25% scaling help

[kjlindgr]

Hey all, looking for a bit of advice here on a E67 project. It's a TBSS that has a 383ci engine and Procharger. Will be a SD tune with ZR1 MAP. Happens to have ID1700 injectors in it which are overkill, however what I'm trying to work with. The IFR of the E67 is limited to 63lb/hr which makes scaling around 25% to cover the ~190lb/hr flow rate of these injectors at 400kpa.

That said, I'm getting balled up a bit trying to get this all to work right. I'm not able to do the IFR + Volts multiplier trick, nor the IFR + Stoich trick due to the limits of both tables in the mix. I tried to scale the more traditional way that the DSTECK write-up suggests but I'm missing something or have any number of things goofed up. Hoping someone can give me some advice on a 25% multiplier startup tune.

The engine will sometimes crank and fire, however it doesn't want to stay running. Spark is all over the place. AFR's swing wildly between rich and lean.

Attached I have the OEM tune along with one I've been trying to modify to get to idle at least. Likely all modifications are incorrect/junk/trash

If anyone can set me down a correct path, I would appreciate it. I'd hate to hack this up so much that it impacts transmission functioning, etc. If anyone has an example tune where they did a 25% scaling on an auto, that would help greatly.

Thanks all!


OEM.hpt
TUNE_boost_patch_0004.hpt

[Ben Charles]

25% scale not going to work.. can triple stoich and lower IFR...

[kjlindgr]

The issue I have with the stoich approach is that there appears to be a hard limit of about 33, which really only allows me to effectively double the value. That would work great if injectors only needed to be scaled 50%. Is there a combination of a few of these that I could implement? I was thinking to max out IFR table at 63 lb/hr, double stoich, and change the IFR/voltage modifier but not sure if that math will work out when doing the cylinder air calculations.

Target IFR needed is 190lb/hr
Max out IFR to 63

(next two either this way or vice versa)
Double stoich should get you to 126
Change injector voltage offset from 1.000 to 1.500 should get you to ~190

But again, not sure if this is will work the way the ECU does its calculations...

[Ben Charles]

I assume you are on e85 then due to triple stoich not working??

If so I would do a 50% scale to make it easier then do double stoich.. basically what I do for 200+ IFR injectors on these ECMs

IFR modifier doesn’t work on all OS so I never go that route

[kjlindgr]

This truck is on gasoline.

Maybe I'm not following well. A 50% scale of these injectors based on ID's info is about 95lb/hr, which surpasses the 63lb/hr limit of the ECU. The stoich hardcoded upper limit looks to be around 33:1 AFR which on gasoline, I'm also only limited to doing a 2x multiplier on before I reach the cap.

Can you guide me a little bit more on which combination of these you would start with? Then I'm assuming the remaining of the scaling is done in the VVE tables or do you tweak things like engine size?

[Mr.z0611]

What type of fuel system? Camshaft?

[kjlindgr]

Return style fuel system (MAP referenced) with a custom ground boost cam from Howards.

[Ben Charles]

Sorry e85 can do the triple stoich, I would do a double stoich and 50% scale that will get you under the 63.x IFR end since return system be a single flat rate

Camshaft won’t matter on this tune procedure

[kjlindgr]

At 400kpa (58PSI) of base pressure, these flow 190lb/hr. Are you suggesting that I turn the base pressure down to 176kpa (25PSI) so I can get to a flow number where 50% scaling is under that 63lb/hr threshold? Below is ID's IFR -

flow.png

[07GTS]

if u dont need the flow then use 43.5psi base pressure might make scaling easier

[Ben Charles]

190 gets cut down to 95 with double stoich... 50% scale cuts that down to 47.5

[JamesSmeby]

Did you get this figured out? I'm kinda in the same position.

[SinisterSilverado]

I?m trying to get my injector data correct for my Bosch 210s on my e38 Pcm, 07GTS can you help me out? Maybe send me one of your old tune files to see if that helps.