I'm going to to call BNR in the morning, but I was wondering if it would be possible to upgrade the Stage 3's somehow to support say 525 HP. That's roughly 100HP over the BNR stage 3's maximum output provided you don't use water/meth injection. Probably not, but hypothetically what would it take. I do know that I could get that amount of HP from a single. I've already done that, but now I want to try to do things a different way.

 

Good luck fighting the laws of thermodynamics.

 

That's highly unlikely, even with a functioning A/I system... Even if the turbos could support that, the manifold would in no way play along.

 

Completely forgot about the manifold. I was for whatever reason thinking only about air flow into the engine not out of it.

 

I am not so sure.. i think the limit may be the A/R of the factory twins, not the manifold or the wheel size. I do not see anything horribly restrictive about the manifold. the exhaust ports in the housing are more restrictive. besides the manifold can always be ported

If you look at the size of the factory USDM turbine wheels (46mm inducer, 38mm exducer), the combined wheel size is roughly 20% bigger than a p-trim wheel. it appears you could even mill the turbines housing to accept a wheel up to 45/55 mm exducer/inducer

If you ditched the factory compressor covers, and made a custom y-pipe, i think that would unlock a lot of options as far as compressor wheel size

I am just trying to figure out what cartridges will bolt up to the factory turbine housing. BNR uses GT28, but i am not sure if it requires some milling to fit

 

^^^Yep. Absolutely correct.


Compressor wheel changes on the stock twins may benefit certain applications, but are not necessarily a huge improvement in and of themselves as it is possible to get plenty of airflow volume from wheels of stock size (or within a few mm thereof, such as the BNRs). That being said, a potential benefit might be realized by using a compressor wheels with a significantly larger exducer to increase the maximum pressure ratio. However, as has been correctly pointed out, the exhaust is the principal limiting factor so there is really is no point [until the exhaust is corrected].

As an interesting side note, the compressor wheels from the stock HT-12s were adopted as a popular and effective upgrade for the hybrid turbos used by some of the 600whp Stealth/VR4 guys. I take two things from this point of fact: the stock wheels are pretty good and, of course, one man's trash is another's treasure. Lol.

 

are those 600whp setups with twins? Or just the stock wheels used in another housing-setting

 

Not sure if this answers your question; however,

Hitachi HT-12 compressor wheels were retrofitted into modded Mitsu TD04 housings. They were run as a parallel twin setup on the 3.0 V6 cars (6G72 engine, iirc).

 

rotaries are generally 30% more inefficient then similar sized piston engines, so its not too much of a stretch that factory FD compressor wheels that max out at 350whp make 600whp on the 3000GT

 

Those 3000GT/Stealth cars in question are running near 30 lbs of boost. A 2 rotor has too much back pressure to be capable of reaching those boost levels except through some boost spike maybe.

The turbos in question are the DR650 by Dynamic Racing, or maybe the DR800.