I have the diode in my ecu... I know what it does... I wanted to know what u know
my original question is: does the diode only bypasses the TB and does not control the WGs... my answer is YES. I tried it with 2 different wastegates and ran numerous tests... these cars need to run at 1.3 bars on 100 octane.. it a different animal...

 

Stephen - can you answer this and save me the trouble of taking out and opening up my ECU??

 

On all packages gt640 and up a diode should be installed. From what I have heard it is possible for these diodes to blow out and then they need to be replaced. They stick out the a sore thumb if its installed. Open up your ecu and you will see it for sure.

Jags

 

So what is your question exactly?

 

According to MIke(zippy) .. his car is boosting only 1.1 sustained... do u think its because he has / has not the diode that is causing his problem?
he should be at 1.3 bars firm.

my answer is... no/.... the diode has nothing to do with the lack of boost.. it only bypasses the TB so u can boost MORE... so once he sets his WGs correctly... he will be at a nice 1.3 bars..
On a side note, for those who are even more interested... u can bypass the stock frequency have, and hook up a greddy boost controller and have TOTAL contolll over ut boost setting.. without having to go thru what Zippy is about to do... u run low boost on pump gas(1.1 bars lets say) and 1.3 bars on 100 octane... as the wether changes so will ur boost.. so with a EBC like greddy u can adjust to change in atmospheric pressure...
thats how turbo cars are really contollered.. no its only reserved to RICE ROCKETS... ITS A STANDARD IN THE TURBO TUNING BUSINESS..

 

I don't think it could be a diode problem because without it the car would be showing more than 1.3bar

And I agree with you on that one

 

Yes .........

 

I think I'm learning more than I should about these damn cars. My mind needs a waste gate or I might diode. I still want the experts (mark, Todd, cjv, stephen, etc.) to tell me what is best for me...off-line of course.

 

Is there a step by step on how to adjust the wastegates anywhere? Pictures of them in the car would help big time.

 

Here's a pic of the diode, very easy to see when you open the ECU cover.

 

Thanks a lot for the pic. I guess I have to pull the ECU out and see what's inside. There is no point cranking up the waste gates if I don't have the diode.... I would be back to TB shut down again.

Mike

 

If you had the diode then you would be making more boost BUT showing less on your readout.

The fact your only showing 1.1bar makes me think its not a diode problem.

The diode is used when a car is making too much boost, say 1.5bar and teh car is shutting down the TB.

Your situation is that your car is only making 1.1bar. I think something else is going on with your car.

Jags

 

As it turned out, I was too damn lazy to pull the sub box out and rip open the ECU. I wanted to buy a jack anyways. I gave my waste gate actuator nuts 1 turn "tighter" and am now solidly holding 1.2 bar. I've seen 1.3 briefly and had a momentary spike to 1.4 bar. I'm considering giving the nuts another 1/2 turn in an attempt to hold 1.3 bar. (Markski suggested 1.5 turns all in) I tested it out today with the temperature at a brisk 6.0'C. I was wondering if I should wait for some warmer weather and check things out before tightening the waste gates any more?

 

Zippy, Im happy to u its working... are u sure both sides are exact(nuts turned same amount..)
Here is the problem... as temp. change so will ur boost... so my suggestion, if happy with what u have, is to get a boost controller installed... taht way u can adjust boost at ur fingertips. but u have to be responsible and not get carried away with the boost....
best to u,
mark

 

Mike,
You have the diode in there. All the ECUs I have done get them with the GT kit. It doesn't bypass anything rather clamps voltage to the sensor to calm the spikes that occur. These boost spikes are translated to voltage spikes on from the sensor which to the ECU thinks is an error. It simply trims that spike so the ECU can see the signal properly. Don’t forget TB shut down can be caused by many things such as misfires, over limit on another sensor and so on. It is in line to protect the motor from any parameter outside the norm in the system.

George, I don't actually do the diodes like that anymore. I came up with a more stealth way on the other side of the board that looks more factory and less likely to be spotted if peering eyes looked. I say that unless I was pressed with time then I normally still board mount them without the wire.