DUAL STAGE BOOST CONTROLLERS - (Low/Hi Boost)

[pushead]

Recently just installed the Turbosmart dual stage boost controller low boost set to 7psi and hi set to 10psi running stock turbo/intercooler.

While i thought running 7psi on low boost is stock, it seems to be much faster?? now boost comes on at 2,700rpm is this normal? i can feel more pull even on low while on high it goes ballastic.

Anyone else experienced similar?

Cheers All.

[51jay]

Are you complaining ???...or what??

Are you relying on the stock boost gauge or do you have aftermarket

The model Turbosmart you have incorporates a wastegate anti creep gizmo which helps to bring on boost earlier

[bbenny]

yeah with the turbosmart gear i have found that they actualy spike higher than what you set, then drop back to the setting.

so it prob feels faster because its hitting that boost level a little higher then dropping to the setting.

[Jay95R33]

You'll also find that a lot of the bleed valves these days have some sort of anti wastegate creep built into them.

So by just installing one and leaving the boost stock, the boost will come in earlier and a bit harder.

When I was on the dyno, the operator was supprised to see my car had usable boost as low as 1800rpm in 4th gear !!

It's cause the bleed valve I'm using has an adjustable anti wastegate valve, as well as the normal bleed valve (it's a TurboXS HPBC).

J

[bbenny]

How does a bleed valve have an anti wastegate creep mechanism?

i understand how an electronic item can sense pressure imput and change the actuator position. but am unsure how the bleed valve does.

thanks!

ben

[Jay95R33]

Ben,

I'm not 100% clued up on it, but from reading the instructions it looks like it has two valves.

The first is a adjustable pressure valve so it will only pass air (that's funny ) when a certain amount of pressure has been reached. Then the second valve bleeds off air to hold the boost at a certain level.

So..... The way I've got mine set up is that the first valve is set to 10psi, so the first valve won't open until it see's 10psi, then the second valve bleeds off enough air to hold 12psi.

This way the wastegate (in theory) see's no pressure until 10psi - which leads to eariler spoolups

J

[pushead]

hey 51jay using my stock boost guage..will be investing in a aftermarket gauge in the near future. when it creeps up it sits just below the +7 mark on stock gauge. It use to run +3.5 1/2 way. How at roughly 5000rpm and above the car jerks alittle.. I have SAFC but haven't tuned it yet.. is this why the car jerks after 5000rpm + because not enough fuel pumping now that it is boosted to 10psi?

THanks for the feedback ppl. much appreciated.

[51jay]

The +7mark=about 1bar or 14.6psi, the halfway mark about 0.5bar or 7.3psi so 10.0psi would be about 3/4 mark. Boost level will be much easier to regulate with a properly graduated aftermarket guage. Sounds like your hitting up to around 12-13psi,....shouldn't hurt it.....enjoy the power.