We had a few issues up top past 6k rpms, we are thinking one of the stock primaries is acting up. 77% duty cycle 550 pri, id2000(2200cc) secondaries, dual walbros with dual feeds, 22psi with a street port, etc etc

P trim Gt35R journal bearing, 1.15 T4 undivided turbo manifold, 3.5" exhaust

Great street turbo setup, torque curve is awesome. Car has a hard time getting any traction even with 285 tires.

 

Turn the boost up!!!!!

 

Pump Gas?

 

I pulled the water injection and went to race gas. Car is making too much torque for pump gas alone. Car is driven on the track, and don't want to take any risks...

http://www.youtube.com/watch?v=hHhyIK_uCtc

 

if the fuel pressure is consistent i would pull all 4 injectors and have them flow tested, i wouldn't rule out the possibility of the ID injectors having an issue.

dual EGTs would help diagnose any possible injector issues without needing a flow test.

 

Lookin good.....

 

So how different do you think the results would have been with the 1.0 A/R turbine housing?

 

300rpms faster boost, not sure on the top end maybe a tiny bit less power.

 

From watching your movie power is dropping by 6500rpm. And at the same time the mixture starts heading rich. It was hovering around 11.5:1 throughout the whole run above about 10psi then then started heading towards 10.5:1.

Anyway, is there more power if you can hold 11.5:1 AFR all the way to 7500rpm? Or is this a safety thing?

If power is staying the same or dropping can you not add additional timing to try maintain the peak number? My understanding was power not rising as RPM rises meant torque dropping ie more timing safe.

 

Yes power drops off because its just too rich. We leaned it out after that run. I am waiting for the injectors to be cleaned to finish this car up. Looking to get some more footage against a gixxer when done...

 

Good cause the kill section has been dead.

 

Can you provide some info on that manifold? I like how clean it is and looks similar to the FD mani... Probably why it has a nice torque curve. I didn't see any of the setups on your website with this manifold.

 

We can make them however you want, we hand make them in house.

I don't do that design anymore, as the w/g has terrible placement for low boost applications. Also fully divided manifolds appear to spool a tick faster, so we just build them that way usually. Anyhow if you want a particular design we can make. I still have a jig to make FC units just like that unit above...

 

Got back on, made some progress. Got the car to be repeatable, and fixed an electrical noise issue. Turned the boost up 1.5 psi and made an additional 22ft more torque everywhere; turbo obivously still has a lot left in it. We are still having some little bugs up top, but we think we have it narrowed down.

While we were at it we pulled up another Rx-7 that was tuned at the same shop with a T4 1.06 GT35R & streetport, but with a twin scroll turbo manifold. Graph comparison is below. Spool is almost identical, the 1.06 car is running 28psi however.

The P trim turbine wheel makes the same power at 4psi less boost, and 10 degrees less timing than the off the shelf GT35R. I am also sure once we have the bugs worked out this car will probably make a ton more torque and blow the stock Gt35R out of the water. P trim spools the same, obviously a lot less stress on the engine( much lower pre turbine back pressure), and can make a lot more power, and its a lot cheaper....

 

What kind of gas are you using?

 

109 octane