Can someone explain why we are not using the req fuel calculator and just estimating the required fuel for our injectors? I have always just accepted it but now it makes me wonder why we are questioning the built in formulas.

Terry

I am using the value that was calculated if it makes you feel any better :). It really doesn't make that big of a difference though, because if you set a req_fuel value to high, you set your VE values a bit lower, if you set your req_fuel value low, you set your VE a bit higher. I think the point is to get your VE values (not including boost) to be under or around 100% at peak. I know using the built in value for req_fuel, without including boosted areas, my VE maxes at around 70% (going from memory). If I changed my req_fuel down a bit, I could get that right up to the 100% mark and simply scale my VE table (it has built in functionality to do this). I don't really know why people don't use the default value, but once my wideband gets here and I can better tune this thing, I'll let you know if I find out any reasons to change said value :).

The reason why everyone is using a non-standard REQ_FUEL value is because that's what MRSLICK had in the MSQ files that he posted.

I use MegaTune calculated REQ_FUEL values in all my installations. This way, when you install a different set of injectors, all you have to due is adjust your REQ_FUEL and enrichment settings. If you use a non-standard REQ_FUEL value, then you have to guess.

this is interesting........2 years of screwing around because MrSlick said so. Ugh back to the basics.

Well, at least me and dougie2 are using the req_fuel that Megatune calculates :). This way, when I replace my injectors, I can use the built in functionality to scale the VE table accordingly, otherwise you'd have to figure out how much to scale it by with either a bit more math, or a bit more manual tuning ;).

when i just tested it, it was only .1 off from what I had entered...went from 7.3 to 7.2, guess it was close enough...

Works just fine thanks guys.

You guys are talkin about what MrSlick said to put in? Now you have me wondering if this is part of my probs. He had/has mine set at 11.0 and Im only running 4G 450cc's.

Does this sound right?

Use the fuel calc located in MT. IT works fine. I have been retuning mine and it is working out fine. I also updated code so i cant be sure but i get a much better idle as well. I can idle smoothly at 15.5 AFR.


Start over. Any info you are following from Slick was not 100% accurate.

you numbers are wrong i can tell you that! my 550's are 6.4 and 450's should be 7.4

Terry

Originally posted by Star Turbo Talon
Use the fuel calc located in MT. IT works fine. I have been retuning mine and it is working out fine. I also updated code so i cant be sure but i get a much better idle as well. I can idle smoothly at 15.5 AFR. Start over. Any info you are following from Slick was not 100% accurate. you numbers are wrong i can tell you that! my 550's are 6.4 and 450's should be 7.4 Terry

Well then something is up, cuz I try to change to 7.4 and the car will not run at all. I even tried staring at 11.0 and tried to drop it by .5 increments and couldnt get below 10.5.

Now I dont know what I did, the car wants to run lean from 14.0 when I give it throttle in nuetral. WTF

Originally posted by DJ420a
Now I dont know what I did, the car wants to run lean from 14.0 when I give it throttle in nuetral. WTF

When you change your required fuel value, you have to change a bunch of other things to like acceleration enrichment, etc...

Yeah, I figured that out last night. Wow theres soooo much to learn.

Thanx man