Front and rear anti-roll bars.

[roodini]

Has anyone fitted the anti-roll bars from the vans to the saloons and if you have what was the difference/benefit in the handling/driveability of the saloon, in comparison to the single thinner front anti-roll bar?
I'd like to carry out the mod to the "pornmobile" if it's worth it.
Plus i've just fitted a set of 175/80 tyres, the ride's been transformed but I was wondering about speedo accuracy. Is the 80 profile close enough for the speedo to be within a hairs breadth or should I do what I do on my motorbike and stick with the flow!

Have a good New Year people.

ps Lovely to see you Bluebell, Chris and Ermintrude.

 

[malcolm]

I've not fitted the van anti-roll bars yet although I plan to do so on my Gordini project. I can help with the physics:

Generally increasing the thickness of the front anti-roll bar will make the car understeer more, and increasing thickness at the rear will make for oversteer. Increasing the stiffness of both at the same time will increase the roll stiffness of the whole car.

I'm not sure how this would affect R4 handling (haven't tried this yet) but I'd guess for wider tyres it might improve roadholding. Certainly the Spanish cars had thicker front and rear anti-roll bars (with standard tyres) and the handling feels more solid. I feel it's worth a try and it's my plan for my Gordini car.

For tyre sizes, 135/80 are standard, but 145/80 tyres make the speedo completely accurate. 155/70, 165/60 or 175/50 would give much the same speedo readings as the 145/80. A 175/80 would make the speedo under-read the speed by about 10%.

 

[roodini]

Thanks for the reply Clem, the hunt is now on for a set of anti-roll bars from a van.
Something else popped into my mind while I was reading through some previous threads, you said that it was prefferable to balance alloy wheels via the centre hole, whereas steel wheels should be balanced via the wheel stud holes, any reason as i'm about to get my wheels balanced next week (Gordini alloys) and I was going to get them done via the stud holes!

 

[malcolm]

I'm guessing if there is a hole in the centre of the wheel then that's what will be used to balance the wheels. The manufacturers would relise this too and would put the hole accurately in the middle.

On the car the wheel nuts are used to locate the wheel on the hubs rather than the hole in the middle, but I suspect balancing on the middle hole would be OK. If you could persuade the balancers to use the wheel nut location it would probably make balancing more accurate, but that probably wouldn't make much difference from balancing on the centre hole.

 

[angel]

There were two sizes of front anti-roll bars: 12mm (normal road saloons) and 16mm (poor road/special versions,all vans). Rear anti-roll bars were fitted to some poor road and special version cars and vans. I have driven both versions of R4s. There seems to be some noticeable increase in suspension stiffness on cars fitted with the large anti-roll bar,not only slightly decreased body roll,but also a little stiffer going over bumps. That said,the "poor road" versions are not too hard or understeer too much,their handling remains typical R4.I still have doubts about the rear anti-roll bar as it is not articulated on the chassis,it only connects the suspension arms,but I keep it on both my "poor road" R4s anyway. Gas-filled shock absorbers (deCarbon,if you can still find them) do the trick at the front they stiffen up the car noticeably as opposed to oil shocks (Monroe,Allinquant etc.)
A completely different story are the "special versions" suspension,these cars (designed mostly for African markets) have the large anti-roll bar and larger van's torsion bars,they are way stiffer than one would expect from a R4!
I think that 175/13 tyres are way too wide for a R4. I have found that even 155/13 tyres were not the best option for a R4 ("poor road" suspension and DeCarbon shocks).It felt a little unpredictable when cornering hard. Of course with standard 845cc engine...

 

[Liam4R4SPARES]

Whilst between jobs many years ago i worked for a stint at a Kwik fit tyre centre and all car wheels are balanced by the centre hole .Apart from that is wheels that do not have a centre hole [Renault Gordini alloys, Early R4, Peugeot 504 etc etc]. To balance these there is a adapter kit that fits the wheel balance machine .It is a kinda like a adjustable legged spider effort that takes a few minutes to set up to fit the wheels .Unfortunately i have found that most tyre shops and fitters have no idea how to use the tool correctly or have the inclination to even attempt to use it.