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Hks 2535 And Skyrocketing Boost!

limpus

By limpus,
in Engines & Forced Induction

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limpus Mentor

limpus

Posted
Posted

Hey fellas, I've got an issue with a hks 2535 which i have just installed on my R32 gtst...everything seems to be in order with no leaks in lines or piping but there seems to be an issue with the boost...it is EXTREMELY laggy and only starts to create positive boost above 3500rpm...which is late even for a rb20...then theres the main problem...after about 5500rpm or so...the boost just skyrockets uncontrollably and doesn't stop rising...i've accidentally hit 1.2 bar on it...the turbo has an adjustable wastegate actuator by the way...can someone shed some light on this please?

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https://www.sau.com.au/forums/topic/159128-hks-2535-and-skyrocketing-boost/
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Gazee Grand Master

Gazee

Posted
Posted

check that the actuator is opening all the way... if it is then make sure the wastegate hole on the back of the turbo is big enough to let the gasses escape... the problem here is that your exh gasses arn't escaping in effect creating more boost.. theres a few threads that people have put up with the same problem just have a look around..

also check that your cat isn't blocked

hope this helps :laugh:

Birnie Veteran

Birnie

Posted
Posted

Haven't left any of your original vacuum tubes unblocked?

I'd check your tubing setup too to be sure.

I installed my turbo (2535) yesterday with the most basic setup..... just the one tube going from the pressure source (nipple off the intake piping) straight to the actuator.

No boost controller at all yet but will soon.

Where are you dude?

If not too far away we can compare setups.

Working in North Sydney today

1400r Veteran

1400r

Posted
Posted

3.5 sounds about right to me my 2530 wasnt coming on much earlier than that

and wind the Actuator out to lower the boost alittle anything under .85 though and you'll get worse boost response

as hks actuators are meant to run on .85 bar

race_snooze Grand Master

race_snooze

Posted
Posted

why are you worried about hitting 1.2bar, thats where my 25/30 sits at on RB25.

As for skyrocketing pretty normal buddy thats where your car is making peak torque and power, as for coming on a bit late well rb20 with that size HKS unit mmmmm. Get it Dynoed.

justin911 Grand Master

justin911

Posted
Posted

nah i think thats about right.. my 2535 on my rb25 starts at about 3000 and realy starts moving by like 35-3700rpm

if you disconnect the wastegate and give her a test real carefuly i think that will show you the fastest it'll boost up so u can compare.. careful thogh cause it'll run at unlimited boost

3500 seems alittle late to me for it to make positive boost but i'll have a look at the rest of the engine again...please keep the suggestions coming fellas...cheers...
limpus Mentor

limpus

Posted
  • Author
Posted
why are you worried about hitting 1.2bar, thats where my 25/30 sits at on RB25.

As for skyrocketing pretty normal buddy thats where your car is making peak torque and power, as for coming on a bit late well rb20 with that size HKS unit mmmmm. Get it Dynoed.

I'm definitely not worried about running 1.2-1.3 bar on that turbo as i plan to do that in the future...i'm worried about it now though because my injectors and afm will be maxed out way before that...i have a remap and the car is tuned to only 165rwkw at the moment...with air fuel mixtures spot on...so if the 2535 is running 1.2 bar...i will defninitely be running lean...and thats even before ignition timing is addressed...so thats why...there no point in dynoing it now as i have yet to get the injectors and z32 on yet...and by skyrocketing i mean it doesn't go to 1.2 and sit there...it keeps going and thats why i got worried...

Gazee Grand Master

Gazee

Posted
Posted

If it keeps going up and up its becasue the exh gasses are not escaping quick enough... start to point the finger at the wastegate, boost controller, turbo and cat.. think about everything that your car needs to let the exhaust gasses escape... if it don't let them escape it wont hold boost.. it'll just keep rising..

i had the same problem and mine turned out to be the wastegate hole on the exh housing of the turbo that needed to be ported out... the hks actuator should only be a 1 bar actuator or less so something is wrong... even try just connecting the vac line from the inlet manifold straight to the wastegate and see how much boost you make.. or the other alternative is to go on the dyno... save you alot of headaches and if it gets dangerously lean they stop the run.. on the road its hard to tell

limpus Mentor

limpus

Posted
  • Author
Posted
If it keeps going up and up its becasue the exh gasses are not escaping quick enough... start to point the finger at the wastegate, boost controller, turbo and cat.. think about everything that your car needs to let the exhaust gasses escape... if it don't let them escape it wont hold boost.. it'll just keep rising..

