140mph speedo

[jclay (RIP 2018)]

Which cars had the 140 MPH Speedos?

Have fun, drive fast, be kewl,

jclay

[KRenken]

My '79 has one.

[jclay (RIP 2018)]

TR7 or TR8?

[ACW30445]

My car has one. Think all the early cars did. My car was built July 1977 per door tag.

My car is titled as a 1977 but I think may technically be considered a 1978 model now.

140 speedo? What optimisim!!! [:D]

[KRenken]

I have a 1979 TR7 DHC. It came with a 140 mph speedometer.

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by ACW30445</i>
140 speedo? What optimisim!!! [:D]<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
140mph = 220kmh not optimistic, realistic [:D]
And the unristricted German autobahn only a few miles away [}:)]


<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1980 TR7 DHC (my first car, being restored at the moment)
In parts a 1980 Californian TR7 DHC FI, 1981 TR7 FHC</i></font id="blue">

[Hasbeen]

My 1980 7 has a 230 kph speedo.
In the early 60s, I raced a Morgan +4. These came
with a 90/100 BHP Triumph TR3A motor.
In 1963, with 76 BHP at the wheels [about 100 fly
wheel], it was timed at 124.6 MPH down Conrod
straight, Bathurst.
The next year, with 115 BHP at the wheels it was
timed at 126.4 MPH.
A 50% increase in horse power had given me less
than 2% increase in top speed. This probably says
a bit about Morgan streamlining, but I think it has
more to do with engine breathing. The TR3A motor runs
out of breathing just over 6000 RPM, even after a lot
of power tuning.
Our 7s offer a lot less wind resistance than my old
Morgan, so a UK spec car, with similar horse power
[about 100] it should be as fast as the Morgan, & be
able to exceed 120 mph, given a suitable road.
I would not expect much more from an 8V motor, as
they appear to get short of breath at the same revs
as the old TR3A motor.
Its of only academic interest here, as driving at
160 Km [90 MPH], in Oz is a much worse sin, than
mudering someone's grandmother.
To think that back in the 60s, when towing my Brabham,
in its trailer, at 90 MPH, I used to get passed by the
interstate trucks, makes you wonder.
In 10, or 15 years, just before they take my drivers
licence off me, I'll take mine for a speed run. I'll report
back, if I survive the shock.
Hasbeen

[hupshall]

Boy, I know somebody's going to find an exception to the rule - but it's probably easier to say what cars didn't have the 140MPH speedos:

80/81 model year cars going to the US market had 80MPH speedo's
Metric countries (Europe, Canada, etc..) got 220KPH speedo's

everyone else, 140MPH

[Sondar]

The standard UK spec 8V TR7 supposedly had 120bhp & a maximum speed of 110mph. The 1977 FHC I had in 1985 reached just that.

My current 4.6 V8 DHC has 240bhp & tops out at about 210kph (130 mph) with the top down. That said, it sorely needs a dyno session & I'll be interested to see what it does then - but I wouldn't expect much more.

Not much of a gain, you might say, for double the horsepower. On the other hand, the V8 gets there one hell of a lot faster.

I'm not sure of the effect of top up / down, but I'd guess there's substantially more drag with it down & of course wind resistance increases dramatically with speed (the square of the speed increase if I recall correctly?).

Sondar

[ACW30445]

"140mph = 220kmh not optimistic, realistic
And the unristricted German autobahn only a few miles away"

Of course I was speaking of a stock 2 liter 8 valve car, but with the stock 13 inch tires and stock gearing it will still be a feat. In fact it won't happen.

I see you have a Sprint, obviously not stock either, so I will give you some benefit of the doubt Beans.

[:D]

"A 50% increase in horse power had given me less
than 2% increase in top speed. This probably says
a bit about Morgan streamlining, but I think it has
more to do with engine breathing. The TR3A motor runs
out of breathing just over 6000 RPM, even after a lot
of power tuning."

Good point..it's not linear.

According to Bill Piggot's book 'Original Triumph TR7 and TR8', the official spec of MPH per 1000 rpm for a stock 4spd. 3.63 geared TR7 was 17.7 MPH per 1000 rpm.

That would be right at 8000 rpm to run 140 MPH...Obviously you change tire size, gearing, rear axle ratio this all changes. It will still be a feat though I say, not impossible though...but highly likely in anything approacing a 'stock' configuration.

Actually the American 8 v 2 liter cars don't compare that bad if you believe the numbers...~90HP vs 105 HP net. When you consider all they did to the cars for emissions that it only lost ~15 HP (claimed) is quite remarkable. Some European cars in the 1970s lost 30-50% or more of their HP (claimed) between the American and Euro versions.

[Beans]

Top speed was about 220 kmh @ 6000 rpm with the original 3.45:1 diff.
As that's quiet a pointless speed I swapped the diff for a 3.9:1 unit.
Will still reach 200 kmh + but is much quicker through the gears [}:)]
And that's what counts on winding country lanes [;)]


<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1980 TR7 DHC (my first car, being restored at the moment)
In parts a 1980 Californian TR7 DHC FI, 1981 TR7 FHC</i></font id="blue">

[silverseven]

My '82 has a 220 kilometre per hour speedo.

My '78 seems to have also had a 140mph/220kmph unit (from what I see of it's past) though the car now has a 230 kmph head.

Ron.

<b>_________________________________________________________________</b>




<i><b>--1978 TR7 fhc----www.triumphtr7.com----1982 TR7 dhc--</b></i>

[Red]

On the subject of instruments, does anyone know if the warning lights changed at all? It's just that my car ('76 UK spec) has these little quirks:

'Coolant' light comes on when I get low on fuel
'Park Brake' light comes on when I pull the choke out

Obviously some PO has been hacking at the wiring, but I was looking at the wiring diagram the other day, and it looks like the early spec cars didn't even have coolant or park brake circuits!
So now I'm wondering if my instrument cluster has been swapped for a later one.

Oh, and I also have 2 Main Beam warning lights - one in the middle row, and one on the top left, by the clock! What the hell is that all about? [:0]
(Only one of them works, by the way!)

Garry

1976 2.0 FHC - Always full of surprises!

[jclay (RIP 2018)]

Here is the layout on my 1980 TR7 (built mid 79)



1. Trip odometer
2. Odometer
3. Demist – Back light heater
4 & 5. Turn indicators
6. Main or high beams for headlights
7. Ignition warning light – Red
8. Oil Pressure warning light – Red
9. Brakes – Parking & brake failure light – Red
10. Belts – Seat Belt warning light
11. Choke – Canada only
12. Fuel – Low fuel warning light (below 6.8 lit. or 1.5 gal)
13. Fog – Fog light warning light
14. Not used in USA vehicles

I hope that helps you!

Have fun, drive fast, be kewl,

jclay

[Red]

Thanks for that - I'll take a look tomorrow to see what's going on!

Although working from memory, it seems (3) & (6) are the opposite way round on my car, I have a second high beam light (not working) at (13), and the coolant light at around (11). Everything else is about the same as far as I can remember.

I'm confused.... [:D]

Garry

1976 2.0 FHC - Always full of surprises!