VW Vortex - Volkswagen Forum banner
61 - 80 of 87 Posts

·
Registered
Joined
·
2,392 Posts
Discussion Starter · #61 ·
Having owned two Mini Cooper S and a series of Rabbits, let me restate what I previously posted.

The original BMC Mini, Mini Cooper, and Mini Cooper S all had a true Independent Rear Suspension (IRS) and ironically handled just like a MK1 FWD Rabbit or Jetta by lifting its inside wheel on a corner. Just an inherent factor of a FWD vehicle.

An IRS on a MK1 Rabbit or Jetta would not handle any better than the IRS on the Mini.

Cheers, WWR.
i've seen what you're talking about in a lot of autocross pictures.
and what you're saying makes sense.
 

·
Registered
Joined
·
1,412 Posts
If you want to be different, try a Weissach rear axle. Not sure if it would fit in a A-1, or work with FWD. You can find them in the PNP's once in awhile. The Nipponese clones are very easy to find.
 

·
Registered
Joined
·
4,820 Posts
i want to learn about things like this
Couple of books you might find interesting:

Competition Car Suspension, by Allan Staniforth, ISBN 185960644X
Race Car Vehicle Dynamics, Milliken & Milliken, ISBN 1-56091-526-9
How To Make Your Car Handle, Fred Puhn, ISBN 0-912656-46-8

WWR recommended these to me a while back. The Milliken and Milliken book is really technical. Way beyond me for the most part still.

Things you should learn about, and WWR mentioned some of them:
roll center
center of gravity
roll couple
roll couple distribution

There's lost of info about how different geometries affect the roll center, as well as how the roll center moves during suspension travel.

Once you understand the suspension geometry of our cars, you'll understand why many rabbit race cars have reverse rake (rear lower than front), why race cars tend to run big rear sway bars, etc.

You'll also be able to understand why a double wishbone suspension can give a better camber curve.

It's a really complex subject, but getting a basic understanding of how it works will be really enlightening.

-Fab
 

·
Registered
Joined
·
1,412 Posts
Couple of books you might find interesting:

Competition Car Suspension, by Allan Staniforth, ISBN 185960644X
Race Car Vehicle Dynamics, Milliken & Milliken, ISBN 1-56091-526-9
How To Make Your Car Handle, Fred Puhn, ISBN 0-912656-46-8

WWR recommended these to me a while back. The Milliken and Milliken book is really technical. Way beyond me for the most part still.

Things you should learn about, and WWR mentioned some of them:
roll center
center of gravity
roll couple
roll couple distribution

There's lost of info about how different geometries affect the roll center, as well as how the roll center moves during suspension travel.

Once you understand the suspension geometry of our cars, you'll understand why many rabbit race cars have reverse rake (rear lower than front), why race cars tend to run big rear sway bars, etc.

You'll also be able to understand why a double wishbone suspension can give a better camber curve.

It's a really complex subject, but getting a basic understanding of how it works will be really enlightening.

-Fab
X2 the Puhn Book. It should be like your bible if you care about street driving. Even though it's old school & doesn't have much FWD, it's an awesome book. Very easy to read & understand. Keep a copy in the bathroom.
 

·
Registered
Joined
·
2,392 Posts
Discussion Starter · #66 ·
If you want to be different, try a Weissach rear axle. Not sure if it would fit in a A-1, or work with FWD. You can find them in the PNP's once in awhile. The Nipponese clones are very easy to find.
got a picture of that? just curious as to what you're talking about. never heard of it.

Couple of books you might find interesting:

Competition Car Suspension, by Allan Staniforth, ISBN 185960644X
Race Car Vehicle Dynamics, Milliken & Milliken, ISBN 1-56091-526-9
How To Make Your Car Handle, Fred Puhn, ISBN 0-912656-46-8

WWR recommended these to me a while back. The Milliken and Milliken book is really technical. Way beyond me for the most part still.

