Crunch at Silverstone -Race Report

After a week away on holiday getting rained on in Shropshire, I returned home to get ready for the 750 Motor Club meeting at Silverstone on he 23rd.   As I was already on holiday from work and we were home in good time on the Friday I thought I'd have plenty of time to get ready.  Oh no... a long and diverting game of "B*gg*er I've lost the Keys to the Winnebago" soon meant that as usual Duncan and I left about an hour later than I intended.  Still we arrived in good time and set about saying Hello to the rest of the RGB paddock.  

It was nice to see Bob back after his diff woes at Cadwell, and generally a nice evening was had by all.   In the week before I went on holiday I had made a couple of changes to the car.  Firstly I had new brake pads on all four corners, and also lowered the bit of aluminium plank on the back of the car that acts a spoiler to give me decent rear downforce and stick the back end down a bit.  I was hoping to reduce the drag penalty and gain top speed, without forfeiting the aero effect.

For the record I was running a 16:54 sprocket combination which worked pretty well. as I was close to the limiter in 6th when approaching the end of the straights.

Practice was pretty eventful,   after having just scraped past the noise meter test and only been allowed out on pain of death and repacking my silencer for the race I promptly left my race gloves on the back of another competitors car and had a long dash back to the Bus to get the spares when I couldn't find them in the car.  I arrived back in the assembly area, sweaty and panting with about 90 seconds left before we went out on circuit only to be handed my original pair of gloves as I got in the car.  I'm a great believer in routines to calm nerves and get "in the Zone" running a 800m sprint in 3 layer nomex did not help!

After 90 seconds of trying to slow my heart rate, we were off.  It's two years since I was last here and I expected to be rusty. I also expected some odd brake effects as the new pads scrubbed down and bedded in.  What I got was a long brake pedal,  which gave me virtually no braking effort at all, unless I gave it a couple of preliminary pumps to compress the fluid.  Not much fun going around copse at 80+ mph hitting the middle pedal several times before I got any retardation.  Still it proved to me I could get around the corner faster than I had previously  believed possible.... even if it wasn't doing my adrenaline levels any good.  This is the way we learn.

This went on for a few laps and was also augmented by random corners of the car locking up at the fluid in each caliper boiled or cooled unevenly.  It really was quite an "entertaining" few laps.  I had to start braking even earlier to get the extra pumps in, and did consider coming in in case I was losing fluid.  But while I could pump it up I elected to stay out.  What I had done was boil the fluid in the calipers, because the new pads were scrubbing and generating too much continuous heat.  The fluid boils releasing gas and gas is compressible ... therefor you get a soft and long pedal.  Eventually with only about 5 mins left in the session the pads scrubbed down far enough to stop boiling the fluid and  the brakes came back to me.   Now with some confidence in the stopping power I started to get on it a bit more, but I only had time for three flying laps and I managed to post a 1:07:50.

This put me 22nd on a grid of 26 and last of the Class B cars.  Arse! Class B pole was 1:04.29 a full three seconds separated us :-(.  Still that was Paul Rogers who was fourth overall on the grid, this gives you some example of how competitive RGB is... 18 grid places separated by just 3 seconds, that's about the same as the F1 Grid. Being just .5 of a second quicker would have moved me 6 grid slots forward. and a whole second would have moved me about 10.  Those scrubbing pads had really hurt me.  Still my Class B rivals Stephen and Neil where only two rows ahead so if I got a good start I could probably catch them.

The race arrived and we had rechecked all the brakes and repacked the can so we were good to go.  however I got a woeful start again! I either seem to be getting massive clutch slip and huge wheel spin (too much revs) or the engine bogs down ( to few revs) and it's really beginning the ANNOY ME!   I must get some start line practice but on a non road legal car its not an easy thing to practice except at a circuit and we get bollocked for doing it in the paddock (rightly so)

Anyway I lost a couple of places to Tony Carpenter and Bob, but closed the gaps on the run up to Copse.  Bob was being a bit circumspect on the run up to Maggots/Beckets complex and I snuck past on the inside.   Next Stuart Tanton seemed to lock a brake and exited stage right as he went straight on at the Maggots kink, and existed my vision.   Even so I wouldn't have been watching him as I had passed him and had to concentrate on Stephen Dean who was spinning at the Beckets Apex and I had to dive right to the inside to avoid him.  Now Stuart made a surprise reappearance from the right about 15feet in front of me.  He actually emerged on to the track from the inside and was  heading towards the out outside of the bend so again I headed inside him.  Alas he promptly span, did a 180 to face the inside of the corner and stopped dead.  I had no where to go but into him at I guess 40Mph.  I managed to avoid the seat area and T boned him just about on the bonnet line of his fury.

