Finally got a chance to put in the pre-spool valve. I'm having some trouble tuning it though. I can't seem to get the amount of boost before the transition and the amount of boost after the transition the same. Afte a little while of driving around and messing with the pre-spool and dawes device I settled on a 10-8-11 pattern. Is this something that you have to live with when using a deawes device and a pre-spool valve or do I just need some more tuning?

Something wierd happened when I first started tuning. With the pre-spool valve fully closed after about 5000RPM the car would buck because the boost would bounce rapidly bounce between 8 and 10 PSI. It want away affter I started openging the pre-spool. Should this concern me?

 

you should be able to get just as much boost on the first turbo as the second turbo by closing the prespool valve. I'm not sure about the bucking. I don't think I have ever completely closed my valve. It doesn't sound right to me though.

 

Hey Zoom,

As far as the bucking, it seems you were trying to take the second turbo from a deap stop to full operation instantly which, as you noticed, doesnt work too well.

As far as your 10-8-11 pattern, I'm thinking that when you hooked-up your dawes controler you removed and capped the line coming out of the wastegate actuator going to the solenoid, right?

If so, try putting the line back on, but with another needle valve inline between the actuator and the solenoid. Start with it all the way closed (which would actually be similar to having it capped if you think about it) and open it a bit at a time to see if it will bring up your primary boost. It may actually bring up your secondary boost as well, so your might have to re-adjust the dawes, but it should help even the boost out a little bit and maybe even reduce the transition lag. This should work becouse the solenoid will bleed some pressure from the dawes device during primary boost, giving you more primary boost, then when the secondary comes online the solenoid closes-up some making you not boost more durring secondary boost. The reason you are boosting more during secondary boost is because exhaust energy is wasted during prespool, but regained after the transition.

If you did'nt cap off the line, then I'm probably on crack.

 

Then that must be some good stuff your on because I didn't remove the line. j/k

I'd rather not mess with any more valves. This will be fine until I can afford a profec or EVC.

With a boost controller like the profec or EVC do I still need the pre-spool valve?

 

Hey Zoom, remember I had a similar prob. tuning my dawes. Well, I took apart the dawes controller and just made sure everything was lined up and screwed it back together. It's been perfect ever since. The little ball in mine was not perfectly round so it had to be lined up properly. Try that. Good luck.

 

I'll try that. should only take a few minutes.

Thanks

 

Any Luck with that Zoom?

 

oh, havn't done it yet. I'll let you know what happens whne I do.

Since the ball in yours wasnt' perfectly round which direction did you put it in? The rounded part facing away from the spring?

 

Couldn't really say. However, it took at least 3 times of unscrewing it and fooling around with it. I did it the first time to see if that would help with no success. Then again, still nothing. On the 3rd try, instantly got a normal boost pattern and have had it ever since. 12-10-12