Speed reading versus tacho reading

[Forkie]

So still playing about with my engine running issue, or more to the point the seeming lack of it.I no longer think i have a gearbox issue, as it is definately changing up twice in D, i believe i was initially barking up the wrong tree. This evening i decided to take it onto the local dual carriage way for the first time, just to see how it was. So at the speedo reading of 50 (my lad had his speed app on and this showed the actual speed was 57mph) the tacho was reading exactly 3k - is that about the correct pairing of readings - 2500S with B/W 35. I realise an auto does not have the legs of a MOD but i really do not recall it being this lathargic.
So my main question here for now is does 3000rpm at 57mph sound correct for a 2500S with B/W 35.

Many thanks in advance.

[Forkie]

As a p.s. the engine seems,and sounds to be working really hard for little return if that makes sense - not a comfortable 8 mile dual carrage way ride at all if i am honest. No rush for another run in the morning thats for sure. Not missing a beat though, temp normal, no rough running. Just seems miles away from the car that i drove 400 odd miles home from Norfolk in the dark 17 years ago.

[johnnydog]

Doesn't the manual or handbook have figures for the speed per 1000 rpm for the different models - that should be an easy way to work out the manufacturers speed for any given rpm or vise versa? I also find the actual speed indicated on Google Maps on a portable Sat Nav or on a mobile phone whilst travelling is quite accurate as an indication as to your speedo accuracy at any given rpm.
There are a lot of variants however - relative to the tyre / wheel size fitted, correct diff, speedo and / or speedo drive, many of which could well have been replaced over the 45 or so years since the car was made.

[iani]

Enter your tyre size and select the 2.5 Auto model then calculate http://www.mintylamb.co.uk/gearspeed/

[Forkie]

Hi, thanks for the replies - the only thing really that has changed in that way are 15" minilites with new tyres , the tyre size chosen by using a guide online to make sure the rolling circumference remained the same as the original S type alloys. As an aside, it has not felt 'right' since it returned to the road earlier this year, when it was still running on the original wheels/tyres. I have no worries about it retaining its original dash and diff. Iani - i followed your info on the link, but there was other info that i could not follow, i may have a look on that site direct, it may give a little bit more information on what i need to fill in. I am edging toward giving Stuart a call that you had suggested a couple of months ago. I was hoping to of been a tad further forward by now but it would appear not!!

[Alec]

Hello Forkie,

it sounds to me as if the engine needs a good tune?
It shouldn't feel lethargic as you put it it.

Alec

[Forkie]

Hi Alec, yes that is what i am hoping is all it needs. My usual go to guy was, and still is meant to be having it back to go through the engine and some other bits to do but as he is very good, he is always booked up unfortunately for me ! Getting a little frustrated now as you can probably detect waiting for 'a slot' hence i am thinking of this chap nearby that Iani has mentioned. I dont like ' jumping about' so to speak with different hands, but at the same time i just want it running right !

[Triumphtastic]

If you have been driving a modern car and not driven a Triumph for years it will feel very different than you remember, particularly in relation to the performance and noise. And you will wonder what on earth you saw in it! Your expectations might not match reality. But instead of driving on a dual carriageway take it on a cross country route preferably with a few twisty bits and feel it gradually come to life. And then you will remember what it is all about!

[Forkie]

Point taken, and point already considered!!!! I just dont want to make things worse, if that is the case. My guy is still keen on sorting her out since speaking to him this eve so i think deep down he is enjoying working on her, a break from the norm!!