help tuning safc for 780cc inj. need #'s to start it up,

[1996dsm]

im hoping to install my 190 wally and 780cc rochester inj. this weekend, im just looking for a mathmatical # so i could (start) tune the car.

 

[ilco187]

Those are pretty big for a afc, you could sell the afc and get a eprom burned so you dont have to blind tune, i have always had bad luck with afc's so i just got a maft and chip burned to keep it simple and from blowing the engine. just a random guess is since they are 34% bigger than stock 450's that you would be doin -34 or so on the afc, dont take that as what to set it at its just a guess.

 

[SpawnedX]

I'm pretty sure the biggest you can go on an SAFC is 650ish, not sure about the Neo.

 

[97blackwidow]

isnt it 750 the biggest u can go on a safc?

 

[my dreamt dsm]

Nope. To confirm your safc... 650 are max. But I never tried the neo before.

 

[nlzn]

+/- 50% of the STOCK injector size is the answer to your question about the AFC.

 

[TurboAnything]

Over 680cc you will not get a proper tune with a SAFC or NEO it it just not going to happen. Your timing and load maps will be so far from the proper places its not even funny.

You need more management you can buy a eprom ECU and Get a chip for your setup or ECMLink. You could also look into flashing a 98+ ECU for your setup.

 

[1996dsm]

im home for break so now i can reply. I do have a eprom with base tune, but i dont have the extra $150 for them to tune it plus the shops like 1 1/2 away from me. i do plan on getting the tune but i was wanting to do this for like the next 2-3 wks (until i get a shop tune). unless i calculated wrong if i drop it -42 it should be equivelent to the way im tuned now, then from there i would assume i could fine tune (as good as i can). correct me if im wrong....

 

[steve]

When you lie to the ECU about the air flow it messes the ECU's idea of what sort of load the engine is under and causes the timing to be advanced. Telling it that almost half as much air is flowing isn't a good idea.

 

[TurboAnything]

If you have an Eprom then all you need is a injector compensation adjustment. I can do that for cheap.

 

[1996dsm]

well i installed everything and tuned it down to good afr's. on cruise im running 14.7-15.1 and on WOT its running 10.7-11.5. The only thing i was curious of my Boost/knock gauge is moving up to ALMOST half way touching the first line MAX. a friend told me the shop that chipped the ECU said its fine as long as it does not go over half. IS THIS CORRECT?

 

[steve]

Sounds like too much timing = knock.
Many people would say any knock is bad, both for performance and for your engine.

 

[1996dsm]

Once i turned the boost up to 18psi the knock went away. Went to a dyno event today (sun) and went ahead and dynoed it. 263 AWHP & 264 TQ, they were surprised on how steady my A/F were and running 780cc with a SAFC. they messed with one of my rpm points, but other than that it was good.

YouTube - GSX Dyno run 3-6-11