Jump to content
SAU Community

Anyone Had Stalling Issues Running A 3" Intake On A 4" Turbo?

Harey

By Harey,
in Engines & Forced Induction

 Share

Recommended Posts

Harey Veteran

Harey

Posted
Posted

Hi all,

I went to see a reputable performance joint yesterday about installing a HKS 2835 Pro S kit I have got my hands on. I already have a 3" metal intake to the Z32 afm and then pod.

However, the new turbo has a 4" intake and the tuner is strongly recommending I move the afm to the cooler piping and run a 4" intake due to reversion and potential stalling issues arising when transitioning on/off boost. He said this seems to occur frequently with the larger compressor covers.

I want to keep my 3" metal intake and leave the afm in the factory location. Even though the turbo has a 4" intake its not designed for huge power (280rwkw max) and from what I can see all the other guys running this turbo dont run 4" intakes.

Has anyone had this issue? Or is it minor, the extra price of this work is scaring me off changing to this turbo.

Harey Veteran

Harey

Posted
  • Author
Posted

just run a 4"-3" reducer, install the kit and be happy :)

That was my original plan, I hadnt even heard of anyone else doing that on this turbo. Do you have experience with this configuration or just everyone else's results?

Harey Veteran

Harey

Posted
  • Author
Posted

not a problem even with an atmo bov fitted, but my HKS2835pros has a 3" intake and surge slots

oh wow yours has a 3" intake as well!! Mine has surge slots too but is definitely 4".

Joeyjoe's turbo has a 3" intake as well. I wonder why mine is 4"??

Harey Veteran

Harey

Posted
  • Author
Posted

Think about how much air is going through the turbo on idle...... Next to none. 3" pipe will be fine. They supply a 3 inch pipe and reducer for a reason. Never heard of any issues

What size intake does yours have? Yours is the KAI version right?

femno Grand Master

femno

Posted
Posted

Put the turbo in and see if you have any dramas before deciding to do the extra work?

We always do the 3076s with 3" hard piping and 3-4" reducer at the turbo and never have any problems. The factory arrangement should provide enough air mass not to disturb the AFM if/when the compressor surges.

Different turbos have different flow characteristics though. I say just give it a shot first then tackle the problem IF it arises.

discopotato03 Grand Master

discopotato03

Posted
Posted

From memory there are two versions of the GT Pro S compressor housing and both are port shrouded . The main difference is that one has a 100mm inlet snout and the other is 90mm with a separate machined boss fitted .

If you have the 100mm version I'd say the way to go would be a reasonable section of 100mm bore hose to let the PS'd comp housing do its thing then reduce to 80mm to suit the Z32 meter .

If tuning isn't a problem you could consider fitting the element and electronics into a 90mm AFM body making the difference only 10mm . 90mm is 3.543 inches and I reckon at 1mm over 3.5" you could stretch something to fit .

A .

Harey Veteran

Harey

Posted
  • Author
Posted

reducer on the turbo will be fine. just make sure theres a bend and as much length as possible between the afm and turbo

I have just finished a custom 3" intake (90 deg bend) with the bov return and breather hose fittings for the current turbo and I do get the issue on my current turbo so I am thinking it might get worse.

Harey Veteran

Harey

Posted
  • Author
Posted

Put the turbo in and see if you have any dramas before deciding to do the extra work?

We always do the 3076s with 3" hard piping and 3-4" reducer at the turbo and never have any problems. The factory arrangement should provide enough air mass not to disturb the AFM if/when the compressor surges.

Different turbos have different flow characteristics though. I say just give it a shot first then tackle the problem IF it arises.

Great to hear with your personal experience with the 3076s, thats great info.

That was my third option, 1. keep current turbo, 2. install new turbo and relocate afm, 3. install current turbo with reducer and see how it is

The only cost that I would double up on would be the tuning.

Harey Veteran

Harey

Posted
  • Author
Posted

From memory there are two versions of the GT Pro S compressor housing and both are port shrouded . The main difference is that one has a 100mm inlet snout and the other is 90mm with a separate machined boss fitted .

If you have the 100mm version I'd say the way to go would be a reasonable section of 100mm bore hose to let the PS'd comp housing do its thing then reduce to 80mm to suit the Z32 meter .

If tuning isn't a problem you could consider fitting the element and electronics into a 90mm AFM body making the difference only 10mm . 90mm is 3.543 inches and I reckon at 1mm over 3.5" you could stretch something to fit .

A .

Bugger I have just finished a custom 3" 90 degree bend with the bov return and the breather fitting. Ended up being a fair bit of work.

