Ralt on a shaker rig

[Rennie Clayton]

And by "shaker rig", I mean "Reno-Fernley Raceway". That place is bumpy. After many, many years away from the FA fray, I finally ventured out timidly to the track and attempted to shake the cobwebs out - having been since the '03 Runoffs that I've driven this car as an FA (and only once with bodywork as a CSR), there were lots and lots of cobwebs. Needless to say, no new track records were set, at least by me.

Anyway, we got two races out of the way, and two finishes along with it. The first race had a bit of drama involved - qualified 7th with an unknown setup, having to tiptoe my way through the rain in my debut session with the car bottoming everywhere and on springs more suited to a locomotive - we slapped a more appropriate setup on the car for the race. Got an outstanding start to slingshot into 4th by the first corner, and battled a bit with Vince Gaddini in his FA / Pro Formula Mazda before settling on the gearbox of a Stohr WF-1 DSR. Just after crossing the start / finish line of my 10th (and race-finish-criteria-meeting-) lap, the left front pushrod adjuster decided it'd had enough, and all of a sudden there I was weaving my way through the esses on three wheels. Race, and day, finished. Got some video of the race for your viewing pleasure:

Disclaimer for dialup users: 70mb file
http://www.dauntlessracing.com/video...Race-Hires.wmv

Race two had a better ending, but was just as dramatic in its own way - got my head screwed on a bit straighter and qualified off pole, still ~3ish seconds off the track record pace set by Dan Selznik last year. Still not getting through the esses flat, not carrying enough speed through the corner coming off the back straight, or onto the front straight... in short, still too many cobwebs. I was 1.2 seconds slower than the pole time, and didn't expect to sniff much in the way of a win. So about this time, we decided it might be appropriate to put the car up on the scales to see where we were - not far off, but we made a few changes anyway just to pass the time. Although I made kind of a noob mistake in that I did not disconnect the bars before adjusting the ride heights & corner weights - oopsie!

What I ended up doing was making the car much worse for the race, having the bars very oddly preloaded - the car was pulling in one direction down the straights, would dart all around under braking and was extremely uncooperative in slow lefthand corners, of which there are 3 critical ones leading onto (and out of) long straights at Reno-Fernley. I had to pull a Mansell to get the car to rotate even a little bit - BANG BANG BANG BANG on the throttle to load / unload the front and get it to grip ever so slightly and not just plow into oblivion and tumbleweeds.

Anyway, back to the race itself - got another blistering start, and pulled a carlength on the polesitter (Tim Micklos in his Stohr WF-1 CSR) to just nip him into T1, then held him at bay for 12 / 15 laps or so before he snuck by me in one of those aforementioned lefthanders. I really, really got killed in those corners, but had enough straightaway speed to keep Tim behind me for most of the race - not more than a few carlengths at most, and most of the time with me seeing a whole lot of Stohr WF-1 filling up my mirrors. Not being one to give up so easily, I decided to see if I could stick around and put up a bit of a fight. I studied Tim's lines, and adopted some techniques that allowed me to inch back up, and with two laps to go, I really was able to stick through one of those critical lefthanders long enough to get a good run down the back straight, and so I snuck by him to retake the lead for good. Despite the car being worse, I picked up a bit more time, and ended the day 1.8 seconds off the lap record pace - not terrifically fast, but it'll have to serve as prep for the Sprints.

Gonna get the car stripped down for the turn-around and hustle our butts out to Elkhart Lake now... see y'all out there!


Cheers
Rennie

[Rick Kirchner]

I thought they were going to fix it. We rented the place a couple years ago right after a really bad winter. It rippled the center straight so much I couldn't go more than half throttle there.

[carnut169]

Holy crap that track looks bumpy! I thought Sebring was bad....
Looks like you had a good race w/ the Mazda for a bit. The yellow FC appears to be a 96? If he had the mono in there it would have been terrible with those bumps.

[SteveLevin]

I don't have empirical data but the back straight seemed much better although still bumpy this year, and you could see where they had ground some pretty significant sections. It's still far from being Thunderhill-smooth...but it's a lot closer to Buttonwillow now.

Steve

[Rennie Clayton]

I don't have empirical data but the back straight seemed much better although still bumpy this year, and you could see where they had ground some pretty significant sections. It's still far from being Thunderhill-smooth...but it's a lot closer to Buttonwillow now.

