Road/occasional Track Car Running Gear Overhaul

[Joshy 0]

Yep, another one of these!

 

With the new year approaching and I want to start considering renewing my car's running gear (Brakes, Suspension, Possibly Steering).

 

I'm shooting for the Dr Jekyll, Mr Hyde sort of thing with this car. I was something that is relatively comfortable for my commute to work and back around the pot hole and speed hump infested roads that make up London, but can also more than hold it's own on track and the very occasional B Road blat.

 

At the moment I am running on standard 1.6 running gear and some Jamex Shocks and Springs which I'm not awfully impressed with. Whilst the ride isn't as harsh as some reviews on the internet make out, it certainly isn't what I'd call comfortable. On track it wasn't much better either, I don't have much experience on track days but even I could tell that it was getting a tad too much understeer. This led to an embarrassing moment when I begun to underestimate the car and foolishly lifted off mid corner. LOOS certainly isn't progressive .

 

The beams of these cars seems to be a complete minefield as far as I can see. Is it worth springing for a rebuilt 309 GTi rear beam? What size ARB and Torsion bar should I run? What about dampers? A bit of research seems to say that the Standard 306 GTI-6 as great for road cars?

 

The Fronts are even more confusing. Speaking to some people I've heard suggestions from everything to Gaz Coilovers to Bilstein's. What sort of Spring/Damper combination is best for that 'Middle of the road' effect between comfort and Performance. Is it worth poly bushing the whole thing (considering the rubber may be knocking on 20 years old)?

 

Is it worth going for different struts? I heard Xsara VTS items can go on with little fuss? What about 309 arms?

 

Brakes - The standard 1.6 items were certainly better than I thought they were going to be, but they didn't really inspire masses of confidence. Whilst I know that it is unnecessary and ups the unsprung weight, but I think I want as beefy brakes as I can easily fit behind 15" wheels. GTI-6/HDI brakes seem to be the winner on the front, but what about the rear? I'm not one of those "It MUST be discs" people, so I'm happy to keep the rears the same if that is alright?

 

What about an uprated master cylinder? Is it absolutely necessary and if not, is it worth it?

 

Steering

 

No issue with steering other than a weird noise on full lock (sounds like it is running low on Fluid, but it hasn't got PAS!?). But would it be worth considering changing the rack? Again, I've heard the Xsara VTS item goes on fairly easy

 

Any suggestions guys?

 

Thanks

 

Josh

[Galifrey 1]

You have a GTI6 motor right?

 

LSD? good for improved handling of LOOS moments!

 

Uprated pads should be fine for your needs, ferodo DS2500/Mintex 1155/CL RC5+ will all improve the braking. Until you have tried those it might be tough to advise where to go with the brakes.

 

What else do you want to achieve?

 

Coilovers for road use are a recipe for increased maintenance, Bilstein B4 are recommended for a good uprated road shock or if you want to save money, I am using Xsara VTS front struts.

 

309 rear beam will increase rear track, changing the arms will increase negative camber reducing some of the hooligan handling characteristics which I actually like. LOOS is great for changing direction.

 

Stiffer springs/torsion bars will reduce body roll but can make the car less forgiving and certainly more crashy on london potholes.

 

What tyres are you running? a change of wheel diameter by 26mm in itself won't change much but will force a tyre change, what don't you like about your current tyres?

 

Everything could be an upgrade or a downgrade depending on what you want to achieve.

[Joshy 0]

Hi there. I think we've already spoken on the OcUK forums .

 

Yep, I'm running a GTI-6 engine. I'm not actually convinced that I need an LSD yet, I certainly didn't have as much problems as I suspected I would get the power down on to the track. have any problems with getting power down out on track.

 

To be honest I just want to create as neutral handling car as possible. I thought that on the Jamex suspension I'm running now it was a tad too reluctant to turn in. I remember needing to use an undercomfortable amount of lock to get around Druids, which makes me want to start considering a shorter rack. Possibly even retrofitting PAS.

 

Were the VTS Struts a worth while upgrade?

[Galifrey 1]

Hi there. I think we've already spoken on the OcUK forums .

 

Yep, I'm running a GTI-6 engine. I'm not actually convinced that I need an LSD yet, I certainly didn't have as much problems as I suspected I would get the power down on to the track. have any problems with getting power down out on track.

 

To be honest I just want to create as neutral handling car as possible. I thought that on the Jamex suspension I'm running now it was a tad too reluctant to turn in. I remember needing to use an undercomfortable amount of lock to get around Druids, which makes me want to start considering a shorter rack. Possibly even retrofitting PAS.

 

Were the VTS Struts a worth while upgrade?

 

The VTS struts seem to have firmed up the damping, so would have to say yes, and at £10 a corner, a cheap upgrade

 

Druids is quite a tight bend, but I assume from what you are saying your front is washing out? Without seeing your driving it's difficult to comment, however, as a rule of thumb, the stiffer you make the suspension, the less grip that end will have. If you have too much grip at the rear (ignoring LOOS for a minute) then the car will want to "push on" thru the bend. Of course going softer can mean more body roll, that changes the tyre contact patch reducing grip, so the right combination of springs and ARB becomes important.

 

More negative camber can cope with more body roll, for that tho, you would want adjustable bottom arms and top mounts I believe.

 

Xsara VTS rack is very quick, I like it a lot, but it does take some getting used to after the stock rack.

 

There will be a group buy for TranX diffs soon, so may be a chance to get one at a good price, and they do a hell of a job of helping keep the front end under control, under power, it seems to literally yank the car in the direction the wheels are facing, however, my only experience so far has been slippery conditions, in the dry I cannot comment.

 

What tyres are you running atm?

[Joshy 0]

I think it was the lack of steering lock that was my problem around Druids. Graham hill bend was where the 'understeer' was the worst, no matter what I did throughout the entire day I could not get the car to take the line that I wanted to take, unless I shaved off a ton of speed I'd just run wide. It was my thinking that the front springs are too stiff, Jamex suspension has a reputation for being unnecessarily stiff so this certainly seems likely?

 

Surtees was were I had my spin, and again I think it was down to me getting a tad too much understeer, causing me to lift of trying to correct my line and subsequently spinning.

 

Tyres were 195/45/15 Yoko A539s (which are nearing the end of their lives now!).

Edited December 20, 2009 by Joshy

[shalmaneser 26]

i guess your problem is probably too stiff front/too soft rear.

 

I'm currently running stiff springs and adjustable dampers at the front but standard stuff at the rear and the understeer is definitely increased over the standard setup. I've just got a 309 rear beam that I'm fitting over the winter to try and balance out the handling, I'll let you know how I get on.

 

personally I'd be looking at how to uprate your rear spring rate, be that 309 beam or bigger 205 length TBs and ARBs.