Grassroots Motorsports
Issue link: http://grassrootsmotorsports.epubxp.com/i/397024
Grassroots Motorsports 142 DREW INGRAM Turner Motorsports 16 S. Hunt Road Amesbury, MA 01913 turnermotorsport.com (800) 280-6966 Maintenance records, espe- cially dealer work, are extremely important. This engine and chas- sis kept BMW busy through the years with rod bearing recalls, VANOS and valvetrain weak spots, software updates, and chassis failures–and at least one class-action lawsuit. I would also want to know about the previ- ous owners: if they tracked the car, if they used aftermarket or OE parts on it, where they had it serviced, and so on. The best suspension upgrade for you depends on what com- plaints you want to address. We like to take a concentrated approach to what the customer wants. We have everything, but just blurting out "Bilstein Club- sport at $4300" is not what every customer wants to hear. The most common complaint about the factory setup is the lack of front grip leading to under- steer. We typically address that with wider front wheels and more negative camber. A front anti- roll bar upgrade also does a lot, especially for street driving. For a track car, the hot kit that we have now is the aforementioned Bilstein Clubsport–unbelievable features and performance. When looking for more power, the frst step is to add a set of headers and delete the cats. However, with the cats in the dumpster, the car won't pass emissions testing. If you have a track-only car, then headers and a standalone ECU are the way to go. We have a Bosch Motorsport plug-in ECU with impressive gains and complete tunability. But the best upgrades with no downsides are gearing and differential upgrades. Gearing makes a huge difference because this engine doesn't make a lot of torque, so getting into the pow- erband sooner is key. The most popular are still 3.91 or 4.10 ratios. Most E46 M3 diffs need a rebuild by 60,000 miles anyway. We do a subframe repair and reinforcement on customer cars at least once a week here. That involves all of the rear suspension bushings and mounts. This car is quickly replacing the E36 M3 as the fun weekend or track day toy. I think people were initially afraid of them–engine failures and recalls didn't help– but as time went by there was less and less to be wary of. Today, there's not much that hasn't been fgured out. But I always warn people that just because the cars are becom- ing cheap, that doesn't mean they need less maintenance or cheaper servicing. They are going to be very pricey for some owners who don't realize what they're getting into. Do it right, not cheap. TECH: BMW E46 M3 TECH TIPS