E92 - Pads & Springs

By John Thorne

Its a different month this month, thus far we’ve covered cat back exhausts and detailing and the plan this month was to cover some aspects of brakes or suspension in detail but we’ve only gone some way in both these areas so we thought we’d cover them this month by introducing the cars other role as the CSL Cup Safety Car.

The CSL Cup is a new race series that we (Thorney Motorsport, Geoff Steel Racing, BM Sport, Simpson Motorsport and Ray West Tuning) have created this year designed and developed for the BMW E46 M3 and CSL only, you may have read some of the race reports in PBMW last month.  As with any race series there comes a time on track where the cars need to be controlled and so we needed to create a Safety Car for the series and the E92 M3 seemed perfect.

A Safety Car is pretty much what it sounds like, its role is to come onto the circuit during the race in the event of a crash or incident that requires the competitors to slow down whilst the incident is cleared so racing can commence. As the CSL Cup cars run on slick tyres the Safety Car needs to be able to lap fast enough to enable the competitors to keep heat in their tyres so it needs to be quick. At Rockingham when the E92 M3 wasn’t ready we had to use a Mini as a safety car and it wasn’t fast enough, as soon as it came in we all struggled to get any grip from the then cold tyres!

As well as being fast the Safety Car needs to have sophisticated roof lights, these are used to communicate to race control and the following drivers what to do, when the lights are on the race cars are not allowed to pass, when they turn off it means the safety car is about to enter the pits and once past the line the cars are allowed to race again – simple.  Now we’re a tuning company/race team, the only thing we know about roof lights is to keep a look out for ones that have blue in them so we contacted Mobile Centre in Evesham for their advice, Mobile Centre is owned by Tim who knows more about LED lights, strobes, lazer detectors and all manner of flashy bits than we could ever hope to and Tim recommended a Federal light bar as used by F1 and numerous law enforcement agencies across Europe and the US so we sorted a Federal Legend LED lightbar.

Now I don’t know about you but I’ve never really taken much interest in lightbars but when this thing arrived we were a bit blown away, for a start it needs to be hard wired into the car so any idea of quickly whipping it off in between racing was quickly dropped but the impressive bit is that the whole thing is programmable via a laptop. There are 48 LED’s (none are blue – that would be illegal) and any combination of flashing sequences can be programmed in, you can even have it pointing one direction or the other via the sequence – pretty cool. So after a bit of wiring and fitting the control box to the dash we programmed it to flash side to side at the back so the drivers know what to do and double flash front so Race Control knew what was happening and job done.

With the lightbar sorted we turned our attention to the car itself. Overall we have been most disappointed with the cars handling and braking and whilst we develop more serious upgrades as suspension and brake kits we wanted to test more cost effective upgrades in these departments.

Initial handling upgrades usually take the form of enhancing the geometry set up, lowering springs and finally full suspension kits, we are currently developing a KW Clubsport kit for the car but in the meantime we thought we’d try the Eibach lowering spring kit combined with a more aggressive geometry. The result is pretty impressive, the car is 40mm lower and combined with more aggressive toe and camber settings front and rear the handling is dramatically improved. Turn in on corners and roundabouts has less role and less bounce and mid corner grip is enhanced by less loading up of the dampers due to overly soft springs. Ride is harder but its not harsh and overall the car looks and drives better in every regards; not bad for a few hundred quid.

Brakes are always a problem for BMW it seems, the E46 M3 brakes were dreadful and whilst the E92 M3 ones are better they are still woeful when you consider the kind of car the M3 is. AP Racing, Alcon, Brembo and others have brakes kit now available for the E92 but with these costing upwards of £4,000 we wanted to try a more cost effective upgrade for those with less extreme requirements.

We’ve long been a fan of Pagid pads so a quick call to Competition Braking (our Pagid supplier) and we got a nice set of RS29 pads to try. We tend to recommend RS29 (also called Pagid Yellows due to their colour) as the top pick for track work or racing but with the heavy E92 chassis we thought it was a good first pick. The only downside with Pagid RS29 pads is that they can squeal if they get dirty for example by spending a lot of time in traffic so they need to be got nice and hot regularly to keep this to a minimum. Braking with the RS29’s is much much better. On standard pads the fade comes in relatively early and they don’t inspire confidence, whilst pads alone are not going to create a dramatic effect the extra confidence they inspire means it is an extremely effective upgrade for not much more money than the relatively poor OEM pads.

The final aspect we’ve been working on has been wheels, we will do a full comparison in weights and costs in the next feature but for Brands Hatch we tried the RAYS TE37 19” wheel that we used to great effect on the CSL. Wider rim width and wider track were no issue on the chassis even with lowered ride height and combined with the Michelin Cup+ tyres the E92 M3 comes on (we got rid of the SP2 tyres the car was supplied with) the car felt nice and planted both on the road and track.

The cars first run as a Safety Car was at Brands Hatch, driven by a designated Safety Car driver (who must possess a competition licence) the driver and observer must stay with the car whenever a race is active. During our two CSL Cup races the car came out once per race, once when Mark Steward spun off at Paddock Hill and once when John Harrison’s suspension collapsed in race two. Comment from the driver? “Best Safety Car I’ve ever driven......can I keep it?”

Next month we should be either finally sorting brakes or suspension but as with all development, we really don’t know until we see the results.

 

John