i had the same problem and mine turned out to be the wastegate hole on the exh housing of the turbo that needed to be ported out... the hks actuator should only be a 1 bar actuator or less so something is wrong... even try just connecting the vac line from the inlet manifold straight to the wastegate and see how much boost you make.. or the other alternative is to go on the dyno... save you alot of headaches and if it gets dangerously lean they stop the run.. on the road its hard to tell

Thanks mate...that kinda suspected that might be the reason...i'll have to pull it off and have a look...cheers...

tigr33 Collaborator

tigr33

Posted
Posted

dont worry man im in the same situation too, it just keeps on spiking, im thinkn just gettin a stock actuator, not this adjustable crap,and just running a boost controller

let me know if u find a solution and if i got one i'll let u know, coz its annoying the hell outa me

RS500 Experienced

RS500

Posted
Posted
Hey fellas, I've got an issue with a hks 2535 which i have just installed on my R32 gtst...everything seems to be in order with no leaks in lines or piping but there seems to be an issue with the boost...it is EXTREMELY laggy and only starts to create positive boost above 3500rpm...which is late even for a rb20...then theres the main problem...after about 5500rpm or so...the boost just skyrockets uncontrollably and doesn't stop rising...i've accidentally hit 1.2 bar on it...the turbo has an adjustable wastegate actuator by the way...can someone shed some light on this please?

do u have a boost controller connected up?

if so, take it off and connect the hose directly from the compressor housing to the actuator.

R31 POWER Mentor

R31 POWER

Posted
Posted

My HKS GT2535 does the same on the RB20det with R32 actuator. It goes 11psi roughly and then creeps to around 15psi with no boost controller.

I thought the acuator was stuffed so tried a RB25det one. 7.5 psi and then creeps up around 12 or something LOL. The turbo is coming off soon so i might grind the f**k out on the waste gate area.

You would think HKS found and rectified this problem, c**ts they are.

WazR32GTSt Grand Master

WazR32GTSt

Posted
Posted

my personal opinion is that if you can afford a HKS 2535 and the required supporting mods, then you can also afford poncams + adjustable cam gears to make it come onto boost a lot earlier. i wouldn't be surprised if you could get it down 500-800rpm based on my own personal experiences

grippy Collaborator

grippy

Posted
Posted

Thats the way they work!! You put a bigger turbo on, you get more lag, more power, more lag, nothing in the world will stop this from happening!! Cams will give you better mid range and bring boost on a little earlier but not by much.

My RB20 runs a HKS2530 and it behaves exactly how it should, boost is on by 4000rpm and rises to 18-20psi.

Goes like a dream. Maybe you were expecting something else. I have never seen a big power turbo make boost below 1000rpm, that is total crap!!!

The HKS internal wastegates are second to none. If you think you can improve on them good luck!!

You must run a boost controller on these turbos and they need to be dyno tuned. Bleed valve is only $50. Come on now and get serious, I cannot believe some of the rubbish that is posted..

limpus Mentor

limpus

Posted
  • Author
Posted
Thats the way they work!! You put a bigger turbo on, you get more lag, more power, more lag, nothing in the world will stop this from happening!! Cams will give you better mid range and bring boost on a little earlier but not by much.

My RB20 runs a HKS2530 and it behaves exactly how it should, boost is on by 4000rpm and rises to 18-20psi.

Goes like a dream. Maybe you were expecting something else. I have never seen a big power turbo make boost below 1000rpm, that is total crap!!!

The HKS internal wastegates are second to none. If you think you can improve on them good luck!!

You must run a boost controller on these turbos and they need to be dyno tuned. Bleed valve is only $50. Come on now and get serious, I cannot believe some of the rubbish that is posted..

Gee...thanks for the technical lesson...i'm a certified mechanic and mechanical engineer and been involved with turbo cars for 4 years...as if i didn't know that a bigger turbo would cause more lag...when i said positive boost at 3500 (NOT 1000rpm) i meant that the boost gauge would read 0.0bar at 3500 or more...now that i know for a fact is abit late...i'm asking for opinions and suggestions here...i don't need to know that i need a boost controller and i need a dyno tune...so before you try to teach me how about you read your own crap first...i don't NEED to run a boost controller if i don't want to...if you say the hks actuators are second to none then they will hold whatever boost level they're meant to hold properly...

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