Apologies for the delay in getting the next article to ‘press,’ a few matters including a misbehaving back were needing my attention! Too much sitting, not enough exercise!
Now that most of the national championship races are over, people are starting to bench race on what setup to get for next year, what’s ‘best’, etc. I was responding to one thread on Miata.net and felt a slightly modified version would be appropriate for TTAC. I’d like to hear from people who have tested/tried different racing setups and what it was like to get, install, test, adjust and fine-tune those setups for the maximum result. I’ll have another article soon where we get back to the high-speed jacking down and display accelerometer data to support evidence of that behavior.
Buying expensive shocks or a ‘big name’ doesn’t guarantee they’re really tuned right, that the adjusters give you maximum grip, or that you’ll be able to integrate them seamlessly into your suspension without lots of head-scratching or potentially frustrating revisions to fix what’s wrong with the shocks.
Most people want to fall in love with whatever they buy – “it’s the best!” It’s natural (and probably a good thing when it comes to relationships!). But neither money nor love buy championships; intelligent choices (or bad choices leading later to better ones), measurement, testing and making effective changes in response to measured results does. Consider it the same as a lab experiment; following the scientific method is the only way to get worthwhile results.
Any number of the vendors that are considered ‘top shelf’ could give someone faster times. But why? and is that setup really ‘the best’? How can you tell if a suspension is really dialed in for maximum performance? That’s nearly impossible to answer. However, data acquisition doesn’t lie, nor do lap times. Combine the two and you have a powerful approach. If you’re able to create a theoretical model of your setup that relates to real-world test results, now you’re really cooking!
Knowing what to measure and then change is where the art and science of suspension tuning merge. I’m definitely still learning, but I’ve been paying attention to shocks from Stock class to XPrepared, street, backroads and track as well. Lessons learned in some areas factor in to others. I took National-level racer Bill Schenker’s advice when I met him for the first time at the Atwater, CA SCCA Solo National Tour in 2007. He slaughtered the very competitive C Street Prepared field. Incredulous, I asked him what made him so fast – ‘suspension!’ So I listened! Studied, tested, built, revised, paid attention to what I saw over the years. Stayed open-minded.
Maximum grip is one vital factor in getting exceptional results. Another factor is the car’s ‘feel’, how it communicates available grip to the driver. Driver ability and preference are the magical third and fourth parameters. From my calculations, actual shock dyno testing, and real-world shock potentiometer/accelerometer/
Some setups will deliver more grip than feel. Others are more about feel than ultimate grip. I can tell what’s being emphasized by looking at dynos and how a car behaves on course . Without interviewing a driver before building shocks, how will the shock builder KNOW what kind of driver they’re working with? Does that builder actually know what creates grip vs. simply gives feel? That’s a subtle but important difference.
I’ve found that a builder usually ASSUMES everyone will want what makes that builder fast, or whatever philosophy that company espouses, or worse, what makes someone ‘feel’ fast. Something stiff and sporty – yay! But there are enough sophisticated options and top-level results showing that ‘feel’ itself isn’t enough.
Does each driver at Nationals (or any race event) have the best setup? Maybe, maybe not. It usually depends upon how long they’ve been improving it. Many racers will readily admit they’re not master suspension tuners. Some can do both, or work with people who can assist in development.
So what kind of tuning will REALLY make you fastest? It’s a very important and oft-overlooked question at least in the amateur racing world. You hear it all the time in the realm of F1 though with driver preference. It’s a fairly big assumption that the shock builder really knows where grip comes from (definitely not intuitive) and that any adjusters present are able to get the maximum effective range for different surfaces or driving preferences.
Some people are faster with very stiff/tight setups, others like smoother/flow-y suspensions. An excessive preference for too stiff will cripple the ultimate grip. You can drive at 100% but if the setup is delivering 95% grip you’ll lose to a 98% driver with a 98% setup.
Low, mid and high speed damping all matter for autocross. Lincoln, NE, new home of the SCCA Solo National Championships, has seams between concrete slabs that induce high shock velocities (easily well over 10 in/sec) especially when taken at 50+ mph. Driver inputs are in the low-speed region. I’ve taken data at Lincoln last year (2011) in George Hudetz’s STX Mazda RX-8. It was about 95% dialed IMO and we were both in trophy position not having done more than a few practice runs in Lincoln. The first day, in searing heat and 90% humidity, I was in 8th (IIRC) out of 43 drivers. It was so easy to trust the car (yes, the RX-8 is an amazing platform!). With a clean run that first day (3 cheap/dumb cones) I would have been in 4th, only 0.6 out of first! Day 2, I slipped two spots to 10th by driving conservatively. I still took home my first trophy at Solo Nats and his car felt like a championship-winning machine! George’s FCM-tuned Street Touring Xtreme responded well, had so much grip (1.3g+ in sweepers) and we both knew we could drive it harder. I was better in sweepers, George faster through slaloms. The data helped show how much potential the car really had and it would have been enough to win the class.
I was glad that the data I’d taken at Packwood and elsewhere helped illustrate the value of our approach, plus further improvements we could make. Even though the data was on an RX-8, it helped me understand tuning as applied to a FWD coupe, RWD sedan, etc. Interconnectedness is a beautiful thing!
To anyone that really want to get a ‘dialed-in’ setup, simply having an adjuster won’t ensure you hit the sweet spot at every shock velocity range. Also, having seen some Penskes delivered without bump stops to a local autocrosser who was also told ‘you don’t need them’ and having a shock subsequently break, I really had to scratch my head at that glaring oversight.
There ARE subtle areas like bump stop tuning that play into a car’s poise and ability to be consistently taken to the limit and beyond (‘there and back again’). (I know certain National champions are making use of these and not just in Stock classes!).
I’ve talked a lot of people out of buying more expensive adjustable options from us when it was pretty clear a well-tuned non-adjustable would do, at least until they really knew what they wanted. Most were extremely competitive right out of the box. I’ve also seen people with single and doubles make good use of the adjusters we’ve designed. They have an extremely wide ranges of forces and are concentrated in the 0-3 in/sec range, just where you want it for driver inputs/feel). We’ve made numerous design iterations on these high-end adjustable options, again tied to user feedback and test results. Suspension is one key part, interacting with our customers and being available for fine-tuning is another.