I've had this boost controller in my truck for almost a year, and it's worked really well so far. Last month I put in my cam (GT 2-3). 3 days later the tranny went out. I just got it back today, and it has a 2600 stall now. I also gutted the cats and wrapped the Y-pipe. Now I'm having trouble with overboosting, by as mch as 3-4 psi. What really concerns me right now is that when it happened I hit 130% IDC and about 14 AFR (and it's a stock motor).

It seems like there's not many tucks using this controller (It came with my used STS kit). I've adusted the solenoid minimum duty and is helped a little. Is it possible my wastegate is too small? (I think it's the standard one that comes with the STS kit) Or are there other settings I need to look at?

TIA

 

what do you have the duty cycle set at? What's the boost setting as well?

 

The boost setting is currently .40, I lowered it from .50. The duty cycle was at 30%, I tried 40% and 50% with no change. Boost would get as high as .75 to .80 with any of these settings.

I haven't driven it much since I got it back, so I'm not completely sure it is staying high or if it just peaking and coming back down. (Spooling too fast for controller to adjust?)

I'kk try to get a shot of the graph up here today.

Thanks

 

Could be your 38mm wastegate if its spiking. Do you have the WG venting in the air or back into the pipe?

 

It's venting to air right now. It was going back into the pipe, but I swapped that months ago.
Is there any piping work that has to be done to change the WG?

Thanks

 

You'll need to make it's feed pipe bigger

 

Thanks guys.
looks like I have more parts to acquire....

 

The other thing that doesn't seem right is that the solenoid never goes past about 60%, even when it's 4psi over sepoint.

 

I finally got around to doing something about this. I bypassed the boost controller solenoid and put a stiffer spring in the wastegate. I was told it is an 8 psi spring (It is painted red). I tried it out tonight and still hit 11 psi and had to play with the throttle to hold it under 8 psi. I have to assume now that the wastegate is too small.

 

I have the red spring in my wastegate and I hit 10 psi with it and have since I installed my kit. I run a pretty strong 9.5 psi now on what is supposed to be a 6 psi spring. When I put my boost control on and turned it up to 10 psi it worked as you would expect it to and at 12 psi as well. I am not sure why the wastegate operates like it does on the spring alone but seems to be fine with the boost control in operation. The boost seems to build a lot faster or with more push with the boost control in operation. It just seems to come on stronger.

I never tried the boost control at less than 10 psi to see if that will smooth out the operation of the wastegate at lower boost pressures but it might be a good experiment in the spring (too cold now...brrrrrr).

If you do change to a larger wastegate I would be interested in your results and what you needed to do to change it out.

If you can get your hands on a mechanical boost control like STS sells I would try a few experiments with it to see if it will cure your erratic boost and over boost problems.