Does ABS sort things out? To a point, yes, but ABS doesn't simply watch wheel speed and react, it's programmed with some basic assumptions to speed up reaction times. Deviate too far from the line-pressure-versus-torque relationship it's expecting and ABS performance-and stopping distances-will suffer.
There's also the small matter of what happens before ABS intervenes. Imagine trail-braking into a corner with rear-biased brakes. Each tire only has a limited amount of grip-if that's used up with braking, there's less for cornering. Even before lock-up, heavily rear-biased brakes will tend to cause brake-induced oversteer. Have fun with that.
On the issue of pedal feel, it's important to realize that the rear brakes don't clamp nearly as hard as the fronts, therefore don't flex nearly as much. There is relatively little pedal feel to be gained in the rear. On the other hand, a Quaife will make a huge difference on the track and, as you guessed, will be a much more effective use of funds.
Q.Who should you believe?
Years ago, while reading SCC, an article directed me to mount my EGT sensor about six inches downstream of the exhaust port exiting the head. However, the directions that came with my gauge want the sensor mounted after my turbocharger (old-school Subaru). Where should I mount the probe to get the most accurate reading for my EGTs?
Galen Helmgren
Bellingham, WA
A.When you think about the purpose of an Exhaust Gas Temperature gauge, the answer becomes pretty obvious. You aren't really interested in the temperature of the exhaust, you want the temperature inside the combustion chamber. Since in-chamber measurement is prohibitively expensive, the next best thing is to measure the exhaust right after it comes out.
Not only does a turbo soak up a lot of heat, but a Subaru turbo is several feet from the exhaust ports, so the exhaust entering the turbo has already cooled substantially.
If someone tells you to keep your pre-turbo EGTs under 900 degrees C and you're measuring after the turbo, you could miss that critical threshold by a couple hundred degrees. By the time you see trouble, pistons could already be melted.
Stick with the six-inch recommendation and, if possible, monitor the cylinder last in line on the fuel rail. On older Subarus, fuel flows into one fuel rail, crosses over to the other, then finally goes through the pressure regulator and back to the tank. In the event that you start outrunning your fuel pump, the last injector is likely to be the first to go lean. High EGTs will be your first warning.
Q.What would F1 do?
Please explain why a manufacturer would fit an anti-roll bar to a vehicle at the factory. I'm under the impression that well-thought-out suspension geometry at the design stage would eliminate the need for one-saving money in the manufacturing process and resulting in a more balanced ride. Granted, more time would have to be invested up front in designing the vehicle properly, and doing things the right way isn't always as important as the manufacturer's bottom line.
In some applications, I'm sure an anti-roll bar may be the result of sacrifices, such as on a grocery getter where trunk space is more important than corner speed and the bar is needed to keep the car upright while tooling around the mall parking lot. What are your thoughts?
Brian Beef
Geneva, IL
A.Whenever you have a theory about how a car would work if it were uncompromised by concerns over cost, packaging or civility, just look at a race car. Skip the production-based stuff and focus on the world of open-wheel cars. Trunk packaging and cost have little influence in Formula One, for example, where a simple brake rotor can cost as much as a cozy Midwestern ranch with a view.