Peters NA6 "Britney"

[PeterB]

Carco fitted a 2nd hand set of extractors to Britney, as she was running stock headers. This runs into a 2" system for now as the 2 1/4" muffler wasn't delivered on time. Hopefully this will help at Wakefield with a bit more top-end grunt.

I ran at the Fairbairn Park Hillclimb on 18 November for a new personal best of 50.31 (0.28 quicker than last round). This gave me a class win in Type 3A just ahead of the quick Nissan Micra (50.34) after a day long struggle.

This time was with a 13.14 first sector, compared to a previous quickest of 12.88. If I can reproduce that quick launch with the rest of this lap, this puts me on the verge of the 49.9 I am hunting.

A fun day had by all.

[PeterB]

I finished off a good year in Britney at the hot and slippery track day at Wakefield Park on 2 December.

Due to the heat I could only get one decent lap a session, then the R888s overheated to a slippery mess, but big power slides in a 1600 is entertaining.

The brake pads didn’t survive the day, so I had to fit a used set I had in reserve to finish off. Otherwise Britney had no problems in the heat, running at an acceptable temperature all day.

I finished up with a 1.14.53 which was only 0.1 off my pb, so I was happy in the circumstances, but couldn’t tell if the extractors made any difference as I couldn’t get the drive out of the corners to make use of any extra power.

This put me equal 1st in class 5M, but I can’t see me making many Eastern Creek rounds next year.

[PeterB]

I have treated Britney to new front Hawk HP+ brake pads (set 3) and fresh fluid to get ready for 2013.

I also picked up a cup holder to replace the ashtray and traded in the red NA hardtop that I had been running on Britney for a silver NB hardtop which will better suit our green NB8A.

Strangely three of the Toyo R888s are only about 2/3 worn after seven events and some road use, with a number of track days left, whilst the 4th is totally gone. The odd one out was the R888 that overheated and feathered up after its first run so it must have been damaged. I have a usable spare left over from the first set, so it will have to see out the next few trackdays.

After 2 years with Britney I have run eight hillclimbs, one driver training day and eighteen track days/supersprints, with class wins at all circuits.

Britney ended up as 1st in class 5M in 2010-11 and 2011-12 and 2nd in type 3A in the 2012 state supersprint series, so has performed well for a resurrected old girl.

On her first run in October 2010, with a rebuilt motor and new KU36 tyres, but dodgy suspension and stock everything else, Britney ran a 1.16.28 at Wakefield on a very good track.

Since setting her up in the current configuration, and running on R888 semi-slicks, Britney has run bests at Wakefield Park of 1.14.81, 1.14.62, 1.14.56, 1.14.62, 1.14.67, 1.14.88, 1.14.43, and then 1.14.53 with extractors, but on a hot day. Other days were slower due to damp conditions.

Given that R888 semi-slicks are arguably worth 1.5 seconds a lap over the KU36 road tyres, it suggests that the modifications I have made are really worth less than 1 second a lap, which proves what a great standard package Mazda built. Bryan’s 1.14 in a stock NA6 on semi-slicks seems to support this assumption.

The similar times on different days in different conditions suggest I have a drivers block and need to unlock something to get that elusive 1.13 which Britney certainly can do !!

A fair bit more horsepower would improve my times a fair bit, but this means cams and computers and the like and a lot more expense, so isn’t an option, or I could try a different approach and consider some Yoko A050 or similar grippier tyres if the budget allows. However, changing the car defeats the attempt to try to improve with Britney as she is.

Maybe I can just focus on the “Old and Bold” award as I become eligible next March !!!

[Charlie Brown]

......... or I could try a different approach and consider some Yoko A050 or similar grippier tyres if the budget allows.

Yep dump the R888's and get some decent boots to see the 13's arrive easily.
http://www.fsport.com.au/special_offers.html

[Guran]

Nice report there Peter. You've had some very consistent times this year. You definitely time to get yourself some GPS datalogging so that you can systematically find ways to improve. My R888s have finally started to come good now that they're just about bald in some parts. So far they've lasted 6 supersprints and the PI 6hr where it was dual entered for the two days - say 10 days worth of track work. Through careful rotation, they're wearing fairly uniformly across the set and mostly devoid of flat spots. However, they are the first and last set of R888s I'll buy. Definitely going back to Bridgestones when I replace these because they're faster, much easier to manage, wear more evenly and predictably ... but much more expensive. My 1:14.98 PB was on RE55s in July 2011, and this year on the R888s I could only do a 1:16.21!

