Recipe for rock steady boost control

[Race Jace]

this is an easy way to have rock solid boost control without having to shell out for those expensive external wastegates. this will work for all houston and stock style wastegates.

when ordering a new turbo, have them leave the waste gate hole unported or small. Then, after running the new turbo for a while it will develope a carbon mark from the puck in the downpipe. now that you have a perfect template of where the puck seats, port the holt to within 1/16" of an inch of this. If you already have a turbo downpipe combo check it to make sure it is as described above.

that is the 1st part.

part 2, use a heavy duty actuator. this available from any of the turbo manufactures, run the line direct from the compressor to the actuator, leaving out the factory solinoid.

part 3, in this line you have run from the compressor to the actuator run a Daws device (Grainger valve)
http://www.dawesdevices.com/boost.html

using the grainger valve and the actuator together, this combo will allows adjustment from 15-30lbs of boost less than 1lb of boost creep.

hope this helps anyone out that is having trouble. I have used this on my own car without any problems for 6 years now.

 

[tim87tr]

Thanks, Jason, good info. I'm buying a car that needs step #3.

 

[bsdlinux]

Sounds like a good plan.

 

[turbo nasty]

Thanx for the info. this is the type feedback that helps us all.

 

[strikeeagle]

Couple of things:

1. How much slop is there in the fit up of the DP to the turbine cover? I have TDHPs and there doesn't seem to be much slop (any slop - and I'm using the supplied allen bolts), but with different DPs I suppose this could change. If so, 1/16" this time might not be 1/16" when the connection is disturbed.

2. How are folks mounting their Grainger valves? I'd really like a better solution that I have now, which is to zip tie it to the vacuum harness.

Thanks.

 

[Mike Licht]

When porting the turbo it is very important to provide a nice radius inside the housing to the wastegate hole. Otherwise the exhaust will just bypass the hole and still creep
Mike Licht

 

[Razor]

This is great but defeats the factory VC bleeder which is used to bring boost down in case of meltdown.

Just an FYI

I use a HD actuator and have the chip pull boost out in the 3rd and 4th to keep things level. If I oopss.. the boost comes down..

My .02.. thx for the link..tho.

 

[tminer]

I've found the boost solenoid to be rock solid. It can only be used to raise boost though, not lower it. I enlarge the wastegate hole a little, but mostly just blend in the backside.

I also read once that for some smaller turbos it is not advisable to maximize the wastegate hole. I am pretty sure that that came from John Craig. It makes sense to me that the optimal size of the hole would vary by combo.

The biggest thing for me has been not to overtighten the wastegate rod. Maybe my actuator is toast, but setting it for more than 12-14 psi with 0% solenoid (or "tuner" style) makes boost control unstable, especially at part throttle.

Tom

 

[Race Jace]

yes there is some slop between the turbo exhaust housing and the mounting holes in the down pipe. What we do is install the downpipe and let the weight of the downpipe hanging off of one side "locate" the flange. then after we run it find out where the puck is sealing it is very easy to duplicate our original install. It does not really matter how you take the slop out of the downpipe flang as long as you do it the same everytime.

When sizing the wastegate hole, the most important thing is to size the hole in relationship to the puck. that is why i described the process like i did instead of calling out a size of hole.

running the wastegate solinoid works fine in stock to moderately modified applications especially to those of you that have the ability to modify your chips to "tailor" in the setup to your particular application. Otherwise we have found that boost control is somewhat eratic especially in higher HP applications. This solinoid however does NOT make boost adjusting idiot proof. The "oops" usually means that serious detonation has occured to the point where timing retard does not correct the situation therefore boost control must be altered by the computer.