Transmission Mission
In regard to Mrs. Duran's biodiesel VW Jetta TDI Wagon (Urgent Unguent, June '08): I'm curious to know if you could provide information on the supposed six-speed automatic transmission. I thought the Mk IV Jetta transmission came only as a four-speed automatic or a five-speed manual. Is this transmission TDI-specific, or was the six-speed a misprint? If it's out there, could it replace the four-speed automatic currently attached to my 2.0L 8V?
Eric Cunha
Lowell, MA
Our mistake. The car did indeed have the stock four-speed automatic. However, as of this printing, the TDI is being converted to manual five-speed to better access the engine's brutal torque.
Z4 M query
I have a few questions for Doug Neilson regarding Project Z4 M: 1. Why did you pick Forgeline wheels over the BBS RGR? RGRs weigh about the same and cost less. 2. Why not have Forgeline make the wheels with the same exact offset as the stock wheels (42 front/30 rear)? 3. In the interest of reducing understeer, why not keep 255mm-wide tires in the rear and go to 245mm in the front?
Doug Brown
San Diego, CA
1.Lightweight wheels were absolutely necessary for this track-focused project, but wheel styling selection is always personal. More importantly, custom wheel widths and offsets were required for tire upsizing, and this is not always possible with off-the-shelf wheels.
2.I wanted wider tires for a larger contact patch (this equates to more grip, therefore greater cornering force), so wheels with one extra inch of width were necessary. This in turn required a change in the offset from stock to fit the new wheels and tires perfectly within the wheel wells without rubbing.
3. The wider tire widths selected, 245 front and 275 rear, give a larger total contact patch than the 245/255 combo you suggest. True, one can reduce understeer by widening the front tire width. However, in Part 4: Suspension (May '08) I deal with dialing out understeer using camber plates and setting camber to -3.2 degrees. This was all part of the master plan. As a side note, in testing, the lap times with camber set to -3.2 were about 1.5 seconds faster compared to laps with the camber set to -2.0 degrees. Increasing negative camber up front significantly improves front-end grip and understeer is greatly reduced. -Doug Neilson
The Unbreakable Benz
I'm a huge German car enthusiast (I have a B5 S4) and I particularly love the project car series. I was very excited when I saw the 1995 Mercedes-Benz C280 show up as something that Greg Brown was going to work on, but there has been no progress on it in what seems like years. Did the C280 go the way of the dodo, or are there still plans for it?
Joe Martin
Winchester, MA
Brown still drives the Benz every day. Given his propensity for breaking cars, it's a stunning testament to M-B build quality. If he can't break it, it's unbreakable.