OK- it's my problem for not having the wideband built yet... but at least I have the stock 02 sensor to see if I'm at least in the right ballpark....
Anyways- I am installing the 4 550cc injectors into my N/A motor, and doing it well before the turbo goes in...

OK- the 550's flow 20% more fuel than the 460's.... theoretically, I should lean my S-AFC out by 20% more across the board in addition to my tuned settings, and acheive the exact same mixture as running with the 460's.

Does this actually apply in reality when I install the 550's??
Thanks!
Dan

 

La bumpa.

 

Seriously- no one knows???? Post has been up for over 12 hours now....

 

Without the SAFC, the car will run like crap and won't accelerate above 5800rpm if you have 4 550s in the car. But, with it, you could do this.

As for how much you should lean it out, if you tune it, then you won't need to worry about taking out 20% beyond your tuning point. If you tune the SAFC to work with the 4 550s then the 20% more flow will theoretically be negated. I would start with 5% taken out and work from there.

You might find you need to only take 10% out at low end, but 15% at top end. I think it was the 86-mid 87 EFI system that ran leaner up top than the other 2nd gens, so depending, 20% across the board might be too much or not enough for some spots on the rpm band

Carl

 

I dont know for sure, but I agree with it in theory. At worst though, it will give you a good starting point.

 

silver88gxl- The car is already tuned with 460s.
If I want to maintain the same A/F ratios with 550's, I should theroetically lean every point out by 20% more...
Damn... where's RETed?