:. Racing .:. 2011 MPRA Warmup
On the heels of a completely underwhelming season opening event at High Plains Raceway, we loaded up the truck, trailer, and race car, and headed west over the Rockies to Miller Motorsports Park.
The event wasn’t an SCCA weekend, but a “MPRA” weekend – a racing series conducted annually by Miller Motorsports Park using the various configurations on the track.
The weekend gave us some sense of forshadowing not even one hour into the trip. Making the turn-off from I-25 to I-80, which would take us west to Utah, I looked in the mirror to see
flashing blue and red. I dutifully pulled over, but the police car rocketed by, and proceeded to park in the middle of the highway. The reason? I-80 was being closed due to
snow, ice, and two jackknifed rigs that couldn’t be extricated due to the poor conditions.
So, we turned around and headed back to Fort Collins, and decided to take an alternate route north, via 287 to Laramie. About 30 minutes in, this proved to be an exciting
decision, as we found ourselves in a whiteout blizzard with 3+ inches of snow blowing across the road. We inched our way over the pass with no excitement other than a
terrified old lady in a Mazda having a big moment around one of the bends.
The nasty weather behind us, we made it to Salt Lake and Tooele with no further dramas, and began setting up camp for the weekend.
One of the big draws for heading out this way was to come run with Chris Farrell in his WF-1, to get a sense of where our competitiveness lay. After a solid run at Runoffs,
and some improvements over the off-season, hopes that we might be within earshot of Chris were running high in my head.
Friday I spent getting to know the track, gradually inching my way up in speed, and down in time. I had the same setup on the car as from HPR, though we’d raised the
front springrate to 1300# at HPR to cure an odd rear-end nervousness that I hadn’t noticed before that weekend. That would be a omen of things to come, as it turns out.
The rear-end instability was still in evidence from HPR, so we complimented the 1300# fronts with 1100# rears (using the higher rear MR still), to see if that would calm down the car.
So far, back with the Goodyears, I couldn’t quite get the same rock solid stability that I had been able to get with the Hoosiers, which paid off so well at HPR and Road America at the
end of last season. At different points we tried lowering the front to get a bit more aero in the car, and then lowering the rear to try and stabilize it as that problem worsened also.
Throughout, extremely high tire wear was showing, with huge chunks of rubber being peeled off of the tires. Also strange was the huge pressure gain we were seeing in the tires –
from 14 cold measured on the gauge to 20 and 21, some tremendous pressure gain.
I couldn’t do any better than a mid-1:26 – troubling since Chris was all the way down in the 1:19 and 1:20 range. We went so far as to put the car on Chris’s platform at lunch to see
if anything looked tremendously out. Heights and weights all looked fine, so we rolled the car back off.
Beyond the handling struggles, The day proceeded mostly OK, other than being shoved off the outside of T3 by an inattentive Mustang at one point. No damage but a small
chunk out of the leading edge of the floor – could have been worse.
I still had two new sets of Goodyears that had been intended for the early season races, so we scrubbed one set of those to use on Saturday, and called it good,
hoping that some of the handling woes were down to some pretty geriatric takeoff Goodyears I’d been practicing on.
For one to file among the “odd” category, we had some folks on our channel during the morning session, so we changed channels on our radios, which we’d never done.
That seems to have cured an intermittent problem with the crew radio not being able to transmit to the driver. A short conversation with SpeedCom verified that can happen
sometimes, so we’ll stick with the new channels and see if that cures our send/receive issues from here on out.
Chris and I spent some time watching my video after dinner, since I was extremely frustrated at my lack of pace. The biggest “Ah-ha” was discovering that I was
slowing way too much for T3 – just a slight lift is necessary, whereas I had been hitting the brakes. Getting the car turned in early definitely helped, though I never could take T3 flat out.
Finally, after looking at my top speeds, I decided to change back to 15/47 sprocketing to try and help acceleration relative to Chris’s light car and Sammy’s powerful one.
Saturday I started without much enthusiasm, since things had been so hectic the day before, and few answers were forthcoming. Rarely have I been more discouraged at the state of
the pace of my car and my driving.
Practice and Qualifying showed much the same problem as before, but now markedly worse – after 4-5 laps, the car would begin to go horribly off towards oversteer. The rear tires
came in looking like somebody had taken a cheese grater too them – great balls of rubber in the wheel wells, and tremendous wear on the inner shoulders.
After qualifying, we put the car on Chris’s pad again to try and figure out what was wrong. This time we checked the setup completely, and found two inexplicable measurements –
rear camber at almost 1.9* on the left rear, and front toe-out of nearly ¼” on the left. Further, front camber measured 1.8* instead of the 1.25* I had measured!
First lesson of the weekend: Do a complete setup of the car each weekend, even if you think it’s OK!
Second lesson of the weekend: Get proper tools to measure your camber!
We reset the car to my intended specs – about 1.1* camber negative up front, and about 0.5* in the rear, and corrected the toe to about 1/32 per side.
Adding to the insanity was a bit of scrambling surrounding the brakes. I’d been struggling with a long pedal after long sweepers, both at HPR, and now at Miller, which is
full of long, high speed sweeping turns. While checking the rears, I noticed that the rear pads were nearly gone, and evidently I’d used my last spare set. Chris made a few
quick phone calls, and we were able to borrow a set from the rear of a Stohr F1000 garaged nearby…may thanks to Rodizio Ivan for that one!
Unfortunately, all the scrambling resulted in virtually zero improvement for either race.
