Just as an FYI in case you were unaware, the settings you put in place for partial throttle are not used at WOT, there is a nother set of setting for high throttle.

I have mine set as low throttle settings are used under 30% throttle and high settings are over 85% or something close to that anyway.

 

Afc2 is -50/+50%. Fuel filter check is a good idea. aftermarket fuel pressure regulators are cheap as well, I reccomend aeromotive.

Just add the bigger injectors its cheap and easy. Then were it is at 50% would end up say 30% instead leaving you more headroom.

I dont quite understand why some "ghetto tune" there expensive cars. Spend the money and do it right ot dont do it at all.

 

Jonny,
If he pulled %19 fuel from the middle looks like he needs to pull more. Maybe -25 to -40 from 4500rpm to 5700rpm
If you need help posting the A/F graphs, If you send me the dyuno files I can post them.

 

hollywood, I dont think pissing away 700.00 would be called ghetto tuning.
I'm not sure if you have ever run this combination but there are lots of guys that have successfully run 310's and still had plenty head room. With my 310's I still had to adjust the SAFC2 on the negative side to pull fuel.

It doesnt make sense to throw money at the problem if you dont have to

I think the point here is to figure out what the problem is instead of just trying this and trying that and needlessly spending hundreds of dollars in the process.

dont you think that is the proper approach?

 

310's in california would be different with 310's in denver, so certain things may work for some but not others.

But good point, the lean condition could be a dyno/operator issue as well...I would get those 10's and lower fixed asap, you may score the cylinder walls running that rich for a period of time.

 

Guys,

Thank you everyone for your input. I will try and answer as many questions as I can.

Hollywood - I live in Tulsa, Oklahoma - which as you may or may not know - is not heavily populated with tuners. This is the only dyno in 200 miles. This guy tuned 1000hp Supra's so I would not call him a "ghetto tuner."

I am not fully versed on this subject so I will tell you what my dyno guy told me. He said the reason why the middle rpm's are showing how they are has something to do with the timing changes and not knowing how it is changing timing. He said you should be changing timing by 1 degrees for every pound of boost - but I am running stock timing and he is unable to change that - something to that affect.

The SAFC only allows you to go to 20% - the SAFC2 is 50%.

He put the settings the way they are to be safe until I can get more fuel in there. I rarely drive the car these days so I am not putting any miles on it the way it is tuned.

Could someone please tell me about the FPR - where to get it, install etc???

I am battling limiter problems, need something to change timing, and desperately want Morris's pulleys - so unless I can sell my 310's with less than 50 miles on them then I don't see replacing the injectors anytime soon

I will post some more of the graphs ( but thank you for the offer Gil )

Thx guys,
Jonny

 

Thanks guys,
Jonny

 

I did not call your dyno guy a ghetto tuner. Ghetto tuning is when u turbo or SC your engine and dont get a proper standalone, and use hack products instead. Ghetto tuning refers to products like the sfc, rising rate fuel pressure regulators, raising past stock fuel pressure, etc...

If the low 10's area is the ecu retarding timing then you are knocking. Are you running 94 octane? Is your cooling system up to par?

 

Jonny, no offense but your AFR should not look like that, no matter whether your tuner has tuned 1000hp supra or not. My guess is that he can't change timing because of the vvti feature that's in our cars that will self-correct whatever modification that's piggybacked to it. I've already talked a bit about this in the past, and that's the main reason why NO piggyback unit will ever work to optimum in our cars. Not SAFC, not e-manage, not unichip. Only standalone (and all of its PITA problems) will be able to fully replace the function of your stock ECU and make it right.

Don't ever drive your car hard with a setting like that. I can guarantee it will be very detrimental for your engine.

 

incorrect.. the OLD, non digital box S-AFC was 5 dials and even it was +/- 30%. The first digital SAFC was +/- 50% but only 8 RPM points could be set and only in 500 rpm increments. the SAFC2 is also +/- 50% but allows 12 RPM points and increments by 200 RPM.

Now back on track.. if he is running you +50% thru the high end, he is most likely maxing out the injectors and they are going static..full open and just dumping. In fact it looks almost that way the whole way thru the graph. do you have a bigger fuel pump?

SAFCs work by modifying the MAF signal to make the ecu give the injectors more fuel (fool it into thinking there is more air volume). Keep in mind that at the same time the ecu will be retarding timing based on that figure. I think the timing is fine, but the fuel mapping stinks.

keep us posted.

 

i just had a thought looking at the graph again and how jumpy it was... did you install new spark plugs? what is the gap on them?

 

the middle range richness was mapped at -19% fuel. The upper end starting around 5800 rpm was mapped for additional fuel up to 50% and there was no change in AF so yes the injectors are maxed out and we are thinking the stock fpr is not handling the walbro 255. The next step is to diagnose what is causing the excess fuel and correct it. The spark plugs I believe are the two step colder plugs and i'm not sure what he had them gapped at...my guess is that the ecu is wandering on the timing because of the excessive fuel.

 

They are brans new NGK plugs that are 1 step colder I believe. The box said not to gap them so I didn't.

Epik - you should get into our conversations we have about this on AIM - sockfocks, morris and I have been talking. PM me your AIM name.

Hopefully Joe (sockfocks) and I can get the FPR installed and running to hopefully circumvent this excess fuel problem.

Thx guys,
Jonny

 

The gap should be around 28-32 for forced induction. Never trust the gapping that comes stock.

 

Jonny, I followed the link you posted over in your thread about fuel pressure regulators, I don't know that it is going to help. The problem it looks like you are having is VOLUME related, not PRESSURE related.

My own take on the dyno echos what many others have said - you have too much fuel in the middle and not enough (not by far, but just a little lean) at the top... but a little too inconsistent for my taste. As others have stated, you want that AFR line as steady as possible. That is exactly what the SAFC2 unit is for, to map to a straight line. That's the angle I would persue first.

Luckily FPR are generally pretty inexpensive so you can give it a shot without a big investment. If you still want to go down this path before you spend the money I'd ask your tuner to first put a pressure guage onto your fuel line and keep an eye on it during the dyno run.

(disclaimer - all my FI experience is based on Nissan engines so take it for what it's worth)