Interesting idea with the larger AFM body. I was trying to stay on the beaten path though :)

Nengun says the two sizes are 80mm and 100mm:

http://www.nengun.com/hks/turbine-gt2835-pro-s

Although I trust you disco more than nengun!

Do you know the reasoning behind the larger intake? It seems funny for a turbo designed for a standard engine to require such modifications.

Harey Veteran

Harey

Posted
  • Author
Posted

Mine is the KAI yes and has a 3" inlet on the turbo. Not the 4" like the pro s

The pro s kits come with a 4" to 3" reducer and a 3" hard intake pipe

See thats the thing all the people on here that I have spoken to with the Pro S (joeyjoejoe, 75coupe and others) all have the 3" intake.

Are you sure the Pro S kits came with a 4" to 3" reducer at the turbo? As far as I know the Pro S kits have been discontinued and only the KAI is still made.

89CAL Grand Master

89CAL

Posted
Posted

Pro s kits came with a 3" to 4" reducer. The one I saw this reducer was black unlike the rest of the hoses which are purple.

They have a 3" hard pipe which is identical to the one supplie with the KAI kit. No need for the reducer with the KAI as it's 3" turbo housing to 3" pipe

Harey Veteran

Harey

Posted
  • Author
Posted

Dave I will post the id number up when I get home.

89CAL, that is promising! Although I am just trying to point out that not all Pro S turbos have a 4" intake. There are two versions, 80mm and 100mm.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • soviet_merlin
      RH9 R32 GTR Build Thread

      By soviet_merlin · Posted

      Oof, I will forevermore have those shredded gears in mind whenever someone talks about showing mechanical sympathy towards their car. Thanks for the photos, fascinating stuff!
    • Dose Pipe Sutututu
      RH9 R32 GTR Build Thread

      By Dose Pipe Sutututu · Posted

      Curious to see how the SpeedTek stuff holds up
    • OST Micah
      RH9 R32 GTR Build Thread

      By OST Micah · Posted

      The holdups last year were drivetrain related. I had the car out right after getting the bearing issue resolved. Third launch and the car didn't move after releasing the clutch. It had sheared all the engagement teeth off the 1st gear.    Thankfully no other damage was done. I set an aftermarket gear beside an OEM gear and found that the engagement teeth on the OEM gear were much larger and better supported. Looking through my bin of spare transmission gears I found that there are two types of tooth on the OEM first gears - the larger tooth and the smaller tooth. It looks like most aftermarket gearset manufacturers base their design on the smaller tooth. OEM large tooth left - Speedtek, OS Giken, etc or OEM small tooth right Decided to give that larger engagement tooth a try. Pressed the ring off an OEM gear and sent it to a transmission manufacturer here in the States. They did their "faceplating" operation with my synchro ring on the Speedtek gear.   I reassembled it, took it back to the track and promptly destroyed the gear itself.  I'll rebuild this and use it as a spare - thankfully just first gear and the countershaft are damaged beyond repair. Definitely disheartening but my welded on engagement tooth ring held up!  Moved to Speedtek's dog engagement design as the gears appear to be much stronger. So far they have taken much more abuse at the track. Also scored a Stillway lockout from the Netherands for super cheap. It's for some other RB transmission so it took a bit of fabrication to fit but honestly a very easy job. I also had to heavily modify the gates as they were very different.   Then for some reason at the last test and tune a silicon coupler below the throttle blew off and took out the radiator and fan. Thankfully it was in the burnout box and not down track. This car is really beating me up - I still haven't made a pass in it. Ran it through the gears many times on the street but it keeps biting me at the track.  Currently in the process of replacing the radiator and remaking the throttle pipe to remove the coupler and use a cast 90 and a vband. I WILL get this thing down the track...
    • Ozdavroz
      Dumb rich kid tries modding for the first time

      By Ozdavroz · Posted

      Covers most of the above points really. There's a few exceptions but most just see driving as an irritating but necessary task they must complete if they want to get anywhere on time. Also see it as a good time to show their awesome multi-tasking abilities on their mobile and/or doing their makeup.  
    • OST Micah
      RH9 R32 GTR Build Thread

      By OST Micah · Posted

      I don't believe I posted pictures of the second oil pump pickup I added so here they are. Data shows it gets oil pressure up to the relief pressure much earlier in the RPM. Is that important? Not likely... This was just another attempt to fix the bearing issues.   I also heavily opened up the inlet to the pump since it now had to flow oil from two pickups. I believe the diameter increased about 1/8".
×
×
  • Create New...