Your know your track is hurtin' when it aspires to be as smooth as Buttonwillow...

... and you know your Ralt is in agony when you come in after a session and the undertray looks like this:



Burned right through the skidplate, and clearanced the tub to dry sump pan adapter pretty aggressively. Luckily we caught it before it bored a hole in the bottom of the engine and we started spewing oil out the bottom of the pan...


Cheers,
Rennie

[Paul LeCain]

Jabroc? Steel at least sparks so you notice it sooner. (We also need its weight).

[Rennie Clayton]

Jabroc? Steel at least sparks so you notice it sooner. (We also need its weight).

Paul,

Kevlar. Many, many layers of Kevlar. So far, we've experimented with steel, jabrock, marine plywood, UHMD, aluminum (yeah yeah, I can hear the cries of derision now...) and Kevlar - and Kevlar by far has provided the best combination of wear resistance, life and bottoming behaviour.

Steel wears pretty nicely, but it gets hotter than hell, tends to form very nasty knife-edged projectiles when worn through (or when you have to reach under the car to perform maintenance) - or better yet when the bolt heads wear / shear off, and holy hell does it do something awful to the feel of the car when it touches pavement. The stuff is extremely draggy and grindy. Also, I prefer the weight elsewhere... 60 bloody pounds of lead to get up to minimums.

Kevlar makes it easy to wrap the entire tub / tunnel interface, and gives the most butter-smooth ride when the car does touch. The wear resistance is reasonable - it doesn't melt like UHMD, and is certainly a step above anything short of steel. It's thin, so the unsprung mass of the car doesn't need to be moved up to accommodate extra material thickness.

Anyway, we're pretty happy with the material. The issue in this case was exactly how severe the continuous bottoming was on this track; at the ride height we were running in that session, any material would have been ground off. Been there, done that, with all of the aforementioned materials.


Cheers,
Rennie

[TimW]

On the bottom of champ cars back in the day, the bottom skid was 3 pieces, the front skid from the pedal bulkhead to the dash bulkhead, the middle skid from the dash bulkhead to the back of tub, then the engine skid until the tunnel rose up for the tunnel. We would use ally, brass & jabroc or a combination depending on how we wanted the weight distribution and/or how much ballast we needed. We had 12 packs of each on the trailer and would replace before the wear got really bad to perhaps damage the tub or create a projectile. We held them on with flathead screws which obviously ground down, but a die grinder cut new slots so they were easy to get out even if worn.

Lets just say the year we ran mostly brass the end of season team dinner funded by scrap metal was quite the affair!

Tim

[Rennie Clayton]

We had 12 packs of each on the trailer and would replace before the wear got really bad to perhaps damage the tub or create a projectile. We held them on with flathead screws which obviously ground down, but a die grinder cut new slots so they were easy to get out even if worn.

Tim - remind me sometime to tell you the tale of when I turned a full-length 20lb steel skidplate into a flying / sliding projectile at 150mph at Phoenix International Raceway.


Cheers,
Rennie

[csrazzle]

Rennie,
Is this video from the camera you got from ebay for 12-13 dollars. We are looking at a video system ourselves and were just curious what one you had on your car for this race. That way I can judge quality of the video vs. dollar amount spent and determine if I want to spend the extra money on a GoPro HD.

Regards,
Michael Baden

[Steve Demeter]

Nice pass on th4e PFM, the first one.

That track looks to be in the 115 mph average speed range and would be really really nice if it was not a shaker test rig.

[nulrich]

Kevlar. Many, many layers of Kevlar. So far, we've experimented with steel, jabrock, marine plywood, UHMD, aluminum (yeah yeah, I can hear the cries of derision now...) and Kevlar - and Kevlar by far has provided the best combination of wear resistance, life and bottoming behaviour.

No cries of derision from me about using aluminum! Pretty common skid plate material in Indycars at one time, not sure about now.

I like the idea of using Kevlar as skid plate material. How thick do you end up making the skid plate, and how long does it last in comparison to stainless? When it wears does it leave little "fuzzies" or a pretty smooth surface?

Nathan

[Stan Clayton]

Nathan, the kevlar pads we make are 4 layers of vacuum-bagged 10-oz kevlar...about .050". They last about as long as stainless (longer than ally), and make fuzzies as they wear. Stan