Fast road springs

[gazzamuffin]

Hi all,

I have a set of TTR fast road and although they are excellent quality I seem to have extremely low ride height can anyone confirm what the dimension should be from the road to the tangent of the wheels arch for both front and rear?

I am constantly bottoming my exhaust and can't help but think I have something wrong!

Thanks

Gazzamuffin

[john1180]

Hi all,

I have a set of TTR fast road and although they are excellent quality I seem to have extremely low ride height can anyone confirm what the dimension should be from the road to the tangent of the wheels arch for both front and rear?

I am constantly bottoming my exhaust and can't help but think I have something wrong!

Thanks

Gazzamuffin

You could try some spacers to raise the height, assuming you're maxed out on the adjustment.

[miked]

Hi David,

Those bump rubbers look very interesting and I think I will try a set.

Hi Rohan,
I take it that if I just tested with some weight to see how much they compress and record that might be interesting.

Mike

[rgh0]

Hi Mike
You may need a rod down the centre to keep them stable while you compress them and measure load versus displacement

cheers
Rohan

[Davidb]

I just read that 128b front and 100lb rear are what the 26R had. When I raced my 26R back in the early/mid eighties it must have had these springs on it-it had not been used since 1970. I remember the car as being very controllable but I have no recollection of the ride harshness-nor would I have cared at the time!
Tony Thompson was just starting to make a name for himself and his car was featured in an article in "Classic Cars" in June of 1985. Tony Dron was very impressed with the car but complained that Thompsons spring rates of 240lb front and 150lb rear barely allowed the car to move. He said "...I would be inclined to do some serious wet weather testing with much softer settings all round if the car were mine". I had no problem competing with other 26Rs I raced against here on the West Coast...
At the time I phoned Tony Thompson and asked him for his tire pressure recommendations and he reluctantly told me-I had to assure him I wasn't going to race in England!

[rgh0]

Hi David
The hard end of full race springs has been getting harder over the years from the original 26R specifications you listed to now be around 300 lb/in front and 200 lb/in rear

This has been driven by both tyres getting more grip and driving styles and track smoothness changing to favor harder set ups. Tony has also personally liked a hard setup and he recommends these harder set ups through his TTR business which carries a lot of weight with many people.


The down side with the very hard setups is that unless you have a high grip smooth and dry track they can get very challenging to keep on the black stuff. When they are quick their quick but the transition to off the track and into the grass is quick and hard to handle. If your a good driver like Tony then you can handle it, if you like me its best to keep it softer

My current Elan 150 lb/in front and 110 lb/in rears plus 7/8 inch roll bar and spaced down rear rubber springs is quick enough and as hard as I can handle with my driving skill on our tracks and in wet and dry weather. This rate is JUST drivable on the roads if you like your ride hard like a traditional English sports car ( MG or Triumph)

If I was driving my Elan on the roads I would go for around 115 lb/in fronts and 90 lb/in rears but keep the stiff roll bar and spaced down rear rubber springs. I have that setup still in my spares boxes (somewhere ) and will go back to it one day when i retire my Elan from racing

cheers
Rohan

[miked]

Hi Rohan & David,

Just following on from those VW Jetta (and other cars) bump rubbers we discussed. I managed to track down the part number with a UK classic VW dealer. Trawling the net I noticed there were A, B & C versions. The guy could help me with what that means. Anyway I ordered two at 7.50 Each (with Dust shield) to see what they are like. Dust shield too big but nice idea.

See Photos. As a bit of a rough experiment I have clamped them in the vice with a set of bathroom scales and managed to press them up to about 80KG before the scales gave up. At 5Kg increments I took length readings.
I also did the same with the original Aeon hollow springs. I appreciate that this is rough but must give some idea of how progressive they are and also their strength. I did this twice and got pretty much the same sort of reading.

Sorry, no software on this old laptop otherwise I could have done a little graph. Should I attempt to get more weight for more readings?

