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Discussion Starter #1
I know this idea has been previously thrashed (and trashed) about, but it doesn’t seem to have come to any conclusion.

Has anyone been able to install a cruise control on the Elise? I have a 2007 and understand the mechanics of the drive by wire system…I’ve read some of the posts about possibly adding the function to the ECU…but nothing seems to have come of it.

I do SIGNIFICANT road trips with my cars (e.g., Chicago to San Diego, Chicago to Tampa, trans-Canada, etc). I drove the Elise to Chicago from Virginia…and other than lack of CC, I find it ideal for road-tripping.

Any suggestions?

john m / ML1
 

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i haven't seen a cruise control for DBW, its harder to do properly since it uses out of phase pots for safety, you could do it with a manual push of the throttle but that might get you on one of those americas _______ driver shows.

its really difficult to do it on the ecu side too, since it has a dedicated part that checks and rechecks the throttle settings constantly and shuts it down if there is an issue, never mind the liability aspects.
 

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CharlieX is the ECU guru and no doubt what he says about the later S2's with drive by wire is correct. I have a 2005 with cruise fitted by a shop in Hale's Corners, Wisconsin. It's been on the car since late 2004 and still works fine. It's based on a kit for the MR2. I have driven the car on three cross country trips and will do a fourth to LOG in May. I find it indispensable for long distance driving as I have arthritis in my ow back and can't sit with my right leg in a fixed position for extended periods. Maybe you should consider trading for an earlier car with mechanical throttle linkage...Dave
 

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use the cable of the cruise control to pull on the throttle pedal.
i did with mine that way.
that way you're not into the ECU.
i never did finally, fully install mine, it became unnecessary before i even got it sorted out.
later removed the whole thing.
sam
 

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Discussion Starter #5
Thanks,
Charlie--respect that you have as much or more insight to ECU than anyone, so I can forget about that.

Dave, I really like the aspects of the '07...trading isn't really an option for me.

Sam, I read some posts about your earlier efforts...I have some experience installing a CC system on a Toyota (a T100) a few years ago ---two things gave me pause about trying a CC system on the EL:
The 'pull' wire was vaccum actuated and was a rather large Vac servo unit---fitting it to the El might be difficult,
and more significantly, the speed sensor was a rather 'ignorant' magnets-on-the-driveshaft arrangement.

Did the setup you were working with take into consideration a 'speed sensor'?

Thanks, again,
John m. /ML1
 

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This is intended for motorcycles (even though it says universal), and you can get a very small vacuum ball for it and it will work, at least for a motorcycle... "Filling" the vacuum ball should be a lot easier for the Elise than for a motorcycle half the size. Don't know if it will work or not, but it does operate with a VERY small vacuum storage.

Amazon.com: Audiovox CCS100 Universal Vacuum Cruise Control: Automotive

EDIT: Brain error. It is intended for automobiles, but it works on motorcycles. Not sure how I messed that up. Ride Safe. Drive Safe. Be Safe.

:)
 

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Discussion Starter #7
yes, thanks. That's very similar to the one I put on my T100 a few years ago. The problem with it is the 'speed sensing'....I'm not sure there's a way to tap into the Elise Vehicle speed sensor. The 'option' with that kit is the (crappy) magnets on a driveshaft arrangement---very poor and cumbersome. The vaccuum canister is still the size of a grapefruit, but I suppose it could be fit....but leads to other questions --- in order to put the 'pull' wire on the accel pedal wire, the servo would have to be in the pass compartment/footwell. Getting engine vaccum up there could be a big PIA.

Regards,
john m /ML1
 

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I'm surprised to learn that it isn't straightforward.

Once the controller knows desired speed, current speed and throttle position shouldn't it be straightforward to adjust the "virtual throttle position" to get speeds right? Maybe the pedal doesn't move, but who cares?
 

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You can bypass all the security checks and override it, but that'd be a really bad idea.

You're not in control of the throttle on a DBW car, the ECU is, you're only in control of the pedal position sensor.

I'm sure someone somewhere has figured out a mechanical system to run the pedal sensors, but disabling the security checks wouldn't be a good idea, since the ecu would have no idea if the pedal sensors had failed.
 

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i used an electric type unit which was tucked up under the right hand under dash.
the actuator cable threaded AFICR high on the front bulkhead and down to the pedal.
the cable was attached to the pedal with the little chain so there was no interference with the normal operation.
i'll look and see what pix i may have.
i didn't get around to the annoying magnet stuff and as time went by, there were more pressing matters at home, plus, i found i was ok without the CC.
i removed the stuff later.
sam
 

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I will be doing mine soon but it is a 2005. I bought a speed sensor that goes into the bell housing. Stock Toyota part.

