99VetteFRC

I am going to start installing my turbos in the next week or so and will be running the HPT 2Bar SD OS.

I have some 80# injectors and need to know how to change the flow rate tables.

I will probably need more help once I get it all up and running.

i r teh noobz

iTrader: (4)

Do you have a data sheet for your injectors? You may need to adjust more than just the flow rate to get it running right.

https://ls1tech.com/forums/attachmen...5&d=1206840581

I haven't gotten around to swapping my injectors yet, but that spreadsheet shows up pretty often when I read how-to articles.

99VetteFRC

I didn't get the sheets. All that I got was 2 flow ratea at 2 different fuil pressures. Shows 80 lb/hr @39.5psi and 84.32 lb/hr@43.5psi. I bought them from ebay.

i r teh noobz

iTrader: (4)

Do some digging and see what you can come up with for offset voltages and stuff.

Taken from another forum regarding setup for larger injectors:


When changing injectors, you should expect to change:
Injector Flow Rate vs kPa
Injector Offset vs Volts (and pressure)
Short Pulse Adjust/Adder
Minimum Pulsewidth
Default Pulsewidth
Minimum Transient Fuel Mass/Time (not available on all PCMs)

Skipping or entering wrong data into any of these can lead to poor air-fuel ratio control or force you to unknowingly skew your MAF and VE calculations which will lead to driveability or idle control issues later.

Greg Banish
Calibrated Success, Inc.

99VetteFRC

Guess I will have to get a dyno shop to handle this. All this is very confusing.

i r teh noobz

iTrader: (4)

Do some searching on your particular injectors. It shouldn't be too difficult to do if you can find good data.

Try checking the tuning forum or the HPT/EFI Live forums.

Youtube has some basic HPT stuff, might be worth a look.

99VetteFRC

TY, I'll look into it, ut I wil probably get the car dyno tuned. I'm a little nervous about blowing it up.

TurboS10

iTrader: (12)

Injector Flow Rate vs kPa flow vs manifold pressure

Injector Offset vs Volts (and pressure) battery voltage affects how fast they open - low volts = slow, think cold startup or it's been sitting a few months- or you got a crappy parts store alternator with the slightly undersized diodes in voltage regulator that likes to drop output voltage when it gets hot... or you've got 3 amps, two electric fans, AC, and a big fuel pump....important table for tuning idle and very light throttle. - Some OBDI users used it to tune idle afr

Short Pulse Adjust/Adder- each injector set is different, but down around 1.5ms pw w/ high z injectors, they don't want to open too well or far. So you get bad spray ect. So you add say 0.2 ms so you actually get 1.5ms pw worth of fuel.With bigger cam etc, the low rpm ve goes away you and you have to pull fuel. Then you run 60's or 80's that flow a 1.5 - 2x stock.... the calculated pw goes below the ~1.5 minimum and it idles for sh....

Minimum Pulsewidth -IDK, sounds like the 1.5ms setting above, some OBDI's used it to swap to an alternate injector firing pattern.
Sequential firing pattern came out w/ late LT1's and did away with that nonsense...helps emissions, mileage, and ring wear.

Default Pulsewidth -IDK

Minimum Transient Fuel Mass/Time (not available on all PCMs)
Sounds like intake port wetting compensation during throttle transition

Greg Banish
Calibrated Success, Inc.- Buy his how to tune CD, it comes with a lot of the table data mentioned earlier.

I'm still learning the OBDII stuff. I started out with OBDI many years ago. Lots of the terms are similar. Just a lot more things you can adjust.

I used to have an A body w/ bbc. I miss it.....

99VetteFRC

I would try tuning, but I really need someone to set me up with a base tune. I am learning some things (the easier stuff to change) with the engine N/A, but next week puttin the turbos on.