Things you should learn about, and WWR mentioned some of them:
roll center
center of gravity
roll couple
roll couple distribution

There's lost of info about how different geometries affect the roll center, as well as how the roll center moves during suspension travel.

Once you understand the suspension geometry of our cars, you'll understand why many rabbit race cars have reverse rake (rear lower than front), why race cars tend to run big rear sway bars, etc.

You'll also be able to understand why a double wishbone suspension can give a better camber curve.

It's a really complex subject, but getting a basic understanding of how it works will be really enlightening.

-Fab
thanks for the info! i'll look those up!
i like complex, i deal with things that are complex better than i do simple stuff, because i over-analyze just about everything :laugh:
so i should be able to understand that information. :)

I can think of another reason.
i'm listening. :)
 

·
Registered
Joined
·
254 Posts
The only other pics i could find of the mk1 rabbit with IRS were these:





Not sure if anyone recognises it? all that i could find was 3 videos of it.



I have heard of some mk1's with IRS that were AWD if that counts?
 

·
Registered
Joined
·
254 Posts
I think the thread has moved on more to being about "If you could fit/design IRS to a mk1 would it be beneficial?" not so much if it is a street or race car as a lot of ideas on race cars can end up on street/track toys.

(edited for grammer)
 

·
Registered
Joined
·
2,392 Posts
Discussion Starter · #73 ·
and the purpose of this just for a "fun street car" is what? NOT WORTH IT.
to you, maybe.


I think the thread has moved on more to being about "If you could fit/design IRS to a mk1 would it be beneficial?" not so much if it is a street or race car as a lot of ideas on race cars can end up on street/track toys.

(edited for grammer)
yeah, i don't see why someone couldn't have a fun car that isn't necessarily a race car... everyone has their ideas of what they want out of their car, and i want mine to handle really well. nothing wrong with that, it's my car.

and that's why i posted this. to get suspension ideas and see what was beneficial and what made no difference, etc.
 

·
Registered
Joined
·
254 Posts
That's why i posted the Reeves mk1 monster, not a race car but a pure track toy tweaked in the right places by 2 great drivers of their time showing what is achievable with a mk1 (ok it doesn't have IRS which this thread is all about but it does have an adapted rear end).
 

·
Registered
Joined
·
50 Posts
Folks, interesting thread - I just caught it by accident having a quick browse through the forum.

The base references for this are what the factory works teams were doing, versus what the man in the street can do.

Works rally teams:


  • Golf 3: toe kits
  • Golf 4: IRS, made to look like a beam with a centre bearing
  • Seat Ibiza kitcar Evo 1: some with toe kits
  • Seat Ibiza kitcar Evo 2: IRS, made to look like a beam with a centre bearing


So the principle is clear: development saw IRS being added to the cars. Roll bars were all through-chassis.

The toe kits have been around years, and create a division as to whether this disturbs the inherent flex in the beams, or is a benefit to the handling. Some say yes, some say no, and someone usually needs to be sent in to separate the two camps. I read in Vortex far less than I would like to, but I have seen the discussions over time.

I'm involved with the Reeves Mk1, have driven it and and produced the video Mike posted. The toe kit has been on the car since 2004, and if it wasn't deemed a benefit, it would have long since been removed. Of course, driving style and set up has its part to play. I've driven it before and after, and the difference was clear.

Still, that's not IRS, but everyone can make it at home easily.

Aside from the blue IRS Rabbit, I've never seen IRS on a Rabbit anywhere else. I don't doubt for a second it's better, but who's got the budget to start clowning around making these things in the hope they'll work? Meantime, Seat Ibiza works rear beams change hands for in excess of EUR10,000, for example. Sure, they're a bit thin on the ground, but Seat Sport put a lot of effort into making them, and no single part is carried across. Whilst they were at it, they incorprated a shimming feature, so they could alter the geometry infinitely, in addition to wheel speed sensors, so it was a far more complex upgrade.

There were rumours of an aluminium Rabbit beam in the UK, but never seen, and %-wise, I think it's nothing more than a rumour. Aside from that, everyone that I've come across is on the standard beam.

