Historic Forest Stage Rally 124 Spider

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
miro-1980
Posts: 684
Joined: Mon Dec 03, 2007 3:40 pm
Location: Warsaw suburb , Poland
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by miro-1980 » Tue Jun 04, 2013 10:40 pm

Re:

I would recommend twin ( switchable from the dash) in the trunk (boot). Do not ask me why but in my mind the electric pumps should be closest to the tank. BTW : there is no maintenance issue as long as you make the pumps redundant.

Also, because of a potential fire hazard in a heated engine bay , it is much safer in the boot.

I have such setup in my 131 and i am very happy with it.

Miro
www.131abarth.pl
GC_93

Rallyroller
Posts: 87
Joined: Tue May 31, 2011 2:40 pm
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Wed Jun 05, 2013 9:50 pm

Hi Miro
Thanks for the input. Re Filter king in engine compartment, I think you are right. If there is a leak from the unit it is better in the boot than a hot engine compartment.
Fuel pumps are switched and fused independently as you suggest.
On another subject, I am about to fit the front hubs and brake. I am using 125/132/Argenta hubs/. Question- with 125 hubs which steering arms do you use?( the arm bolted to the hub, connecting to the track rod end). The original 124 or 125/132/Argenta? Looking at them, they are very similar, but the Argenta has larger track rod end tapers. Are these the same tapers as the Lada item?
GC_13

miro-1980
Posts: 684
Joined: Mon Dec 03, 2007 3:40 pm
Location: Warsaw suburb , Poland
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by miro-1980 » Wed Jun 05, 2013 10:33 pm

Re:

If I understand you correctly:

There are several; differences :

1/ diameter from the steering rod
I am using M14 because this is stronger than the smaller M12
diemsions.jpg
diemsions.jpg (52.77 KiB) Viewed 1692 times
diemsions 1.jpg
diemsions 1.jpg (34.5 KiB) Viewed 1692 times
M 14.jpg
M 14.jpg (46.13 KiB) Viewed 1692 times
2/ Shape and dimensions from the hub steering arm :
hub conneting bolts .jpg
hub conneting bolts .jpg (31.43 KiB) Viewed 1692 times
I do not remember exactly but even with shape and some dimensions differences they are compatible ( both based on M10)

I would suggest that you use strongest possible setup. Mind you, I looked over the list of homologated modifications fr 131 abarth.

There are really three elements which were changed : the steering , suspension and brakes. The steering suspension was made more and more panzer. This was sue to killer gravel rallies like Acropolis .

Acropolis is likely not something you aim for , but your modifications will be not as extensive either , so using stronger rod ends seems like a good idea.
www.131abarth.pl
GC_93

Rallyroller
Posts: 87
Joined: Tue May 31, 2011 2:40 pm
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Thu Jun 06, 2013 10:32 am

Hi Miro
Many Thanks for the information. I will look deeper into this. As yet I have not yet reinforced the track rod arms. Certainly having different ( stronger) track rod ends on the hub end could be another route.
While I will not enter the Acropoliss Rally, some of the stages in the UK can cut up a bit, but not too badly. However, I have to contend with my driving talents, so there is always the possibility of visiting the undergrowth and ditches.
The one problem with the 124 ( certainly the Standard set up) is its lack of front suspension strength. There has to be a balance with strengthening any aspect on a car ( suspension, engine, transmission). The strongest point of any chain is the weakest link. As you strengthen each part, then the next part becomes the weakest link. On the 124 steering the track rod arms are very weak (just thin split tube). These bend very easily on rough roads. So you strengthen them, and the next weak link is the centre steering bar or the steering box/ steering idler arm. The problem with these two items is that they are more difficult to change on a rally. The idea is to have track rod arms that don’t bend at the first rough section, but should these still be the weakest item? It is easier to change the track rod arms than a steering arm.
I have already strengthened the steering arms on the steering box and drag link. The one area left is the centre steering bar. This is not so easy to modify. For now I may just strengthen the track rod arms and leave the centre arm and see what happens. The centre bar can be changed at a rally service in a short time.
I will have to get out on the stages and see what happens. As you stated, you can’t plan for everything, and you must finalise the build specification to be able to complete the build!

