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September 19, 2005
It's amazing that third party performance kits work at all
In general, superchargers are lauded for their simplicity and reliability. The blower itself is guaranteed for 100,000 miles and doesn't need any maintenance at all. Combine that with a company famous for its engineering, experience, and customer support, such as Comptech USA in El Dorado Hills, Calif., and you have an unbeatable combination. Well, yes and no. It really depends on your expectations. When you consider that it costs automobile manufacturer billions to design a new platform and millions to create even small parts, and that it then takes millions of test miles and a couple of years of actual production to work out all (or most) of the bugs, it's amazing that performance kits, like superchargers, work at all. I mean, the design budget is minuscule, and often only a few dozen of an item are sold. Yet, customers have very high expectations and are quick to diss a company or product if it doesn't perform flawlessly.
This morning I witnessed an example of the struggle relatively small tuning companies go through. I stopped by Comptech to have them replace my 3.6-inch blower pulley with a 3.3-inch one in order to increase boost from 6 to 8.5 psi. One of Comptech's experienced mechanics did the work. He found a couple of parts that showed wear and replaced them. Once everything was back together he started the car to see if everything worked as it should. It seemed that way until he pulled the throttle cable a bit to see if the belt was nice and tight under load and changing rpm. Well, as he let go of the throttle and the engine rapidly dropped revs, the belt sort of slackened on top of the power steering pulley for a split second. It looked like it hopped just a bit. Needless to say, you don't want that. The belt might come off.
A Comptech design engineer stopped by and the matter was discussed. Did part of the tensioner catch somewhere and not flex back properly? Did the tensioner move too much? Everything came apart again, and the engineer installed a small metal insert to stabilize the long bolt. The mechanic cautioned that the thread of the bolt might catch in the bolt. The assembly went back in, but the belt still did that little hop when the throttle was released. Was the belt too loose? It was tightened until it bottomed out. The hop was still there. So the tensioner assembly came off again and was taken apart. The engineer took the two springs and tested them on some machine. Aha! They did not have the proper tension. New springs were installed and the tensioner went back in. The hop was still there, which meant that the tension of the springs was momentarily overcome. The assembly was tightened beyond spec and that fixed the problem, but that did not seem an acceptable solution to the Comptech engineer. He came back with two small springs that fit inside the larger springs. They had to be cut to fit properly. Ryan, the mechanic, wasn't too happy as he still felt the steel insert would make the threaded bolt catch. Steve, the engineer, felt otherwise. So the tensioner assembly was fitted with the dual springs, and then tightened (there was discussion as to how much to tighten; the mechanic felt it should be less than what was in the instructions). Anyway, with the new double springs, the hop was gone. No one seemed completely happy as there was agreement that the threaded bolt MIGHT catch on the steel insert, and that might either eat away the insert or dig into the bolt. Nothing terrible would happen, but it just wasn't a totally satisfying solution.
Now multiply that experience with all the things that can possibly go wrong, or not quite right, in an aftermarket supercharger system with all its brackets, fittings, nuts, bolts, belts and whatever else, and consider that the kit then gets installed into cars with very different modifications, often by people who are not professional mechanics, and it's a miracle these kits work as well as they do. The lesson really is that we should never expect perfection and flawless operation. Those who can't stomach that possibility should probably remain stock.
Posted by conradb212 at September 19, 2005 2:02 PM