KG ------ VW Spring ----- Aeon Spring

0 ------------ 81mm ------------ 81mm
5 ------------ 80mm ------------ 80mm
10 ------------ 79mm ------------ 79mm
15 ------------ 76mm ------------ 78mm
20 ------------ 75mm ------------ 78mm
25 ------------ 72mm ------------ 77mm
30 ------------ 70mm ------------ 76mm
35 ------------ 69mm ------------ 75mm
40 ------------ 67mm ------------ 75mm
45 ------------ 66mm ------------ 73mm
50 ------------ 65mm ------------ 72mm
55 ------------ 63mm ------------ 70mm
60 ------------ 62mm ------------ 70mm
65 ------------ 61mm ------------ 69mm
70 ------------ 59mm ------------ 67mm
75 ------------ 57mm ------------ 64mm
80 ------------ 56mm ------------ 62mm
85 ------------ 54mm ------------ scales limit


So any thoughts. I fitted the new TTR (100lb) fast road springs at the back and used those short yellow poly TTR bump stops to get me back on the road. I also took your advice Rohan and got some nylon stock and cut two 15mm spacers for each side (above and below). I have not really tested this properly yet with running in the new MKF gearbox. Also still making adjustments to the ride height. That said it seems pretty good and I am not riding onto the bump stops with two of us in and half a tank of fuel under normal straight forward direction driving.
Since the springs do settle I have adjusted the perches to give an "A" frame angle of about 2 inches droop from the horizontal when the car is empty.

What do we think? Shall I try these VW ones. Notice the little 90 degree ribs between the rubber do nut bits to balance the squish.

Thanks Mike

[rgh0]

The spring rate of the VW units looks pretty good. The difference with the original Aeon springs is not significant. i would give them a go with the spacers and see how you like it.

cheers
Rohan

[miked]

Thanks Rohan, I will change out to these shortly. I put 300 miles on it yesterday and those nylon spacers work nicely when the car bottoms out in dips preventing the wheels going too deep into droop. Two of us in it and 3/4 tank of fuel. Also felt good in the bends even with the shorter bump stop. The spring have bedded a bit so need a further lift.

Cheers

Mike

[fatboyoz]

Hi Mike,
Am just about to replace my disintegrated bump stops.
Could you please supply me the part number for the VW bump stops that you show in this thread.
Did you fit them in the end?
If so, are you happy with them?
I presently have TTR Gaz front shocks and springs. Not sure of spring rate. 115lb?
Have 80lb, 14", 2.25" Faulkner springs on the rear with the TTR limited droop Koni shocks. The bump stops were from a Holden sedan (Aussie made GM) that have since turned to powder.
Have been very pleased with the 80lb springs, but am considering having a set of Faulkner 90lb, 14" springs made to cater for the extra load when the car is fully loaded for a road trip.
Anyway, a reply on your experience with the bump stops would be greatly appreciated. It is not easy to find a similarly performing bump stop as per the original Aeon hollow rubber springs.
Cheers,
Colin.

Hi Rohan & David,

Just following on from those VW Jetta (and other cars) bump rubbers we discussed. I managed to track down the part number with a UK classic VW dealer. Trawling the net I noticed there were A, B & C versions. The guy could help me with what that means. Anyway I ordered two at 7.50 Each (with Dust shield) to see what they are like. Dust shield too big but nice idea.

See Photos. As a bit of a rough experiment I have clamped them in the vice with a set of bathroom scales and managed to press them up to about 80KG before the scales gave up. At 5Kg increments I took length readings.
I also did the same with the original Aeon hollow springs. I appreciate that this is rough but must give some idea of how progressive they are and also their strength. I did this twice and got pretty much the same sort of reading.

Sorry, no software on this old laptop otherwise I could have done a little graph. Should I attempt to get more weight for more readings?

KG ------ VW Spring ----- Aeon Spring

0 ------------ 81mm ------------ 81mm
5 ------------ 80mm ------------ 80mm
10 ------------ 79mm ------------ 79mm
15 ------------ 76mm ------------ 78mm
20 ------------ 75mm ------------ 78mm
25 ------------ 72mm ------------ 77mm
30 ------------ 70mm ------------ 76mm
35 ------------ 69mm ------------ 75mm
40 ------------ 67mm ------------ 75mm
45 ------------ 66mm ------------ 73mm
50 ------------ 65mm ------------ 72mm
55 ------------ 63mm ------------ 70mm
60 ------------ 62mm ------------ 70mm
65 ------------ 61mm ------------ 69mm
70 ------------ 59mm ------------ 67mm
75 ------------ 57mm ------------ 64mm
80 ------------ 56mm ------------ 62mm
85 ------------ 54mm ------------ scales limit