RallyRoller
GC_13

ace124
Posts: 60
Joined: Mon Sep 04, 2006 2:09 am
Location: Pafos Cyprus
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by ace124 » Thu Jun 06, 2013 6:56 pm

The tie rod ends Miro has posted are 131 type female. The 124 runs different tapers and they are male type.
They cannot interchange.You want your steering arms to be parallel to the ground so as to minimise bump steer.
The 125/132 steering arms can be used if you use a bush to take up the space (bigger taper/hole).
They will lower your outward track rod position. So depending on your ride height you can select the appropriate steering arms
to position your track arms closer to where they need to be. The 125 type arms are also used when the inner control arm pivot is relocated
higher up the cross member to correct roll centres when the car is lowered. They will help position the outer track rod tie rod end lower to
the ground and keep the track arm parallel.
Hope i made sense.

Rallyroller
Posts: 87
Joined: Tue May 31, 2011 2:40 pm
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Jun 07, 2013 9:12 am

Thanks ace124. Useful information. Re bump steer, this is something I will think about. I won’t really be able to look at it until I get the care on its wheels. (Hopefully soon)

Takes me back to when I was an apprentice. I was an engineering apprentice at Michelin Tyres in the 1970s. Part of the training was to be sent to different departments. I had 6 weeks in the tyre testing department, where they carried out tests on cars for major companies, investigating suspension design etc. I now remember the situation with bump steer and the methods used to reduce it. They had a system where they measured toe in over the full travel height of the suspension. They used air cushions and hydraulic rams to pull the car down on full compression of the suspension. I also remember the lengths they went to for Group 1 saloon racers which, if I remember correctly, included repositioning the steering gear on the chassis. Not sure I will go to that length, but now you have pointed these things out I will look into the situation in more detail. It will be interesting to see how increasing the ride height (which it has it has been) will affect the geometry.


Rally roller
GC_13

ace124
Posts: 60
Joined: Mon Sep 04, 2006 2:09 am
Location: Pafos Cyprus
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by ace124 » Fri Jun 07, 2013 9:44 am

You can make a simple jig to check bump steer which is basically toe change due to ride height changes from bumps, leaning in corners, braking and accelerating.
If you need ideas on design let me know. Otherwise Im sure something would come up if you Google.
Alternatively if you need more precise adjustsbility you can replace the outer tie rod end with a spherical rod joint and drill out the taper in the steering arms to parallel.
Now all you need to do is shim the rod end up or down and just use a bolt to hold the rod end to the steering arm.

Rallyroller
Posts: 87
Joined: Tue May 31, 2011 2:40 pm
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Jun 14, 2013 4:53 pm

Hi Guys

A question.

I am fitting the fuel pumps in the boot. ( Twin Facet silver top) . If you look at the pictures on the second page of this thread you will see the alloy tank in position. The fuel outlet is on the left (looking from the back of the car). The tank goes down to the boot floor.
I am looking at mounting the pumps on the rear chassis member on the left next to the tank. However, I am a bit concerned as one pump ( or more accurately the fittings) will be quite close to the tank.
The option is to mount them on top of the chassis rail but this raises them higher. Question- how high can they go before they wont work? I have seen various comments on the web and the only technical info I can find states 12”-84” dry head.
My concern with mounting location is safety as much as anything. They could go on the rear panel, but if you hit anything backwards they would be venerable and possibly puncture the tank. The same thing with the side member, although having just drilled through this for mounting, I think it is unlikely that the chassis member would move much.
The current mounting positions the pump inlet about 3” above the tank outlet. Two other possible positions would move the pump inlet up to 6” and 9”.
The pumps are individually wired and fused.
Running the pipes is another problem I am working through. I was considering the aero style alloy connections, but have discounted them on cost. Have you seen the prices of the fittings? I have bought road worthy cars for less money than the cost of 1 fitting. I will go for more conventional good quality fittings, clamps and hose ( Aeroquip manufactured.)
I have just re- read the MSA regs again. I have 6x8 continuous copper pipe fuel line in the car. However, that is not enough- it has to be “protected”. However I could leave the original pipes under the car if I wanted, so that they could get ripped off at the first corner, and that is ok for my safety. I am not quite sure what damage could be caused inside the car with the pipes run along the centre tunnel ( so you don’t damage them when you side swipe a tree) , but the MSA obviously know something I don’t. I note that some people put very thin alloy sheet over the pipes. My view is that would only protect the pipes if it is secured properly and of suitable thickness. Another option is sleeve it with plastic tube. Not sure which way to go. ( It will teach me to read what is written , not what I think it says.)
Dont misunderstand my comments on the MSA and safety. When I was hanging upside down in my belts in the old 124 ST while on its roof, one of the first thoughts that went through my head was “ its a good job the MSA think about all this safety stuff.” The next was “ If I hit this buckle to release the harness, I am going to fall on my head “ – which I did. They ought to have courses on how to get out of an upside down car.
GC_13

miro-1980
Posts: 684
Joined: Mon Dec 03, 2007 3:40 pm
Location: Warsaw suburb , Poland
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by miro-1980 » Fri Jun 14, 2013 10:35 pm

