Jump to content
SAU Community

Recommended Posts

hey guys n maybe gals.... i've recently recieved my new gt35r but have been wondering about whether or not increasing my compressor wheel to 66mm will be of any benifit to me, see the reason i question it is my hp target is between 450hp-500hp at the wheels but im not after anymore than that as engine may not handle the power, i have spoken to the turbo place who i got it from and they believe that the upgrade is not neccassary for the power im after, also increasing to the 66mm compressor wheel would make the turbo abit lazier as it requires more shaft energy to spin it... the ONLY reason i was looking at the upgrade really was to try make the power with not such a hi boost level (25psi or around about) if upsizing comp wheel was going to help me achieve that power at a lower boost level then i would do it, otherwise i will leave turbo as it is....your thoughts>?????

Link to comment
https://www.sau.com.au/forums/topic/182091-upgrading-compressor-wheel/
Share on other sites

i personally would leave it. 450-500rwhp is well within the limits of the gt35r, and you will have a more responsive turbo.

Dont be scared of boost, boost doesnt kill motors, bad tuning and detonation does. Running 30+psi isnt a problem on the gt35r if need be

30psi. :S Not on pump fuel or without water injection.

Boost is a restriction to airflow. You need to get the motor breathing well. If you cant get it out the only way to get more in is by pushing up the boost.

The GT35r is good for up to around 400rwkw.

If the build is well thought out. Around 20psi on pump and no need for WI. If you simply bolt it on with a pair of cams don't expect to push much past 330rwkw. Cams, plenum, exh. manifold are all needed.

GT35R is a 3582R in current speak yeah? so by 66mm are you talking about the inducer size? going from an 82mm wheel up to like a 94mm wheel which has about a 68mm inducer? The thing will be a nugget! That assumes you can fit all the bits together.

You'll get more benefit from fitting a bigger exhaust housing than you will from increasing the compressor side and leaving the exhaust alone.

Or if you are really concerned then do it properly and get a 4088 which at least has a matched compressor and turbine and will flow more than enough for your power target assuming the engine can breath well enough.

GT35R is a 3582R in current speak yeah?

He’s most likely talking about the "GT35/66" or "GT35/84" comp wheel measured from inducer / exducer respectively. Its the wheel from a T04R.

As mentioned, a stock GT35/40 will do your 500rwhp, or 378rwkw. It'll do 400-430 depending on setup.

I think to highflow a GT35r would raise its flow rate to the detriment of spool time, considering you wont be running over 380 odd kw's.

Would give head room for later on spose :D

30psi. :S Not on pump fuel or without water injection.

Boost is a restriction to airflow. You need to get the motor breathing well. If you cant get it out the only way to get more in is by pushing up the boost.

The GT35r is good for up to around 400rwkw.

If the build is well thought out. Around 20psi on pump and no need for WI. If you simply bolt it on with a pair of cams don't expect to push much past 330rwkw. Cams, plenum, exh. manifold are all needed.

i know of a few people running 30psi on the gt35r on pump fuel with no problems, i dont see this as a problem

True boost is a restriction but in his signature "Rb26 crank and rods, Ross forged piston, o-ringed block, 1.6mm copper headgasket, rod bolt kit and head stud kit, reprofiled cams, heavy duty valve springs, head port work, n1 oil pump, hks twin plate clutch, 600x300 front mount cooler...no turbo at the moment........ "

i'd say he's done enough to get the motor breathing well..

i have spoken to the turbo place who i got it from and they believe that the upgrade is not neccassary for the power im after, also increasing to the 66mm compressor wheel would make the turbo abit lazier as it requires more shaft energy to spin it...

The turbo place is correct, no reason to doubt what they are saying

nope, they were ej20's, one is running 37psi

i just think that 30psi, with his mods, with a good tune on pump it would be fine but hey, if he gets it tuned and it starts to ping on ultimate 98 at 30psi with a rich tune and careful timing then i'm obviously wrong

yeah was only seeing wat use thought of it, was an extra 400 bucks to do it.... but yeah i'll run wat i have n change from there, im still using stock cams and intake plenum so tune on that then upgrade cams then tune and see the difference

yeah was only seeing wat use thought of it, was an extra 400 bucks to do it.... but yeah i'll run wat i have n change from there, im still using stock cams and intake plenum so tune on that then upgrade cams then tune and see the difference

Strangely enough I thought I'd provided you with enough info to show it'd be a bit premature to look at going a T66 compressor. In my opinion a .82a/r GT3582R is almost overkill for what you are after... and for prosperities sake if you wanted to go "to the next level" a GT4088R in my opinion would be a far better choice than some frankenstein using a god knows how old design compressor.

isnt that conversion for people who are pushing the 35r to its limit, so they swap the compressor over to the t04z wheel and it allows them to flow abit more...maybe go from 400kws to say 420-430kws or thereabouts. But a super efficient engine would be needed so there is no restriction, as said above i would also think the exhaust side would start causing an issue with back pressure.

Has anyone seen or heard of the results of upgrading the compressor wheel to the to4z item, compared to a GT35???

Im looking to max out my GT35 (.82 turbine) soon, currently makes 510rwhp on 17.5psi, can anyone confirm the upgrade works?

I see, I'd have recognized it if Sweetr33 wasn't calling it a 66mm wheel. The T67 compressor on a GT35 is called by some who do it a GT37R if I remember rightly. That combo DOES provide a bit of an increase on a high flowing/high boost setup. Definitely comes with more lag as well, though I don't know that its very popular. GT4088R definitely sounds like a more sensible way of going about it - though the GT37R is a direct replacement for a GT3582R, nothing has to be changed but the turbo and the tune.

Think its something like a 50whp improvement or something? And yeah its for someone pushing their limits.

I see, I'd have recognized it if Sweetr33 wasn't calling it a 66mm wheel. The T67 compressor on a GT35 is called by some who do it a GT37R if I remember rightly. That combo DOES provide a bit of an increase on a high flowing/high boost setup. Definitely comes with more lag as well, though I don't know that its very popular. GT4088R definitely sounds like a more sensible way of going about it - though the GT37R is a direct replacement for a GT3582R, nothing has to be changed but the turbo and the tune.

Think its something like a 50whp improvement or something? And yeah its for someone pushing their limits.

So you have done the upgrade as a befroe and after on the same engine without other mods? 50rwhp gain?

How much extra lag we talking in RPM to make full boost?

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


  • Similar Content

  • Latest Posts

    • For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
    • Sorry, just assumed that talk of coloured pads meant EBC red/green/yellow/shit stuff. I don't know the DBA pads, but it's a reasonable bet that they will be OK. DBA make good stuff generally. Those 4000 series rotors I linked to are very good. I may well replace the RDA rotors I have with those when required.
    • The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.
    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
×
×
  • Create New...