I am in the process of building a hybrid turbo and I ordered what I thought was a TO4B H-trim wheel. The exducer and inducer measurements are correct but it has 6 blades like a TO4E wheel. Is this correct or is this a different wheel. Here are a few pics.

 

So you are measuring approximately 58.5mm/70mm? I don't think its going to make 2 ***** of difference and from what I have read online the lower blade count wheels flow more.

I have the 'inferior' 8/16 blade V-trim and it is still capable of spinning semi slicks at 180kph/110mph.

It makes so big a spread of power I had to change to 3.636 diff gears to drop wheel torque to get traction in 2nd and 3rd gear. Before I made the gearing taller 3rd gear was all wheelspin. Pretty powerful if you can't use full throttle until 140kph/87mph.

 

how much boost were you running with that setup? The wheel I am swapping this in place of is the v trim one, but I thought this would be tons better. If I can make decent power with the v-trim wheel I would rather not spend the cash getting my housing machined to fit the wheel I posted.

 

you should be able to get 300 whp out of that v trim i did

 

From the BNR dynos I've seen, it's not a huge difference between a V-trim and an H-trim. It seems like 10-20 whp at most. The compressor maps are very very similar: http://fc3spro.com/TECH/TURBO/compmap.html

Solareon made 323 whp with a BNR stg. 2 (H-trim wheel) at something like 14 psi (where peak HP was calculated): https://www.rx7club.com/time-slips-dyno-128/bnr-stg-2-323-hp-884507/.

I also found this listed of Garrett part numbers/wheel sizes if it helps. I guess this shows the difference between a V1 and V2-trim: blade count.

8 Blade T04B:
409179-0021, 70x48.36, 48 trim, S trim
409179-0022, 70x49.50, 50 trim
409179-0023, 70x51.61, 54 trim
409179-0024, 70x54.00, 60 trim
409179-0025, 70x55.37, 63 trim, V trim
6 blade T04B
409826-0006, 70x48.35, 48 trim
409826-0012, 70x52.85, 57 trim
409826-0014, 70x55.30, 62 trim
409826-0015, 70x58.40, 70 trim, H trim

 

ok, I see. I think im just going to keep the smaller wheel and spend money else where like injectors lol. Thanks for all the info.

 

To compare apples.

The V-trim will be operating at 55% efficiency around full flow at higher boost settings. The H-trim will be around 60% efficiency where th V-trim was 55.

At that operating point the difference in the air in the intercooler pipe before it has gone through the intercooler is going to be something like 15degC.

Say it was 135degC with the H-trim, the V-trim air might be 150degC. Throw it through the intercooler, which if its nice and big and road speed is up, which it should be if you are making 300+rwhp and you've got a 1degC difference between the two turbos. That is the beauty of intercooling bugger all power difference, not even 1hp

A nice big well flowing intercooler is going to do way more. If you design the intercooler for less than 0.5psi pressure drop at full flow and 85% efficiency you'll do something good.

 

Make sure you build your hybrid turbo using series 5 turbine housing. From the results I have seen it does not make a big power difference if you weld up the internal wastegate and use one or two externals or if you use the internal.

I've got some sheets of pretty respectable power figures using the internal gate and just grinding out the back of the standard turbos backing cover, and then having your fabricator hammer a piece of 2.75 or 3" pipe to and oval shape and welded on.

For fueling on pump you should budget about 900cc per rotor thats operating on 85% duty and having enough fuel to do 10.5:1 mixtures which is leaving some room.

If you wish to run on E85 (7:1 mixtures) you should budget about 1300cc per rotor. In a practical sense I would use

Pump fuel: S5 turbo primaries 550cc and then Bosch EV-1 842s (1600cc) secondaries
E85: S5 turbo primaries with ID2000 secondaries.

Make sure you consult someone who has experience with your ECU. My ecu can do a silky smooth transistion between 550cc and 1600cc. I set my ECU to make the transition when my duty cycle exceeds 80 or 85%

You will also need electronic boost with RPM input to make the most of it. A walbro 255 fuel pump should cut it using pump fuel, but if you use E85 certainly use a bosch 044.

 

I don't plan to run more than 1 bar of boost. Is it necessary to run more than that to make close to 300hp?

 

Are you at sea level? 1bar will be fine to make over 300rwhp. I have seen them make 200rwhp on 8ish psi, but I think that comes back to having a small amount of cumulative compromises on every support system. My mates car has a cat, 2 mufflers and using 2.5" exhaust. Hes also not prepared to cut big holes in the radiator support panels for 2.5" overcooler pipework and 3" or 4" cold air feeds.

If you start talking about having a full 3-4" heat isolated air feed with a massive K&N pod, well designed 3" mandrel bent exhaust with only a single centre offset. A screamer pipe or 2. Heavy springs in a genuine tial gate. RPM based electronic boost. 2.5" intercooler pipeworking with a minimum amount of bends and they are all large radius. a 500x300x76mm cooler (or larger). Highest octane pump or E85 I think you can be looking for between 300-370rwhp.

 

I'm in Texas not sure how much above sea level I am though. My setup is s4 hybrid turbo, bnr potted turbine housing, 60 ar compressor housing and to4b v trim. 720cc injectors all the way around, rtek 2.1, jacobs cdi box, front mount with very short piping. The intercooler is from a srt4 and mounted in place of the radiator. As for the wastegate actuator I will be ordering one off eBay hopefully one with higher spring tension.

 

Also I have s4 n/a rotors

 

Ever get this sorted out?

 

Yes sir. Should be in the 300 range. I'm at 15psi and plan to dyne it soon. Gonna kick it up to 17 psi and park it there. Don't feel comfortable going higher.

 

I'm now running 25psi. Its mental

 

I'd imagine you should be making more than 300. My buddy was doing that by 13 psi on a bnr stage 1 (v trim wheel). Can't wait to see the results!

I feel you on stopping at 17 psi, I'm running 9.4's myself and I plan to stop at 15, so I'm really debating whether to go w/ a stage 2 (H-trim) or stage 3 (60-1) if I want to make 350whp @ 15. Your results should help me decide. Thanks.