mgrotel

iTrader: (3)

can you make it so the rev limit just bounces instead of cutting off the fuel with uprev osiris?

i always plan to shift before that point, but in the case i for some reason do not, i would rather have the rpms bouncing off the limiter instead of cutting fuel. my reasoning being that i will be on nitrous on occasion and cutting fuel with nitrous is not the best of ideas, if you know what i mean. thanks

SparkleCityHop

iTrader: (30)

I'm no Uprev tuning pro, but I have Uprev and I'm in the middle of setting it up for my own progressive nitrous controller, so this hit close to home. These are my thoughts:

They recommend setting the throttle cut rev limit 100rpm below your fuel cut rev limit. With nitrous, I'll be using a controller with WOT switch that senses "by wire" so the throttle cut will shutdown nitrous at the lower (throttle cut) limit - even with the pedal to the floor, it will no longer be "at WOT". The controller also runs an RPM window switch and I'm setting the top of that window just below the throttle cut rev limit.

For example, assuming a raised rev limit to 7300:

Uprev Fuel cut rev limit 7300rpm
Uprev WOT Throttle cut rev limit 7200rpm
Nitrous Controller WOT Throttle sensor "by wire"
Nitrous Controller RPM Window - 3000-7100

The controller also has a lean afr nitrous cutoff, which is a nice safety feature.

mgrotel

iTrader: (3)

yea, i can always just use the window switch to cut it off before then, but another saftey feature would be nice especially if its as easy as hitting a few buttons in the tuning software.

i would also add that even if your solenoids close at 7100 in your example, there might some nitrous still going through the lines after that. i know there probably wouldnt be, but the rpms are climbing awefully fast on spray so we are talking about a split second between 7100 and 7300 when all fuel is suddenly gone. i just like to err on the side of caution. but you are right, using the window switch is what i do and should be enough.


edit: i guess if i follow my logic all the way through this example, there would then be some fuel still in the lines after the fuel was cut at 7300, so that would leave a saftey buffer too i guess

SparkleCityHop

iTrader: (30)

It's not that different than letting off the throttle (as far as what's left in the lines).

The main part of your question could have been answered just with the throttle cut limit vs fuel cut limit, I probably muddied it up with the other switch questions, but felt those were probably a given safety consideration for a decent sized shot.

mgrotel

iTrader: (3)

yea, i still think it would be nice to have it bounce off the limiter instead of a fuel cutoff, so if anyone knows if osiris can do that, please let me know, thanks

0jiggy0

iTrader: (13)

He just told you twice. It wont be hitting fuel cut, try reading what he actually wrote.

viceversa

iTrader: (1)

mgrotel

iTrader: (3)

why dont you two read? no where was my original question answered, no where. he didnt tell me anything i already didnt know. if there is one thing i know, its nit setups.

once again, my original question:

can uprev osiris change the fuel cutoff to make it bounce off the limiter and keep moving fuel into the motor?

SparkleCityHop

iTrader: (30)

Set the fuel cut high. Set the throttle cut where you actually want it limited.

mgrotel

iTrader: (3)

is the throttle cut you are talking about part of your nitrous wot switch or are the throttle cut and fuel cut both part of the osiris software?

Vince@R/TTuning

iTrader: (7)

Bouncing off the rev limiter is fuel cut....essencillay u hit the limit...it cuts fuel..drops 200rpms(or whatever u set it at) turns the injectors back on...and then custs it again when you hit the limiter.

UPREV does not have a ignition cut option....as they are pretty dangerous anyway...

mgrotel

iTrader: (3)

ok, thanks vince.
i guess my question should be is there a way to make it go back to fueling quicker then? because now when i hit the rev limiter, it cuts fuel for a really long time, like a matter of seconds before i can go again. id rather it cut for a split second only like you refer to. thanks

Vince@R/TTuning

iTrader: (7)

^^^ that sounds like throttle cut actually. So what u will wanna do is raise your throttle cut to above your fuel cut and then make your fuel cut wherever ya want. Then make your fuel restore a 100 rpms lower. That will make it pretty quick. Also on the nitrous cars we set up we stop spraying at 6500 and fuel cut is 6800...

mgrotel

iTrader: (3)

perfect, thanks man

SparkleCityHop

iTrader: (30)

I thought that fuel cut was the one that took longer to recover from when it happened, whereas throttle cut was just that once you hit the rpm, it dialed back your throttle from being sensed as WOT and acted as if the throttle voltage was lower that WOT. But Vince is going to know much better than me - I'm an Uprev noob. I was probably just making the wrong assumption about how the two different limits that you can set in the software work.

djamps

iTrader: (1)

Fuel cut/restore is instantanious. It cuts fuel at a set RPM and restores fuel at a lower set RPM. So it can be as slow/quick as you set it to be.

Throttle cut on the other hand is a slow process... take VDC for instance (which relies on throttle cut to control wheel spin).

mgrotel

iTrader: (3)

good to know, i will make sure mine is set to fuel cut, my vdc is already disabled, thanks

SparkleCityHop

iTrader: (30)

This is why I love this site. I learn something new every day. Thanks guys!

redline06

Perfect! I was thinking about this all week but now I know lol thanks guys