IFR table values with 36LB FAST injectors

[Kurtomac]

I had a pro tuner hit me up with a base tune for my soon to be HCI 02 Z06 stock fuel system with the exeption of 36lb injectors....took a look at the IFR tables and plugged in the value on the excel table on here and the values arent even close...what should they be...anyone want to take a look at my current tune vs my mail order get me going after my HC tune let me know I'll shoot you an email with the tunes
Mods to be done....
TFS 215 heads
236 238 601 605 113+2 cam
FAST 92 intake
LS2 tbody both ported
already have headers and offroad x pipe
asp pulley
36 lb injectors
yella terra rockers and i think thats about it...
after i install I'll run some logs and AUTO VE and Auto maf
running a LC1 wideband

[Kurtomac]

bump....plugged in stock numbers it 28.8lb injectors and numbers dont match up to a stock z tune....whats the deal?

[hquick]

Post your stock and modded tune on here.
Some tuners use the IFR table to adjust fuelling.

[TFZ_Z06]

Could that be 28lb/hr inj rated at 40.3psi and now being used at 55? In any case, just an idea:

I am basing this on the fact that the car runs great w/the stock injector settings. In any case, the slope of the injector line is ~0.241:

If for example, if 36 lb/hr injectors flow (unknown inj data):

34.5 lb/hr @40 psi fuel pressure
36.6 lb/hr @45 psi
38.6 lb/hr @50 psi
40.4 lb/hr @55 psi

Then I would set FUELINJ LB/HR:

LB/HR = x[psi] * 0.241 + 37.6285 For a 40.4lb/hr injector.

Setting psi at 11.6 = 40.4 lb/hr
Setting psi at 0 = 37.6 lb/hr

After setting two endpoints, I used the linear tool in the EFILive Software to interpolate between points.

PSI LB/HR
0.0 37.600000
0.7 37.775000
1.5 37.950000
2.2 38.125000
2.9 38.300000
3.6 38.475000
4.4 38.650000
5.1 38.825000
5.8 39.000000
6.5 39.175000
7.3 39.350000
8.0 39.525000
8.7 39.700000
9.4 39.875000
10.2 40.050000
10.9 40.225000
11.6 40.400000

If you have a STOCK vehicle with only an injector changes, it would be easy to do, you could just change the vacuum data until STFT are zero then interpolate the rest. Unfortunately, most of us must theoretically set the injectors, then VE tune. If you tune for inj and VE is wrong, then you are off anyway.

[Kurtomac]

heres my tune thats in the car now...its a headers no cats intake z06....going HCI...attached is also the mail order
still dont understand why if i enter stock injector values in 96supras table i dont get the values in a stock z tune
thanks guys

[TFZ_Z06]

heres my tune thats in the car now...its a headers no cats intake z06....going HCI...attached is also the mail order
still dont understand why if i enter stock injector values in 96supras table i dont get the values in a stock z tune
thanks guys

The stock inj line for an 02 Z06 is set at a slope of

0.240536 For lb/hr and psi.
0.004394 For gm/sec and kpa.

This works with the injector voltage offset table and stock tuning. This is another reason I will only use stock style injectors with the same resistance.

The EFILIVE tabsheet of that spreadsheet is 0.00729235 and 0.39904 respectively. The HPT slope for kpa is 0.005556076.

The reason the inj values are not the same is because both tabs of the spreadsheet use different line slopes for the injectors. In real time tuning, the
injector offset voltages are also a concern as well as individual injector resistance, varied line pressures. In any case, its just a simple matter of different tuning math by GM vs the spreadsheet math.

The spreadsheet does offer good starter data, though I prefer using the same slopes as stock and inj style. I'm sure there is enough flexibility in tuning VE and many other params to get around any small variance in inj data.

[Kurtomac]

ok well i did what makes sense to me the stock value at a 28.8 lb injector used this formula both at 20kpa....
stock value (28.8) at 20kpa=3.7656
36lb ifr table value x
this is what i did 3.7656/28.8lb injector
x/36lb injector
so 3.7656 times 36 devided by 28.8 (cross multiplication) and got x to equal 4.707

value in my mail order tune =5.0234
value at 20kpa with 36lb plugged into the spreadsheet =5.367

[Kurtomac]

stock 28.8 vs 36 is a 24.444444444444% increase so you can follow the above post....so stock 3.7656x 1.2444444444444= approx 4.7...so further explain stock slope

[Kurtomac]

ok i reread your post a couple times....dont know where youre coming up with your grams/second per kpa value....wait...almost posted then redid the math took the 80 value and subtracted the zero value and divided by 80....got your exact number of 0.004394.....if you do this in incriments of 5 instead of the whole 80 then the numbers go down in increments of .0000002 per 5kpa....IE from 5 to 0 the difference per kpa is 0.0046876 from 10 to 5 its 0.0046874 doesnt know if this would make the slope different....i think it would be more accurated to do the cross multiplication per 5kpa....reguardless as long as you get this table close...tuning the ve table and maf tables to get commanded and actual to equal each other i think i should be good

btw where did they get this .007xxxx value they use in efilive if thats not the case....just to set us up rich just in case and then tune from there?
thanks