Mancup Drag Racing – Top Fuel July 23-24

on

July 26, 2016   Mancup Drag racing   Top Fuel July 23-24 

And it was a hot one in Memphis!

The third of the five ManCup races was held at Memphis International Raceway last weekend, July 23-24.

Memphis is renowned as being hot and humid and this year’s race was no exception.  We rolled into the pits Friday about 3 in the afternoon, and the temp touched 100 degrees.  This wasn’t allowing for the heat index that put it over 111.  You do go through some sketchy areas to get to the track right off the Interstate, but I could tell the areas were getting better as the number of broken windows decreased.

Waiting for Sam and the crew to arrive was a good chance to practice biofeedback and self-delusion (feel cool/it isn’t really that hot).

About two hours after the planned arrival of the Oklahoma rig, the big white semi rolled through the gates.  The reason for the late arrival was explained by the fact that the trailer ball on the hitch broke off at 65 mph.  The trailer dropping down onto the frame and held by the safety chains narrowly averted complete disaster, but the damage to the trailer was substantial, buckling the front section of frame and tearing the step mount off.  Luckily it was only 20 minutes out from Sam’s shop, so unhooking the trailer (the rest of the way) and heading back allowed Sam to weld the part back together, as nobody was open at that time of the morning.  Two hours and 15 minutes later they were back on the road.

Excitement was to follow them further as they crested a hill and saw traffic stopped dead.  It had been stopped long enough that everyone had put it in Park, so there weren’t any brake lights.  It was all Dale could do to jump on the brake pedal and flat-spot 10 tires, narrowly missing the vehicles up ahead.

The rest of the trip was hot if uneventful, with the A/C in the semi at less than optimum.

Getting parked, it was time to head to the motel and shower up.  Dinner was the next event with some of the crew heading just down the road and the rest of us back into Memphis to Beale Street for barbecue.

I am a huge blues fan, so Beale Street was OK with me.  Arriving, we saw a few other racers and Hot Rod Crissy, a top-notch photographer, among the crowd.  My wife and I made the trip down and then up the street, and to be honest, there were only a two or three places that had music I would have spent the time to hear.  It was a big circus as far as I was concerned.  I can usually go through a swap meet in 20 to 30 minutes and that was what this was like.  Getting back to the barbecue joint, we weren’t disappointed by the food.  Great and lots of it.

Thunderstorms during the night were the order of business and dawn arrived cloudy but not raining.  After tanking up on breakfast we went to the track and proceeded to clear the water out of the pits to allow for unloading.

As the bike was put up on the jack, decisions had to be made concerning the tuning for a slippery surface.  We suffered at our most recent race, the Rockingham event, and didn’t want a repeat of that.

Without getting into a big long technical discourse on centrifugal slider clutch theory (that I’d be hard-pressed to pull off), one of the hallmarks of Sam’s Top Fueler was horsepower.  This bike runs as strong as any of them.  The other is smoking the tire.  This happened every other pass under good conditions and when the traction isn’t good, predictably regularly.  One of the tuning basics in this type of clutch is how much weight is on the first set of arms (called primary arms) that swings out and closes up the clutch.  The more weight on the arms, the more force at the same rpm will be applied to the clutch to close it up.  In a car or on a bike most people have felt the difference when they slide the clutch to get going versus dropping the hammer.  That is the way this works.

You can make changes in the primary arm weight to ease up the application force and rate.  Less weight is gentler, more weight, more aggressive.  We opted for gentler and Mike Dryden made the appropriate change.  There are changes to the springs in the clutch that need to accompany these weight changes and those were made as well.  It is a sometimes-complicated balancing act that we have dealt with here over the years in our Top Fuel Bikes, funnycars, Top Fuel cars and most recently the Ducati dragbike platform.  As different as the applications are, they still use the same rules of physics to work.

Finishing up the servicing and preparation we started to feel the lack of Bruno.  He is the bulldozer of the crew and is ready in a heartbeat to take on any task and adds a physicality that some of us older types struggle for.  Due to a huge job commitment back home, he will have to wait until Rockingham to rejoin us.

