Moejoe

iTrader: (1)

I did some searching and found very little info on the waste gate for the stock twins. I'm having the problem of regulating boost with an electronic boost controller. No matter what the gain is adjusted to. No matter what the boost is set at. I have pulled the hose from the waste gate and capped off the waste gate. I still got boost spike. From what I have read and been told, you should not be able to boost more than 5 to 8 lbs. If there is other info out there, please share it. Has anyone had a stock waste gate go bad?

Mahjik

iTrader: (1)

What are the mods on your car?

crcleofdst

What are your mods? If your running a Downpipe, midpipe, and catback you will need to port your wastegate, or run a restrictor plate.


Read this for more info on wastegate porting:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-port-wastegate-426526/


*edit*

Mahjik beat me to it...

Moejoe

iTrader: (1)

I was hoping you would see this Mahjik. Maxed out stock twins. I bought them from you, actually. 850 primary and 1300 seconds. All supporting mods. Managed by PFC. Running non sequential. All work in the above linked thread has been done. All work on my turbos was done by Rotarded.

RTS3GEN

hook up the stepping motor/boost controller solenoid in the right direction?

Mahjik

iTrader: (1)

Don't think you bought any turbos from me. I've never shipped any out to anyone.

It is possible that you still have too much flow for the stock wastegate. Some people have had issues where even porting doesn't help. In those situations there are one two possibilities:

1. Replace the wastegate door with a larger door so porting can be increased
2. Add restriction into the exhaust path by way of a restriction plate

I would try #2 just to see if they helps the problem out. It's a quick test and not permanent.

RTS3GEN

And it works! Are you getting a spike or creep? I was getting creep something fierce after gasket matching and extrude honing my upper and lower intake manifolds as well as the turbo housings. Was creeping from 7psi to 16psi. Made a stainless restrictor plate with a 2 3/4" opening and works great, keeps boost rock steady and cost me about 8 bucks in parts and time!

Moejoe

iTrader: (1)

I just had to check my PM's from last year. You are correct. They were purchased from another member who has provided a great deal of info to this site. I'm searching the restriction plate for location and pics.

Moejoe

iTrader: (1)

Spike! hard. The thing pulls like a freight train then slams a boost spike.

Do you have pics and details of your set up? Btw, I have all the same work done.

dgeesaman

iTrader: (7)

Inspect the vacuum lines going in each direction from the wastegate and precontrol actuators. Remove each one and inspect for leaks, and trace them all the way up to the boost control solenoids.

Also be sure the actuator rods are still properly fastened to the flapper door arms.

Dave

Moejoe

iTrader: (1)

I should have mentioned that everything from the turbos to the mid pipe was removed and inspected. Everything checked out.

dgeesaman

iTrader: (7)

Even the vacuum lines running from the actuators to the solenoids? Make sure you inspect those closely.

Moejoe

iTrader: (1)

Yes, those have been checked and are new with only 6000 miles on them. But, yes, they have been checked.

dgeesaman

iTrader: (7)

No problem, but reading literally, the only thing between the turbos and midpipe is one downpipe and two gaskets.

I have heard of electric BCs with a bad solenoid or a bad controller unit. Perhaps it's worth installing an alternate setup at this point?

Dave

Moejoe

iTrader: (1)

Dave, that is the next step if this restriction plate is not the key. I have been tip toeing around this build for too long over this.

Thanks for the info and all the responses guys. Keep the ideas coming if you like. I will update when I have more info.

Moejoe

iTrader: (1)

Well today I decided I was going to swap out boost controllers. I ran out of time on the install, however I think it's going to be the right move. I will be out of town for 2 weeks and will get back to it when I return. I decided to do some rewiring while I was in there on the wide band, stereo, and the alarm. I just didn't like how things were when I got in there. So, I might as well get it the way I want it if I'm already messing with it. I'm not a big fan of messing with electronics, but it's about half way done with everything. I have a friend who knows all about that stuff and might be able to finish it for me over the weekend. I will update this thread with the out come. Thanks again for the replies.