My 131 abarth (never ending) story - 2017 season updates

[WhizzMan]

I am curious as to why you would cover the floor with aluminum sheeting. I've seen people do that sometimes, but I really can't figure out why you would do that in a race car?

[Guy Croft]

It's not a bad thing to do. The old floorpan gets a bit of a battering in competition use and you can actually wear thru it. Hard to believe I know but I have exp it myself.

Not sure about full covering but certainly some alloy step-plate is a good idea in the most highly stressed areas, like where you rest your feet and heels.

G

[miro-1980]

RE:Covering the floor.

Certainty not all of it !

The pilot ill get a foot rest and a perforated sheet where his feet rest normally not on a stage. This is to protect his feet from heat as well as strengthen the floor in this area .

The driver will get a perforated sheet just to protect the chassis from wear and also to strengthen this area a bit.

Miro

[miro-1980]

Speedo and rev limiter installation .

The speedo is quite small (50x30x20 mm).It needs to be well visible while driving. After putting it in several places to check the looks and installation possibilities the decision was made to put it just underneath the temp gauges on the left side of the dash. It fits just under the mounting pods of the temp gauges. It is not part of the original gr 4 dash, but looks acceptable In this position it is well within sight of the driver all the time , and cables will be easy to lead through including the button to switch functions. ( remember this can show not only speed , but also 0-100 acceleration, max speed,serve as odometer, trip meter etc).

speedo SPA .jpg (80.34 KiB) Viewed 10738 times

This should not hurt the dash looks too much.

The speedo control switch is very small

speedo switch look 1 .jpg (20.02 KiB) Viewed 10737 times

and can be mounted near the display on the dash.

speedo switch place 1.jpg (66.62 KiB) Viewed 10737 times

Re Rev Limiter / speed shift .

The unit turned up to be much smaller than expected: 70x40x30 mm.

REV LIMIT 2 .jpg (112.29 KiB) Viewed 10738 times

The unit does not have to be within hand reach while strapped in harness, as adjustments are not made made when the car is on stage. However the shift up and shift down lights must be clearly and readily visible to the driver (strapped in harness and in helmet). Placing the unit on top of dashboard is out of the question. It looks out of place on a gr 4 dash and spoils its look totally. I thought to place it over the roll cage near the roof but did not have my helmet handy to test visibility. I am afraid this will not be a good place when we change the seats. The driver will sit significantly lower and in this place the unit may not be in his full view while driving. However, placing it on a left side support bar of the roll cage (on the driver's side) allows full view of the shift up and shift down lights. It also allows for easy installation and no problem with lying the wires (under the foam).

rev place 2 .jpg (48.39 KiB) Viewed 10738 times

The launch control switch:

Again there are several possibilities, but in fact trying to install it on the original steering gr 4 will steering wheel would be sacrilegious. Putting it on the dash is totally out of the question - so what remains is the shift lever. As the lever is hollow the wires can be fed inside. The grip top is made of rubber so installing the switch on top of the shift lever grip should not be very hard.

shift lever 3 .jpg (38.62 KiB) Viewed 10738 times

The shift switch (launch control switch) is quite small and requires only 20 mm of space in the shift lever to be mounted. Than the wires can be put on the outside (to avoid contact with the shift lever coming out the gearbox) and down through the boot (than additionally shielded to avoid damage) and to the control unit.

The Clutch switch :

The clutch switch is required for speed shift feature as well as launch control. It should be mounted on the clutch pedal very much like the brake light switch on brake pedal.

clutch switch.jpg (50.12 KiB) Viewed 10738 times

For an unknown reason there is a factory mounting for a this switch. (Anybody knows the reason this mounting exists ?)


Miro .

[miro-1980]

Labourer and Intellectual?
Do I hear echoes of the class struggle here, Miro? ;-)
In these parts when someone says there is light at the end of the tunnel, the answer is it'll be the headlamps of an oncoming express train...
Tom

Tom,

As Walesa used to say "Socialism is in people's heads not in the political system" ( look around ...)

But class struggle in the cockpit - not really , it is to boost egos of the co-pilots who must have far more courage than the diver. I could not be a co driver - I'd s... myself ....

Miro

[miro-1980]

SCARY ACCIDENT

Found this on 131mirafiori.com.

Apparently the main gearbox shaft broke off just outside the gearbox.

LNJ11-BlowedUpParts-08-466x350.jpg (58.55 KiB) Viewed 10659 times

LNJ11-BlowedUpParts-09-466x350.jpg (56.51 KiB) Viewed 10659 times

The damage is real scary, though the drive walked away reportedly with only a bruise to one leg.

What can be done to protect from such an event? Maybe welding into the tunnel several massive steel braces , reinforced on sides by bars to the sides (under the floor ) might be effective. Any comments suggestions .

