Jump to content
SAU Community

Would A 2860 -7 Or -9 Benefit From Ported Exhaust Housing?

ZT-R

By ZT-R,
in Engines & Forced Induction

 Share

Recommended Posts

ZT-R Enthusiast

ZT-R

Posted
Posted

Hey guys I talked to ATP turbo and they said they will soon have the GTX2860 as a bolt in for the skyline. I am looking for 450-500whp in my S30 240z. I know that kind of power is typically the GT2860-5 which has 76 .64 a/r turbine. the -7(n1) and -9 (gtss) have 62 trim .64 a/r. Do you think by extrude honing the -7/-9 .64 a/r housing that would have any benefit to the turbo still using the smaller .62 trim wheel? or is the wheel what is keeping this turbine back in power?

Thanks.

lee

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

lol hold up - you know what it'll be. Just a milled housing to suit.

It won't be a proper Garrett one, and will likely mean rubbish performance as we've seen in the past.

Do you think by extrude honing the -7/-9 .64 a/r housing that would have any benefit to the turbo still using the smaller .62 trim wheel? or is the wheel what is keeping this turbine back in power?

The -5 turbine and the -9 turbine are the same size... They both use the 76 trim wheel.

The -7 uses the smaller trim.

All honing will do, is hurt the blistering response - which is why you make that turbo selection in the first place.

ZT-R Enthusiast

ZT-R

Posted
  • Author
Posted

On garret website turbo 2859r (707160-9) shows a 62 trim .64 a/r

the -7 ( (N1) 707160-7) 2860r shows 62 trim .64 a/r

the 2860-5 (707160-5) show a 76 trim .64 a/r

the site is sort of misleading because 2860r are listed as 2860r (1) 2860r (2) 2860r (3). the GTSS is the 2859r so there is 4. i believe the 2860 (3) is essentially a disco potato, its part number is 739548-9 so dont confuse the to -9 turbos.

ZT-R Enthusiast

ZT-R

Posted
  • Author
Posted

Hold up. Any more info on this?

From ATP email today.

"They would be just like the -7 and -10 turbos. You won't get the GTX comp housings with built in anti-surge though and so these will have the skyline style compressor housings with 2 bolt inlet and 2 bolt outlet and no way to integrate the anti-surge machining.

discopotato03 Grand Master

discopotato03

Posted
Posted

Works like this , you have the basic T28 turbine in I think 62 trim and a few turbos got the nice GT28 NS111 turbine in 62 trim as well . It has fewer more open blades than the normal GT28 turbine and in performance apps is a good thing .

I don't have time to look ATM but off the top of my head the GT2854R/GT2859R/GT2860R (707160-7) turbos got the 62T NS111 turbine .

If you see a GT28 based turbo with a 76 trim turbine its the larger trim version of the NS111 like say HKS spec Garrett "GT2530s" get .

Many won't agree but my take on turbine and housing size choices is more about where you want the boost and torque to be than maximum power output up high - in a roadie anyway .

Also I doubt theres room on an RB26 style compressor housings to incorporate port shrouding and make it work with a GTRs inlet plumbing .

You also take the risk of going out on a limb with GTX compressors and plain comp housings .

Its one thing to increase a compressors pumping capacity and another to bank on it not surging . The only way to know is to try and its an expensive exercise if it does surge .

The factry style turbo layout on an RB26 was designed for a purpose and the tight packaging doesn't leave much room to make major alterations . IMO you need to try and get them right the first time and if it was me I'd go conservatively with something known like -9s .

A .

ZT-R Enthusiast

ZT-R

Posted
  • Author
Posted

Not the exhaust manifold porting, the turbine housing for the turbo. I really would like the -9 I think but I havent seen any rwd numbers close to the 500 mark. Thats why im wondering if you ported the housing of the -9 turbo from a .64 A/R to something like a .72 A/R or something (light extrude hone), if it would gain any up top, I know you would probably loose a touch of spool though.

discopotato03 Grand Master

discopotato03

Posted
Posted

Turbines and their housings are always a compromise , where you gain at the top you lose at the bottom . AFAIK Garrett and HKS only made RB26 specific turbine housings in 0.64 A/R and its questionable that porting them would make much difference .

I think the way to make an RB26 wider ranging without increasing its capacity is to give it some form of variable cam timing and play with fuel octane and static CRs . Ideally more cubes but thats expensive to do as well .

A .

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

    • Turbodoc
      Noobie Stagea owner..

      By Turbodoc · Posted

      Hey Dave, welcome aboard! Good to see another soon-to-be Stagea owner here. The wagons are awesome — plenty of space, still got that Skyline DNA, and loads of potential if you’re into mods. Definitely post up pics when you get it, everyone here loves seeing new builds. What model/year are you looking at?
    • GTSBoy
      Duncan's V37.......race car?

      By GTSBoy · Posted

      See if you can thermal epoxy a heatsink or two onto it?
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
×
×
  • Create New...