Smallhorses
Staff Emeritus
- 7,260
Roadster 4hrs Endurance
Being as no-one appears to have made a pictorical report of this race to date, I feel that this effort, probably my final one, is worthy of it's own thread.
Previous runnings of this race have seen me earn 76, 104 and 147 points respectively in 3 different cars. This time I'm gunning for more points, but still without using NOS.
Finding that the Mazda MX-5 Miata (NA) '89 in my garage had been modified for running in the Roadster Cup under Mazda manufacturers events, and was purchased as a 6.2 mile used special, it's not able to be downgraded sufficiently in power or made heavy enough to see a significant points increase here.
I therefore go off in search of a well used '89, and as I'm on day 3478, there happens to be a red one with 52,829.4 miles on the clock in the Historic Used Car Lot. Purchased it for 5,949Cr and set about upgrading it for it's arduous 4hr task ahead.
It's showing 107HP in the garage screen, and appears to have tar for oil. I'm leaving it that way though, and I add 110kg of ballast for good measure, taking the weight up to 1050kg, identical to that of the Mazda MX-5 Miata 1600 NR-A (NB,J) '04 that I ran last time, but lagging by some 17HP in power. I fit N tyres of all grades, racing brakes, brake controller, full-custom transmission, triple plate clutch, racing flywheel, 1.5-way LSD, carbon driveshaft and full-custom suspension.
Practicing with 75kg ballast at Tsukuba I'm able to come up with a setup that runs in the low to mid-1'12s on N3s all round, and since this had given me 2 laps victory before, I upped the ballast a little until low to mid-1'13s were obtained.
Setup:
Mazda MX-5 Miata (NA) '89 (N1/N3 Tyres) / FR / 107HP / 1050kg / 9.8kg/HP
Brake Controller: Front 10, Rear 11
Driving Aids: 0 / 0 / 0
Transmission: Autoset 3, Final Drive 4.690 (optimised for use of just 4 gears to minimise shifting and time lost due to shifting.)
Spring Rate: Front 11.0, Rear 8.8
Ride Height: Front 104, Rear 103
Shock Bound: Front 4, Rear 6
Shock Rebound: Front 4, Rear 6
Camber Angle: Front 2.3, Rear 1.7
Toe Angle: Front 0, Rear -1
Stabilisers: Front 3, Rear 5
Weight Balance: 110kg, -15
I now set off in search of the same lineup as before...
Somewhere between 10 & 20 enter/exits later, it appears.
1st Mazda MX-5 Miata SR-Limited (J) '97 (Pits every 41 - 42 laps)
2nd Mazda MX-5 Miata S-Special Type I (J) '95 (Pits every 41 - 42 laps)
3rd Mazda MX-5 Miata 1.8 RS (J) '98 (Pits every 41 - 42 laps)
4th Mazda MX-5 Miata J-Limited II (J) '93 (Pits every 42 - 43 laps)
5th Mazda MX-5 Miata V-Special Type II (J) '93 (Pits every 42 - 43 laps)
6th Mazda MX-5 Miata (NA) '89 (Pits on lap 1, then every 34 laps thereafter)
Race Highlights:
Hour 1:
Pitted ending lap 1 to change front tyres to N3s, still keeping the A-spec points high, but allowing much better laptimes. Ended outlap 34s behind the leader and set about catching the pack as the SR-Limited begins to edge away from them. Harder to close up on the pack than in my previous attempt, but lap 6 comes in at 1'13.251, before I get 3 wheels off-track outside the large kerb at the exit of the final turn of lap 7, a move which is repeated ending lap 18. By the end of lap 20, the gap to the leader is 24.922s and the fastest laptime down to 1'13.148 (Lap 16) but leaving me over 10s down on the pace of my previous outing here. Lap 22 is the first in the sub-1'13 range, coming in a shade below at 1'12.945. Gap drops to just over 22s, but goes up again following a 4-wheels-off-track moment at the exit of turn 1 on lap 31, although no barrier contact is made. As my left front tyre begins to go off, my laptimes drop into the 1'14s and I'm 28s behind the leader when I pit ending lap 35, taking on new tyres but no fuel.
Completed outlap at 56.010 behind the leader, leaving a tremendous uphill battle.
Hour mark passes 1'11.061 into lap 48, in 5th place, 18.492s behind the leader.
Hour 2:
Held up by the J-Limited through lap 49, but get a good run on him down to the 2nd hairpin on lap 50, executing a pass around the outside, avoiding contact at the exit of the bend by making full use of the rumble strip and set off in pursuit of the 3rd placed S-Special. I catch up to him on lap 51, and make my move at the beginning of lap 52 having got a good run out of the last turn. I outbrake him into turn 1 and all appears to be clean until he tags the back bumper of my red '89 as we leave the apex of the turn. Knock another 1/10th off my personal lap record ending lap 55 in 1'12.746 and leaving 13.998s gap to the leading SR-Limited. Laptime drops again on lap 58, this time to 1'12.700, and leaving 12.693s to the leader as I'm beginning to make tangible inroads into the gap to the 1.8 RS in 2nd place. Pit in ending lap 69, from 3rd place and a little over 10s behind the leader, coming to a stop in my pitstall with almost an hour and 26 minutes of the race elapsed. I've used only 36 units of fuel at this point, so I refuse the fuelling hose again,
Complete my outlap 37.361s behind the leader and begin the onerous task of catching the 5 cars ahead of me having dropped back to 6th place again. Pushing hard to maintain the gap since their tyres are in the optimal range, I forget that mine are cold and run wide over the kerb exiting the final turn of lap 72. Able to wrestle the car back onto the tarmac without any issues though. Begin to lap consistently in the high 1'12 range and catch up to the 5th placed V-Special on lap 80 having dropped the gap to the leader by 5s. I'm held up for a few laps trying to find a clean way past, and eventually I get a great run out of the last turn of lap 82 which sets me up for a repeat of my first clean outbraking move on him into turn 1 of lap 83. The 1.8 RS stops a lap earlier than expected from 2nd place ending his 83rd lap and emerges only yards in front of me as I begin my 84th lap. The leader stops from around 32s ahead of me ending his 84th lap as expected, and is followed in by the S-Special who loses his position to the 2nd placed J-Limited who has yet to make his 2nd stop and both the 1.8 RS who moves into 3rd place, and me, only fractions of a second behind the 1.8 RS in 4th place. The J-Limited stops ending his 85th lap, a lap earlier than anticipated, and in doing so hands over 2nd place to the 1.8 RS and 3rd place to me. Outbraked the 1.8 RS up the inside into the 2nd hairpin on lap 86, passing cleanly into 2nd place, my highest ranking so far, and set off after the leader, some 7s up the road. The gap drops precipitously for the next few laps until by lap 90 I'm glued to the rear of the leading SR-Limited and trying to find a way by. He's holding me up as we're lapping in the mid-1'14s, but I'm unable to find an opening for a clean pass.
