When are wider tires in autocross not faster? - "335" lessons learned and the season so far!

Five events into the Autocross season Grant reflects on how the 335/30/18 size tires have affected his highly modified 2008 Mustang GT. We go over the issue of cold weather events and the inability to heat up a larger tire and some other obvious issues associated with having a car that is more than 5" wider than stock.

Five events into the Autocross season Grant reflects on how the 335/30/18 size tires have affected his highly modified 2008 Mustang GT. We go over the issue of cold weather events and the inability to heat up a larger tire and some other obvious issues associated with having a car that is more than 5" wider than stock.

2018 Autocross Event #2 Amelia Island Airport

Photos by @Conedodger240

BMW E39 M5

BMW set the golden standard for the sport sedan with the release of the E39 body style M5 for the 2000 model year.  Even almost two decades later, it delivers a sporty, luxurious, visceral driving experience unmatched by most modern cars.

What made the E39 M5 so special?

It was only offered with a 6-speed manual transmission.  Every single E39 M5 every built has three pedals.  So if you see someone driving one, you know he or she is the real deal!  The lack of any automatic option kept away the wannabe enthusiast crowd.

The 400hp S62 V8 debuted with this car.  It has 5 liters of displacement, which was and still is enormous for a DOHC European car.  Double-VANOS (BMW's variable valve timing) adjusted exhaust and intake cams for more power and fuel efficiency, and as an added bonus were notoriously expensive to repair.  It has eight individual throttle bodies underneath its gloriously weird intake plenum.  The S62 remains known for being maintainable only by professional mechanics and OCD engineers, insanely punchy on the throttle response, and sounding like a cyborg T-rex's mating call on full throttle. 

This car speaks to me because it looks like it could be driven only by dentists, yet has gobs of torque and handles like it's on rails.  Especially after it has aged so many years, no one really recognizes it except true car nerds.  You get the occasional gas station conversation from fellow enthusiasts but no regular members of the public hassle you.  Mustangs and imports with huge wings don't try to race you on the street, but if they did they would be embarrassed by how quickly it gets to the office.

My particular car has Ground Control coilovers, a square wheel setup with 9.5" widths all around, muffler delete, magnaflow sport cats, a CSF aluminum radiator, ESS Tuning / Vortech supercharger kit, Snow Performance water mist system, and a tune from Matt at HD Tuning. 

 2021 Update: The supercharger is still working well, and I’ve done a few mods to help it work even better. One is replacing the ESS intake (which includes a flexible intake hose that collapses under throttle) with a hard carbon fiber elbow and a short section of silicone . This new intake may or may not stay cooler, but it certainly doesn’t collapse under throttle. I also added a splash-resistant pre-filter sock for protection against wet Florida driving conditions. Eventually I will increase the intake filter size but I need to completely delete the fog lights first. I’ve made one other pretty cool mod which is a Mighty Mouse atmospheric vent catch can mounted with a custom mount I designed. On the supercharger’s bypass valve, you can either recirculate the excess boost back to the inlet side of the supercharger (which creates immense intake air temperatures), or you can vent it directly to atmosphere inside the engine bay. I was doing the latter and it was soaking the engine bay in oil. This is the reason I bypass the stock Air/Oil separator system with the catch can. Now I can still vent the bypass valve to atmosphere, but it is dry air with no oil vapor. Oil vapor from the valve covers now relieves directly to atmosphere via the catch can and its vent. This can make for some bad smells after startup, but nothing too bad.