Trip meter fitting

[seandoyle]

As per title,what’s involved in fitting a trip meter. I’m interested in entry level Brantz I think, unless someone has a better suggestion. Other than the bracket needed on the passenger side, it’s the speedo & electrics etc than I’m most curious about.

[agricola]

They are easy to fit.
You can either cut the speedo cable then slide the sensor over the inner and re join the outer with jubilee clips.
If you struggle to route the cable minispares do extra long cables.
Also be careful with plugs as interference can be a problem.
Alternatively you can use a magnetic sensor I did this by putting tags on 2 of the Hardy spicers bolts (diagonally opposite) that worked well too and the sensor can be tucked up and protected by the sump guard. If you calibrate them properly they are accurate. Remember to choose your Brantz carefully as some events wont allow those that show average speed.

[surfblue63]

The electrics are quite simple. It just needs a fused live feed, which Brantz can supply. All the sensor stuff comes with the Brantz kit.
As for the speedo fitting there are a few options. I purchased a Brantz International Pro2, just before lockdown, to go into my rally car I have yet to fit it, but looking at the instructions it shouldn't take more than a few hours. I have gone for the sensor (BR1) that fits into the existing speedo cable. To fit you have to cut the outer cable and attach the sensor part into it. On the electrical side the cable from the meter just connects to the spades on the sensor. I've gone for this method as the speedo is going to be mounted onto a works type flat dash panel and all the parts will be inside the car and away from the elements.
You can get sensors that fit onto the back of a speedo, or onto the gearbox, or read from a wheel. On a Mini fitting the wheel type sensor is difficult because of the size of the brake hubs, the gearbox option is also a pain because of clearance issues.

Your first stop should be this web page were all the Brantz meter and sensor manuals can be found.

https://www.brantz.co.uk/manuals

[GraemeC]

Personally (and it purely a preference) I don’t like the speedo cable option as if the cable breaks at the gearbox then your trip stops. I also don’t think they are as accurate and are susceptible to false readings from wheel spin etc.

Similarly for using a hall effect sensor on any ‘driven’ part of the drive train as wheel spin affects the accuracy.

I chose to put a sensor in the rear brake drum, reading off the wheels stud heads as they go past. I have a sensor in each drum and a switch to swap between them, so if one fails I still have trip. Ideally I should calibrate the trip to each one for each event, but I’ll admit I never go that far.

[SMOKE GREY]

Personally (and it purely a preference) I don’t like the speedo cable option as if the cable breaks at the gearbox then your trip stops. I also don’t think they are as accurate and are susceptible to false readings from wheel spin etc.

Similarly for using a hall effect sensor on any ‘driven’ part of the drive train as wheel spin affects the accuracy.

I chose to put a sensor in the rear brake drum, reading off the wheels stud heads as they go past. I have a sensor in each drum and a switch to swap between them, so if one fails I still have trip. Ideally I should calibrate the trip to each one for each event, but I’ll admit I never go that far.

I am with Graeme on this one, the speedo sensor is the easy one to do, but is not as accurate if you are on loose surfaces, or going quickly. We had a sensor fitted in the rear drum of Paddys 6EMO, for the RAC, which proved a god send, particularly when we were in the Caerwent military complex in the dark, with a junction between every

sensor.jpg

sensor.jpg

50 and 200 yards, flat out in the lower three gears for twenty minutes, the speedo type would have been dire. All depends on your needs though. Attached is a pic of the sensor in the rear drum on my rally car.

[Catmint]

Seem to recall that Brantz recomended taking a fused supply direct from the battery and that all terminals should of the soldered type. As mentiuoned before good quality silicone plug leads are a must especially if you fit a digi clock as well.

Like the idea of the rear sensor, though accuracy was never our great issue as it always seemed to go tits up after the second junction for other reasons

[agricola]

If you are doing HRCR road rallies, 12 cars the speedo drive is good enough as the test arent normally measured so road calibration is good enough, change the odd cable etc. For the rough stage type stuff then look to more sophisticated setups, rear brakes very neat setup.

[GraemeC]

I think I'd say the exact opposite - HRCR road rallies, especially with regularity, you definitely need the accuracy if you want results. Even more so for HERO events.
Stage rallies probably don't even need a Brantz most of the time

[agricola]

Yes but at a 20, 30 mph regularity you shouldnt have wheel spin and speedo were used for years on Haldas etc. Its surely down to calibration in the end its only about transferring wheel rpm into distance? Or am I missing something?

[GraemeC]

Not all regularities are on sealed surfaces and when on a loose surface and a tight turn it is easy to spin a wheel, even at low speeds.
Plus, with traffic, controls, devious route instructions etc actually speeds regularly go way above the averages.

Yes speedo cables was used for Haldas, but at a point in time when everyone was using that technology. Now people are using more and more accurate methods (not all new tech either with the use of Curtas measuring time in deci-minutes - that really makes my head hurt!).

Of course, even sensing the rear wheel will create some inaccuracies with one wheel travelling further than the other in bends and wheels locking up under braking, but generally it is less.

[agricola]

So avoid handbrake turns then!!!!

[seandoyle]

Thanks for the positive & helpful replies.