DSC00875

Pulling into the waterbox, I verified the rear tire pressure and headed downtrack.  After the Eddyville race when the rear tire camera was first used, we started raising the pressure and now are at a fairly high number, compared to our starting point.  The higher pressure helps stabilize the tire in both the transition from the “wrinkle” sidewall at the hit of the throttle to the squaring up down track as well as when the throttle is closed to minimize the bouncing that can accompany the deceleration.

Mitch Brown was taking Bruno’s place with the starter and as soon as the bike was fired, he booked downtrack to join me to push back.

I was about the same distance out as I was at Eddyville, but Sam didn’t go nearly as far on the burnout, so a trot back to meet him was next.  I asked why the difference and he explained he didn’t want to get the tire and clutch as hot. I thought maybe he was taking pity on us in the heat.

Picking up and pushing with Mitch we got him back and lined up.  Sam rolled into the beams and Mike hit the high idle leave and at the green, Sam streaked away.

No tire smoke.  A-freaking-mazing!!

He ran through the lights at a 6.04 second e.t. at only 214 mph.

Back at the trailer we were a bit mystified where the mph went (or didn’t come).  Sam admitted he was in Eddyville short-track mode and clicked it off early.  I can see how that would happen as the shut-down area at this track is all uphill and it looks a bit like a wall from the starting line and if you are approaching it at 200 mph even more so.  Extrapolated from the time the throttle was off, it was a very likely 5 second run.  It was very encouraging and the second best run out of the trailer for the bike ever.  The 60-foot time was a 1.05 second clocking which is decent on a good track, the best this bike ever having was the 1.00 at Valdosta last fall on the 5.88 run.

There was another unique treat in store at this point in time.  Sam had mentioned that he did a chassis replacement for Glen Kerr who is restoring another twin-engined Triumph nitro dragbike.  Glen is the owner of Dubble Trubble, a historically significant motorcycle and the one he presented to Sam was an old Boris Murray piece from the mid-sixties.  I saw this bike at Eddyville last year and it was rough.  All Sam could do was build a replca chassis as there wasn’t enough left of the original to work with that hadn’t been booger welded, ground, sawn, and otherwise rendered useless.  It was a similar situation I was presented with for John Gilchrist and “Kermit”, the H2.  So many fatigue cracks, poor welds, etc.  Sam remade the front chassis section, motor plates, fuel tanks, and transmission mounting plate.  As you can see, the work is gorgeous.  That is another perk of working for Sam is that everything is well-done on the bikes.

Servicing the bike, we went back up for the second round of qualifying.  It was hotter yet so a little more clutch came out of it to compensate for the higher track temperature and the corresponding reduction in traction.

Sam ran the right lane this time in keeping with the requirement that each competitor has to switch lanes each round of qualifying.  At the hit, the bike left well and then drifted a bit to the right, getting slightly out of the “groove” which is what the best traction area of the track is called, whether circle track, roadracing, or at the dragstrip.  There is even a groove on dirt tracks where rubber is laid down during the race.   This caused the tire to spin up a bit, hurting the elapsed time and mph.  This was a 6.42 at 225 mph.

When we got back to the pits we discovered a hurt exhaust valve and needed to change motors.  This may have happened when the tire spun and it upset the loading on the motor.

We had the motor in and with another adjustment of the clutch tuneup we were out for the last round of qualifying.

By now we were feeling the heat, and extra care needed to be taken to be certain nothing was overlooked.  A last setting of the rear tire pressure and down the track I go.

It was getting later, on towards 7 o’clock, so now the fire shows.  The You Tube coverage of the event is exceptionally well done covering this event.

Sam lined it up and let it fly.  The 6.09 was a decent enough e.t., but the mph was a bit less than expected.  This mystery was to bedevil us on Sunday.

Letting the oil out of the bike and checking the cylinder leakage to make sure we weren’t going to have to change another motor, we were ready to call it a day, a darned good day with four solid runs, no tire smoke and #1 Qualifier!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s