The impact shoved us both onto the grass and I stalled.  I quickly restarted and drove on, by now suffering the ignominy of following the safety car around after the pack. 

Up front there is only body work the water radiator and the front floor.   I quickly decided that the steering and suspension was ok, I couldn't hear the floor rubbing and my feet weren't getting wet and the rad wasn't steaming so lets get back in the game.  There was however a new big gap visible up front which My camera can see the road through so no doubt it wasn't going to be pretty.   I was followed by both Stephen and Stuart some further 5 and 15 seconds further back so at least I wasn't last.

Over the next few laps I caught and passed Judy, Tony, Mike Allen,Bob  and Tony Gaunt helped me along by spinning at Copse.  Stephen and Stuart both retired behind me and some other attrition in the pack meant that I actually finished 17th and 4th in class B only one place behind Neil Constable Berry. Best lap time was 1:07:5 again and unsurprisingly I was lapped close to the end by Derek.  My Best Theoretical lap on the logger is only 1:06.79  so I'm actually pretty consistent, consistently 2 seconds off the pace that is :-(.  I think Neil CB has now pretty much sown up the 3rd spot in the Championship with that extra vital point... but he and I have been trading places and points all season which is great fun so let the battle continue at Oulton Park in two weeks.

So I learned scrubbing pads are bad, how to race with a long brake pedal, how not to avoid a crash and stay in the game if you can, oh and the Low drag configuration seemed to work well too.... some positives at least to take away.

Silverstone - This can't ever end well

This is never going to end well is it?

More details tomorrow.

Surprisingly after this impact I finished 4th in class and 17th on the road.

The Championship is Getting Interesting,

I've never been in a position before where the top of the results table is of any relevance to me. But this year I'm taking a keen interest in the RGB championship.

The full current championship table is here :---> RGB POINTS.

But I've uploaded a snippet, and as you can I'm riding high at 10th on the table.

Now lets not kid ourselves here! Being 10th in the table does not mean that I'm the 10th fastest driver in the championship, far from it.  In fact I'm regularly beaten by everybody below me in this snip of the table and there are several faster people than me sidelined by failures (like Colin Duce) but Hey I can only race the people who are on the grid. 

The fact that I'm 10th is is more an artifact of the fact that points are awarded by class rather than by position on the road.  So all other things being equal,  say Tim Hoverd finishes 3rd in class C, but 10th overall on the track  he would score 9 points,  If I finished 2nd in class B I would score 10 points even if Tim actually beat me by 5 places on the road (which often happens) and this elevates me up the table despite being slower than Tim (Sorry Mate)

The thing that is interesting here is the Class B standings, because these are my peers, guys with the same power and similar (albeit lighter cars). a Quick squint at the table shows that I'm 5th in Class B behind Paul Rogers, Neil C-B, Josh S, Stephen. In fact Stephen, Josh and I are within 2 points of each other.  The interesting wrinkle is that this is a "drop 2" championship, meaning that over the fourteen rounds every body can only count 12 scores... so you drop your two lowest scores (but you can't drop disqualifications which are shown in red)

So lets look at the table again, and make the assumption that everybody turns up and scores points in each of the remaining four rounds.

• Paul is plainly romping away with  first place with an effective score of 105 pts as he drops just 1 and a blank
  
• Neil's effective score is actually 66 points as he has been Mr Consistency so far and finished every round so he must drop two 7s.
• Josh is on 66 points too, as he hasn't competed in every round so he has got several zeros to choose to drop. In fact when he races Josh usually comes second in class B.
• Stephen is on 64 as he has had a couple of DNFs so will drop these zeros.
• I'm actually on 63 as I can drop a zero and a 1 from Brands and Anglesey.

So with four rounds to go and assuming consistency  Paul and Josh will likely be first and second, which leaves me, Neil and Stephen to fight for Championship 3rd in class B and an even bigger pot at the end of the season.  And we're all very consistent and tightly packed in terms of performance.   I beat Neil at Anglesey, Brands and Donnington, Stephen beat us both at Brands but I beat him at Anglesey and Cadwell.  So basically all to play for.

I need to beat both of them in the next three races as Silverstone and  Oulton Park (2).  If I do that then  we'll arrive at the last race of the season each with realistic  shot at the Class B 3rd.