Miro

PS: this car had only 85 hp

M

[WhizzMan]

This is not as uncommon in racing as you may think. Usually, steel "braces" are put around the shaft to prevent it from "slamming" if it should come loose. That way, you have a chance to stop the car before the shaft eats through the tunnel. The biggest precaution you really can take is to inspect all bolts, couplings, bearings of the shaft every time before driving.

[Guy Croft]

The cause is likely this: propshaft removed and then not refitted in the same polar orientation. They are (or used to be) balanced on the car.

It is vital to have a propshaft balanced as an independent item.

I drove a MkII Escort rally car many years ago that exhibited that 'phenomenon' - the propshaft, at about 70mph suddenly went into massive resonant vibration, nearly shook the car to pieces, only my immediate & emergency braking brought it back under control.


G

[TomLouwrier]

Mounting hole for a 'brake light' switch over the clutch pedal will have been for an optional cruise control.

[miro-1980]

Mounting hole for a 'brake light' switch over the clutch pedal will have been for an optional cruise control.

Tom, this was a real surprise to find it there . and could not figure why . I did not know they had cruise control on fiats these days ...but I ma very glad. This will make my work much easier...

Miro

[miro-1980]

This is not as uncommon in racing as you may think. Usually, steel "braces" are put around the shaft to prevent it from "slamming" if it should come loose. That way, you have a chance to stop the car before the shaft eats through the tunnel. The biggest precaution you really can take is to inspect all bolts, couplings, bearings of the shaft every time before driving.

I have never seen it or heard of it , but these pictures looked quite scary ...

Apparently , this time it was the main gearbox shaft ... not very easy to inspect.

I have the car inspected before every race/rally , but installing the braces is a good idea and I will do it.

Miro

[miro-1980]

The cause is likely this: propshaft removed and then not refitted in the same polar orientation. They are (or used to be) balanced on the car.

It is vital to have a propshaft balanced as an independent item.

I drove a MkII Escort rally car many years ago that exhibited that 'phenomenon' - the propshaft, at about 70mph suddenly went into massive resonant vibration, nearly shook the car to pieces, only my immediate & emergency braking brought it back under control.

G

My propshaft is balanced separately. but still it is something to think about ...

The Abarth version had a drum installed over the gearbox /propshaft connection. Any idea why ?

Was this to strengthen the connection and or to protect from effects of a broken shaft ?

See pictures below :

Original picture :

Kopia capture #14.jpg (30.87 KiB) Viewed 10680 times

I( was investigation possibility or replicating it in my car and found ta guy whop actually did it.

Below are pictures of the original drum (left) and a remake to fit standard gearbox ( right )

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drum2.jpg (50.63 KiB) Viewed 10680 times

Also pictures taken after fitting it :

drum installed from under .jpg (35.3 KiB) Viewed 10680 times

drum installed over .jpg (53.16 KiB) Viewed 10679 times

Would such installation create more of a problem in case the propshaft brakes or be more controllable?

I was thinking of putting the braces as follows:

1/ over the drum

2/ over the propshaft on its first support or maybe a little further back , where the shaft is thicker .

braces.jpg (42.18 KiB) Viewed 10680 times

The braces could be a one piece steel ring made of 5x 30 mm strip bolted to the floor or made of two pieces ( the top welded in and bottom bolted and the bottom bolted. This would hopefully limit the shaft travel and give the driver more time to stop the car.

Any comments / ideas ?

Miro

[Urbancamo]

Hi Miro!

It's similar structure as i've seen on many RWD rallycars which don't have only slip joint on gearbox's tail.

The metal gage is protecting if the rubber donut explodes. In high rpms with straight gear, it's possible. And it's holding hole assembly together even if the donut get's to pieces. You can still drive to finish line...

I have broken two rubber donut's in civilian use in modest rpm's (4000+) and i have to say it's very unpleasent. On the second explosion fuel- and brakelines were bent in V-shape! Even 8 mm steel pipe is like nothing when 100 grams on rubber gets airborne...

Since then i have straightened the engine/gearbox assembly and no nore exploded donuts. There was slight misorientation with prop shaft and engine/gearbox assembly and that was creating high stress in rubber donut.
The line needs to be perfectly straight, otherwise the donut heats up and after period of time, it explodes.

Hope this helps.

Btw. the Abarth is like candy...love it.

[pastaroni34]

I have seen and built similar guibo/donut cages before, though I must admit this design is clean and more robust. I like it. This is definitely on my list of parts to make next.

[Walezy]

Why not making propshaft without rubber part? I was using one piece propshaft in my Fiat with ford gearbox. it made no problems and many escort guys are using it. You eliminate the problem of exploded rubbers.