Reverse rpm limiter - is there?
05-31-2008, 09:42 AM
#1
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Reverse rpm limiter - is there?
Has anyone built a safety feature limiting rpm's when R is engaged? Suggestions? I do have few ideas in mind, but what is the most elegant...
- NY News last year: 11ppl killed as man in his 80's slips foot from Chevy brk pedal in R onto accel pedal, vehicle jumps over a group of ppl...
- News from seventies, Audi stops altogether selling pwrful Audi 200: blondies crash through garage doors on street while R....
The dilemma: when theres lots of pwr, put on R, small push with careless toe will cause inertia to push the leg more (fast repeat 10x) -and- car starts to rocket at full speed backwards. Unawares will freeze from fear, cant stop this dive on time.
Now. My fully loaded heavier than stock N/A family car start to go 6s. from 0-60mph (non accidentally)
. On Volvo scale T6, this means 280hp... dunno wassup, but no more sleepin horses in my barn.
oops R --->mama will accidentally kill smbdy if this R-problem is not solved...
Give out u input pls.
- NY News last year: 11ppl killed as man in his 80's slips foot from Chevy brk pedal in R onto accel pedal, vehicle jumps over a group of ppl...
- News from seventies, Audi stops altogether selling pwrful Audi 200: blondies crash through garage doors on street while R....
The dilemma: when theres lots of pwr, put on R, small push with careless toe will cause inertia to push the leg more (fast repeat 10x) -and- car starts to rocket at full speed backwards. Unawares will freeze from fear, cant stop this dive on time.
Now. My fully loaded heavier than stock N/A family car start to go 6s. from 0-60mph (non accidentally)
. On Volvo scale T6, this means 280hp... dunno wassup, but no more sleepin horses in my barn.oops R --->mama will accidentally kill smbdy if this R-problem is not solved...
Give out u input pls.
05-31-2008, 10:06 AM
#2
Has anyone built a safety feature limiting rpm's when R is engaged? Suggestions? I do have few ideas in mind, but what is the most elegant...
- NY News last year: 11ppl killed as man in his 80's slips foot from Chevy brk pedal in R onto accel pedal, vehicle jumps over a group of ppl...
- News from seventies, Audi stops altogether selling pwrful Audi 200: blondies crash through garage doors on street while R....
The dilemma: when theres lots of pwr, put on R, small push with careless toe will cause inertia to push the leg more (fast repeat 10x) -and- car starts to rocket at full speed backwards. Unawares will freeze from fear, cant stop this dive on time.
Now. My fully loaded heavier than stock N/A family car start to go 6s. from 0-60mph (non accidentally). On Volvo scale T6, this means 280hp... dunno wassup, but no more sleepin horses in my barn.
oops R --->mama will accidentally kill smbdy if this R-problem is not solved...
Give out u input pls.
- NY News last year: 11ppl killed as man in his 80's slips foot from Chevy brk pedal in R onto accel pedal, vehicle jumps over a group of ppl...
- News from seventies, Audi stops altogether selling pwrful Audi 200: blondies crash through garage doors on street while R....
The dilemma: when theres lots of pwr, put on R, small push with careless toe will cause inertia to push the leg more (fast repeat 10x) -and- car starts to rocket at full speed backwards. Unawares will freeze from fear, cant stop this dive on time.
Now. My fully loaded heavier than stock N/A family car start to go 6s. from 0-60mph (non accidentally)
. On Volvo scale T6, this means 280hp... dunno wassup, but no more sleepin horses in my barn.oops R --->mama will accidentally kill smbdy if this R-problem is not solved...
Give out u input pls.
05-31-2008, 10:39 AM
#3
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Well, Mandatory Mama 2x4" under pedal... not practical.
05-31-2008, 10:47 AM
#4
no need to send tranny into safe mode... why would you have to? which of your ideas involved putting it into safe mode?
05-31-2008, 11:09 AM
#5
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Rpm sensor.
05-31-2008, 11:31 AM
#6
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rpms switch (bakers electronics is the shiz) that cut's power to the injectors only in reverse. Would be effective, shouldn't give codes, but would involve some intense brainstorming for the wiring diagram.