I have been thinking of doing this for a while...since dwkoski did his. I have so many things to do before summer including getting my Seven back on the road...installing a Sector SC kit for a fellow LOONY and finishing up my 71 Elan. I have been rather busy with work so the Lotus stuff takes a back seat.

I also have to install those motor mount things....and I want to put in that new short shift kit...
 

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I'm sure someone somewhere has figured out a mechanical system to run the pedal sensors, but disabling the security checks wouldn't be a good idea, since the ecu would have no idea if the pedal sensors had failed.
I don't meant to hassle you, but I also don't get what this means. If the pedal sensors fail, doesn't that mean any TBW car is screwed, cruise control or otherwise?
 

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No worries chris.

the pedal has two sensors built in so it can reference them both to make sure its working ok, if either of them reads incorrectly the car immediately overrides the pedal input and sets a throttle restriction, allowing you to safely slow down.

so if you override the input inside the ecu for the cruise control, the ecu has no way of knowing if the input is coming from the pedal or the cruise control unit, so how does it know if the pedal sensors have failed, if you're overriding them.

the cruise control would have to exactly duplicate the dual pedal sensors in order for it to work, so a mechanical actuator on the pedal box would probably be easier.
 

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Discussion Starter #14
I will be doing mine soon but it is a 2005. I bought a speed sensor that goes into the bell housing. Stock Toyota part.

I have been thinking of doing this for a while...since dwkoski did his. I have so many things to do before summer including getting my Seven back on the road...installing a Sector SC kit for a fellow LOONY and finishing up my 71 Elan. I have been rather busy with work so the Lotus stuff takes a back seat.

I also have to install those motor mount things....and I want to put in that new short shift kit...
>>> bought a speed sensor that goes into the bell housing. Stock Toyota part.

can you tell me more about this? Is is a constant or pulsed output---do they give you the specs?(..presume microvolts?)

THx,
john
 

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>>> bought a speed sensor that goes into the bell housing. Stock Toyota part.

can you tell me more about this? Is is a constant or pulsed output---do they give you the specs?(..presume microvolts?)

THx,
john
Pulsed, 4 per revolution. 12v signal (IIRC). Damm expensive for what it is too.
 

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>>> bought a speed sensor that goes into the bell housing. Stock Toyota part.

can you tell me more about this? Is is a constant or pulsed output---do they give you the specs?(..presume microvolts?)
Check this thread: http://www.lotustalk.com/forums/f133/touring-radio-not-wired-speed-8644/ for information on the stock Toyota speed sensor that plugs into the transmission. It pulses (on off switch) as it is rotated - the speed of the pulses is proportional to the speed of the car.

QUOTE=ads_green;1228083]Pulsed, 4 per revolution. 12v signal (IIRC). Damm expensive for what it is too.[/QUOTE]

Around $220 for a new one from Toyota. But in this thread http://www.lotustalk.com/forums/f129/needed-speed-pulses-cruise-control-39615/, Tony mentions that he picked up a used one (I assume) for a 2004 Toyota Matrix for $40. The speed sensor is used in a lot of the Toyota models...
 

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No worries chris.

the pedal has two sensors built in so it can reference them both to make sure its working ok, if either of them reads incorrectly the car immediately overrides the pedal input and sets a throttle restriction, allowing you to safely slow down.

so if you override the input inside the ecu for the cruise control, the ecu has no way of knowing if the input is coming from the pedal or the cruise control unit, so how does it know if the pedal sensors have failed, if you're overriding them.

the cruise control would have to exactly duplicate the dual pedal sensors in order for it to work, so a mechanical actuator on the pedal box would probably be easier.
I've thought about using a programmable logic controller to correlate an input of VSS frequency to dual outputs (fed through a DPDT relay) to the signal coming from the pedal box...

The pedalpox is probably linear, and even if it's one pot increasing and one pot decreasing, it's still totally within realm of a PLC or even a simple microcontroller.
 

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Discussion Starter #20
I've thought about using a programmable logic controller to correlate an input of VSS frequency to dual outputs (fed through a DPDT relay) to the signal coming from the pedal box...

The pedalpox is probably linear, and even if it's one pot increasing and one pot decreasing, it's still totally within realm of a PLC or even a simple microcontroller.
Wouldn't (inadvertently) touching the pedal then throw the signaling off?

john m. /ml1
 
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