[PeterB]

Britney

MX5Wakefield July 2011 3.jpg

So after starting with a tired and damaged 1989 NA6 the car specifications are now :

Restoration :
CARCO rebuilt 1600 with original bore, pistons and cams.
New water pump, cam belt, hoses and plug leads.
New alternator.
NA6 standard radiator with plastic panel to help airflow.
1800 clutch.
NA6 5-speed with new gearshift kit fitted.
New rear wheel bearings and drive shafts rebuilt.
NB8A 15"x6" with Pirelli road tyres for street use.

Performance:
Head is shaved and has cleaned up ports, running 12 degrees advance on 98 ulp as compression is unknown.
2nd hand extractors and cat, 2" cat back exhaust.
DDMWorks pod filter with heat shield from Rspeed (replaces stock air box).
NB KYB AGX adjustable shocks with Ground Effect springs (375 lb front and 250 lb rear).
Camber : front -2.2, rear -1.8 with maximum caster at front.
Red (?) aftermarket swaybars (rear adjustable).
Carco front swaybar brace (to stop mounts cracking again).
Mania front and rear underbody braces
Torsen 2 lsd with 4.3:1 ratio, NB driveshafts and tail shaft (ex NB automatic via MX5 Mania).
Slotted front NA disks with Hawk HP+ pads, stock rear 1600 disks and Lucas pads.
15x6.5" rims with Toyo R888 GG semi-slicks 205x50x15 running at 32-33 psi hot for track.

Safety / BodyworK:
Brown-Davis NB steel roll over protection system (can be CAMS approved) with padding.
Sparco Sprint V drivers seat on re-drilled NA seat rails.
Monza 3" 6-point clip-in harness using eyelets.
NB lined hard top with demister - silver (soft top removed as damaged).
Full interior trim with Kenwood stereo.
Drift flat bottom steering wheel (same bolt pattern as original Momo).
Rspeed OEM style front lip (rear lip not yet fitted).

Britney has been built for use at Wakefield Park track days/supersprints with a best of 1.14.4 and has won class 5M for 2010/11/12 and Fairbairn hillclimb (50.31), Canberra, so I am a happy MX5er.

[PeterB]

Well I will remember the 20 January track day for some time. From hero to zero in one corner.

The day started cool and there was fantastic grip until it started to heat up.

Britney was going like a rocket and I smashed my previous pb of 1.14.4 down to 1.13.53 (with a 1.13.8, 1.14.0 and 1.14.2 to back it up) and was having the best day I have had for years.

The extractors seemed to be helping as I was getting the rev limiter in a few spots not previously achieved, but it was the grip level that really allowed me to throw her around and punch out of the corners - one of those days to go on maximum attack. Maybe changing from a red to a siver roof is worth some time !!!

I also stopped to help put out a grass fire in the outfield.

However, a very over-ambitious lunge taking a very wide (Mitch style) line into turn 3 turned sour when I drifted nicely into turn 3 as planned, but did not get the grip I had anticipated (and was getting previously), so continued drifting straight across the track, flicked back when I hit the grass and slid sideways into the corner 4 Flag point at considerable speed.

I always wondered how it was possible to hit that flag point - this one was pure driver error, particularly in not allowing enough for the grip loss on the hotter part of the day.

My apologies to the photographer standing in the flagpoint who must have got the shock of his life.

I will pick up Britney tomorrow as I wasn't sure if there was suspension damage. Britney will rise again, but my ego needs a major rebuild as this is the first serious damage I have done on a track.

The passenger door is stoved in and window smashed so will need replacing, front guard munched and some damage to the rear guard - a pretty big hit from where I was sitting, but she was still drivable.

I was very glad for the race seat and harness, as it held me well in the side-on impact, although I am sure I will be black and blue tomorrow.

Bugger, but still a 1.13. - I am delighted with that !!!!!

[Jeo]

Not a brilliant outcome for the day but into the 13's is nice. Hopefully she all comes good mate.

[Guran]

I was really sorry to see Britney parked against the turn 4 flag point. Then relieved when I saw you drive out of it just as the red flag appeared. The stoved in panels and door were a right mess. Hopefully there's no structural damage to the body under the front quarter panel.

But dammit Peter! I had to slow down for your yellow flag and it cost me about half second (it was 1:16.4 instead).

