External Waisgate Problem

[flat out]

G'day

 

my mates car is fitter with an external waist gate, it had a 16 psi spring, but unfortunately rb30e's don't like 16 psi with a stock computer,

 

so he has brought a 6.6? psi spring and we fitted it, it was a fraction smaller in diameter and about 2cm shorter but still well captive when fitted, our problem is we have fitted it but its venting to atmosphere on idle, its not making boost according to the gauge but flutters when you back off

 

we are planing on taking it off and checking every thing tomorrow night but can any one give us any pointers?

 

 

thanks casey

[love ke70]

id be worried too if my "waist gate" was venting when i didnt want it to...

 

just keep adding washers til the waste gate does what you want it to. or cut the 16 pound spring :laff:

[DearmanKE]

by adding washers does that raise the level it vents at or lower it?

[love ke70]

well he said the new spring was 20mm shorter than the old spring, and its now venting to atmosphere, so if you can add 10 mm to it, you'll probably be in a pretty good ballpark of where you wanna be :lolcry:

[DearmanKE]

I'm not sure how thecould be way off, but by spaceing the spring and compressing it more. then wont this make the spring release with less pressure to help it

 

or do they work the other way in which the spring pushes against the pressure, so stiffening the spring would raise the pressure needed to open the gate

 

 

ah yes it must work that way, much more logical once i think about it.

[Taz_Rx]

haha you getting confused cause of what I told you about BOV's on AE86 today?

 

Yes waste gates open into the flow of gas, not pushed open by it. The boost line to a waste gate is what pushes it open. :lolcry:

[ALL-W3T]

+1 for spacing the spring.

[flat out]

surly not simon, surly the waist gate works pretty much the same as a bov?

[Taz_Rx]

Yes it does "work pretty much the same as a BOV", but in a different direction.

VACUUM line on the top of a BOV basically sucks it open when there is post butterfly vacuum.

BOOST line on the top of a wastgate pushes the gate open when desire pressure is reached.

:)

[DearmanKE]

it all makes sense now,

 

i wonder how a wastegate would go instead of a BOV in a blow through setup between the SC and carby... can have that to limit boost, and BOV to stop carby from blowing up.

anyway getting offtopic sorry lol

[Taz_Rx]

Yeah that would work also with a boost line onto the wastegate.

Could have like a screamer pipe that just vents compressed air, if it vents too much, boost will drop and WG will close up again. :)