tr7triumph.com

Hi

I'm relocating the battery to the boot, can some one advise me on the power rating of the cable from the battery to the starter motor. I'm looking at 3 sizes 110, 135 and 170 amp.

John

80 DHC Green
77 FHC White

John- Over hear they are sized by the wire
Stock TR8's were about a #4

On my rewire I used a #0



Don
Stick a Wedge In It
80 TR7 V8 Kick in the pants

The factory used 37 strand cable. Which I believe is 170 amp rating.

TR8

Hi Don
Thank you for the quick response.
I'm afraid I don't know what size #4 or #0 mean, I thought wires were rated by the current they can safely carry.

Just been and done a google search, I think you are referring to the AWG standard. From what I've read AWG 4 as a current rating of 135 amps, your AWG 0 is rated at 245 amps, that might be a over kill so I will go for the AWG 4. Unless some one no's better.

Thank you
John

80 DHC Green
77 FHC White

John- That's why I said over here [:D]
Mine is definitely overkill, but i plan on having other things than stock run through the battery.

Don
Stick a Wedge In It
80 TR7 V8 Kick in the pants

While normally you would size the cable by the volt/amps that it is intended to carry your best bet for a battery cable is use the largest that is practical.

The line loss on a DC system is quite high at the amperages needed to work the starter, the larger cable will have less line loss thus more power to start on a cold morning or after you forget to turn the fog lights off.

Edward Hamer
Petaluma CA

Hi guys

Thanks for all this good advice. It's given me plenty to think about.

John


80 DHC Green
77 FHC White

Johnny- Something you'll need is the TR8 battery cable cover that runs on the pass. side.

Don
Stick a Wedge In It
80 TR7 V8 Kick in the pants

Hi Don
Some thing else to add to the ever growing list of things I need.

This part is new on me though, never herd about it before, are you sure it's needed?

My plan is to run the cable down the right side, drivers side here in the UK, along the inner sill to a junction box, then a cable from the junction box to the starter motor and another to the fuse box.

What rout dose the cable take on an original TR8?

John


80 DHC Green
77 FHC White

I'll post a pic
This is how they go


covered by this


Thank you Darrell

Don
Stick a Wedge In It
80 TR7 V8 Kick in the pants

Thanks Don

That's about the rout I may be taking only with the cable lower down and covered by the carpet.

My car is just a rolling shell at the moment. I started rebuilding it about 5 years ago but lost interest. With no interior fitting to get in the way routing the cable should be easy.

John

Here she is, in my garage, got a bit dusty over the years.




80 DHC Green
77 FHC White

Mines an 8 clone and that wasn't added for some reason.
My #0 cable is to big to cover by the carpet

Don
Stick a Wedge In It
80 TR7 V8 Kick in the pants

I can see, that cable is a monster. I don't think my requirements will need something that big.

John

80 DHC Green
77 FHC White

there are charts for this , bear in mind that your starter really can pull a lot of amps,I work with electrical vehicles 24VDC powered ,even those pull 120Amps, if your car is not starting (cold etc ) and/or has not enough cable thicknes the amps going trough the wires will heat up the cabling..or can even fry them (seen it once, not a pretty sight)

make sure there is at least a 300A fuse on the battery side...just in case..

a very nice chart (AWG format)



regs,
luc

Hi,

I ran mine on the V8 down the passenger side ( if you drive on the ' wrong ' side of the road then the drivers side [:p] ) once in the engine bay fitted a FIA battery kill switch, this allowed me to join the cable and provide take off for 12 volt permanent live's and naturally a security device.


Cheers John


LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty Now with an overdrive conversion

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6, BUILT NOT BROUGHT !!!!