as the second is blown.

[Draven]

I had no idea where the wastegate was located.. that was my main problem
I'm going to do as norbie says and leave it in TTC, or posibly just return it to making small boost below 4000rpm (and keep it below 4000rpm)

[cambelt]

Yes dont blow your no 1 turbo , we dont want ceramic pieces inside the motor again, 2nd time may not be so lucky
Dave

[Mr Ed]

Rear turbo might just not be working due to no power to the control circuit. This is what Dennis (2JZR31) and possibly me had wrong.

Just check the plug on the rack of vacuum lines over the turbos and see if one of the pins has +12v.

[Koffee-Black]

Mine was doing the same thing man, but intermittently! Ended up being the throttle cable, needed adjusting! WTF!

[Draven]

I've already manually opened both gates, and it made no difference, so I'm guessing my 2nd turbo is gone.

love the 10 things quote

[Mr Ed]

love the 10 things quote

Ultimate pick up line, Ive used it successfully many times.

[Draven]

for me it's usually just "is *that* your car?!?", then whoever gets stuck in the back bitches about the lack of room

[Mr Ed]

Bet not too many people know where the line about the diamond in your sig comes from.....its a Pink Floyd song supposedly about the original member (vocals) who had too much acid and went into "hiding" for 30 years. Died last week.

[Draven]

yeah
there's a thread in the outhouse dedicated to him, so you may be suprised how many know about him (apart from the obvious old farts hanging around the forum.. love you guys )

[Mr Ed]

yeah
there's a thread in the outhouse dedicated to him, so you may be suprised how many know about him (apart from the obvious old farts hanging around the forum.. love you guys )

Damn, I thought I was clever.

[2JZR31]

Yes dont blow your no 1 turbo , we dont want ceramic pieces inside the motor again, 2nd time may not be so lucky
Dave

Tell me more about the ceramic in the engine? Was it a 2JZ, what happend? I am always paranoid about this. Was in in TTC or SEQ?

As I said in the Supra forum, this is a bad idea, but is easily done by switching the wires to the EGCV and IACV VSVs so they cant operate.