You can't look at the <68% islands on a flow map from two different sources for a 10% flow difference.

 

ok - but did you realise the 50trim we are talking about here is a 75mm wheel ?

 

This should clear this up a bit:



Also note the shaft RPMs needed to attain these flows.

 

how did you do that ? mad computer skillz .......

Anyhoo
BNR offers 2 upgrade wheels for the greddy - the 50 trim above and the 60-1 that everyone so far has upgraded to .
My point is that perhaps the 50trim may be the better upgrade for the greddy housing .


I'm not sure what your point was about the 3271 ...........

 

Sorry I haven't chimed in in quite a while.

I use the 60-1 compressor wheels in a lot of applications. The TD06 compressor cover is not a restriction at all. I think the wastegate actuartors need to be more heavy duty to keep from being blown open causing the boost drop to occur.

If you guys want to special order your own compressor, I can make it happen. I am not biased to any compressor wheel.

The stock 18G compressor flows 40 lb/min. 50 trim flows 48 lb/min. 60-1 flows 58-60 lb/min.

Bryan@BNR

 

At what efficiency and Pr? (Otherwise, those numbers are useless.)

 

You can throw all this technical stuff out the door when you have bigger displacement/rotary engines. Just because a compressor wheel has a higher pressure ratio (18G is a 20psi-24 psi peak efficiency map), doesn't mean the life cant be sucked out of them at a lower pressure ratio. 60-1(max efficiency from 14-22psi) and the 50 trim wheels (16-24psi max efficiency), even those compressor wheels with a rotary engine are breathless after 14-16 psi.

Compressor maps are great and informational, but engines have their efficiencies as well. They both play huge roll in turbocharger efficiencies. Think of it this way, the engine is an air pump and the turbocharger is an air pump. One can out do the other and change all the paper data :D.

Bryan@BNR
205 640 1193

 

You didn't answer the question.

You say that the "50 trim flows 48 lb/min" and the "60-1 flows 58-60 lb/min".
At what Pr do these turbos provide that amount of flow?

OBVIOUSLY a rotary motor will "suck the life" out of a turbo in a different manner than a piston motor. But that "sucking" can be perfectly quantified by this information.

 

I did answer your question. It will be different on each engine rather than on paper (compressor map). Max flow of the compressor wheel is different on each engine. Some engines have better heads, more aggressive cams. Some engines have restrictive heads, mild cams which will take more pressure to make the same compressor output. When the compressor wheel reaches its plataeu, thats it hits the compressor surge line and falls out of its efficiency range.

On paper in a controlled invironment with no compressor housings, the compressor maps are made. Surrounding factors such as engine VE, turbine housing/compressor housing configurations, and back pressures are not calculated in making of the compressor maps.

50 trim is only good for 12-13 psi on a rotary engine (compressor map says its good for up to 25 psi)
60-1 is only good for 15-16 psi on a rotary engine (compressor map says its good for low 20's psi)
18G is only good for 7 psi on a rotary engine (compressor map says its good for 25 psi)

You can run more than 12-16psi on on a 50 trim or a 60-1, but you will gain nothing but mid range tq. That means the compressor wheels are out of volume.

Bryan@BNR

 

So, no you did NOT answer my question.

This:
is factually incorrect.
I didn't ask you for the total flow through the motor. For obvious reasons, you do not know that.

You make a claim of a certain flow mass without stating how that flow mass is achieved.
I (we) are well aware that the total flow through the system will be dependent on a myriad of factors in each build.
But the compressor of the turbo has a fixed capability that does not depend on anything (unless you intentionally modify/restrict it outside of the compressor housing).

So, once again, upon what specification do you make the statement "50 trim flows 48 lb/min" and "60-1 flows 58-60 lb/min"?

 

think post compressor pressure when on Pr. not manifold pressure

 

Well I guess I have been a failure for 12 years Mazdamaniac. Most HP ever recorded on 2nd generationhybrid turbo RX7's, most HP ever recorded on 3rd generation twin hybrids, and most HP ever recorded on Toyota Supra sequentials.

I have over 60 turbochargers to build up for customers and don't have time to elaborate anymore...


Bryan@BNR

 

Bryan:



Ive been a customer of Bryan's for a long time. Bryan has been doing this for longer, and is a house-hold name in the RX7 community. (you know, back when a rotary powered street car might actually be fast?)

You all could benefit to learn a thing or two from what he is doing. Hes probably gone faster in a rotary powered vehicle than anyone on this forum.

 

No need to make a dig towards the 8 to argue your position. Lots of members here have owned other rotary powered vehicles and understand the history of the motor.

 

Probably. I just find it funny that the guys fighting to break out of the 15's and bust into triple digit trap speeds are trying to tell one of the "who's who" of the turbo world how a turbo works.

 

STiPower, the not knowing who's who cuts both ways. You should read up who is doing what on this board before coming to any conclusions.

 

What is up with you people?

I asked a simple question. I couldn't care less if Bryan is Jesus. Just answer the freaking question!

Instead of bowing to the cult of personality, use your f*cking brain.

 

Your question was answered, and answered correctly. The problem is you don't understand what a right answer would look like in this case to know whats right and what isn't.

You had someone tell you a while back that you need to see a compressor map for any turbo sold or advertised without really knowing how it applies to how you are using it, and that "if they say a wheel is rated at a certain flow, make sure you demand to know the pressure its making that volume".

The volume a turbo will flow at a specified pressure will vary upon the motor it is attached to. There is no other answer than that, thats how it works.

 

Simple question has complex answer. In order to know the pressure ratio of peak flow, you must know the engine volumetric efficiency to approximate the percentage of efficiency of the compressor wheel in your applications(s).

A properly tuned 13Bt or 13Brew makes around 400 RWHP/460 BHP on 15-16 psi of boost with a 60-1. That is around the maximum flow rate of the compressor wheel. In a rotary it takes approximately 1.9 CFM to make 1 bhp. So the 60-1 is rated right at 850 CFM. Take 850 CFM and divide by 14.27 to convert it to lb/min which equals 59.57 lb/min maximum compressor output in application.

Bryan@BNR

 

Incorrect.

Incorrect.


Are you guys serious?

 

heh - I started a shitfight

 

^look what you dun did.

 

I don't understand what the "fight" is about.

The assertion was made that "X" turbo flows "Y" pounds of air.

I want to know exactly under what conditions this occurs.
Instead of hemming and hawing about engine flow etc I just want to know where the number came from.
I have absolutely no problem getting the data on this. I want to know why the claimant is having such a difficult time.

 

lets see... i've had Jim Mederer on here.... Carlos Lopez... Abel's been on here.... a couple of those crazy Australians that have set records.. so yeah not faster than everyone whose been on the forum and that doesnt matter. "We" know who Bryan is and we value his input. but that doesnt mean he can't be questioned about his posts.

We question everyone. nothing wrong with that. Notice you slung the mud and not MM or Bryan.

 

Here is a scinereo for ya. You have a honda B16 engine with a 60-1 running 15 psi of boost. Also you have a Ford 302 with a 60-1 running 15 psi. They are running the same boost levels. Their pressure ratios are the same. What you are claiming is both engines are flowing the same volume of air since the compressor is at a fixed 15 psi?

If the compressor has a "fixed capability" you think both engines would produce the same amount of volume if the turbos were at 15 psi?