Congrats on the 1:13.53 PB. That beats Slammer's 2004 record of 1:13.57, and is only bettered by Tony Williams' PB of 1:12.80. Tony's car has quite a bit more than 85rwkW too. Even if this turns out to be Britney's last stand ... that's going out in style!

[PeterB]

Britney will be back, she drove back to the pits ok and I couldn't see any obvious underlying damage, but I will check thoroughly when I get the panels off.

I tried using a time attack technique of some quick laps with cooler tyres, then a slowish cool down lap, then another couple of quicks. This seemed to work, and she felt so good all morning, definitely the best she has ever gone and this morning in the cool was one of the grippiest I have run.

My final lap was just over-ambitious as I lost more grip than I expected in the heat.

Sorry about the yellow flags !!!

We will return.

[PeterB]

Ignoring my little incident at the flag point, Sunday was the best day I can remember in Britney and in the cooler morning conditions she felt great with fantastic grip - I had an absolute ball.

I had a previous best of 1.14.43 (the only time under 1.14.5) and I went into the 20 Jan track day knowing that I was in a rut and the car should be able to match Mitch’s 1.13.6, so I watched all the in-car videos I could find, particularly Mitch’s.

The in-car suggested that I had been losing my time in turn 2 and then turns 3, 4 and 5, and that I was being too conservative up the top, so an all-or-nothing approach was required to break the pattern. I also decided to try a time attack approach of quick laps, then a slower one to settle, then quick again to gain time around the finish line.

The extractor definitely gave it some more mid range power and, as it was pulling out of corners better, I also picked up time up the straights.

I put on new front HP+ brake pads which I bedded in well on the street and only needed a quick bed at the track. The brakes were great with excellent stopping and no lock-ups. The R888s were well worn which seems to be when they are at their best.

For Run 1 I did three brisk laps to settle the brakes in, testing a couple of different lines, and then one slower lap to cool off. The slow lap had let the traffic get away, so I had a free track and definitely had more grip than ever because of the cool conditions.

My 5th lap definitely felt like the fastest I had ever done. By slowing lap 4 I was able to take a slow in/fast out approach across the fishhook start line and had to grab 4th about 20 metres earlier than previously down the back straight. I got a good clean run out of 10 and 2 thanks to the grip levels and tried a more aggressive line into 3 which worked well and I carried much more speed through 4 and 5, which meant I ran into the rev limiter in 3rd before the fishhook which had never happened before. As this was the last lap I concentrated on lunging fast to the line as I didn’t need to worry about the speed out.

I knew it was my best lap ever, but was amazed at the time and wouldn’t believe it unless I could get close to it on later laps. - 1:16.08 1:15.09 1:15.42 1:22.86 1:13.53

Run 2 I pushed as hard as I could from the start and tried to be even more aggressive, but the tyres got hot and so I went slower rather than faster - the same old story - but still all laps were around or under my previous pb. - 1:14.29 1:14.57 1:14.87 1:14.47 1:14.59

Run 3 was warming up so I tried a more controlled approach for lap 2 and was rewarded for it, then over drove again, not allowing enough cool off on lap 4. - 1:14.54 1:13.89 1:14.77 1:15.06 1:14.42 1:14.61

Run 4 was warmer again and the fast/slow/fast approach got an acceptable time given grip was going off. - 1:14.40 1:14.66 1:22.42 1:14.06 1:14.44

Run 5 was warmer again, but lap 1 felt still felt good and there was some cloud cover so I went for a super (or is that stupid) aggressive approach, throwing it a turn 3 as hard as I could and we know how that finished - 1:14.88 dnf bugger, but she did cross the finish line under her own power.

So seven laps under my previous pb, with two in the 1.13 - sorry Britney but it was worth the pain.

So it seems that “controlled” aggression is the key.

I have run a tape measure over Britney and all seems within specifications, so a front guard, door and a bit of banging will make her happy again

[Tony]

...and a bit of banging will make her happy again

[Jeo]

Pics, or do I just have to drop past Carco?

[Guran]

So it seems that “controlled” aggression is the key.

[PeterB]

Pics, or do I just have to drop past Carco?

I am fixing at home with bits from Carco. I have emailed a couple of photos to you.

The Sparco is a throw away, but it did its job extremely well.

I am interested to see the photographers photos to see if it explains exactly where it all went wrong.