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Convert TC to S spec

Posted: Sat Sep 22, 2018 9:32 pm
by dolomitejohn
Hi all
I might just have found a 2500 TC auto for sale.
Was looking for an S manual but hey..
Questions are.....

1) how easy is it to swap the dash panels to an S spec? Is it just plug and play or does the body or engine harness need changing?

2) it's an auto. What is the rev difference between auto and man od at 70 mph? If I swapped out the gearbox for a man od do I need to change the diff, gear box mount, props haft or any thing else?

2) I once had a dolomite 1500hl auto which was dreadful on the motorway. I converted to man od and it became a different car. Is the 2500 TC high revving at 70 mph or nice and torquey and relaxed?

Thanks all

John

Re: Convert TC to S spec

Posted: Sat Sep 22, 2018 11:56 pm
by johnnydog
It is very easy to change the dash panel in a TC to S spec assuming you have the parts. The wiring loom needs no modification; just removing the individual wires from each gauge in the single cluster to the individual instruments. You need the different wood panel for the clock in the centre but the wiring simply needs moving over to the centre as its is long enough to reach.
The diff is the same for both vehicles (3.45 whether manual or auto). The manual is lower revving at motorway speeds than the auto version - my S is doing about 2700 ish rpm at 70 mph in overdrive top.
The front springs are softer (and longer) on an S than a TC, as the 'S' has an anti roll bar, although I doubt it makes a great deal of difference keeping the harder springs. If you wanted to fit an ARB, besides the bar itself, you need the front cross member with the mounting brackets, and the drop links and lower suspension arms with the brackets.
The sales brochure stated that the S had 'higher overall gearing' than the TC - this was only down to the TC having 185 X 13 tyres, where as the S had 175 X 14 tyres with alloys. The mechanicals were all the same.
You would also need the extra trim parts - the black plastic trim on the rear light panel, the vinyl 'C' pillar trim, the alloys, and of course the front grille badge, S badges on the C pillars and the 2500S badge on the back right. The S had a smaller steering wheel than the TC.
PAS wasn't standard on the TC like the S; something else to think about!
The S had tinted glass fitted as standard; although it was an option to specify clear glass! The TC was just fitted with clear glass.
It would also never have an 'MP' VIN no which would be a give away too!

Changing one from an auto to manual is a whole different scenario - you would need the gearbox, flywheel, clutch assembly, all clutch hydraulics, pedal box, propshaft, gear-lever, gear lever trim, exhaust down pipe and centre section and supporting brackets to the gearbox (cross member is the same), correct length speedo cable, wiring for the overdrive and the relays etc. Doable, but having a scrap donor car would make life so much easier.

If you particularly want an S, I would wait for the right car to come along, although good S models are becoming hard to find. It isn't as if there are plenty of scrap ones to use as donors either!

It all depends on how far you want to go to make it S spec, and having a manual over an auto, against waiting for the right S to cone along!

Re: Convert TC to S spec

Posted: Sun Sep 23, 2018 8:14 am
by dolomitejohn
Hi Jonnydog

Thanks for the reply. Very comprehensive.
Does the TC dash wiring include the Tacho feed or would I have to run a new wire from the coil?

Also back to ratios and wheels sizes etc.
The car I am looking a has some aftermarket wheels that look very similar to the S alloys (however they are definite not).
They are fitted with 205/65/ R15 91V tyres

I can never get my head round the rolling circumferences, but clearly these tyres are very different to the orriginal spec.

HAve you got any advice / experience on how these would affect handling, road noise, grip, Speed reading and I guess clearances to the arches.

Looks wise they are great....

Thanks Jonny Dog.

Re: Convert TC to S spec

Posted: Sun Sep 23, 2018 10:29 am
by Phil T
I 'converted' my 1974 2000 dash to the multi dial format, ie what you are basically proposing, and there is a white wire feeding the tacho in wiring loom regardless of which dash is fitted.

The issue I had was that the connectors were not standard, and has to do a bit of dash loom rejigging, but wasn't too onerous.

Re: Convert TC to S spec

Posted: Sun Sep 23, 2018 12:32 pm
by dolomitejohn
Thanks Phil.

Re: Convert TC to S spec

Posted: Sun Sep 23, 2018 7:03 pm
by johnnydog
I have only ever converted a facelift 2500 TC to S spec - not a 2000.
Most used dash panels generally have the short loom from the back of the instruments attached, which means it is just a plug and play. The main loom from the side of the steering column to the car has the wiring for both tacho and non tacho cars; the short loom from the instruments connects to this connector block, but on a non tacho car the terminal is blank on the dash side.
If your new dash doesn't have the short loom attached, you would have to rig up the tacho feed to the car loom connector block by the steering column. All the wiring from your existing instruments would just need connecting to the relative individual gauges.
Early Mk2 2000's had all the wiring required for the PI, whereas my early 2500S has the inertia switch wiring tucked behind the wiper motor. I would assume therefore that a 2500TC will have the correct loom for a tacho dash.
As regards the tyre sizes, Dave B on here runs 15" Minilites on his 2500, but I don't know his full tyre size.
There must be a web site that gives the rolling circumference of various wheel and tyre sizes?

Re: Convert TC to S spec

Posted: Sun Sep 23, 2018 8:31 pm
by dolomitejohn
Thanks Guys. It sounds like the dash swap is an easy upgrade.

I just need the car now..........

John

Re: Convert TC to S spec

Posted: Mon Sep 24, 2018 11:41 am
by Dave B
I dont know what you are prepared to pay for a good manual S, but this seems to be worth a look, a South African spec 2500S.
https://www.ebay.co.uk/itm/1977-TRIUMPH ... Swuxhbnj6X
In the long run a lot easier than faffing about with gearbox swaps and the like!

Yes......

Posted: Mon Sep 24, 2018 11:48 am
by sprint95m
johnnydog wrote:
Sun Sep 23, 2018 7:03 pm
There must be a web site that gives the rolling circumference of various wheel and tyre sizes?
Indeed there is....
https://www.willtheyfit.com/index.php?w ... offset2=22


(I tried doing a relevant comparison but don't know what the offset on an S is.)

Ian.

Re: Convert TC to S spec

Posted: Mon Sep 24, 2018 11:58 am
by Dave B
johnnydog wrote:
Sun Sep 23, 2018 7:03 pm
As regards the tyre sizes, Dave B on here runs 15" Minilites on his 2500, but I don't know his full tyre size.
There must be a web site that gives the rolling circumference of various wheel and tyre sizes?
I use 195/65/15 on my 2500, and they are a very snug fit in the rear arches, dont know how anyone got 205's in there!
https://tiresize.com/tyre-size-calculator/