RotaryRocket23

Okay, so I've been doing a lot of reading concerning tuning of rotaries and single turbo and what the timing should be at, etc.

I've done various tuning with a variety of different platforms, all piston motors. What I generally did with piston motors was dial in the timing until I seen it wasn't making anymore power or got a hint of knock and dialed it back slightly.

Now with my rotary powered vehicle, I am hearing this is a big no-no.

Right now I have some numbers in my head. I wanted to know if anyone could provide some insight on whether I'm on the right track or some advice/pointers.

Right now, I am looking at dialing it in to a 11 - 11.5 AFR, having the timing coming down to 11-12 degrees and rising back to 15-16 after peak torque and maintaing a 15 degree split.

The car is a FD3S, GT35R @ 14 lbs of boost, running AI (50/50 mix) on 91 pump. Tuning is controlled by PFC.

Not looking to push the envelope, just want a nice reliable tune so I can take this bitch road racing.

metalCORE

iTrader: (2)

...as i've heard from a professional turbo mechanic down here in germany, the GT35 is optimized and works best with pressures from 2 psi and above...

...just wanted to mention, 'cause i've seen many people using the GT35 and running very low boost...

RotaryRocket23

Thanks for that invaluable information.

I just took my turbo off and threw it in the garbage. Thank god you let me know that or else I would have had a completely inefficient turbo setup.

Jason

iTrader: (5)

You can run a little more timing at that boost level and A/F's are fine. Run a 12 split.

RotaryRocket23

Thanks Jason

Any specific tips for knowing when to not touch the timing?

arghx

iTrader: (3)

you can do it the old fashioned way. Put a fresh set of plugs in. Do a dyno pull or two, and read the plugs from there--this is easier if you are not using the stock plugs. The stock knock sensor reading you get on the PFC is not always reliable. It depends on the car honestly.

The other thing you can do is run dual egt gauges in the turbo manifold runners.

RotaryRocket23

If I start dialing it up until it stops gaining power on the dyno, is this an acceptable way to tune?

Reading the plugs is an excellent idea, but I don't know how much useful information that is going to give me concerning timing threshold.

fd_neal

iTrader: (4)

i run 13* advance (logged) at peak torque, 10* split, AFR of 11.0 at 13-14psi, on 91 octane. Was a reliable setup for most of the race season, probably 150-200laps. I lost what i believe to be a side seal on my front rotor at the last track day, im not sure why yet. I hit fuel cut, had primary ignition coil problems, and i ramp the timing up to 20* (logged) at redline. Point is, the numbers youre thinking should be reliable but things happen...

RotaryRocket23

Oh yeah, I realize stuff happens. I have 2 vehicles just for that reason. I know my rotary is unreliable because of the level of modification, so I have a stock ITR for a DD.