WAHUSKER

iTrader: (4)

I'm trying to get my WOT fuel perfected. Right now my VE cells above 5k are set to 1.6-1.8, but HPT says the max is 28.0. Does the adjustment really go that high? I can't seem to find anything about this via searches....

Or would I be better off tweaking the inj flow rate table to compensate for the boost factor?

foff667

iTrader: (2)

VE in an 00 WS6 should have a max of 367% if im not mistaken off the top of my head. Not sure where your getting 1.6-1.8???

jimmyblue

iTrader: (11)

It's peculiar that you'd have a VE that high, and up there in RPM.
Are you trying to fake your way past a 1-bar MAP sensor or like
that?

ChrisS@sdpc

It sounds as if you are talking about the Power Enrichment table and not the VE table. The Power Enrichment table does have limits from 0-28. What is your target AFR? That table is used as a factor in computing commanded AFR (i.e. 14.7/factor = commanded AFR, 14.7/1.6 = 9.18 commanded AFR). If you are having issues with WOT AFR, you might not be getting the fueling you need as a result of the pressure differential across the injector. Are you running a 2 bar OS?

Doc

iTrader: (9)

If you are talking about the VE table, my limited knowledge/experience with HPT led me to believe it could only express/display the table as a percentage of perfect efficiency which is based off of the cyclinder volume calibration, if that value is not correct(you have a 402, is it accounted for?) then the VE table will not display correctly as a percentage.

If you can display the VE table in HPT as grams per cylinder*Kelvin/KPa (which is the default for EFI Live) or just grams per cylinder or grams per second then the values of 1.6-1.8 seem to make more sense. 1.6-1.8 as an EQ ratio value which, as a unit of measure for the PE table, would be super rich.

No. The inj flow rate table is what it is...Youre injectors and the pump's ability under load to provide flow. Use the RHS spreadsheet or better yet Fuel Pressure sensor and log the values, set it and forget it. As somebody asked before are you running a 2bar OS? That is the best way to compensate for the boost.

Doc

iTrader: (9)

Ok, from 13 views when I threw my 2 cents in till now, 55, no comment? Could an HPT peep please enlighten me and others (no sarcasm, I just want to help my friend use/understand HPT) on the viewing options for the VE Table. Thanks.

foff667

iTrader: (2)

Is there a question in there Doc?

WAHUSKER

iTrader: (4)

Yeah, sorry, I had my VE table open when I posted.....I meant PE. And yes, I am trying to tweak around 1 BAR. I have Mega Squirt on the car with a 3 BAR sensor, but so far it's been having issues (voltage I think). The car acts like the fuel shuts off momentarily when I hit the throttle. I am trying to get both issues resolved to dyno the car.

I have a Aero regulator ref'd to boost & a KB BAP with a 2 BAR ref driving my Racetronix pump to try to hold the pressure up. It drops a little at hi rpms but so far I can't seem to get the a/f to stay in the 11s up hi. So I was wondering how hi I can tweak the PE table. Or is that the wrong approach?

I know, I really should go with 2-3 BAR HPT. I had issues the 1st time I tried SD tuning, but MS showed me it can be tuned. But I haven't done it yet.

Doc

iTrader: (9)

Yes Bill, the question is what unit display options for the VE table does HPT have?

jimmyblue

iTrader: (11)

As far as I can see it's (VE) only %, for display / edit. The rest
of what takes it to grams, is done behind the curtain. Not
that it matters to the result I think.

With the manifold referenced regulator is the fuel pressure still
fading up top, and can you see the upstream pressure as well
as rail and manifold? If you have to command crazy PE numbers
to get the "right answer" somebody's falling down somewhere.
You might also want to see the injector duty cycle as the last
link of that chain. And be sure some sort of misfire issue (even
as simple as over-gapped plugs) isn't just hoaxing the wideband
with unburnt air, might be firing trouble at that high a boost?

I think surveying points along the fuel delivery path, for pressure,
is where I'd start though. PE failing to make a difference kind of
says something's bound up.

foff667

iTrader: (2)

Theoretical % to make it simpler to understand.

Doc

iTrader: (9)

Excellent Jimmy! My sentiment exactly. I had similar issues up top until I did the Autometer Fuel Pressure Sensor mod on the end of the rail. I used the EGR power and input, rewriting the Calculated EGR PID to utilize the FPS. I logged batt volts and FPS noticed the batt volts dropping like a rock and the FP following suit at WOT. I theorized that the original 98 alternator was letting me down. Now at WOT, the alt falls offline and the batt has to be up to snuff to carry the load. Mine was definitely not. I rebuilt the alt and upgraded it to a 140 amp o/p and, bingo problem went away. Autozone's alt checker said my bad alt was good to go, after taking it apart I found one of the six diodes bad on the rectifier that the Autozone bench checker didn't catch. Lots of things going on "behind the curtain" in all or any sofware package. About the display units, either way is fine by me, the only concern I have or had as a "newb" with the % of theoretical maximum was that I thought that logically 100% was 100% and going beyond it was meaningless. I struggled with lean conditions and messed with the PE table to make up for things. My stupid mistake. I am now OLSD w/ the RR acting in conjunction with my LC-1 as a fuel trim feedback ckt, only full wideband vice NBO2. So for anybody else just starting out, if you are using the %theoretical maximum display units then that's all it is...theory. That is why you can have ~300% figures.

Thanks Bill, not being all that familiar with HPT I hooked up my Road Runner on a friend's vehicle who was having fueling up top issues. We made some great progress with the RR and at the end of the day we wanted to extrapolate the work we did with the RR in EFI Live to his PCM. I am not licensed to his PCM and I was trying to figure out the least painful way to "export" the work (He uses HPT). The first obstacle was the fact that I had my VE setttings in grams/cyl and he had %theory... I couldn't figure out how to change the VE display settings in HPT so I changed them in EFI Live. Thus, my question in this thread. I thought it might just be me not being all that familiar with the HPT software.
We still had to hand sribe the work...I bet Marcin being the Excel ninja he is would know how to cut, copy, and paste such a thing...Hint, hint.

After having done the FPS mod I highly recommend everybody do it.

RedHardSupra

iTrader: (1)

i see the bat signal in the sky...
remember that the pressure you measure with the autometer fuel pressure sensor you get only the static portion of the total pressure. the pressure driving the injectors is a sum of static and dynamic pressure. the dynamic pressure is mostly related on the speed of fuel (read: RPM)
so that drop of pressure you're seeing is only a part of a story. if your voltage is constant, and the fuel pump is big enough to keep up with the injectors, i bet you the drop is directly proportional to the rpm^2.

the only sucky part about this is that all my december writeups are wrong, because i wasn't aware of this little bernoulli's principle until a pknowless brough it up...damn phd's