Sunday, July 17, 2011

Mitigating Innovation Risk Via Testing

I received an email last week from a supplier (and friendly competitor) expressing concern about the clamps that we were using in our new ULTRAliteLINES. His concern was based on the fact that Gates, the manufacturer of the clamps, recommends them 'for vehicle coolant hose only'. I very much appreciated the feedback from him as it made me realize that others would also raise this concern - even though we are using it with hose engineered for coolant, oil and other fluids. So this blog entry serves to show our approach to insuring the performance of our product.

We knew our kit was a novel application of these components and did not know of any other companies that were using it this way. These lightweight Startlite hose, clamps and BSP fittings, were so cool (to us geeks) that we wanted to determine if they were fit for use in our application. Since coolant and oil as fluids look extremely similar to each other from the clamp's perspective. The only system differences are a small temp difference (coolant goes to 240F or so, oil to 270F) and the significant difference of pressure (15psi vs 100psi). The material properties are irrelevant to our hose system as neither fluid comes in contact with the clamp since our arrangement is over a barbed fitting, not a reused hose that could have oil on it. Therefore, pressure capability was the only real concern for our testing to investigate.

We felt spending the time and money to conduct track and lab testing would be the right path for this kit. It added 4 months to our development schedule but clearly needed to be done as we knew of no others who run this combination.

Ryan, who developed the ULTRAliteLINES, and I have a combined 25+yrs in the OE and Tier 1 auto industry. I spent 12yrs developing new products at 3M Automotive and subjecting these parts to OE specification and internal tests. Developing lab tests that would predict the lifetime of a part was always a Holy Grailish endeavor. There are committees of scientists and engineers who work towards striking the right balance between real world testing and simulated testing done in a lab. We decided a combination of lab with actual in-car testing would be the best indicator of how the product would hold up. Frankly, thoroughly testing this creative 'joint' would be the only thing that would allow us to sleep at night!

Laboratory tests:
We found a lab in MI that specializes in automotive line and fitting testing. They would be able to subject our kit to extreme conditions we could never replicate on the street or track. We sent them three samples of our kit and had them run two types of tests:
  1. Pressure Proof: 150degC@150psi for 30minutes and check for leaks
  2. Burst: increase pressure until failure
These tests represent extreme conditions that would never be seen in our cars. But by testing in this manner, we can fatigue the product and try to extract a failure. Accelerated tests can help predict potential failures, so extreme conditions are warranted. Since our budget did not allow optimization of this joint, we did not test various combinations. We only tested the configuration that we felt would be the best for our kit.

We created a marketing piece that shows the test results. You can see it here: LAB results. Essentially we passed the Pressure Proof tests and showed a safety factor of 3 to 5 times on the Burst test. This test is quite extreme as it is run immediately after the Pressure Proof test. Basically, the fittings blew out of the hose at pressures that were 3 to 5 times higher than they would ever see - even at peak operating levels. Frankly the test showed that the joint was withstanding 6 times normal operating pressures. As an engineer, this is a comforting margin and insures blissful sleep.

Track testing:
Subjecting parts to the track can be some of the best testing possible. This testing will insure that the cars can run even more reliably on the street. We installed the ULTRAliteLINES onto our Blue Car, a 2004 Elise. We initially ran it at the Big Track at Willow Springs, then at CA Speedway (Auto Club Speedway) and then finally at Laguna Seca. Here is a video from Laguna Seca: Blue@Laguna. We were testing several other products as well but the ULTRAliteLINES were run for a total of 11hrs (including dyno, etc) and approx. 360 track miles.
We used our AiM data system to record key parameters like oil temp and pressure. We also reviewed the lateral acceleration numbers to see how the pressures were holding up with our gPAN. The car showed oil temps of approx 200degF which is well under the 300deg F used in the Pressure Proof testing. The actual oil pressures we logged ranged from the high 40s psi to the low 60s psi. This was a third to half of what was used in the lab testing and far, far below the Burst test results of 344, 452, 565 psi. Ryan's OE experience suggested that a peak pressure of 100psi would be the extreme level experienced by our lines.

Other Considerations:
Proper component selection is key for a reliable system. Each of the parts we chose, come from reputable automotive companies who have done extensive testing. We simply supplemented their work with tests that were specific to our needs.

The Aeroquip Startlite hose has been used for fuel, oil and coolant applications successfully and has been fully tested by Eaton Corp. The braided hose actually imparts a clamping force onto the fittings, much like a 'Chinese Finger Trap' when you pull it. The Lotus twin oil coolers utilizes a fair amount of rubber hose. This became a clear opportunity, for weight reduction, if we used Startlite, since it is 40% lighter than typical rubber hose.

The Gates clamps were the newest and novelist item in our system. They have the ability to dynamically adjust compression based on temp. They also work very well when applied over hose/fitting barbs as they have much more clamp surface area and better conform the hose to the fitting barbs. The Gates clamps also claim to be impervious to ALL automotive type fluids.

Combining all these features made good engineering sense to us. We just need some testing to insure we were onto a good thing...and separate us from the typical approach that is used in the aftermarket.

Options For the Ultra Cautious:
I recognize that some in our community may still want more security. For them, I suggest the tried and true hose clamp. They can easily be added as a secondary clamp over our Gates clamps or as the primary clamp. They add just a tad bit more weight...I suspect Colin Chapman would simply run our kit as is...

No comments: