Jump to content
SAU Community

Recommended Posts

Hi guys, i bought a garrett gt3582r as part of a turbo kit for my r33 gtr with the .82 rer housing. The turbo i have comes with the 2.5inch 4 bolt exhuast outlet. I have noticed the gt3582r also comes with the 3 inch v band exhuast outlet. Does this 3 inch vband actually just taper up to 3 inch and offer better performance or is the outlet actually bigger than my turbos outlet?

Edited by asps91
Link to comment
https://www.sau.com.au/forums/topic/440696-gt3582r-exhaust-housing/
Share on other sites

Best turbine performance/efficiency is achieved by the biggest pressure drop across the turbine.

Consider that the distance from turbine blade to the 4 bolt flange face is ~50ish mm, and that measurement would not vary significantly whether you are talking 2.5 or 3 inch outlet. The diameter of the outlet will be the same at the exit of the turbine rotor, so the difference is the rate of expansion available over 50ish mm to where the exhaust dump pipe bolts up. I'd suspect the difference won't be enough to be concerned about in most instances.

Sure the 3 inch outlet version should be a technically better option, but the question is what are you using the car for, what is the target power output (airflow considerations), and what dump pipe design are you using? 4 inch dump is a pretty massive thing that might pose difficulties in fitting all the pipework into available space. 3 or 3.5 inch will perform very well and far easier to fit down past the firewall.

I'd be making sure that your dump uses a shoulder section to give rapid size change from the turbine outlet to whatever dump pipe diameter you choose. That should assist with ensuring best pressure drop across the turbine.

im looking to make close to 400kw on e85 through my rb26. The 4 inch dump fits up perfectly. The cars going in for a tune tommorow and was not sure if i was wasting my time with the turbo i have. I rang GCG turbos to find out about a to4z compressor wheel conversion and they told me not to bother with the 2.5 inch exhuast housing as it just wont make the power but i found it a little hard to beleive as i had a feeling the outlet was the same at the wheel on the 3 inch v-band and the 2.5 4 bolt. This confirms it :)

Asking GCG anything is possibly not the best idea.

You could easily get that power from a 3 inch dump if you are talking about an externally gated setup. I doubt the turbine outlet size is a worry.

The T04R wheel that gets used in those "GT35/T04Z conversions is not exactly a modern wheel and I think a decent billet compressor would do better .

You could have a V band adapter machined up and welded to your housing to create a 3" or larger outlet on the same cone angle as the housing .

A .

Asking GCG anything is possibly not the best idea.

You could easily get that power from a 3 inch dump if you are talking about an externally gated setup. I doubt the turbine outlet size is a worry.

Yea, ive gathered that haha. I am externally gated ;) Cant wait for the tune tommorow!

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

    • Sounds like you've got an interesting adventure ahead here with local support if you have trouble! My guess is that, unboosted, you will be OK with a small upgrade like -9. What will happen is that once the stock ECU sees more airflow than it expects it will add a heap of fuel and pull a heap of timing to be safe because it can't understand how it could get that much air without there being an issue. You will see clouds of black smoke and it won't pull hard through the midrange and top end. So, overall it will be a bit frustrating but should be OK. If you are still nervous set the base timing back 2o through the CAS, but it will be even more sluggish everywhere. As said above through...this is not my guarantee your engine won't be blown into a million pieces, leaving you looking for very hard to find parts A better idea is get a computer with logging ASAP, wire in a wide band O2 sensor and a use remote tuner. I've done multiple cars this way and while it is not as good as a specific tune on a dyno they can get it 90% right. I'd suggest if you can afford an R33 GTR these days you can afford an ECU and tune. And if you can't afford that you sure won't be able to afford the rebuild if it goes bad in the meantime,.  
    • Yeah it would be nice if someone took the time to put that sort of information together, but there are a lot of variations in looms. I think you are making this way hard for yourself if you just want to get it running....sourcing an SR20 with the right wiring will be a billion times easier than matching the RB loom to an S15 chassis. If you do end up going this way, you just need to trace every wire in the loom with a multimeter, 95% of them will go to a location you can confirm at the ECU.....and then post it up for the next person who needs it  
    • Just top it up with water, and keep a general idea of how much you added. It is normal for water to be pushed into and pulled out of the reservoir through the cap, and it should not be more than half full or it will be likely to overflow when hot. Any decent mechanic can do a pressure test of the cooling system to confirm if you have a leak. Keep in mind if it is only leaking a little and when hot it may well evaporate before you see it hit the ground
    • I'd ask the shop what they used and use that. Mixing coolants is sometimes OK, sometimes not, and you have know the details of each coolant to know whether it's a good idea or not.
    • Is it alright to top up with just another green coolant?
×
×
  • Create New...