Whilst the ARB argument goes that it ties either side together, whether IRS or not, certainly an ARB mounted away from a beam won't bind up like one strapped to it will.

If there's more debate in the thread, I'll bring some pictures to the party :thumbup:
 

·
Registered
Joined
·
2,392 Posts
Discussion Starter · #76 ·
Folks, interesting thread - I just caught it by accident having a quick browse through the forum.

The base references for this are what the factory works teams were doing, versus what the man in the street can do.

Works rally teams:


  • Golf 3: toe kits
  • Golf 4: IRS, made to look like a beam with a centre bearing
  • Seat Ibiza kitcar Evo 1: some with toe kits
  • Seat Ibiza kitcar Evo 2: IRS, made to look like a beam with a centre bearing


So the principle is clear: development saw IRS being added to the cars. Roll bars were all through-chassis.

The toe kits have been around years, and create a division as to whether this disturbs the inherent flex in the beams, or is a benefit to the handling. Some say yes, some say no, and someone usually needs to be sent in to separate the two camps. I read in Vortex far less than I would like to, but I have seen the discussions over time.

I'm involved with the Reeves Mk1, have driven it and and produced the video Mike posted. The toe kit has been on the car since 2004, and if it wasn't deemed a benefit, it would have long since been removed. Of course, driving style and set up has its part to play. I've driven it before and after, and the difference was clear.

Still, that's not IRS, but everyone can make it at home easily.

Aside from the blue IRS Rabbit, I've never seen IRS on a Rabbit anywhere else. I don't doubt for a second it's better, but who's got the budget to start clowning around making these things in the hope they'll work? Meantime, Seat Ibiza works rear beams change hands for in excess of EUR10,000, for example. Sure, they're a bit thin on the ground, but Seat Sport put a lot of effort into making them, and no single part is carried across. Whilst they were at it, they incorprated a shimming feature, so they could alter the geometry infinitely, in addition to wheel speed sensors, so it was a far more complex upgrade.

There were rumours of an aluminium Rabbit beam in the UK, but never seen, and %-wise, I think it's nothing more than a rumour. Aside from that, everyone that I've come across is on the standard beam.

Whilst the ARB argument goes that it ties either side together, whether IRS or not, certainly an ARB mounted away from a beam won't bind up like one strapped to it will.

If there's more debate in the thread, I'll bring some pictures to the party :thumbup:
interesting stuff. :)
 

·
Registered
Joined
·
4,820 Posts
I recall seeing a Rabbit with independant rear suspension when I was searching for information on building an electric vehicle.
Unless you modify the geometry, simply splitting the beam and adding a bearing in the same axis as the original doesn't do anything but remove the built in sway bar functionality.

Splitting the beam and moving the inboard pivot towards the rear would introduce some camber change during suspension travel (similar to the early 3 series BMW.)

The beam split as in the electric rabbit you linked doesn't accomplish anything, really.
 

·
Registered
Joined
·
50 Posts
Initially looking at it, it's firmly in "why didn't I think of that?" territory! (apart from wondering where the strength in the centre mount anchor points is achieved).

Whilst you say that it achieves nothing apart from removing sway bar functionality, it is no different from the aforementioned Golf 4 or Seat Ibiza Kit Car Evo 2. I think I'd better post some pictures! They spent a lot of money on those expensive axles for various reasons, including strength over and above standard, but they were at pains to make them independent.

Using the Escort Cosworth rally cars as another reference point, as soon as the WRC regs changed in 1997, M-Sport swiftly binned the trailing arms of the Group A car and replaced them with lateral links, the same as the Impreza had had for years.

These cars are of course 4WD, but the dynamic camber and toe change of a lateral link suspension appeared be favoured over the limitations of semi-trailing arms.

This wasn't possible on the Golfs or Seats - the original design had to remain, ie that of a beam.
 
61 - 80 of 87 Posts
Top