Will my Brantz work if the car odo doesn't
Discussion
Asking here following the demise of Classic Rally Chat.
My car’s cable-driven milometer in my new classic rally car doesn’t work and the speedometer needle fluctuates. The cable is new and the fault seems to be in the “clocks” rather than the cable. I haven’t fitted the Brantz (from my old car) yet. Will the Brantz still be accurate? I realise it counts cable revolutions and therefore should be unaffected as long as the cable is revolving, but might the broken mechanism cause the cable to revolve inconsistently and therefore the Brantz to be inaccurate? Having trounble finding replacement clocks.
My car’s cable-driven milometer in my new classic rally car doesn’t work and the speedometer needle fluctuates. The cable is new and the fault seems to be in the “clocks” rather than the cable. I haven’t fitted the Brantz (from my old car) yet. Will the Brantz still be accurate? I realise it counts cable revolutions and therefore should be unaffected as long as the cable is revolving, but might the broken mechanism cause the cable to revolve inconsistently and therefore the Brantz to be inaccurate? Having trounble finding replacement clocks.
Mmm... tricky one that. I would suggest:
find an empty dual carriageway somewhere
drive a short section at 20mph
drive it again at 30mph
drive it again at 40mph
etc
...and see whether the distance recorded on the Brantz is the same in each case. You'll have to guess what speed you're doing of course if the speedo's flaky, but you see what I mean.
If at all possible, also cross-check that distance against a satnav (which really should be accurate).
If it all checks out ok then I'd be inclined to think that the poorly speedo isn't affecting the cable.
find an empty dual carriageway somewhere
drive a short section at 20mph
drive it again at 30mph
drive it again at 40mph
etc
...and see whether the distance recorded on the Brantz is the same in each case. You'll have to guess what speed you're doing of course if the speedo's flaky, but you see what I mean.
If at all possible, also cross-check that distance against a satnav (which really should be accurate).
If it all checks out ok then I'd be inclined to think that the poorly speedo isn't affecting the cable.
robg2 said:
Mmm... tricky one that. I would suggest:
find an empty dual carriageway somewhere
drive a short section at 20mph
drive it again at 30mph
drive it again at 40mph
etc
...and see whether the distance recorded on the Brantz is the same in each case. You'll have to guess what speed you're doing of course if the speedo's flaky, but you see what I mean.
If at all possible, also cross-check that distance against a satnav (which really should be accurate).
If it all checks out ok then I'd be inclined to think that the poorly speedo isn't affecting the cable.
Going to check it with sat nav - genius. find an empty dual carriageway somewhere
drive a short section at 20mph
drive it again at 30mph
drive it again at 40mph
etc
...and see whether the distance recorded on the Brantz is the same in each case. You'll have to guess what speed you're doing of course if the speedo's flaky, but you see what I mean.
If at all possible, also cross-check that distance against a satnav (which really should be accurate).
If it all checks out ok then I'd be inclined to think that the poorly speedo isn't affecting the cable.
Chris.
The Brantz speedo sensor should't be affected by the clocks malfunctioning as long as the mechanical attachment of the speedo cable at the gearbox end is fine and the cable is in one piece the Brantz should be OK.
Not sure if you do Facebook or not, but there is a classic rally chat page, where a few of the regulars from the forum still discuss things. You might need to be invited to join though??.
The Brantz speedo sensor should't be affected by the clocks malfunctioning as long as the mechanical attachment of the speedo cable at the gearbox end is fine and the cable is in one piece the Brantz should be OK.
Not sure if you do Facebook or not, but there is a classic rally chat page, where a few of the regulars from the forum still discuss things. You might need to be invited to join though??.
velocemitch said:
Chris.
The Brantz speedo sensor should't be affected by the clocks malfunctioning as long as the mechanical attachment of the speedo cable at the gearbox end is fine and the cable is in one piece the Brantz should be OK.
Not sure if you do Facebook or not, but there is a classic rally chat page, where a few of the regulars from the forum still discuss things. You might need to be invited to join though??.
Hi, Thanks for the reply. I've searched on Facebook but all I can find is a French classic rally group. The Brantz speedo sensor should't be affected by the clocks malfunctioning as long as the mechanical attachment of the speedo cable at the gearbox end is fine and the cable is in one piece the Brantz should be OK.
Not sure if you do Facebook or not, but there is a classic rally chat page, where a few of the regulars from the forum still discuss things. You might need to be invited to join though??.
The answer depends on how you're drawing a feed for the Brantz and where your car's problem lies.
If you're using a gearbox output, hall sensor or wheel sensor for the Brantz then you should be a-ok.
If, like most people, you use the speedo cable it depends. If your tacho issues are down to the cable then you may have problems with the Brantz. If the problem is simply with the clocks then I'd imagine you'd be fine.
As above said, get a Tom Tom or similar (you could probably even use an iPhone sat nav but don't know as I don't have an iPhone) - then find a stretch of road longer than one mile, ideally with a couple of roundabouts at either end.
Pop your Brantz into calibration mode (100 of the number selector on most) and do a calibration using a mile readout on Sat Nav. Stop, round up the number on the Brantz to the nearest 3 digits and then put this into the 3 digit selector on the Brantz. This will give you a rough mile - not good enough for competing but good enough to work out if you have a problem.
Then go back, reset the Brantz and drive the same 'mile' at various speeds.
This should tell you if you have a prob or not. The reading should be roughly the same no matter what speed you're going. Try not to spin the wheels
If you're using a gearbox output, hall sensor or wheel sensor for the Brantz then you should be a-ok.
If, like most people, you use the speedo cable it depends. If your tacho issues are down to the cable then you may have problems with the Brantz. If the problem is simply with the clocks then I'd imagine you'd be fine.
As above said, get a Tom Tom or similar (you could probably even use an iPhone sat nav but don't know as I don't have an iPhone) - then find a stretch of road longer than one mile, ideally with a couple of roundabouts at either end.
Pop your Brantz into calibration mode (100 of the number selector on most) and do a calibration using a mile readout on Sat Nav. Stop, round up the number on the Brantz to the nearest 3 digits and then put this into the 3 digit selector on the Brantz. This will give you a rough mile - not good enough for competing but good enough to work out if you have a problem.
Then go back, reset the Brantz and drive the same 'mile' at various speeds.
This should tell you if you have a prob or not. The reading should be roughly the same no matter what speed you're going. Try not to spin the wheels
Gassing Station | UK Club Motorsport | Top of Page | What's New | My Stuff