I am having problems generating boost over 23.5 PSI with the bleed valve and closed loop boost. I could switch to a manual boost controller but I really want the retain the ability to switch maps and boost on the fly. Any suggestions? There are no boost leaks and the Boost Map is maxed out at 500.

 

Swap over to the GM solenoid, 80% duty should get you there.. there's a setup trick to prevent problems and make it plug and play, if I see you some time in the next few days I'll show you how I set mine up.

I can consistently hit 25psi tapering to 22psi at around 70% duty on the GM solenoid.. The bleed system has a very small adjustment window with the ABC..

 

I do want to check out your setup. Maybe Friday night if you are out. How much is it for a GM solenoid and does it bolt up in the stock location without too much fuss?

 

Yep..it was easy to find a place for it, I did actually put it right where the stock one used to be.. I think the solenoid and pigtail for it was about $30 total and the "pins" to make the wiring harness to interface with the stock plug cost under $5 in misc parts to find the right type/size spade connector. I didn't have to make any perminent alteration to the stock BCS wiring to make it work.

 

I'll try to make it out on friday, Nicole is leaving for her florida trip on saturday so I need to see what time she wants to get home friday night.

 

Both of these new products look promising. How do you think that they compare to the GM solenoid? I was also wondering if anyone has been able to maintain high boost with the bleed type system or is it just impossible without a EBC or MBC?

https://www.evolutionm.net/forums/sh...d.php?t=143070

https://www.evolutionm.net/forums/sh...44#post2128244

 

I have been able to.. At least to some extent, unfortunately the amount of pressure that needs to bleed gets greater than the system can bleed given the size of the bleed valve and solenoid's useful range as boost increases, which is why it will work fine until around 20psi, when I started consistently running over 21psi of boost, i switched over to the GM solenoid.

a Forge adjustable actuator is a good start to get you in the range your looking to hit, but I prefer to control it using some sort of solenoid so you have the ability to drop your boost for bad gas or other issues.. so the forge is a good compromise to get you in the low range you want.. 26psi with no option to run lower is kinda scary for their other solution.

The Perrin solenoid looks to be a plunger valve also and therefore for the cost, there's not a huge difference. There is one advantage that the perrin appears to have, and that is it probably won't overheat or burn out if you run it at 100% for any (like when the UTEC is idling and you haven't manually set the boost control and the ECU is controlling it) Unfortunately at twice the price, I don't know that it would make it worthwhile over the GM solenoid since they essentially function the same way. I want to try the Perrin, but just to see if it overheats or not for sure.. Once I figure out the magic number for the resistor on my solenoid, that won't be a problem for me (It never was a real problem unless your running passthrough with all ECU in your map1 boost control map)

I think ultimately it really depends on the amount of control you want. With the bleed system, you have a 3-5psi range of control, the ABC alters the window where it occurs, but once your running boost over a certain level, it seems that neither can bleed enough to be able to prevent the tapering. The GM solenoid has a range from wastegate pressure (0% duty, to 27psi (95% duty) with 60%-70% duty being the most useful range offering 22-25psi on a stock turbo (and similar small turbos)

 

What about using another pressure restrictor at the turbo? I did this and gained 5 psi. Also you could use a male to male hose barb w/ a small hole to bleed out some pressure. I used that before I upgraded to my bigger turbo. That is what Vishnu uses to increase boost on cars that have boost issues.

 

I wonder what Dave Buschur did to the stock solenoid to make it hold better? It had better be very involved for the price that he wants plus a core. Somehow I doubt that it is that complicated. We should disect yours and try to figure it out.

 

Thats basically what the ABC does.. you can open it more than 2 turns, mine was 2.5 turns to get the level I wanted, but it still tapered down.. It was only after I used a different solenoid that it helped alot.

The restrictor idea is better simply because it lowers the pressure through it and not bleeds it, I think anything that "bleeds" pressure will eventually be outflowed and the boost tapers down.

 

The actuator? Well Considering its shape, perhaps a precise "Crushing" of the unit to increase the spring pressure.. Since any other method would require cutting it open, replacing the spring, and rewelding it, which is certainly feasable given their capable of doing that.

 

I would love to hear more about this. Did you use a stock restrictor pill. Did you just put this inline with the other factory restrictor at the turbo? Did this additional restrictor help tappering? Thanks in advance

 

From looking at the Vishnu bleed, it seems to be nonadjustable, but you could probably use it inline with the solenoid in place of the ABC (or in addition to it)

Their documentation basically says to use it to take the place of the solenoid's function. So you have no EBC type control (Whether you need it or not is your own decision) Any of those bleed systems (stock included) tend to spike at peak torque, then settle down to the boost levels its adjusted for, where the bleed systems suffer over a restrictor system is as boost levels go higher, they bleed the same rate of air, so it results in a bit of tapering..

Regardless I think anything you choose will be an improvement, I'm just not too convinced of any mechanical means (besides an MBC) after having tried different bleeders and restrictors over the past year.

I have a little technique using an MBC setup, and continuing to utilize the stock solenoid that I was using for awhile, I hooked up the MBC in the standard method, then I t'ed the pressure side of the MBC to the stock bleeder (this will give you electronic control to raise boost more) The MBC serves as your replacement for the restrictors and you can set your low point, 19psi, 21psi, etc.. You set it by plugging the T fitting to the solenoid and setting your low boost, then you can use the solenoid to raise it above that level.

It works "Marginally" well.. but it will work better than anything other than the GM/Perrin solenoid if you still require EBC features.

 

Well, you got a chance to check out the GM Solenoid, works pretty well in closed loop, not sure its what you want, but at least it gives you an idea of what your options are. The Perrin solenoid will work the same way FWIW..