Speed limiter

[Wedge fan]

Hi Guys - first post here.  From searching the forum I can see that setting up a "pit lane" speed limiter is possible whereby fuel and/or ignition "cutting" is used.  Can this be used as a limiter on the road as well or could it result in engine damage if used for prolonged driving?  There are many roads with averaging cameras around me and I find the speed limiting function on my daily driver invaluable.  Can any of the Link ECUs be configured to use the electronic throttle body to do this - is this even possible?  Unsure how this is done in, say, my Mercedes.  

The car is a 1974 Lotus Elite with a 2.5l supercharged Lotus 912 engine.

Thanks for your help.

Pete

 

[koracing]

Certainly if you have a good speed signal it should be possible to set up a limiter that wouldn't damage the motor to limit speed based on a one or more parameters --  multi-position rotary switch for example, or by speed and by gear for example.  Cutting fuel is usually not too damaging and whatever limiter you choose is probably not something you would want to actually "ride", but rather a limiter that doesn't allow you to exceed a level of speed allowing you to drive just under that limit per normal.  Alternatively you could probably engage a severe power reduction as required when a particular set of parameters is met - large timing reduction for example.  Something like this would not cut per-se but it would really slow the acceleration down making it possible for you to more easily monitor speed if you engage that mode.

[Confused]

If you've got E-Throttle, then you can get easily make use of the Cruise Control feature!

All you need is a set of cruise buttons - either one that has multiple individual outputs (and the corresponding number of Digital Inputs free), or one that uses a 5v feed and only needs a single Analogue Input, and a brake switch wired to a Digital Input.

I've used a Mitsubishi cruise control switch on my 1967 Ford Anglia 105E, which is of the type that only needs an analogue input.

This functions just like cruise in an OEM car, you can set, cancel, resume, increase and decrease set speed, and using the brake also disengages.

 

Take a look in the Help in PC Link at the Cruise Control feature to see more details!

[Wedge fan]

Thanks very much guys.  I will be using an E-throttle and the idea of cruise control is a good one - but in a line of traffic you're forever having to change the settings to speed up or slow down.  A speed limiter allows you to follow the traffic without changing the setting but stops you exceeding the limit if a gap opens up in front of you.  Stops you having to constantly keep looking at the speedo!  Much safer.

Nice to know if I use the "pit lane" speed limit format the engine would be safe.  You're right Kris - I wouldn't be "riding" this setting.

Thanks for the pointer to the help files Confused.

Can the E-throttle be used for speed limiting do you think?

Pete

[koracing]

I think you should be able to the e-throttle to not allow as much open by using multiple target tables triggered by some input logic and starting to close the throttle to reduce power when you go over the speed desired.

[Wedge fan]

Thanks for all your help.  I'm now pretty sure that I can set this up in an XtremeX.  Just got to buy one now 

Pete