Hi ,

You have raised a key subjects:

1/ fuel tank/system valves/ switches (automatic cut off switch; gravity activated roll over valve)
2/ protection of the fuel lines ( electrical grounding , what material, how connected, etc.)
3/ positioning of the the fuel pumps, fuel lines

FIA rules say :

Automatic fuel cut-off:

Recommended for all groups:
All fuel feed pipes going to the engine must be provided with
automatic cut-off valves located directly on the fuel tank
which automatically close all the fuel lines under pressure if
one of these lines in the fuel system is fractured or leaks.

My comment: I am not sure how this is to work. I suppose this is pressure based switch which will be activated if the pressure drops indicting fuel leak ???

Compulsory:
All the fuel pumps must only operate when the engine is
running, except during the starting process.

Fuel cell ventilation

The ventilation line of the fuel cell as far as the valves
described below must have the same specifications as those
of the fuel lines (Article 3.2) and must be fitted with a system
complying with the following conditions :
- Gravity activated roll-over valve
- Float chamber ventilation valve
- Blow-off valve with a maximum over pressure of 200 mbar,
working when the float chamber ventilation valve is closed.
If the internal diameter of the fuel tank breather venting tube
is greater than 20 mm, a non-return valve homologated by
the FIA and as defined in Article 253-14.5 must be fitted.

So much for the rules.

In your specific case:


Re positioning of the fuel pumps.


I would mount them to the right of the tank.
More space , not too close to the tank, a very strong place.

Re: fuel pump safety.

You need to assure your pump will be switched off automatically in two cases :
1/ the car overturns
2/ the car impacts an obstacle
3/ you have a fuel line leak or rupture

The first two are easy , but # 3 is something I do not understand.

Aside from a gravity valve on the tank I have (on my 131) a simple Fiat device which will switch off the fuel pumps in case of an impact or roll over. It came ( if I remember correctly from am old Cinquecento or Seicento. As this is basically a steel ball sitting in a steel spring cup covered by a rubber cap I have it positioned between the seats near the hand brake handle. So if if switches the pumps on a major bump ( not impact) I can reactivate it immediately and continue going ...

The kill switch in my 131 kills (deactivates) all electrical connections) switches the car off and kills the fuel pumps.

In my 124 which is basically a "club racer" and has a standard tank have installed an impact switch which will switch off all electricity from the pumps in case of impact . I hope also in a case of a roll over ... I still am to change for a kill switch that would also cut off ignition ( kill the engine)


Re fuel lines safety :

I am using braided flexible lines, They run inside left of the driver's seat. I have to review it.

If you run the lines along the tunnel this is probably the safest.
www.131abarth.pl
GC_93

Rallyroller
Posts: 87
Joined: Tue May 31, 2011 2:40 pm
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Sat Jun 15, 2013 8:41 pm

Hi Miro

Thanks for the input.
Re position of pumps, the room on the right is for spare wheels so no room for the pumps.
You raise a good point about the cut off. MSA regs (UK motorsport regs) do not require a switch to cut fuel automatically in case of a leak. Obviously the main cut out switch stops the pumps. I like your idea of an inertia switch in case of an accident. Also fitting next to the handbrake is a good idea. I will look into this mod. I understand some switches have additional contacts so you can wire it to a light so it tells you when it has tripped.

Re fuel tank ventilation, a gravity activated roll over valve is not mandatory. The only stipulation is that the fuel tank vent must not leak fuel in the event of the car rolling. There are 2 simple ways to achieve this. One is with a suitable valve that closes with any pressure from the fuel tank side (set at 200mb I think). The other option is to fit a pipe that allows air in but won’t allow fuel out after a roll. This is just about correct routing of the pipe to ensure syphoning does not happen. From experience, this is not as easy as it appears. When I rolled the ST there was a small spillage from the vent pipe.
I will investigate how this will work with this tank.
GC_13

Guy Croft
Site Admin
Posts: 5004
Joined: Sun Jun 18, 2006 9:31 am
Location: Lincoln, UK
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Guy Croft » Sun Jun 16, 2013 1:54 pm

The pump/s go in the boot so the are 'pushing' not 'pullling'.

