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December 5, 2007
Supercharger weak spot: the belt
There's nothing like taking a car with a clean bill of health to the track, and so the supercharged RSX has seen some duty as of late. After the dog-days of summer with Sacramento temperatures in the triple-figures, going racing in cooler October and November nights was pleasant indeed, and I hoped it would bring good 1/4-mile times, which it did, to a degree.
As I often do, I brought along my notebook computer and datalogged my runs to see if there was detonation and whether the car ran rich or lean. I've long since given up my earlier quest (obsession, really) to get an absolutely flat, perfect air-fuel ratio at all revs as it is simply not possible. Get it just right, and a week later it's all out of whack again for one reason or another. Temperature, datalogging conditions, maybe even different gas. Who knows. So now I primarily concentrate on the bigger picture: make sure fuel is approximately right without any big peaks or valleys, and make sure there is no detonation.
One cool October evening the car ran quite well, knocking off 13.6 time trial runs on my street tires, and I hoped for even better once it got cooler yet (and perhaps with, finally, The Perfect Launch). Alas, just before eliminations began I opened the hood when someone asked to see the Comptech supercharger and what do I see but another almost shredded belt! With the new tensioner that was supposed to fix everything. I called it a night and babied the car home.
A consultation with Shad and Ryan at Driving Ambition revealed that the belt had apparently stretched enough to max out the tensioner's internal adjustment, and so all it took was one little belt hop to shred a couple of grooves. A new, shorter belt went on and Ryan explained to me how to adjust the tensioner.
Back to the track. The car, again, ran great, doing 13.6 and 13.5 runs, but my launches were miserable and so I lost in early rounds each time, not being able to really see what the engine with its belt totally tight at last could do. With the old tensioner I never saw more than 8.2 psi of boost. With the new one that is now up to 9.5 and sometimes 10psi, and the car feels very strong.
Posted by conradb212 at December 5, 2007 3:36 PM