Dawes Devices Gets Schooled by a Customer!
Every once in a while, you have to admit that your customers can teach you things ;-) This is one of those cases. Recently, I was schooled by one of my customers, resulting in the introduction of this new product. First, some back-story is in order:
When I first developed the TDI Boost Controller for VW/Audi applications (later adopted by Nissan Patrol owners), I elected to use the stainless steel ball of our Basic Boost Controller, instead of the more expensive synthetic ball of the Hybrid (we were FIRST in that technology, by the way). The Hybrid was developed to control the oscillation that sometimes occurs in very small or very large gasoline turbo applications. But in testing, there did not seem to be any difference between the two, in the TDI application. That has something to do with it being a diesel, as well as a VNT, and also turbo size. Too much to get into here, but basically I didn't want to increase the price for something that would not increase performance. Testing our non-TDI controllers on GM, Cummins, and Ford diesel engines also showed that there was no advantage in using the synthetic ball. Spool up, spiking, and oscillation, were all fully controlled, with the Basic. Note, the internal design on the Basic is the same as the TDI, they just have different tips. Then, the other day, one of our US customers showed us something interesting......
One of the advantages to living in Detroit is that I often get to associate with engineers that work in the auto industry. These guys have access to test equipment and vehicles that are way beyond anything that we could afford. However, I often get testing info from them, that I can use in product development. So, the other day I was shown something interesting. The customer had a full data recorder connected to his big diesel pickup truck, recording all kinds of stuff like fuel flow, EGT, and boost, in addition to various accelerometers. He was showing me how on the road, the boost controller performed better than the factory solenoid (of course) with more area under the curve and a more stable peak. But off road, things were different. There were cases where the boost suddenly dropped, without a movement corresponding change in the accelerator position. Then he showed me the accelerometer data, that tracked the vehicle motion. It seemed that whenever he went over a really rough patch of test road (and if you've every been to Detroit---all the roads are that way!) the boost would fluctuate. I'll save you the story of four hours of investigation and a sore back and just say that in the end, I determined that the problem occurred if the boost controller was mounted vertically, but not horizontally. It appeared that the ball was jumping off the seat when the truck hit a big bump. Now keep in mind that these were BIG jarring bumps. Like running over curbstones at 45 mph. If he was driving over sand dunes, or even off road, I'm not sure he would have had the same issue. Anyway, relative to the spring force, that stainless steel ball has a bit of mass. I guessed that swapping in the synthetic ball from the Hybrid might help. Turns out it SOLVED the problem completely. We tried mounting the controller vertically, both upside down and right side up, sideways, etc. Then we wailed over the same stretch of road at different speeds and could not reproduce the problem. Went back to the stainless ball and the problem came back. So, I sent him on his way, with the Hybrid ball installed. About an hour ago I got a call from him saying that he reviewed all the data from his trip to the test track yesterday and the problem has been completely solved. So, it looks like there IS an advantage to the Hybrid, in certain off-road circumstances. As a result, I'm now offering this as an option for the standard MK II TDI Boost Controller. If you are an avid off-roader, you may want this advantage. I should say that no one from the Patrol group has EVER complained about this problem, but if I didn't offer the option, I couldn't sleep at night. So, although I am certain that you would be satisfied with the standard MK II controller, you now have another option. Thank you all, for your business and support!
3 Bar Racing Inc.