05-31-2008, 11:42 AM
#7
but i was thinking that might be more effective for the MAF instead, to limit the fuel output to a falsified MAF signal, same thing, using a fixed resistor to switch in once you hit your desired RPM. since the MAF says how much air is coming in, that means you can only use x amount of fuel for that MAF level b/c y amount of air can only burn x amount of fuel... so maybe that would work better than faking the RPM signal
Last edited by CapedCadaver; 05-31-2008 at 11:46 AM.
05-31-2008, 11:51 AM
#8
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one way to do it is to have that rpm switch, to activate an SPDT relay, to switch the ECU's rpm input from the car's RPM sensor to another power source, which would have a resistor drop the voltage to emulate whatever RPM you want to limit it to (whether 2000 or w/e), and the ECU would say "o ok, we're going 2000rpm at WOT, let's use this much gas."
but i was thinking that might be more effective for the MAF instead, to limit the fuel output to a falsified MAF signal, same thing, using a fixed resistor to switch in once you hit your desired RPM. since the MAF says how much air is coming in, that means you can only use x amount of fuel for that MAF level b/c y amount of air can only burn x amount of fuel... so maybe that would work better than faking the RPM signal
but i was thinking that might be more effective for the MAF instead, to limit the fuel output to a falsified MAF signal, same thing, using a fixed resistor to switch in once you hit your desired RPM. since the MAF says how much air is coming in, that means you can only use x amount of fuel for that MAF level b/c y amount of air can only burn x amount of fuel... so maybe that would work better than faking the RPM signal
This is the warped signal when distr grounding fails = IT DOES. IF. Grounding has not been thoroughly cleaned. http://www.cardomain.com/ride/748507/10
http://www.cardomain.com/ride/748507/9
05-31-2008, 11:57 AM
#9
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It has to work seamlessly w/o hesitation.
05-31-2008, 12:05 PM
#10
the hard part about it is that it'll have one signal for level ground, but the MAF signal will be higher to maintain 2000rpm backing uphill, and less when backing downhill.. so maybe MAF is not the best idea after all. argh. how to make the rpm stay at the limit... retard timing perhaps?
05-31-2008, 12:31 PM
#11
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the hard part about it is that it'll have one signal for level ground, but the MAF signal will be higher to maintain 2000rpm backing uphill, and less when backing downhill.. so maybe MAF is not the best idea after all. argh. how to make the rpm stay at the limit... retard timing perhaps?
05-31-2008, 12:51 PM
#12
well an RPM limiter is going to have to tie-in to these other systems of the car and manipulate them anyways. as far as i can see the MAF, although it might act a little choppy, is the best way to do it... what if the MAF only gets disabled with RPM is over 1900rpm.. that way it's got a 100rpm buffer for the MAF to impose its limit of 2000rpm, and make it 2100-2200 on a VE for the 2300rpm MAF-unplugged limit. That sounds like a winner.
05-31-2008, 09:32 PM
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06-01-2008, 06:13 AM
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06-01-2008, 09:29 AM
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06-01-2008, 10:09 AM
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06-01-2008, 10:53 AM
#21
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06-08-2008, 10:59 PM
#23
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06-09-2008, 02:38 PM
#24
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Not full of kids actually, my class always gets out earlier than the others because of how bad the rednecks drive their trucks in the parking lot and I always look straight behind myself over my right shoulder. I'm not talking racing I just throw it into reverse, turn around and put the pedal down till it hits about 2500rpm not that I can really see exactly where it is at since I'm looking behind me but I know the engine well enough that I can just tell based on the sound.
06-09-2008, 02:51 PM
#25
Not full of kids actually, my class always gets out earlier than the others because of how bad the rednecks drive their trucks in the parking lot and I always look straight behind myself over my right shoulder. I'm not talking racing I just throw it into reverse, turn around and put the pedal down till it hits about 2500rpm not that I can really see exactly where it is at since I'm looking behind me but I know the engine well enough that I can just tell based on the sound.
now i do know someone who is "better at backing it up than going the regular way" but a) she's got a big booty
and b) she's still getting used to her first-ever manual tranny car. 
06-09-2008, 03:12 PM
#26
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I agree, I wouldn't recommend a 15 or 16 year old to just hit the pedal since someone who doesn't know what they are doing could easily spin out (or plain out learn how to do a donut on accident). I've slowly learned what I can handle with my maxima and I wouldn't attempt to drive a new car the same way. I doubt even I could floor it to the redline without losing control of it and likely the only time I'll ever perform such a maneuver will be when I'm trying to lose the cops in a need for speed game.
