The DJ

My car has been running really rich so I pulled out some fuel via PIM's from the upper rpm range. It's all around 97.2% with the exception of the 8000rpm is around 98.6%. Most of my fuel in the lower rpm's is about 100%.
My question is at first when I took some fuel out of the upper rpm's, would that alone affect idle? It's very much rougher than befroe when all my PIMS were at 100% (default?) I tried to lower the 100% in the lower rpms but I don't want to screw anything up. I know I need a dyno tune but in the meantime, just advice.......should I just keep lowering the PIM's in the lower rpm's and drive it around each time I make a change? Shouold I make any changes to the lower P01/N01 fuel cells?

Badog

Nope. As long as you don't change the PIMs at idle.

cewrx7r1

iTrader: (2)

Only the "normal" set works with are cars.
If you went into another optional set, even to look; then when you come out and do not go back inside normal, your PFC defaults to a rich limp home mode.

Most likely to did this!

The DJ

Yeah Chuck, it idled rough when I went ot look at the % in the other options. I remember speaking with you awhile back - thanks again for the advice. I had "bored out" 850's (1200's) installed in my secondaries by T&R Racing but Anthony had a feeling he had given me just 850's again. So now I have the commander assigned to 850 Pr 850 Sec. But I did smooth out the idle alot myself after Anthony set it and I took some fuel out of the top with the help of Steve Khan.
I can't complain for Dyno time. I want to go to KD Rotary because I feel T&R are really busy getting that car back up from the ground that caught fire and I feel like I would be taking a backseat for now. I just want the right injector's installed that I thought were going in......

pluto

If you have 850cc injectors in your primary, by changing them to 850cc on PFC doesn't do anything. PFC only recognize secondaries when you change the values. What you need to do is on the same menu, change your primaries from 100% to 68%, (% difference from 550 to 850cc). That should fix your idling problem and running rich at WOT. I guess when you and I exchanged PM, I might not remembered you mentioning about having 850cc injectors in your primaries?? Just remember, to set your PIM back to 100% because now your injector duty cycle will be less.

The DJ

Thanks Pluto........I definitly have 850 primaries......the stupid question is if the "bored out" 850's for secondaries really are......I'll try that. I'm working on buying the custom rail/1600 combo from RX7store since I'll be single over the winter........

SPOautos

Why not get it from Steve since he's helping you out with the tuning. He has good prices too ya know. I'm sure he can supply that stuff to ya.

STEPHEN

The DJ

My bad Steve, I never knew you sold stuff...........

suganuma

www.gothamracing.com

Badog

Steve,

Don't you mean 64.7 for FRONT PRIMARY and REAR PRIMARY, with .04, and Q PRIMARY set to 850?

pluto

if you do the calculation, it'll actually come out to 64.7% like you said but things are not always perfect (injectors may not flow 850cc like it should) and its much safer to use 68% than the exact #. besides, running 3% richer doesn't hurt since its just the primaries.

Badog

Steve,

Have you heard about running a little richer in the rear rotor versus the front? In terms of adding some "fudge" to the % difference that we are talking about.

Where you put your "fudge" factor is up to the tuner, I guess. I like it built into the numbers I target, rather than the delivery system. It's all good, though.

Keep kicking **** and taking names, Steve!

pluto

The rear rotor runs hotter because both the oil and coolant passage goes to the rear last so it creates more heat when compared to the front. by adding more fuel to the rear helps cooling the rear housing and prevent it from detonation when the motor is tuned at the edge. The only way to really make it more effective is to have two EGT probe (one for the front and one for the rear) and monitor your EGT temp to compensate for the lack of heat dissipation. I think that an average street car, where most people tuned their cars to 11:0-11:5 a/f ratio, shouldn't have to worry about it. There're so many other factors in the equation where you really can't just add more fuel to one to compensate unless you can truely monitor what each chamber (front and rear) is doing. If I remembered correctly, I think that the rear secondary runner on the LIM is narrower than the front. so when all said and done, it's probably about the same between the front and the rear temperature (assuming all injectors were balanced and operating normally). It's a good idea though...