If they are pulling - the low pressure in the line can make the petrol boil in the pipe at altitude on hot days. The engine will run really badly - if at all.

If you mount the pump with the engine you must run a fuel return line to keep it cool.

The best place for the regulator? Not a big issue but in any case you'd best have a fuel gauge near the carbs so you can see the line pressure real-time. No carb for these TC engines needs more than 3.5psi - 4 psi with pump running and engine off. More than that and the carbs are sure to flood. The regulators with built-in gauge are NOT as accurate as the inline ones shown below. That is useful and 100% true feedback from my Weber agent Northampton Motorsport by the way...

GC
Attachments
0-15psi fuel pressure gauge.JPG
0-15psi fuel pressure gauge.JPG (118.86 KiB) Viewed 1576 times
Guy Croft, owner

PumaPhil
Posts: 71
Joined: Mon Apr 22, 2013 5:18 pm
Location: Lincolnshire, UK
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by PumaPhil » Tue Aug 13, 2013 12:32 pm

Hello Rallyroller,

Guy has steered me to looking at your thread as it has a lot of useful information. I recently acquired a Californian import 1977 CS1 which I want for road use and I am planning on Guy doing his magic on the engine this winter. As an aside, I am new to the world of 124s and Guy's name kept cropping up on various Fiat 124 related sites and I made the pleasant discovery that Guy's place is only 25 minutes drive from where I live in Lincolnshire!

The question I have is regarding brakes, I need to upgrade the original ones and Guy suggested getting Whoa! Brakes yet I see you used 911 ones. Are these a simple fit and if so which 911 model do they come from? I'm hoping they would be comparable to the Whoa! items but cheaper - as like most I'm trying to protect the wallet from the inevitable 'mission-creep'.

Good luck with the rest of your prep.

Phil
GC-05
'If you think experts are expensive, you should try amateurs!'

A redline run my GC's engine: https://www.youtube.com/watch?v=80nEhsJbH2w

Simon
Posts: 145
Joined: Sat Aug 01, 2009 6:55 pm
Location: Leicester
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Simon » Tue Aug 13, 2013 1:06 pm

Hi Phil,

I have fitted the unvented disc Whoa! upgrade on mine but it will be a couple of weeks before I get the car MOT'd and on the road to know how it performs. I actually have an incomplete vented disc kit too (discs, calipers but no brackets), but opted for 13" wheels which doesn't allow enough clearance. So it is surplus to requirements at present if you decide to go down that route. I believe that another member, Sandro, is looking at an Uno Turbo setup too. As you will probably have seen when searching this site, there are other strengthening mods you would be wise to make to the wishbones and crossmember components too. I have yet to do these, but I will before venturing on the track with it.

Simon.
GC_15

Guy Croft
Site Admin
Posts: 5004
Joined: Sun Jun 18, 2006 9:31 am
Location: Lincoln, UK
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by Guy Croft » Tue Aug 13, 2013 2:56 pm

Go with the Whoa and nice offer from Simon!

Missing bits contact my good friend stateside - Jon Logan at www.midwest124.com

G
Guy Croft, owner

PumaPhil
Posts: 71
Joined: Mon Apr 22, 2013 5:18 pm
Location: Lincolnshire, UK
Contact:

Re: Historic Forest Stage Rally 124 Spider

Post by PumaPhil » Tue Aug 13, 2013 5:58 pm

Hello Simon,

Thanks fort the offer, is the vented disk kit you have spare from a Whoa! upgrade? Also, what brackets are required? Sorry if this is a pretty basic question but I'm new to this, you could always PM me if required.

I have fitted 15" replica Cromodoro wheels so I guess the clearance shouldn't be an issue for me.

I have heard about strengthening mods but not really investigated them but thanks for the steer, I'll check them out. I imagine once I have a GC engine my plans to have a 'nice run-about' may be somewhat skewed by the temptation to flex my right foot a lot more once it's up and running, so safety mods may become more pertinent.

thank you,

Phil
GC-05
'If you think experts are expensive, you should try amateurs!'

A redline run my GC's engine: https://www.youtube.com/watch?v=80nEhsJbH2w

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest