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I Cant Hold Boost.

scotty nm35

By scotty nm35,
in Four Door Family & Wagoneers

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scotty nm35 Grand Master

scotty nm35

Posted
Posted

I got the idea today to modify the stock actuator to hold more pressure on the wastegate flap. I want to see if it holds boost better.

A simple spring mounted to the shaft did the trick.

Without spring, 14psi cracked the flap.

With spring, 19-20. Should do the job but can I swap it into the car? Bloody tight down there.

post-63525-1285505108_thumb.jpg

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scotty nm35 Grand Master

scotty nm35

Posted
  • Author
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what metal is the spring made of?

exposing steels to temps over 200°c can alter the internal structure of the metal and will affect the "strength" of the spring

Im sure it will be fine, its a fair way from the exhaust housing and plenty of room for a sheild. Worst case it fails giving me lower boost anyway, as im map sensored it should adjust the mixtures with no issues.

  • 4 weeks later...
Sunkist Grand Master

Sunkist

Posted
Posted
Havent installed it yet, because its a PITA to get down there. Next time the intake is off...

lol i think you should do it on wednesday when i come by. :)

i could help you as well if you like?.. maybe hold a light? im gonna get hold of a resistor tomorrow as well.. give me a call when your free.

scotty nm35 Grand Master

scotty nm35

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lol i think you should do it on wednesday when i come by. :down:

i could help you as well if you like?.. maybe hold a light? im gonna get hold of a resistor tomorrow as well.. give me a call when your free.

Sounds good, I need to fit the replacement rear springs too, I will give you a hand between swigs. :P

Ghetto mods to the torque converter lockup, Niiice... lol.

scotty nm35 Grand Master

scotty nm35

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whats the torque converter mod??? i might need it as mine is fooked :D

Cant tell you all my sercrets. :)

Its just cutting the torque converter lockup solenoid wire at the TCM and running it through a resistor to simulate the solenoid load. (so the trans ecu doesnt fault)

This will disable the lockup completely and allow the cooling circuit to remain on also. (they are both part of the same solenoid) Between that and a shift kit, the box should be fine, providing you have the nissan fluid in there...

ARTZ Grand Master

ARTZ

Posted
Posted
I got the idea today to modify the stock actuator to hold more pressure on the wastegate flap. I want to see if it holds boost better.

A simple spring mounted to the shaft did the trick.

Without spring, 14psi cracked the flap.

With spring, 19-20. Should do the job but can I swap it into the car? Bloody tight down there.

Cant you modify a stronger actuator to fit?

scotty nm35 Grand Master

scotty nm35

Posted
  • Author
Posted
Cant you modify a stronger actuator to fit?

Its a weird one, I would need to make a new shaft and stuff around. I will probably be upgrading engines in 6 months with a GT35 so no point buying a $100 actuator and butchering it to fit, its only a stiffer spring anyway.

This will work out free and easy to do, and if it can hold the boost a bit longer it will be worth the small effort.

scotty nm35 Grand Master

scotty nm35

Posted
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yeah just looking at the pic it is a weird one, also noticed the date, and last i spoke to you i think you were already holding 20psi so guess i should get with the times hey... :)

No, its still not holding, the 300kw run was at 17 psi, I would obviously like to hold 20psi flat line at least with the ethanol, not sure the engine can hold that though, will have to wait and see. :D

zei20l Grand Master

zei20l

Posted
Posted
Cant tell you all my sercrets. :P

Its just cutting the torque converter lockup solenoid wire at the TCM and running it through a resistor to simulate the solenoid load. (so the trans ecu doesnt fault)

This will disable the lockup completely and allow the cooling circuit to remain on also. (they are both part of the same solenoid) Between that and a shift kit, the box should be fine, providing you have the nissan fluid in there...

hmm, this sounds good. I could setup a switch to enable the lockup circuit again for when im highway driving (like going to melbourne for my tune)

zei20l Grand Master

zei20l

Posted
Posted
No, its still not holding, the 300kw run was at 17 psi, I would obviously like to hold 20psi flat line at least with the ethanol, not sure the engine can hold that though, will have to wait and see. :P

are you using the factory boost solenoid?

do you have an EBC? if not, get one!

scotty nm35 Grand Master

scotty nm35

Posted
  • Author
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are you using the factory boost solenoid?

do you have an EBC? if not, get one!

Blitz spec R, should normally do the job but im guessing the flap is blowing open under the pressure in the manifold. We only have a low pressure actuator due to the "low boost" setting at cold start.

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