But If I have any more DNFs I'm out of the game... ditto for Stephen and Neil.  At this end of the season every point and every finish counts :-) which is why Neil's 2nd from the pitlane at Cadwell could be crucial.

Thing is the last race of the season is at Mallory... and I'm cr*p there. Plus it's on October 12th and likely to be wet.   it may come down to whose best in the wet on the last day of the season.... what an exciting prospect :-)

The other thing to mention is that a top 20 position means that you can "claim" that number as your race number for next year, I like 68 as it has specific importance to me ... but a single digit number may cause me to reconsider :-)

Doldrums at Donnington, but Another Class Podium

I guess its is a measure of how far I've progressed this season that I can go home with a 2nd place in class B, (which I'm delighted about)... but still be dissapointed with my performance and feel that I wasn't "On it" at Donnington.

Anyway the full race report follows.

Prior to Donnington I loaded yet another iteration of the modified fuel map to continue the development on this part of the car.  The other major change I made was to change the front sprocket to a 16 point one.  This gives me a diff ratio of 16:54 or 3.375 which is slightly taller than the ratio I used at Cadwell and should have given me a theoretical top speed of around 130mph.

However my telemetry indicates that my maximum speeds were only 113 mph at 10580 rpm at the end of the back straight, which is really hurting my lap times when compared to the fast guys.  There was however a strong headwind which wouldn't have helped . But most telling really is the fact that when reviewing the video I am woefully slow in Coppice, which hurts my corner exit speed and hence my speed at the end of the straight.  I simply was too cautious and not sliding it around enough in that part of the track.

I did the all comers race as a way of getting some testing time in before the RGB race.   Proper testing is hellishly expensive at Donnington so this seemed a reasonable alternative.  As it turned out I managed a 1:22.58 which is a full four seconds better than my last visit here 2 years ago.  This put me 9th on the grid.  The grid generally reflected the general performance differentials of the series... 10 of the first 11 places were RGB cars, then next half dozen or so the Hot Hatch boys and girls (for whom this was actually a championship race)  and then a melange of various other Tin Tops.  Judy from RGB had qualified a bit further back and was surrounded by no less than 10 Toyota MR2s so she was in for some fun.

One issue with being on the track with so any Tin Tops is that you realize just how low, light, fast and insubstantial an RGB car is when compared to even a Golf, it's like racing cliffs of steel.   This was brought home to me when I nearly got wiped out by one of them on the green flag lap as we weaved to warm the tires. I think I was in her blind spot or below the line of her mirrors.

Anyway no harm done and in the race I got a reasonable start as the RGB boys lead, unsurprisingly by Derek stormed away from the grid. I stuck with Ilsa Cox the only Hot Hatch to be in amongst the RGB pack  for a few laps,  But then Neil Constable Berry and Phil Alcock from RGB had a coming together at Redgate and I backed out of it.  I was in this race to test... not to fight and possibly damage the car.... so I let a few Tin Tops through while I started to focus on particular corners like the Craners and Old hairpin.  By the end I pretty pleased with coming flying down the Craners with only a slight lift... when I was last here that terrified me :-)

Anyway I improved my laptime to 1:22.10.

RGB qualifying was pretty good, I managed to find myself in a bit of gap, behind Tim and was pleasantly surprised to find that we held station for a considerable portion of the practice session.  The track was slippery due to oil dropped in a previous quali session and one of our group also dropped a bunch of oil so by the end of the session it was pretty slippery between Redgate and Old Hairpin.  

I managed a 1:22 3 which put me 14th on the grid and second in class B.  Paul Rogers set Class B "pole" with a 1:19.92 and was fourth overall.   Most surprising of all Tim was 3 places further back.  The first time I had ever out qualified Tim on equal terms :-)  that was worth a "Whoo Hoo" and an appropriate amount of Paddock gloating :-).

