Today I started tuning again for more boost in preporation for some dyno runs next week. I've hit a wall at 24psi then drops to 22psi at highet rpms. I would think I've maxed out the turbo allready. MY AVC-R duy cycle at off=15psi,35%=20psi, 40%=22psi, then at 45% to 70% = 24psi then falls off to 22.
I really don'r think I've maxed out the 80mm turbo. I tried 1.32 & 1.15 A/R exhaust housings with no change other that a few hundred rpms of spool time. I've double checked all vacume lines, connecters, pipes, etc.

Any ideas of something I missed?

Jered

 

Any boost controller can only go a certain amount above wastegate spring pressure, and still be accurate. I try to stick to only 10lbs over spring, and it sounds like you are 15lbs over spring? Maybe stick in a 20psi wastegate spring and try for more boost then.

 

OK So I shimmed the wastegate spring. Now I get 21 psi w/o avc-r and it starts gained just a bit with the controller 25 then drops to 23.

I would be suprised if I am flowing over 100lbs of air at that rate.

Here is the map for the turbo





Any other ideas?

 

Have you measured the pressure drop between the compressor and the intake manifold? The turbo could be running around a 2.8 PR, in which case there could be a 100lb/min airflow rate if the engine has a good VE due to porting.

 

I measured the compressor wheel and its correct. I was thinking they may have sent my an incorrect turbo.

I'll take a reading off the compressor outlet vs. manifold pressure, just for curriosity sake.

The motor has Judge Ito ports. With messing with a few turbo calculators a 100+ lbs is possible.

 

Do you think you are running over 680rwhp?

 

ported at 24 psi he damn well ought to be!

i think it is quite possible that you are over the flow limit of the turbo. 100#/min=~850 bhp on a rotary. figure 18% drivetrain loss, thats ~700rwhp, which seems like a very reasonable number for that boost level

 

I'll know soon. I've verified everything I can so there is little downtime at the dyno. I ended up taking the air cleaner off and it helped a little.

As for pressure drop, I have about 2 psi pressure drop from the port on the turbo outlet to the inake manifold.


I searched and found an old post from a guy is russia with basicly the same setup. He made 780rwhp with a Inovative 80mm.

https://www.rx7club.com/showthread.p...ighlight=gt80r

 

So how much power are you making at 21psi and 24psi? Should be close to 900whp at 24psi...

 

It would be nice to see over 850, but i don't think the turbo will do that for a rotary aplication. I'm not going to risk a motor running leaner than a 11.5AFR.
I'll find out shortly what kinda power it has. I had to postpone the dyno this week, because I am going to Pheonix area for a few days to check out a casino / resort we might be building next spring.

 

what series is your block?