I don't like the idea of such a feature being installed on my car and the people that would need something of this nature don't need to be driving since they lack common sense so I don't see what the point of such a device is. You'd think people driving crazy in reverse would be more likely to hit a non-moving object which is less likely to be occupied than that car that is in front of them when they run a redlight. I'd rather see unsafe drivers taken off the road than companies investing in restricting things like reverse RPM.
I don't like the idea of such a feature being installed on my car and the people that would need something of this nature don't need to be driving since they lack common sense so I don't see what the point of such a device is. You'd think people driving crazy in reverse would be more likely to hit a non-moving object which is less likely to be occupied than that car that is in front of them when they run a redlight. I'd rather see unsafe drivers taken off the road than companies investing in restricting things like reverse RPM.
06-09-2008, 03:27 PM
#27
I agree, I wouldn't recommend a 15 or 16 year old to just hit the pedal since someone who doesn't know what they are doing could easily spin out (or plain out learn how to do a donut on accident). I've slowly learned what I can handle with my maxima and I wouldn't attempt to drive a new car the same way. I doubt even I could floor it to the redline without losing control of it and likely the only time I'll ever perform such a maneuver will be when I'm trying to lose the cops in a need for speed game.
I don't like the idea of such a feature being installed on my car and the people that would need something of this nature don't need to be driving since they lack common sense so I don't see what the point of such a device is. You'd think people driving crazy in reverse would be more likely to hit a non-moving object which is less likely to be occupied than that car that is in front of them when they run a redlight. I'd rather see unsafe drivers taken off the road than companies investing in restricting things like reverse RPM.
I don't like the idea of such a feature being installed on my car and the people that would need something of this nature don't need to be driving since they lack common sense so I don't see what the point of such a device is. You'd think people driving crazy in reverse would be more likely to hit a non-moving object which is less likely to be occupied than that car that is in front of them when they run a redlight. I'd rather see unsafe drivers taken off the road than companies investing in restricting things like reverse RPM.
06-09-2008, 03:45 PM
#28
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Can't say I know the feeling, I never have experienced any problems - I usually plant the heel of my foot on the floor of the car and it stays where I want it. I've had a problem on my mom's Xterra though, when you hit a bump on that thing your foot really doesn't want to stay in one place.
06-09-2008, 03:51 PM
#29
Can't say I know the feeling, I never have experienced any problems - I usually plant the heel of my foot on the floor of the car and it stays where I want it. I've had a problem on my mom's Xterra though, when you hit a bump on that thing your foot really doesn't want to stay in one place.
06-09-2008, 04:02 PM
#31
I dont even touch the accel to reverse. there is more than enough power for an "idle" engine, combined with the gearing for reverse to back up with sufficient quickness that only an idiot would take it above 2k. unless you have the worlds ****tiest engine?
06-09-2008, 04:03 PM
#32
it wasn't at all.. it was so gaping that the shifter moved side-to-side on/off throttle.... like a full gate side-to-side. almost impossible to drive, almost impossible to pick gears. reverse wasn't as harsh though... engine just pushed down and stayed there.
06-09-2008, 04:08 PM
#34
true, generally i only use the gas when reversing if i'm waaaay out in the open and know there's nothing to hit, or if i parked downhill. and that includes the launch into reverse... still don't really need gas for that.
06-09-2008, 10:31 PM
#36
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06-09-2008, 11:01 PM
#37
Why would anyone want a reverse rev limiter? My Taurus wagon was limited to 2200RPM in reverse and I hated it (built into the ECU programing though). Really ruined reverse J-turns and fun in the snow....
06-10-2008, 12:03 AM
#38
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Why o Why: havent u heard of a bypass sw? Dummies cant read nor use it, safety feature ON.
06-10-2008, 07:21 PM
#39
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I read it so don't be rude and insulting or go find a Scandanavian Maxima forum where everyone can read to your satisfaction.
You said that "mama will kill someone if this isn't solved"
should she be in a car that has to have a limiter to keep her from loosing control and killing or injuring someone? maybe she should find another method of transportation where she can't hurt anyone (walking, riding a bike)
Last edited by gapboi210; 06-10-2008 at 10:42 PM.
06-10-2008, 08:58 PM
#40
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