Does your VAG handle? It depends...

[kaanage]

There is a lot of discussion here about mods to make cars handle better.

But what does that mean? Why are some of the mods mentioned controversial?

One of the keys is to honestly define what your goals are - ie how you drive. It's no good saying that you want your car to have maximum grip through corners, not be affected by bumps, be stable / agile / comfortable / invigorating / relaxing....
It won't happen - especially not with cars with a torsion beam rear end (Golfs Mk1-4, Polos etc).

And it's no good pining for a racetrack optimised setup when driving through the hills or along the coast is your goal.

Thousands of posts on the web attempt to dissect handling but some of the best I have found were posted on another VW site which came out of a discussion on the VW Vortex site. The best part is that after these 2 introductory posts on basic definitions, the 2 authors post about traits and modification specific to cars with MacPherson Strut front ends and Torsion Beam rear ends - ie a LOT of cars on this forum.

The actual thread is cluttered with not particularly helpful comments by other posters so I'll link the relevent posts here

Why does my car understeer?

What do I want out of my car?

[kaanage]

Why did VAG make my car handle this way?

How the stock suspension works Part a

How the stock suspension works Part b

[GTD_XU1]

Thanks kaanage, a good read. It helped explain to me some of the "suck it and see" things I did to my XU-1 millions of years ago.

[kaanage]

Actually, it gets better as they start discussing the ramifications of mods for the usages described in the 2nd post

Autocross Suspensions

Shine Racing Services were a US VW tuning company that developed a very fast MkIII Golf race car. Sadly, they closed late last year but the link is to their info page which has some interesting observations and opinions.

Road Racing, and the Shine Real Street Suspension Part a
Road Racing, and the Shine Real Street Suspension Part b

And now they get into suspension geometry effects
Roll Centers and Weight Transfer Part a
Roll Centers and Weight Transfer Part b

[Tim]

Some interesting reading so far!

[kaanage]

Finally the topic is wrapped up with discussion of GT (fast safe road use) driving
GT Suspension Part a

GT Suspension Part b (Rear Anti Roll Bar with Stock Springs) and Conclusion

I hope others found these links as informative and enjoyable as I did.

There are some other snippets from the thread which were interesting to further discuss certain points which I may dig out and link up.

[bennjamin]

Id like to input some real world average driver experience - a larger rear bar upgrade (on a porky mkv gti) tightens up the handling - it does not make the car unstable like discussed. Alittle unbalanced , but still very safe. Even excessive heat in the tyres and speed on the track , i couldnt get the car into a controlled slide. Very safe !

Unless you are overspeeding or shifting the weight on bald tyres or a very wet surface there isnt a chance to slide the back out at all.
Definitely getting the front upgraded too !

[Tom87]

The article is good but possibly is also good to keep in mind it is discussing a Mk4 which has different suspension to the Mk5 (as it discusses).

Plus the Mk5 has ESP. Even when it is "off" the program running only really allows wheelspin with minimal increase in allowable slide before it pulls you into line again. Not that you'd want to disable this for a road car, i am positive this feature has saved my hide before.

BTW @ bennjamin, what you describe in your second last sentence is exactly what the article on the tdiclub forum is talking about preventing for a road car. :p

[bennjamin]

BTW @ bennjamin, what you describe in your second last sentence is exactly what the article on the tdiclub forum is talking about preventing for a road car. :p

Yeah i definitely replied with a "from a hoon on the track" perspective lol. You are totally right the car is doing alot of work keeping the chassis neutral and safe

[kaanage]

Exactly. The multi-link rear end makes a car much more forgiving than the torsion beam.

That said, I have been on a cruise in the hills where a MkV R32 dropped really low and with a massive rear ARB ended up off the road from snap lift off oversteer, so it is important not to over do things (I'm guessing the car felt really "pointy" in normal conditions).

[gavs]

Does your VAG handle? It depends...

Excellent work Greg as always, you have linked to a couple of my favourite articles there, especially regarding lowering on vehicles with Macpherson Strut/lower A arm suspensions.

[Martin]

The VW clearly has a healthy amount of built in understeer, hence harder rear bars don't make it nasty
I guess it depends how hard you go on the rear roll bar - most street bars are only 30% stiffer
But if the car is used on the street you want to be aware of how it behaves in the wet also...

Have a read of this (very old) road test for a laugh
(it's one reason why I'm cautious of KIA/Hyundai handling)
AutoSpeed - New Car Test - Piloting the 1999 Hyundai FX Coupe

My Mazda 3 has very good handling properties but in the wet I can lift the throttle, turn in and get the rear to slide around (it's really easy to stop/control)
I haven't tried the same thing in my Skoda Octavia as yet (MKV suspension)
I've installed harder front and rear roll bars and harder springs - it's certainly sitting flatter during hard cornering...

[Guy_H]

Exactly. The multi-link rear end makes a car much more forgiving than the torsion beam.

That said, I have been on a cruise in the hills where a MkV R32 dropped really low and with a massive rear ARB ended up off the road from snap lift off oversteer, so it is important not to over do things (I'm guessing the car felt really "pointy" in normal conditions).

I have had at least 4 customers write their cars off like this because of ill handling vehicles (majority of issue is whacking on a big rear sway bar) and one was seriously hurt. That is the main reason I don't wan't to see any of our forum members maimed or killed - because the car feels "great" around the street with a big rear bar.

The problem as Bennjamin describes & is reinforced by kaanage is that the "average" driver can't & won't be able to react to snap oversteer. Causing a big problem for themselves, let alone other road users that happen to be in the wrong place @ the wrong time.

[kaanage]

Some of the posts that weren't central to the topic but were of some relevance

Sadly, the following post no longer has active links to the pictures that help illustrate the points being made - still worth reading and trying to follow, through
A digression on geometry changes with suspension movement

Why VW reduced the precision of the Audi TT's handling (and the Golf equivalents)

Stock handling and the Elk test relevance!

[Water Boy]

Just had a good read. Hadnt heard of those Shine racing guys before but thanks heaps for the link.