So any thoughts. I fitted the new TTR (100lb) fast road springs at the back and used those short yellow poly TTR bump stops to get me back on the road. I also took your advice Rohan and got some nylon stock and cut two 15mm spacers for each side (above and below). I have not really tested this properly yet with running in the new MKF gearbox. Also still making adjustments to the ride height. That said it seems pretty good and I am not riding onto the bump stops with two of us in and half a tank of fuel under normal straight forward direction driving.
Since the springs do settle I have adjusted the perches to give an "A" frame angle of about 2 inches droop from the horizontal when the car is empty.

What do we think? Shall I try these VW ones. Notice the little 90 degree ribs between the rubber do nut bits to balance the squish.

Thanks Mike

[vstibbard]

Would you mind posting the VW part number for the bump stops please.
Cheers
V

[fatboyoz]

Hi V,
I managed to track down some of these bumpstops. Got them from Porsche dealer Autohaus Hamilton in Chatswood. List price $23.15, only charged me $6 each +GST+postage.Their part number: 171412303C.
Be careful with this part number. I initially ordered some of these from Porsche Brisbane, and even though they were the same part number, the items were completely different to the ones I received from Chatswood.
The actual number on the bumpstops is: 08384 620. I think they are made by/for Febi Bilstein.
VW/Audi use them as well. Their part number: 357 412 303 E.

Have sent my Konis to Lilydale for checking/overhaul. Hope to have the Elan back on the road in a couple of weeks.
Cheers,
Colin.











uote="vstibbard"]Would you mind posting the VW part number for the bump stops please.
Cheers
V[/quote]

[Frogelan]

This is one of my favourite threads to follow (I have already pestered Rohan and Nicolas Mauduit on this before).

I'm aiming at a road / rally use and a soft set up for track use. Soft front springs and a strong ARB (sway) to give a dry set up and a weaker ARB for wet use. I also have FIA legal rear spring tubes and dampers (ie no adjustable platforms or the trick multi adjustable dampers which cost a bomb).

This is what I have discovered so far (NB: I am still noodling with my rolling chassis):

- The TTR "Tour Auto" spec is something like 275 front and 150? rear. I bought a set to find out and returned them as 275 seemed far too stiff IMHO compared to the OE 26R spec. They sound fine for smooth tracks and many racers swear by TT's recommendations. After watching many cars at Spa, I would say that TT is probably not far off for DRY TRACK use.

- I have opted for 150 fronts and 120 rears after listening to Rohan and Nicolas Mauduit. Both seem to have exactly the right logic on this. I'm not sure whether the spring lengths are correct, so I will not pollute the debate, especially as I am trying to get to the minimum ride height (100mm, 80mm under the exhaust) without spacers which is not useful to non-racers.

- I have bought the Febi Bilsteins as shown by Mike and the +2 spacers (both as recommended by Rohan.

What I do not know is...

- would it be better for the (aluminium) +2 bump spring spacer (not shown on the +2 suspension diagrams that I have seen) to be replaced by a machined nylon equivalent to avoid wear).
- are dush shields (shown above) necessary / useful ? Do they serve a secondary purpose ?

Ideas anyone ?

[rgh0]

What I do not know is...

- would it be better for the (aluminium) +2 bump spring spacer (not shown on the +2 suspension diagrams that I have seen) to be replaced by a machined nylon equivalent to avoid wear).
- are dush shields (shown above) necessary / useful ? Do they serve a secondary purpose ?

Ideas anyone ?

The original alloy bump stops had a lip so the could be crimped onto the top of the strut tube. They did not touch the rod so wear not a problem. i use them on the PLus2 still. On the Elan I fitted machined nylon that is a light fit on the damper rod as an alternative above and below the Aeon. These sit stationary on the damper rod and move slightly with the aeon compression, less unsprung weight

I removed the front dust shields on my Elan many years ago to aid cooling on the track, with no ill effects observed.

cheers
Rohan

[Frogelan]

Thanks Rohan!

I will make up some nylon Febi Bilsten spacers...