Hour mark passes 41.796s into lap 97, in 1st place, 2.529s ahead of 2nd placed SR-Limited.
Hour 3:
Pit in from just under 4s lead on lap 103, and drop back down to 3rd place. Have used 53 units of fuel in 103 laps so far, an average of just over 1/2 a unit per lap. Thus a 34 lap stint should require ~ 17 1/2 units.
The 1.8 RS pits ending his 124th lap, leaving me to take over 2nd place and then, having been reeled in to under 10s lead, the SR-Limited pits unexpectedly after 41 laps instead of 42, ending his 125th lap, and leaving me to breeze into the lead again. The S-Special in 3rd place maintains his 42 lap window, going in ending his 126th lap and dropping into last place temporarily. The J-Limited and V-Special pit almost together ending their 127th laps, and handing back 4th place to the S-Special and 3rd place to the 1.8 RS. I'm lapping consistently in the 1'12.7xx - 1'13.2xx range, and extend the gap to 2nd place to almost 30s, as I also catch the backmarking V-Special. Have my first minor off-track excursion of the hour in lap 133 as I run over the rumble strip and onto the grass with 4 tyres exiting the bend under the Dunlop Bridge. I'm held up by the V-Special in the last 4 laps before my 137th lap pitstop, lapping in the 1'14 - 1'15 range, but unable to pass due to worn tyres. This allows the SR-Limited to sneak back up to 26s behind as I hit the pitlane. 10 fuel units remain, and are replenished to a 19 unit level before taking off again, escaping with the lead, but just barely as I complete the outlap with just 0.651s in hand over the SR-Limited. He doesn't challenge hard even with his warmer tyres, and as mine warm to their task I'm able to edge away a fraction of a second at a time.
Hour mark passes 1'07.180 into lap 145, in 1st place, 4.030s ahead of 2nd placed SR-Limited.
Hour 4:
Not much happens in the first 10 minutes of this hour, my tyres are now up to temperature and I'm pulling away from the 2nd placed SR-Limited such that as I complete a new fast laptime of 1'12.524 on lap 153, I've opened the lead up to over 10s. It does appear that the SR-Limited has also been caught by the 1.8 RS, and their scrapping seems to be holding them up. Down to just a single fuel bar again, I finally push below the 1'12 and a half second barrier on lap 163, dropping in at 1'12.477 and now leading by over 16s as the rest of the cars in the field have their tyres wearing while they near their final pitstops, which I anticipate will begin around lap 165. Indeed, it is the 1.8 RS who has been running a very close 3rd behind the SR-Limited that kicks off this round of stops, diving pitwards at the end of his 166th lap and able to emerge still holding 3rd place. The SR-Limited goes in ending his 167th lap from 2nd place, emerging again just marginally ahead of the 1.8 RS with whom he'll rekindle the scrap that's left them trailing a little behind me. 4th placed S-Special is next to go in, also ending his 167th lap, dropping back into 6th place, and temporarily losing a lap to my 1st placed car. The J-Limited pits from the 4th place he's inherited ending his 169th lap as too does the 5th placed V-Special, both of them losing a temporary lap to me, and a place each to the S-Special who moves back into 4th position.
Pit in myself ending my 171st lap, and relinquish the 4th, 5th and 6th placed cars from being a lap behind me. According to the timers, I was 50.s ahead of the scrap for 2nd place between the SR-Limited & 1.8 RS at the 2nd checkpoint on my inlap. I have just 1 unit of fuel remaining in the tank, so I was cutting it close,
Hour mark passes 37.067s into lap 194, in 1st place, 20.722s ahead of 2nd placed SR-Limited.
Result:
1st Mazda MX-5 Miata (NA) '89 4:00'36.964 (194 laps completed, 252.7 miles)
2nd Mazda MX-5 Miata SR-Limited (J) '97 (+~20s)
3rd Mazda MX-5 Miata 1.8 RS (J) '98 (+~27s)
4th Mazda MX-5 Miata S-Special Type I (J) '95 (+~50s)
5th Mazda MX-5 Miata J-Limited II (J) '93 (+~1'00)
6th Mazda MX-5 Miata V-Special Type II (J) '93 (+~1'13)
In hindsight, practicing in a race with tyrewear on, 💡 would've showed me that my choice of setting the ballast forward was a mistake as it caused the front tyres to wear quicker, and setting it towards the rear may have improved tyre life, which in turn may have meant being able to carry a little more extra weight and gaining another few A-spec points.
However, I'm really, really happy with what I've done here, so I'm going to leave it at that!
Last edited: