124 or 125(132/Argenta) hubs for Rally Spider

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
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Rallyroller
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124 or 125(132/Argenta) hubs for Rally Spider

Post by Rallyroller » Wed Jun 01, 2011 3:43 pm

Hi Guys

I am newly registered on the forum, but I have been a visitor for many years. Best forum on the web.
As is human nature, there is a reason for my participation. After a number of years of false starts, I am now finally preparing my Spider for the BHRC historic Rally Championship and I would appreciate some comment from you chaps on a number of issues. I will start with a little history of me and the car.

I bought a rally prepared BS1 spider in 1983. I ran it for 3 years in local club road and stage events with some moderate success in the club championships. The car was rally prepared by its first owner ( an English army officer stationed in Germany) The car had a number of Abarth factory parts including suspension skids, front tension rods, sump guar d and mounting bar, gearbox mounting and cross member, lightened cam wheels, and a big wing alloy sump. ( Yes it is actually alloy not painted steel.) The car was fitted with a Borg Wanrer LSD, Piper head and cams, 4:2:1 exhaust. For a 1608 it went quite well (believed to be around 135 bhp) and certainly held its own in the up to 2 litre class.
As usually happens things change and I needed to build a garage to put the car in. Roll on 3 years, the garage was built and the car was brought inside having spent 3 years in a field. ( It started and I drove it into the garage, much to my wife’s amazement. )

Roll on another 15 years and after many “I’ll get that car going one day” moments I finally bought a rally prepared 124ST and entered that into selected rounds of the BHRC . Some of the parts were swapped from the old Spider including twin carbs, LSD, etc. We ran the car for 3 seasons, did not have much success, but had great fun and even scared myself a few times.

During this time I started to look more closely at the Spider, and realised that perhaps 3 years in a field had left the shell a little worse for wear. Another BS Spider (an American Import) came available, so I bought this to prepare for rallying. 2006 end of season neared, so thoughts of selling the ST and having a massive push on the Spider over the winter were planned. That was interrupted by a roll on my last event in the ST. ( One competitor was surprised as he said the ST did not go fast enough to roll- well at least I got further than he did- he reached the 3rd corner before putting it off and out of the rally. )

Anyway- after much consideration the ST was sold to a guy in Ireland (The ST was still drivable) and I then concentrated on the Spider build. That was 4 years ago. In that time I have scrapped the original Spider ( after removing all of the bits) bought 2 other Spiders – 1 for parts , one as a possible rally conversion and started to acquire some parts.
Having decided that the second Spider is easier to prepare- ( better chassis but worse bodywork) the shell has finally gone to the garage to be seam welded and have the cage fitted. Hopefully it will be back this week, and I can start on the initial build before stripping down and sending back for paint.

There are a number of questions I have and certainly would like to pick your brains on some of the issues over the next few weeks. So where to start?
First the spec of the car is not to mirror ex works cars so much, but to be a cost effective ( ie cheap) rally car that is not an Escort and is easy to prepare and maintain. I am looking at Class C3- Cars before end 1974 under 2 litre. I have the homolgation papers and numerous articles and books about the early ( pre IRS Abarth ) Spiders. The regs state that only mods used at the time can be used, and you have to have “documentary” evidence to prove any mod. ( Not sure how many Scruteneer know Fiats that well). I’ll start with the suspension.

Front Standard with strengthened wish bones, cross member, rose jointed tension rods connected to sump guard cross member, complete with single leaf spring skids. Standard ( new) rubber bushing on wish bones. Rose jointed antiroll bar mount to wishbone with superflex support bushes. ( standard roll bar) . Strengthened track control arms ( and plenty of spares ones!) Strengthened cross member.
Brakes- 256mm vented discs with 911 callipers.
13” wheels on 30mm/side spacers.

Rear end
Strengthened axle. Extended top links, rose jointed and rubber bushed upper and lower links. (actually modified Mk1 Escort rally parts). Rose jointed and rubber bushed Panhard Rod. Aeon rubber bump stops. 15 mm anti rollbar ( Standard on early 124 Spiders!)
256 solid discs 911 rear callipers with original callipers for mechanical hand brake.
LSD.
Regarding engine, I will probably go for and 1800, not sure of full spec yet. ( depends on how much money I have left) . Hoping min 150 bhp 170 would be nice. Gearbox will theoretically be standard, as cannot afford a Colloti or ZF.
There are weak parts in the spec. However, in the historic rallying you are limited to 7” wheels so even on tarmac you will not have too much grip. I will mainly be contesting forest events. ( Certainly to start with).
The front suspension was always the weak point and the problem with any competition car is that as you strengthen things up you just move the weakest link. Also I am trying to keep the weight down to reduce stress on everything. ( My co driver does not know yet but he may need to go on a diet!)

So the first area to consider are the front hubs. 132 or 124? I have both. I understand the concept of the 132(125) hubs as these were homologated early on for the spider. However, my understanding is that as a straight swop they lower the ride height by 10mm. This then reduces suspension travel, which for a gravel rally car is not good in the first place. Again if you were using rose jointed suspension ( like on the special lower wishbone of the works cars) then perhaps the hub became the weak link? So what are the thoughts- use 132 parts and suffer from reduced suspension travel or keep the 124 ones? ( note from my past experience the weak part is the steering arms and track control arms- even I managed to bend those!) Reducing the bump stop will help negate the suspension travel, but bump stops are there for a reason- and reducing the length surely means that overall you have less travel?
What about 124 hubs for forest and 132 for tarmac? ( giving a 10mm ride height reduction without having to change the front springs ? ( Note front springs for forest are much stronger than you would normally expect on a loose surface car. This increase in spring rate on the 124ST made a huge difference to the handling on the loose.)
I look forward to your comments- I have lots of other ideas and questions to follow.
GC_13

WhizzMan
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by WhizzMan » Wed Jun 01, 2011 7:05 pm

It sounds like a fun project to build and even more fun to run it. I have no experience with this, so it may be a daft question, but is powerflex bushing "period correct" for this car?
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Guy Croft
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by Guy Croft » Thu Jun 02, 2011 11:47 am

nice post but no photos??

G

Rallyroller
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by Rallyroller » Fri Jun 03, 2011 1:21 pm

Hi Whizzman

Re the rules for period parts, it is a bit of a grey area.
For instance, in mainland Europe many different items are allowed in "historic rallying". In the UK they are a bit stricter.

You have to prove that the technology was available and used on rally cars. However, certain things are allowed. (Like bias brake system even if not used on the actual makes and model of car.) Regarding "Powerfelx" it is just a harder rubber/plastic mount. (Nylon or PTFE were used in period.) As rose joints were used in a lot of suspension areas, the use of "poly bushes" is only using the same method of standard- just a different material.

Certainly in historic rallying it is general knowledge that the cars are quicker than in period. Even though the spec of the engines is very similar- the technology and know how to make them go faster has improved, so power outputs are up even though the same size carbs, valves etc are used. Even brake pad material and tyre technology has improved.

I think the reason for the increase in popularity of historic rallying in the UK is 2 fold. Firstly spectators find the cars exciting to watch. Most are rear wheel drive. From a competitor’s point of view, the amount of development is limited. Nobody is saying that a BDG engined Grp 4 Escort is cheap- but once you have prepared it there is very little that can be done to improve it. Therefore the car is good for a few seasons without major mods or expense.



I'll post some pics when I get the car back (next week now due to transport issues)
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TR-Spider
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by TR-Spider » Mon Jun 13, 2011 8:47 am

So the first area to consider are the front hubs. 132 or 124? I have both. I understand the concept of the 132(125) hubs as these were homologated early on for the spider. However, my understanding is that as a straight swop they lower the ride height by 10mm.
Correct.
This then reduces suspension travel, which for a gravel rally car is not good in the first place.
No, if you shorten the upper bump stop by 10 mm, suspension travel remains constant. I had no issue with the tires touching the body at full dive. However, your oilpan-to-street-clearance reduces by 10 mm, which can be crucial...
Again if you were using rose jointed suspension ( like on the special lower wishbone of the works cars) then perhaps the hub became the weak link?
I do not think the hub becomes a week link.
So what are the thoughts- use 132 parts and suffer from reduced suspension travel or keep the 124 ones? ( note from my past experience the weak part is the steering arms and track control arms- even I managed to bend those!) Reducing the bump stop will help negate the suspension travel, but bump stops are there for a reason- and reducing the length surely means that overall you have less travel?
quote]

132 hubs as roadholding is superiour. Bumpstop see above, its not only shortening, also reshape to original parabolic shape.
What about 124 hubs for forest and 132 for tarmac? ( giving a 10mm ride height reduction without having to change the front springs ? ( Note front springs for forest are much stronger than you would normally expect on a loose surface car. This increase in spring rate on the 124ST made a huge difference to the handling on the loose.)
I look forward to your comments- I have lots of other ideas and questions to follow.
Again 132 hubs for both. I would rather raise the rideheight slightly with longer springs or washers on top of the springs to get the required ground clearance.


Please lets see some photos...

Thomas
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TR-Spider
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by TR-Spider » Thu Jun 16, 2011 5:59 pm

Some photos of spacers to go between springs and chassis.
I used the original 124 rubber-sheetmetal springseats and embedded them in aluminium rings.
A flat rubber ring (not shown) goes between spacer and chassis.
I hope the photos are self-explaining.
It sure was some manufacturing effort, but its a proper solution.

Thomas
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Rallyroller
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Re: 124 or 125(132/Argenta) hubs for Rally Spider

Post by Rallyroller » Fri Jun 24, 2011 4:29 pm

Thanks TR Spider

Interestingly my original Rally Spider had something similar. They were made out of some sort of hard composite. Looked more like fibreglass resin, but harder. As the guy who built the car was an officer in the army stationed in Germany, and a lot of the mods on the car were made and constructed out of some pretty strange but exotic materials so they could be made out of anything. They increased the ride height by about 8mm.

I will certainly consider your mods when I get the front suspension on.

Car delayed at the welders, so should be back in a week or so.
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