For the first short “Heat Race”, in a desparate attempt to find some balance, I moved the rear flap up to its maximum angle to see if it would stick the back end. No such luck. While I had a very
entertaining scrap with the Pro Mazda for the first few laps (see video), and pulling off a nice pass in T6, eventually the rear tires went away, and there was nothing left to try and drive with.
I came in early.
For the second "Main Race" of Saturday, I started at the back, having pulled in early from the race. The start was very entertaining, as I zipped by several cars at the green, and once again began
chasing the Pro Mazda, nearly getting by a few times, though he'd definitely learned his lesson of where I was quicker than he! However, as before, the car went horribly towards oversteer after just
a few laps, and I came in, disappointed and dejected.
I awoke Sunday staring at the roof of the RV, trying to find some sort of motivation to get out of bed. Two days of absolute thrashing with nothing to show for it, and being embarrassingly off
the pace, my enthusiasm for yet another day of poor handling, and head scratching was pretty low, especially as we were really running out of ideas.
Aerodynamically, in a desperate attempt to find some balance, I moved the rear flap to its maximum angle to see if it would help stick the back end. The morning warmup provided no significant change.
There was definitely more aero grip, even some understeer in long corners, but the dominant characteristic of long run oversteer remained in force. Wing change. Very planted, even too much so.
Along the way, we discovered that the holes in my wing assembly didn’t correspond to Chris’s – the same position in the flap would yield different wing angles
Lesson #3 of the weekend: Rely on measured angles, not on "3rd hole" type notes.
Finally, thinking the only possibility left must be the tires, we put the car back on Chris's pad, and set up the car as identically to his as we could. Springs, cambers, toes, heights, even a
borrowed set of Hoosiers, just in case the Goodyears were no match for the high tire wear at Miller.
While on the pad, as a final step, Chris began setting tire pressures. He paused a minute and said "How much pressure do you guys have in the tires?"
We replied "about 14psi cold on the Goodyears, and about 15 on the Hoosiers".
A smile began to spread across his face: "Come look at this a minute."
I wandered over there, and he put the gauge on a tire: 20.5psi. I put my gauge on it: 15psi.
You have got to be kidding me.
Two and a half days of thrashing, frustration, and heartache, down to a tire pressure gauge that had gone over all wonky over the off-season. A huge amount of relief began to wash over me -
a gauge reading 25% low on something as critical as tire pressure HAD to be the problem.
So, I rolled out to the grid for the "Heat" race on Sunday, hopeful that finally I would be able to have some pace in the car. As it turns out, the grid was nearly deserted, as all of the FM's
and ProFM's had left. The one FC had broken, as well as the FB, so it was just Chris, Sam, and I. As it turns out Sam only lasted half a lap, as his bodywork came somehow adrift on the opening
lap. The race
turned into just Chris and I chasing eachother around, and Chris passing me pretty much at will.
However, excellent news: the car was FINALLY somewhat reasonably balanced throughout the session. It did not feel particularly fast, suffering from understeer in the higher speed corners, but at least
now I was able to drive a whole race.
For the heat race, loathe to change much else, I simply dropped the rear wing angle a touch, thinking that perhaps if I could improve the balance I might be able to keep things more planted
in the corners. Between sessions, an ENORMOUS wind storm kicked up. We saw it rolling in from the south, and hurriedly closed off all the doors in the garage. The storm absolutely raged around us,
throwing plastic lunch tables off of the balcony of the main building onto the paddock below. Once again we felt very fortunate not to have put up our canopy, as it would have been taken and turned
into shards for sure.
All three of us took the green for the "Main" race, and this time, had a good time passing and re-passing eachother for most of the race. Eventually something happened with Sam's brakes. On the entry
to the three D's he had a spin, which I narrowly avoided. Chris and I slowed up so he could catch up again, but as we approached turn 5, I was him closing at a huge rate. I left him go up the
inside as his closing speed was tremendous, thinking "there is NO way he's going to make this corner!", and as it turns out, he did not.
In my rearview mirror I saw a huge cloud of Utah dust erupt from the nether regions of the T1 runoff area. He did eventually make his way out, but he retired to the pits with some sort of brake failure.
As before, Chris and I motored around in lockstep having fun - at some points he was so close up under my rear wing that all I could see was his rear wings! Pictures from the side from a fellow's
Go-Pro show that he was at times less than six inches from my rear spar! And, as before, on the last lap, Chris lit the afterburners and was gone in a flash.
We packed up and headed home. I spent the drive back still feeling pretty dissappointed about the whole weekend. I'd really thought I might be closer than the 4-6 seconds off that we were, what with
Chris having a stock engine in the car. With that expectation in mind, being that far back was really a blow. Ah well - we can still do this for fun...
Other conclusions - buy good tools, dammit. After seeing how far off the pressures and cambers were, we traded our gauges out for a digital intercomp gauge, and a "smart camber" digital level, respectively.
These should serve much better than my old tools.
Briefly, based on tire temperatures, around 1.1* F and .3* rear seemed to be the happy spot, though we'll continue to verify at Sprints and the HPR double later this year. Using Chris's setup at
the lower motion ratio didn't provide a hugely different feeling than I was used to, so I'll go back to the 1200/1200 baseline that worked well at Runoffs, using the higher 1:1 rear motion ratio,
per Chris Billings, as that will give a bit more motion for the shock to act upon.
Mostly, just happy to have this weekend behind me.
Saturday "Heat" Race
Saturday "Main" Race
Sunday "Main" Race
Exterior You-Tube Video (Sunday Main)