SDSefi assistance needed also fuel pressure

[Ron240zxt]

Hello all,

Well i need some assistance or information on setting up a reliable timing curve for a lets say 8.9 to 1 compression engine running 20psi of boost. Also any one have a idea what psi the factory RX7 550cc injectors run at? ie is it 32lb with the vacumm port unplugged off the regulator...

 

Thanks for the help.

Ron 240zxt

[Scottie-GNZ]

Ron,

 

I do not think anyone can build you ignition maps that will be just right for your setup. I suggest you follow my guideline to establish a baseline, then adjust from there.

 

Here goes. VERY IMPORTANT, to properly set up the ignition for boost, you have to build 2 maps, IGN and IGN RET/MANPRESS. IGN sets the initial timing and advance and IGN RET/MANPRESS (ignition retard based on manifold pressure) retards timing based on boost. The combination of the values of the 2 maps is the total ignition.

 

First, build a IGN map with 20*BTDC at idle and ramp it up to 34* at 3400RPMs (full advance), then take that 34* value all the way to redline. Next build an IGN RET map that starts to retard the timing at say 2-3# boost and ramp it up to retard 10* at 15# boost so that the total timing is 24* at 15# boost. Since you are just about guaranteed to be running over 3400RPMs at 15# boost, you would then have 34* advance minus 10* retard for a total of 24* @ 15#. If you have a 2-bar MAP sensor, that is as far as you can go and any boost beyond 15# will have 24* timing. If you have a 3-bar sensor, continue pulling timing at 1* / 1# which would net a total timing of 19* at 20# boost.

 

Remember, this is a baseline and you need to monitor and tune from that point, especially if you intend to run 20# on pump gas. Remember Morgan? He started with that baseline and he ended up adding more timing and the car responded well.

 

Hope I did not make it confusing. This is for all who will eventually be programming their SDS. I am intentionally not providing a full map because I think it is a good idea to understand the principle so you can build your own and more important, know how and why adjustments need to be made.

 

Hope I am not coming across as the "school-mom" .

 

As for the FP, I am not sure so you might want to ask on a RX-7 board or maybe BLKMGK knows. Typically, OEMs are set at 36# and aftermarkets at 43#.

[Guest Anonymous]

just how hard is it to tune with the SDS system? i am thinking about eventually swapping the 2.3T motor out of my t-bird and into a pinto as my daily driver. and i was thinking it would make it a LOT easier to do the swap with that system. i want to run the 3ME-F unit. nice to be able to chuck the dizzy out of the picture. oh, speaking of my 2.3T, i just had a VERY nice find for it. i went to a local pic-n-pull and scored a t3 turbo (my car model year came with a smaller IHI) for 20 bucks . i just have to go get it tomorrow, i tried to take it yesterday but it was so cold that my hands went numb and refused to obey me. thats when i decided i should get back to my car, turn the heater on full blast, wait till i could move my hands again, drive home and come back on a warmer day .

[Scottie-GNZ]

Hey Ron,

 

did my post help?

[Ron240zxt]

Hey Scottie,

Yes Vary much help full. I wrote down what im going to do just havent got around to inputing it yet. Maybe Thursday im off. I was so disappointed when she started detinating once again

Thanks for the Help

Ron

[Scottie-GNZ]

Did you see the inj duty cycle when it was detonating? Certainly could be the timing, but you want to make sure the DC was not out of whack.

[Ron240zxt]

Unfortunally i wasnt able to look at the duty cycle.

I was to upset when it detonated. to even try it again...

tommorows another day.

Thanks for all the help

Ron