There are several things you can do to your car that really make a performance difference that don’t cost ANY MONEY. These are obviously the best kind.Throttle linkage adjustment:
Over the years I have found that almost all BMWs I’ve looked at or owned were not getting the throttle all the way open! The throttle cable stretches over time to the point where they may only be getting 3/4 open. The easiest horsepower your will ever get is to readjust the cable. Open the hood, and look at the throttle linkage.
- With the car off, step on the gas pedal, pressing it all the way to the floor. Do this several times until you are sure where the linkage stops.
- The same place? Probably not! Another way to check is to have someone hold the gas pedal down, and then with your hand see if you can open it further. If so, the next step is to adjust the cable.
- The throttle cable runs from the throttle linkage into the black cable housing a few inches from the end of the cable, and is held in place by a metal bracket. The end of the throttle cable housing is threaded, and it runs through a 17mm nut that is attached to the bracket by a rubber grommet.
- Hold the 17mm nut on the grommet with one wrench and turn the cable end counterclockwise with a 13mm wrench, both of which should be in your tool kit. You can see the end of the cable back out of the housing as you do this, making the cable to the throttle SHORTER. Now try the throttle again, double checking to make sure it gets all the way open.
- Test drive it! Hope it makes as big a difference in your car as it did in mine.
Brake Pedal Height:
The height of the brake pedal is the single biggest determining factor on whether a car is easy to heal and toe during downshifts with a manual transmission, and it also controls how the brake pedal FEELS when you apply the brakes, even with an automatic transmission.
Almost all (I can’t think of any, but I hate absolutes) BMW brake pedals are adjustable for height. If you would like to adjust it, you must loosen the 17mm lock nut on the brake rod that comes into the passenger compartment. This locknut is on there TIGHT, as the folks who put these things together don’t want a liability issue from loose nuts.
Take two 17mm wrenches, remove the underdash valence, and crawl under as far as you can. Follow the brake pedal up to the linkage, and you will see a threaded rod that threads into a u-shaped bracket that attaches to the pedal. Jammed against this bracket is the 17mm lock nut that keeps the rod from unthreading, which is what you want to do. Use one 17mm wrench to hold the bracket, (it’s a little loose, but it works) and the other to break loose the nut. On over half the cars I’ve done this to I have had to heat the nut to get it loose.
Open flames under the dash are NOT recommended if at all possible for lots of reasons we won’t get into here. If you can’t get it loose, I strongly urge you to take the car to your local mechanic to let him break it loose. If you have a good relationship with him, he probably won’t charge much if you already have the valence off.
Once loose, spin the rod clockwise to raise the brake pedal to the desired height. Lock the nut down, and drive. If it’s not right, do it again. One thing I did find out the hard way, is that if you adjust out too far, the brake pedal hits the stop and then you push the rod into the master cylinder, applying the brakes! Went to drive the car and it wouldn’t move. Oops. Just make sure you can roll the car by hand, and you’re set. Good luck!
P.S. If you’ve ever wanted to learn to doubleclutch but don’t know how, it’s explained in detail in “Doubleclutching for Dummies”, also on my web site www.driversedge.com.
Author: Jeff Krause
Hoosier Tracks Mar/Apr ’98
Hoosier BMW Car Club, Inc.