In the race I got my customary crap start and Tim got a flyer,  passing me before we even got to Redgate, I also lost a place to Phil Alcock, and then 2 wheels on the grass at Old Hairpin slowed me just enough so that I avoided the Tim as he span into the gravel at McLeans.   As mentioned earlier my main problem was that I was not carrying nearly enough speed through Coppice.Redgate,the Craners and Old Hairpin were all OK or good... but elsewhere I just didn't seem to be on it enough. The car wasn't sliding under me and in essence it felt too controlled, too easy.  Which is a sure sign that I'm not pushing hard enough. One notable battle was with Rob Grant (again) We had a couple of laps of me closing him down and failing to be brave enough to pass him under braking.  but eventually my better line through old hairpin told and I had the momentum to get him under the Bluebird Bridge. Then I was chasing new boy James Walker in his Class A busa Powered Westfield... but he retired on Lap 6 and that broadly left me racing myself, although I had to maintain enough speed so that Neil Constable Berry didn't arrive in my mirrors (but I suspect he was being a bit circumspect after repairing his damage in the all comers race)

In the end I finished 13th overall, 2nd in ClassB and six seconds ahead of the Neil Constable Berry, but I felt I could have found most of those extra two seconds per lap between me and Paul Rogers. And I was a bit disappointed with my performance.  To top it off there was no trophy for 2nd in Class B due to the somewhat depleted entry. 

However on the plus side... another personal best lap time by four seconds, another class podium, I out qualified Tim, beat Neil and brought it home in one piece. All good positive things :-)

Other Uses for Telemetry - Air/Fuel Ratio Analysis

One of the things I log on my data logger is air\fuel Ratio.  I use an Innovate Motorsports LC-1 wideband lambda sensor and log it to my DL-1 logger at a rate of 100hz.  The Lambda sensor outputs a range of 0-5v based on an air/fuel ratio of 10 -20 AFR.   Therefore in my Dl1 I can derive  the actual AFR ratio using the equation AFR=(v*2)+10.

The sensor measures the unburnt oxygen in the exhaust and is a crucial tool for getting the best out of an engine. This is the same similar kit that many rolling roads wi

ll use.

The sensor monitors the unburnt oxygen in the exhaust, in perfect conditions a ratio of 14.7 parts air to 1 part fuel will result in all the available oxygen being burnt with the fuel and therefore maximum efficiency and fuel economy.   This is the Stoichiometric ratio or "Stoich".  But the world is seldom a perfect place and due to factors like flame front travel time across the cylinder at ignition it may be that all the oxygen atoms don't get a chance to to meet a compatible hydrocarbon molecule and do their inciendary tango before the exhaust valve opens.   Therefore in performance cars or under heavy acceleration you want more fuel in the cylinders than the stoich ratio would suggest, to ensur

e that all possible energy is derived from burning a

ll the available oxygen. Because I can add more fuel but I can't add more oxygen without either Nitrous

 injection or forced induction I use the AFR numbers to control my engines fueling via a Power Commander USB piggy back controller.  Max power for petrol is engine dependent and varies with the  engine's combustion characteristics but is usually in the range 12.5-13.7 AFR

Since discovering I was running lean earlier in the year I been monitoring the AFR numbers in the logger and I was surprised to learn after Anglesey that I was running very rich  AFR approx 10 which is certainly costing me power.  The Power Commander allows me to tailor my fueling by adding or removing fuel in each of the throttle positions 2,5,10,20,40,60,80 and 100% at 250rpm intervals across the rev range. (some 376 cells)

So I've been doing some fairly extensive AFR analysis, which basically involves the following steps

1. Export the data from the DL1 as a CSV file, typically this is 120000 rows of data
2. Load into excel
3. Write a few formulae to exclude any values that are not under acceleration, or not in the middle 50% of the target range for each rpm or throttle cell.
4. Pivot table the results to produce an average of the selected valid entries
5. Decide on my target AFR  (13.4) and produce a variance table.
6. Using a multiplier (based on experience from earlier changes) to produce a table of changes that I can apply to my PowerCommander Fuel Map to hit the the target AFR across the range.

A graph of the the results is above.  

While this is not the best way to interpret the figures (staring at the table of numbers colour coded by variance from the target does that) you can see that there is lean peak at around 4000RPm at 20% throttle, and that there are also a couple of lean peaks at around 8000 RPM at 80% throttle. I need to add fuel here. I'm also pretty rich at the midrange where I need to reduce fuelling. I'm not really bothered about low throttle openings as in a racer you very rarely in this position.  You can also see that even at the 100% throttle position (closest to the view) the AFR value gradually leans off as you go from 4000rpm to 12000 rpm.  This I am looking to correct.

Mainly I'm interested in the 100% throttle range, but I am also progressively cleaning up the rest of the map to get a good clean throttle response.  Once I'm hitting my target AFR across the range I can then use the BHP and torque calculators in the DL1 analysis software to identify if my target of 13.4 is correct.  Is 13.6 better or would 13 give more power?  With the map dialled in across the board it's a 10 second job to add a small percentage of fuel everywhere.  Anyway it is interesting stuff and I've learned a few things in he process