DUH!!!... I should just be able to tap into one of the 4 sensors tap by the ABS unit then to get my speed (MPH)..

What do you think?

//Gilbert

 

The injector shut off is to save gas. On carb cars, the vacuum just skyrockets, and it sucks some gas, making those wonderful pop sounds under engine braking. This fuel shut off is only possible with fuel injection, where you can make sure no gas is put into the cylender.
I haven't looked when I've hit the ECU RPM limits.... But it's probably similar, except it just drops power strokes randomly (I think).
I haven't tried the ABS sensors as inputs... But be carefull, as it seems that the analog inputs (maybe the speed as well) has noise on em. Don't know if this wil confuse the ABS system....

Matt

 

Ok, I better be careful here.. I don't have the expertise when it comes to electrical stuff/analog/hertz, all that stuff.. I better ask the PLX forum/admin to see what my options would be..

What does it actually mean that the inputs has noise on them? Is there some type of a filter/one way valve kind a thing that can be put , so the noise won't go back to the ABS module..? So I guess this is the same as one of the threads above when you mentioned about not tapping into the knock sensor yet since it might just confuse the DME... I'm really surprised why/how the inputs are "noisy"... PLX should have somehow put something so it's a clean line..

Thanks

///Gilbert

 

Noise onto the knock sensor wasn't a surprise, this may not make sense, but that's why Mini used a shielded twisted pair into an isolated, differential input.
It seems the PLX guys know their digital stuff, but for the analog they give you those capacitors in the kit. These act like filters, somewhat, but are only a bandaid... Proper analog signal handling would have eliminated the need, but added some costs ($50 -$100 to the end user).
If you tap into the ABS wheel speed signal, check to see if the signals are carried in a shielded two conductor wire. If so, tread lightly... If it's just a single conductor, have at it. My guess is that it's the former....

Matt

 

Matt,

900°C is this correct? That equates to around 1700°F. I was always under the impression that 1300°F was the safe limit before you heat the pistons to the point of failure. I know some folks that have melted pistons at 1700°F measured off the header. Now this was on Turbo Diesels, so not sure what differences there is between a gasser that is sc & one that is turboed.

Thanks!

btw nice write-up!

 

do you have any update on your r-500. After readin your review and instalation, i am rethinking my options. Have you found a way to work out rpm as an actual number etc...?

 

nice job on the wiring Dr. O. heres a link to the SAFC-II wiring which includes the RPM pick up. If you still haven't wired it yet.. its post number 15
https://www.northamericanmotoring.co...highlight=safc