I understand your approach (I think), but it just seems wrong to vent when we can throttle. Re-read my previous post and if what I'm saying doesn't makes sense I'll try to clarify. I may be misunderstanding something, but if not, throttling has to be better, because it would to be more efficient than venting. If the previous post isn't clear, let me know and I'll try again. Venting seems to me like venting a turbo rather than using a waste gate, and to me, that just seems wrong. What (if anything) am I missing?

 

AFSC12 setup only
But if you close the throttle a bit yes you will prevented system from fully pressurizing the throttle volume up to the max the compressor can put out; however do you want to watch the pressure gauge constantly and try to control the actually pressure going to the engine when on the road/track by adjusting the throttle angle. Not a good idea!!!



The above statement only applies to the AFSC12 system that I want; the standard AFSC8.2.0 or 2.2l would not need the venting system because no madder what you do the pressure out of the compressor would never go above 8psi.

It might just be easer if I try to explain it to you over the phone if this post does not explain it. PM me with phone# date and time.

 

The calculations are in and it appears that the system I have in my mind would work at least on paper. I sent the plans to RED MX5 (Chuck) to see if he can find any major errors in judgment on my part.

 

Any more update on the rx8 tuning and the progress on s2k setup???

 

No new info from RP or from the info I can extract from the RX-8 AFSC thread.

As soon as I hear or read something that is worthy to be brought over the s2k AFSC thread I will do so.

 

Perhaps I don't have a clear picture of the setup in my head but wouldn't a throttle plate ahead of the compressor cause an uneven velocity distribution across the compressor face?

 

Yes the TB will be relocated to the inlet side of the compressor and is necessary to throttle the system since the compressor is directly tied to the crank pulley.

If you placed the TB directly in front it might create some turbulence at small throttle angles but the effects if any would be very small.


Once I get my system up and running I was going to see what with happen to hp/tq if I move the TB way up by the Filter assembly and have a very long straight tube before the inlet. See back a page or two for a diagram of what I am planning on doing with my setup. this may increase the HP/TQ a very small amount but the increased Throttle volume may have negative side effects on throttle response due to the need the fill the long intake tube with ambient pressure when the TB is at 100% angle before the compressor get enough mass flow to start creating boost pressure.

Real world test have shown improvements in flow dynamics ( = more hp/tq) by using a longer tube on the inlet to a turbo. This is because it creates a more uniform pressure front to the inlet side of the turbine. However the %increases to HP/Tq are very small (1-4%) so unless you are running a very high HP/TQ motor the 1 to 4% will not really show up on a dyno or reduce your lap time.


The only real way to show this is a real world test unless you have access to a very advanced piece of software that is capable of doing computational fluid dynamic calculations.

 

Kinda like what I do all day.

 

It would be interesting to see an actual CFD analysis coupled to hardware testing but I understand this is a "volunteer" car forum

My previous post is just food-for-thought. I do, however, prefer the pressure regulation method. That way you had direct control of boost pressure.

I'm really looking forward to this, good luck!

 

The TB would still need to be placed in front of the compressor in either design AFSC8.2.0 or 2.2 and the AFSC12.

Only the AFSC12 (12psi compressor max out put) would require the pressure reg idea.


But it all depends on if RP would be willing to build a 12psi compressor.