Best Springs for Handling?

[Jonathan Lewis]

if the Holden engine is deeper than the Triumph unit, has someone put spacers between the front suspension crossmember and the chassis rails in order to give sump clearance without fouling the bonnet above? ... could this perhaps be raising the front ride height (which does look high) and leading to a positive camber condition?

that, surely, will not affect the ride height just alter the angle of the track control arm relative to the base of the strut (which will alter the camber also?) and probably result in the track control arm contacting the bump stop?

Fair point, Alec - the compressed length of the struts would effectively determine the ride height, so packing between the crossmember and chassis rails would effectively just lower the crossmember . As you say, there would be some change to the suspension geometry in terms of camber and free movement, unless this has been 'corrected' by longer springs and/or packers, which could then give an increased ride height...

As Colin has pointed out, the issue may just be sagging rear springs unbalancing the whole. FWIW, I've just applied the Monarch method of ride height measurement to the rear arches of mine (PFL standard ride height on CW 395lb/in springs) and the resulting dimension from wheel centre to arch lip is a tad short of 12".

[murcod]

Thanks for all the replies.

The ride height is ~11 1/4" -> 11 1/2" at the rear - but it's not on level ground at the moment. The front is around 4" higher.

I had a change of mind and went ahead with ordering the Witor progressive front springs - because the local springs aren't progressive. Freight for two was only 22 pounds, so I don't know how Chris estimated 100 pounds for 4 springs?!

Research is pointing towards my larger 3.3l engine as being lighter than the Triumph 2.5l ( which is supposedly 185kg) ; which would help contribute to the high front ride height. I've also ordered the lifted rear spring insulators and figure with the lowered front springs and lifted rear insulators I might be able to get something a bit more satisfactory. The rate of the rear springs feels good, with the front end doing most of the initial roll in corners.

BTW do Triumph TR6 rear springs fit in a 2500? Strange question, but the rears appeared to be non original and had what appeared to be "TR6" written on them in paint pen?

[Jonathan Lewis]

BTW do Triumph TR6 rear springs fit in a 2500? Strange question, but the rears appeared to be non original and had what appeared to be "TR6" written on them in paint pen?

From a quick examination of the parts books, the spring insulators are the same, therefore presumably the spring diameters must be similar also. The actual springs themselves are different, however, and I'm afraid I have no idea what the fitted/free lengths of TR6 items are...

[Mike Stevens]

I would have thought that TR6 springs would be of a lower rate - after all, the TR6 is a 2+2 (if you're small) but the 2000 a good 4 seater with more boot space.

Lower rate would mean lower rear - sound familiar?

Good luck with the spring changes. I've been reading this thread with interest!

Cheers,
Mike.

[Jonathan Lewis]

I would have thought that TR6 springs would be of a lower rate - after all, the TR6 is a 2+2 (if you're small) but the 2000 a good 4 seater with more boot space.

So would I but, according to a Haynes TR5/6 manual which I've now managed to dig out, the sportscar actually has a higher rate at 349lb/in against 277lb/in for a PFL saloon, though not as much as the 430lb/in for a PFL estate. Free length, however, is shorter at a quoted 10.92in rather than 12.41in (saloon) or 11.42in (estate).

[CAR]

My rear springs are the same as Jonathan's and highly recommended, a vast improvement over the saggy mess that the original springs gave and not harsh even when driving without passengers.

Colin.

[murcod]

I would have thought that TR6 springs would be of a lower rate - after all, the TR6 is a 2+2 (if you're small) but the 2000 a good 4 seater with more boot space.

So would I but, according to a Haynes TR5/6 manual which I've now managed to dig out, the sportscar actually has a higher rate at 349lb/in against 277lb/in for a PFL saloon, though not as much as the 430lb/in for a PFL estate. Free length, however, is shorter at a quoted 10.92in rather than 12.41in (saloon) or 11.42in (estate).

Interesting. I don't suppose it says the number of coils in each spring type- that might be a way to identify them?

They certainly don't seem to be short springs as when I changed the trailing arm I had to undo the shock and drop the arm right down to remove the spring.

I measured the heights on level ground (and with 3/4 tank of fuel) rear is around 29.5cm, front 36cm. (11.6" and 14.2")

The front camber doesn't look too bad. I'm wondering if the camber quickly goes (more) positive as soon as the front wheels are slightly turned? Thinking about it, the camber has always looked at it's worse immediately after turning the wheels back to straight ahead and parking. Perhaps if I had let it roll forward with the wheels straight the camber would "settle" and be less positive.

[Jonathan Lewis]

I don't suppose it says the number of coils in each spring type- that might be a way to identify them?

TR6 – 6 ¾
Mk1 saloon – 10 ½
Mk1 Estate – 9 ¾
PFL Mk2 saloon – 8 ¼
PFL Mk2 Estate – 7 ¾

Sources: Haynes (TR), Triumph (2000/2500)

[andyborris]

Chris Witor offers several different front springs.

Three 160 springs, with differing ride heights, the 200/400 one and a 175 “cruise” spring.

Why is the 175 one “not for fast driving”, when it's stiffer then a standard spring and most of the other springs?

Thanks

Andy

[murcod]

I'd imagine there wouldn't be much difference noticeable between a 160 and 170 lb/inch spring (apart from the ride height.)

I'll check the number of coils later today- thanks Jonathon.