Help with surge under part throttle

[TurboBob]

perhaps, but as far as I remember, its also the only turbo car not available with a manual transmission.

Bob

 

[1952ray]

He's sorta right.

whats happening (in my opinion) with this part throttle surge is: High pressure and low flow.

The wastegate is set for ~ 20+ psi, and the turbo is creating 20 psi in the intercooler, but the driver has backed out of the throttle to limit manifold pressure.
So the turbo is running full boost but the flow is being restricted. This puts the turbo in the surge region of the compressor map.

2 solutions: dampen the surging (his resonator, a tornado, stock MAF, stock intercooler, whatever), or reduce the wastegate setting at less than WOT (there are a couple ways to do this).

__discuss__ ....

Bob

Could you explain a little more (wastegate setting at less that WOT) a couple of ways to do this ?

Thanks

 

[TTA976]

If you set the WG # to less than half of wot and use the boost controller from there to increase and put BOV right before the TB the surging would be elimated.

Joe

 

[TurboBuRick]

A solenoid style closed loop boost control that would allow for full boost to the wg under a set tps.

Thoughts?

Rick

 

[Tom Tom Turbo]

I've thought of the BOV route, just never wanted to mess with plumbing it (and never saw a need for it) until now


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[aminga]

A solenoid style closed loop boost control that w
Thoughts?

Rick

ISAC can do this.

 

[TurboBob]

ISAC can do this.

SD2 can do it also.

the wastegate programming in the chips can be set up to do it also.

the aftermarket ECU's can be set up (most of them) for this.

very few aftermarket boost controllers have a TPS input for stuff like this.

Bob

 

[1952ray]

SD2 can do it also.

the wastegate programming in the chips can be set up to do it also.

the aftermarket ECU's can be set up (most of them) for this.

very few aftermarket boost controllers have a TPS input for stuff like this.

Bob

Your chip and TT chip (wastegate programming )

 

[TurboBob]

pretty much all chips. the stock software has a wastegate vs tps table, but nobody really uses it.

actually I think I removed it from most of my recent chips to save space, I would need to look.

as far as TT, you would need to ask Eric.

Bob

 

[TurboBuRick]

ISAC can do this.

My Tpro does it and a whole lot more.

Rick

 

[TurboBob]

 

[1952ray]

pretty much all chips. the stock software has a wastegate vs tps table, but nobody really uses it.

actually I think I removed it from most of my recent chips to save space, I would need to look.

as far as TT, you would need to ask Eric.

Bob

Thank you Bob

 

[TurboBuRick]

A bov will not help with part throttle surge. That only works when the throttle is closed.

Rick

 

[TTA976]

Its the wastegate preload is the issue. Bov helps keep your compressor wheel connected to your turbine when you let off the gas or let the boost drop a bit.

If you hold the throttle at the same through the cruise the load starts drops as the rpm increases. Which is very similar to letting off the gas and surging.

Joe

 

[1952ray]

What a shame, there does not seem to be a clear cut answer to this problem. Lots of posts, do this do that, go broke doing all of this. Use the Tpro and get a smiley face from Bob, whatever that means. Use a BOV, ok what's that going to do if your not using SD2. Go with the ISCA, ok every member thinks the rest of us fell out of the womb knowing what that means. There have been lots of posts about this issue, however there does not seem to be a overall fix. Even the big dogs on this site don't have a good answer.

 

[TTA976]

Lower the wastegate preload the better street manners it will have. Rule of thumb is normally a mbc will double your cracking pressure. So if you want to run 26 psi then 14 psi spring will get you there. But the low cracking pressure will allow the wastegate to open during your part throttle pull .

If it stays closed then it's running tits out so you reach the point of maximum ve your motor can handle you get surge.

Joe

 

[we4Mateo]

What a shame, there does not seem to be a clear cut answer to this problem. Lots of posts, do this do that, go broke doing all of this. Use the Tpro and get a smiley face from Bob, whatever that means. Use a BOV, ok what's that going to do if your not using SD2. Go with the ISCA, ok every member thinks the rest of us fell out of the womb knowing what that means. There have been lots of posts about this issue, however there does not seem to be a overall fix. Ever the big dogs on this site don't have a good answer.

More than one way to skin a cat: bottom line, either the engine needs to eat more or the turbo needs to slow down during the times that surge is experienced. How you do that is what we are discussing and I refer back to the cat thing.

 

[1952ray]

More than one way to skin a cat: bottom line, either the engine needs to eat more or the turbo needs to slow down during the times that surge is experienced. How you do that is what we are discussing and I refer back to the cat thing.

Ok, that's cool. Just want one cat skinning, which is ???

 

[SCOOBY DOO]

WFO is how I deal with it.

 

[Pronto]

Try that resonator box thingie. You could even make one up.