Rear SUSPENSION Differences: OLD vs NEW

[alerno]

Hi,

I have recently driven an mk7 Fiesta in Catalonia and was blown at how amazing it handles. Seriously. I had been driving my E21 BMW so that climbing on that little Ford felt like a rebirth, and it reminded me totally of how our belovèd Pumitas handle. So I have decided to sell my BMW and register my Puma.

Thing is, before I do: I remember (but I can't find) discussions debating the old, pre-99, suspension vs the newer one. I even remember one of you had fitted the older set-up to his after-99 car. I have a 2000 1,7, I bought Eibach springs (took me months to find them) that I plan to them with stock dampers.

But I want the very best, the Pumita at its fullest. So, may ask:

- Can anyone DESCRIBE WITH EVERY POSSIBLE DETAIL AND NUANCE HOW THE OLD SET-UP FEELS in comparison to the new one?

- What objective and practical differences there are?

- Photos or graphs of the differences.

I am off course interested to know how each setup is in relation to OVERSTEER-UNDERSTEER.

Any info, anything is much appreciated.

 

[Wild E. Coyote]

To the best of my knowledge, I can't tell that there is a handling difference in old vs. new rear axle. The practical differences:
The old one is narrower and the car comes with 10 mm spacers at rear (cast aluminum items) which are mostly due to be replaced. Also, they use the fork mount rear shocks.
The newer axle is wider by 20 mms and so cars don't use spacers and the shocks are eye mount type (the bottom fixation points, i.e.)

 

[alerno]

Hi,

Thanks for the reply. If the track at the rear, including spacers, is narrower it is definitely meant to understeer less as the front has better grip. Since Puma don't understeer almost, the net result might then be slight more oversteer.

But of course this is just speculation, any ACTUAL experience of anyone driving both setups would be different.

 

[Wild E. Coyote]

No, you misunderstood. The axle itself is narrower, but the spacers bring the track back out by 20 mms. Since the new axle is wider, and the car uses no spacers, the net rear track is the same.One can only speculate about the actual stiffness of the rear axle with spacers and itself being narrower in comparison with the wider axle and no spacers setup (which hence include shorter bolts!).
Both axles are interchangeable on any puma provided you supply the matching shocks. Again, since one is bolted to the axle centrally (fork mount) there is no torsion at pickup (the fixing axis goes straight through the axle body). On the eye mount the pickup point as adjacent to the actual axle and there is some flexion inevitable as there is flexing moment there trying to twist the axle. That is the theory. Most probably there are no differences in actual practice

 

[alerno]

Thanks again!. Good to know. Would you happen to have any pictures of the pieces?

Has anyone else driven the setups back-to-back?

 

[Wild E. Coyote]

Here you can see the shocks with fork mounting. http://www.pumapeople.com/stuff/1466687132/gallery_7126_46_1647634.jpg

And here you can see coilovers with eye mount. http://pumabuild.com/pumacat/product_info.php?products_id=230

I am not implying they are the same (the very pieces shown here), just the ones I could find quickly for presentation purposes.

The rear spacer on older models looks like this: http://www.ebay.co.uk/itm/2-x-FORD-FIESTA-KA-PUMA-FOCUS-20mm-Spacer-Kit-Rear-Axle-Handling-Upgrade-20-5mm/121655929585?epid=1560990461&hash=item1c53422af1:g:NtwAAOSwX61ZAgr~

You can find billet ones floating around ebay, or you can get them made to your spec as they are not very difficuilt to reproduce. You can get them made to alter the rear suspension geometry if that is what you are after (or to bring it back to OEM specs as there is no adjustment provided at rear and most of them are now more or less bent out of allignment)

The newer axle: https://www.ebay.co.uk/itm/2001-FORD-PUMA-MK2-1-7L-PETROL-3-DOOR-REAR-AXLE-BEAM/372002433054?fits=Car+Make%3AFord%7CModel%3APuma&hash=item569d12a81e:g:zesAAOSwjvJZW42T

 

[Ian G]

Sure the track ends up being the same size? For geometry purposes the two setups are identical Ithink.

 

[alerno]

Thanks so much! As soon as I get home I'll have a look.