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Rb20 Actuator Spiking To 16psi

Rekin

By Rekin,
in Engines & Forced Induction

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Rekin Grand Master

Rekin

Posted
Posted

Hey,

When i had my standard rb20 turbo with full exhaust and intercooler, the only boost control i had was the factory rb20 actuator.

With this setup it would leak/spike to about 13psi (from the factory 10psi setting)

This was most likely due to the larger exhaust flow making it creep up to 13psi.

Even using a manual bleed valve, it wasnt able to go below 13psi...

After i put in a hks2530 with the same rb20 actuator, it spikes now to 15psi...

Is there any reason why it isnt holding itself at 10psi?

Plenty of r33 owners put on rb20 actuators on their car's and hold 10psi..mine seem to be all over the place haha.

Im pretty sure the wastegate flap was checked to see if its not getting caught on the dump pipe (as it is a split style)

So yeah, is it normal for it to spike to 15psi on standard actuator? Car will eventually be tuned to 17-18psi using a manual bleed valve.

Thanks

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gotRICE? Veteran

gotRICE?

Posted
Posted (edited)

A bleed valve is going to make it higher.. its bleeding air so the actuator doesnt get the "10psi" doesnt it? So that wont help

Maybe the actuator rod isnt long enough on the HKS turbo? So its only opening half way or not quote fully?

I thought the HKS turbos had their own actuator?

Like these ones

rangerover047ff8.jpg

EDIT: i just re-read it. You have the split dump.

I had that too, and with the RB20 actuator on my RB25 it would creep to 14-15psi.

I know for sure it wasnt catching either as i had it modded so it wouldnt.

It sucks, but put a stock dump pipe on and try it. As soon as i put my OEM dump pipe + HKS front on it dropped to a perfect 10psi all day every day.

SAU will love this! This is my theory...

SlitDumpFail.jpg

What you think?

Edited by gotRICE?
Rekin Grand Master

Rekin

Posted
  • Author
Posted

haha nice drawing.

The HKS2530 was purchased 2nd hand without a hks actuator. The turbo was since then rebuilt and my old rb20 actuator used.

I am using a stainless steel Bos-Importing split front/dump pipe (batmbl)

Thanks

gotRICE? Veteran

gotRICE?

Posted
Posted
haha nice drawing.

The HKS2530 was purchased 2nd hand without a hks actuator. The turbo was since then rebuilt and my old rb20 actuator used.

I am using a stainless steel Bos-Importing split front/dump pipe (batmbl)

Thanks

In that case, ignore my n00bness ;)

But in saying that, i find the best way to figure shit out is buy going backwards if you know what i mean. You add something and get a problem, try eliminate it easily, failing, then maybe try replacing some stock parts you know?

Rekin Grand Master

Rekin

Posted
  • Author
Posted
dont know anything about those dumps are they quality or chinese crap?

They very good quality dumps, SAU has had several groupbuy threads and they cost around $400 mark

http://www.skylinesaustralia.com/forums/Ba...l&hl=batmbl

Does anyone have a split front/dump pipe with an aftermarket turbo? Any problems with spiking with standard actuator. It must be either the dump or the actuator causing it because it would spike to 13psi on my factory turbo..

Cheers for help

limpus Mentor

limpus

Posted
Posted

I would hardly call 13psi spiking first and foremost...

What other mods do you have on the car...any form of intake or exhaust mods like a cooler or 3" exhaust and it will run more that 10psi...let alone with an aftermarket turbo that flows more...

And fyi even with a bleed valve you can't lower boost...only raise it...and with a bleed valve you will still experience a little of this so called "spiking" even if it was running right as its a manual system and it takes time to react and come to a steady state...

Also...check your wastegate flap AGAIN because although it might be opening it might not be opening fully...you said you're pretty sure...unless you did it yourself...never be sure...the flaps on HKS 25xx turbos have been known to foul on the split dumps...

AND FINALLY...hks turbos are more efficient around 1-1.2 bar anyway...so harden up....

Rekin Grand Master

Rekin

Posted
  • Author
Posted
I would hardly call 13psi spiking first and foremost...

What other mods do you have on the car...any form of intake or exhaust mods like a cooler or 3" exhaust and it will run more that 10psi...let alone with an aftermarket turbo that flows more...

And fyi even with a bleed valve you can't lower boost...only raise it...and with a bleed valve you will still experience a little of this so called "spiking" even if it was running right as its a manual system and it takes time to react and come to a steady state...

Also...check your wastegate flap AGAIN because although it might be opening it might not be opening fully...you said you're pretty sure...unless you did it yourself...never be sure...the flaps on HKS 25xx turbos have been known to foul on the split dumps...

AND FINALLY...hks turbos are more efficient around 1-1.2 bar anyway...so harden up....

it was hitting 13psi on the standard rb20 turbo and did not worry about it. As larger exhaust and intercooler would increase it from 10psi

Once the hks2530 went on its hitting 15psi and some cases 16psi on a standard rb20 actuator (with no boost control devices).

Just wanted to clarify if its normal for the standard 10psi actuator to allow up to 16psi..

Madaz Grand Master

Madaz

Posted
Posted

i think its quiet find for standard actuator

im running 18psi with high flow turbo and standard R33 actuator with a AM performance split dump i noticed when i went to a full AM performance exhaust i picked up about 4-5 psi because the exhaust was more free flowing

i run a EBC now and hit 1.3 bar constantly

R31 POWER Mentor

R31 POWER

Posted
Posted

Mine does the same but the only difference is i got the gt2535. Learn to live with it lol. I've changed dumps (screamer/ bellmouth) r33 acuator (went to about 10psi but laggy as hell), hose's, taken out boost controller and still. Just smash 20psi into and enjoy it :)

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