fbodysetc

iTrader: (5)

What do I need to change to put 30lb injectors in. I have hptuners so any help would appreciated. Thanks Nathan

horist

what year car?

Easy way would be to just upscale the injector table... 99-00 cars have 26lb injectors, 98, 01 and 02 have 28 lb injectors

May take additional tweaking of VE depending on the flow characteristics of the injectors you're putting in...

Edit: Incorrect values removed

fbodysetc

iTrader: (5)

Sorry I guess I should add that my injectors are 30lb ford motor sports and my car is an 01.

horist

ok, I think the 30lb FMS are rated at 3 bar... so since 4 bar is 25% more flow, the 30lbers would act as 37.5lb/hr injectors in our cars...

I'll try to find out wether the 28lb/hr injectors are 28 @ 3 bar or 28@ 4 bar

if they're 28 @ 4 bar then you'd scale the IFR table by 125% ... but if they're 28@3 bar you'd only scale 107%

I'll see if I can find out... if anyone knows for sure please post up

horist

ok... last edit

1 bar is 14.7psi
2 bar is then 29.4psi
3 bar is 44.1 psi
4 bar is 58.8 psi

so your 30lb @ 3bar is going to be 34.64lb @ 4 bar
so you're scaling from a 28@4 to a 34.64@4
so a difference of 23.7%

so scale the table by 1.237%

Thanks for the assistance HumpinSS I was off w/the PSI for the various bar levels... but my math was right

Also found out that HP Tuners has a unit conversion tool , tool unit conversion that lets you convert your injectors from flow of x @ y psi to what they flow at z psi


Edit fixed percent

HumpinSS

iTrader: (1)

Yeah what he said

fbodysetc

iTrader: (5)

So times everything by 1.19?

horist

Lemme verify my math real quick

30@ 3 is 34.64@4

so now we need to know the percent difference between a 34.64 and 28 injector
34.64/28.8 = 1.237 ... so there's a 123.7% difference between the two

Check:
28*1.237 = 34.636

OK... I don't know what I was pressing to get the above values

scale the table by 1.237 and that should be a good starting point

horist

Flow Rate vs KPA: Stock 01 table:

28.71 28.89 29.08 29.27 29.45 29.58 29.76 29.95 30.13 30.26 30.44 30.63 30.82 30.94 31.13 31.31 31.44

Your Table should read: (just did a times 1.237 on all)
35.51 35.74 35.97 36.21 36.43 36.59 36.81 37.05 37.27 37.43 37.65 37.89 38.12 38.27 38.51 38.73 38.89

fbodysetc

iTrader: (5)

In a magazine I have it says to divide new pressure by old pressure then multiply by old flow rate and that would equal new flow rate so...
60 divided by 42 times 28 equals 39.99

SSean

Thats some good info, thanks!

horist

yea you're right... the difference between 3 bar and 4 bar 133% ... when I use the conversion formula in HPT it says the difference is only 115.5%

so almost exactly 1/2 ... maybe something here I don't understand?

Assuming you just use

4bar psi / 3 bar psi you get a difference of 33%

so 30 * 133% is 39.9

39.9 / 28 = 1.425 so a difference of 142.5 %

fbodysetc

iTrader: (5)

Thanks for your help.

fbodysetc

iTrader: (5)

Who did the tuning on your car ? My cam is a little bigger than yours except the ls is tighter. Im new to this tuning stuff just wondering what all you might have changed.

fbodysetc

iTrader: (5)

Can either one of you answer this..... When I put my motor togther I put new crank rods pistons but never did a crank relearn but it doesnt throw the crank relearn code. It runs good sometimes but then will go into a spitting sputtering fit while at part throttle. Also 75% of the time it seems like it is missing at idle part throttle. Would the tune being off cause this are do I have to have a crank relearn done. My came is pretty big also 24X 240X 109 +6 6XX lift

horist

ok... this is interesting ... HumpinSS found this site:
http://www.racetronix.com/621020.html

if you look at the static values ... 31.6 @ 3 and 36.5 at 4

using the formula 31.6* 1.33 you get 42 ... but using the formula in HP Tuners you get 36.49

I called Keith to inquire about this to make sure it was calculating right and he confirmed it was correct (he had to pull over on the road and whip out the laptop but he confirmed the formula... hehe)... and this site seems to demonstrate that...

so I would use 34.64/28 = 1.237 ... so 1.237 as a scale

SSean

A crank re-learn shouldnt be nessesary. The miss at part throttle is more than likley a tuning issue related to the healthy sized cam you have, though there is no real way to know until you were to start logging. What tuning do you have done so far?

To answer your other question, I'm actually tuning my own car. Do a little searching around on this board, there is a LOT of good info. The HP tuner board has some good info as well, but is a newer/smaller board, might have a better chance here, but also have an increased chance of getting bad info here, no offense to anyone here, just since there is so much more traffic. If you want to tune it yourself, read around...read a lot.

fbodysetc

iTrader: (5)

I havent done much yet just the basic stuff. Im fixing to put the injectors in and then try to figure out what to do

SSean

I'll let Horist chime in on this one. I have a pretty good understanding of how it all works, and latley, in reading and hands on, its all been comming together, but I dont want to tell you to do one thing or another.

Horist, please correct me if I'm wrong, but what I would do (what I'm doing with mine) Is starting out by scaling the VE table (putting my car in SD mode and going from there). Once that is dialed in, bring the other tables, more specifically MAF table, in line with that and make minor adjustments where nessesary for everything to come together. This is just for part throttle, WOT will come when the part throttle stuff is done. Of course its not that easy but thats a real brief summary :p

horist

PE adds fuel for more aggressive driving... from what I've read and heard though it's best to have an accurate VE table first and foremost... putting the car into Speed Density and using a WB02 to ensure as many cells as possible are running 14.7 AFR with as little variation in fuel trims as possible...

once you have a good VE table that's 14.7 everywhere or damn close to it, you can hook theMAF up and see how far off your VE is now... and scale it as appropriate until you have a clean looking STFT/LTFT (close to 0 which indicates you're getting 14.7:1 AFR in those MAP vs RPMs).

If you add new injectors obviously your fueling will be off... generally pushing you over 25 max for LTRIMs ... so then you can scale your IFRs using the mathmatical equations and it should get you pretty close to your good VE table again (again w/some tweaks possibly)

The PE table adds fuel during WOT (actually I think it's standard > 35% throttle) ... now if you have a good VE table... and the cells all hit 14.7:1 .. it's easier to dial the PE tables in... (WB02 isn't really necessary for this part throttle tuning though... since the narrowband O2s operate their best at 14.7:1 you can tune off of the Short Term Fuel Trims or Long Terms)

example , you want 12.8:1 AFR at WOT at a given RPM ... a PE value of 1 will yield 14.7:1 AFR at WOT which isn't good...

But a PE table of 14.7/12.8 ... 1.148 will give you (or attempt to give you close to) 12.8:1 AFR at WOT

Wideband helps alot in this full throttle stuff... just tomake sure you're running where you want and not too lean though...

Running an SD only tune you don't have to worry about the MAF... but if you do things to make the engine run more efficient you have to retune hte VE (so if you had cells that were VE of 90% ... 90% of the air entering is useable for combustion... if you somehow got it so that you're actually using 95% of the air, you'd be running lean... more air with less fuel) ... not enough to go boom or anything but could cause the LTRIMs to rise