So this was our second attempt at tarmac rallying in Taiwan. The first round in DaWu went so well that we thought we might as well take part in all 6 championship races this year and see if we can't finish the season in the top 3. Seeing as we had committed to completing the championship, we needed to bring our 2005 Subaru Impreza GD WRX up to spec.
Our brake and coilover setup remained the same as round 1; Front 330x32mm 6-pots, rear 330x28mm 4-pots, both with 0.45u 600C race pads, and PB coilovers with pillowball mounts and F8kg R6kg spring rates. The road wasn't too bumpy, so we set the damping to a medium setting 17 clicks front, and 12 clicks rear. That way we had some room to harden or soften the ride depending on how the first stage went. We set the ride height to the Impreza's OEM specifications as there was no need for raised suspension on this road.
We also squeezed an extra 50whp out of the EJ205 engine bringing it up 330whp, which is really more than enough for tarmac rallying. We did this by upgrading the fuel injectors to the 565cc EJ25 version, new fuel pump, boost control solenoid set to 1.3bar, and an ECU remap courtesy of expert Subaru tuner Les Sharp. Being one of only a few people in Taiwan using opensource software, he was able to get the most out of our latest upgrades, and after 15 hours of data logging and mapping we were confident that we had a good setup. In addition to that, we installed a new set of spark plugs and ignition coils as they were starting to show some wear. Finally, we invested in a set of Federal 595R semi-slick race tyres to replace the road tryes we used in the last round.
The results were fantastic, we were getting more boost coming out of the bends at 3000rpm and the new tyres gave us enough grip to keep the back end in check with the extra power (most of the time). The only thing letting us down was the standard 5 speed WRX gearbox. The next job on our to-do list is change the final gear ratio so that we're are higher rpm's when cornering and have instant boost at the pedal, but we'll come back to that later.
On Friday afternoon we arrived in TouCheng on the north east coast of Taiwan and co-driver Nick Gysbers got to work writing our pace notes for the first stage on Saturday morning. Embracing his role, it took 6 him drafts before he was 100% satisfied with the final copy. The road conditions were a bit different from the last round in DaWu. It was an uphill climb along a narrow and twisting road. Almost every corner was blind, several of which were tightening hairpins leading to harsh drops down the mountainside. Lets just say we were slightly concerned about the road conditions.
After a fairly decent night's sleep, and not too many beers (just for the nerves), It was race day 1...
There were around 160 entrants for round 2 of the TRRC, and 11 in our class, 4WD street car. That is almost double the number of vehicles that entered last round, so we had our work cut out for us! We set off on our first stage at 9:29am on Saturday morning. The road had actualy been swept the day before so the surface was excellent, there wasn't too much debris on the road and the rain had held out so we got some nice traction with the new tyres.
We finished our first of 4 stages without too much drama, and came back with a time of 5 minutes 38 seconds. We had no idea if that was a good time or not because we hadn't seen anyone else's time sheets by that point. We didn't have any mechanical issues to repair after the first stage, so we had 4 hours to wait around until our final stage of the day at 14:29.
To be honest, I would have rather just done the second stage straight away rather than bake in the 37C heat for the next 4 hours. Being from the UK, my body just can't take the heat and humidity experienced during the Taiwanese summers. By the time we ready to start our 2nd stage I must have sweated around 4 litres of liquid and was just about ready pass out.
Anyway, no rest for the wicked, it was time to get buckled up and ready for stage 2. Like I said, we weren't sure how our time on the first stage compared to the other competitors in our group, so tried to maintain the same pace. It turned out we had done a 5 minutes 33 seconds, which was 5 seconds faster, this was probably down to there being a bit more rubber laid down on the road. Either way, we were fairly satisfied with day one.
We finally had a chance to check the time sheet on Saturday night, and we discovered that we were currently in 4th place out of 11. The driver in 3rd place had beaten us on both the first and second stage which meant the only way we had a chance to grab 3rd position was beat him on the 3rd and 4th stages to match him on points, and hope that our total time was lower than his.
We were 8 seconds slower on SS1 and only 1 second slower on SS2, so there wasn't much difference between the 2 cars. We only needed to squeeze a little more out of the car to beat his times, so in a last ditch effort we increased the tyre pressure to 38psi, and turned the coilover damping all the way ip to 30 clicks front and rear, the hardest setting!
After 5 hours sleep and a few more beers (again, only for the nerves of course), we got up and headed down for day 2...
The skies were blue and it hadn't rained a drop over-night, which was good news for us considering we hadn't prepared any wet tyres! A few cars had slid off the road on SS1 and SS2, so there were were a fair few stones and some soil on a few of the hairpin bends, but all-in-all the conditions were fine (especially in a 4WD car).
We managed to knock 8 seconds off our best time in SS3, whereas other drivers were generally knocking 5 seconds off, so the tyre pressure and damping force adjustments had worked. We were happy with our pace of 5 minutes 25 seconds, and aimed to match it on SS4.
Unfortunately it wasn't to be. We pushed a little too hard on SS4, and with exhaustion starting to take hold, we made a couple of errors. The biggest of which happened on the second-to-last corner, 20 metres from the finish line. We came around a right 6 bend a little too fast, the rear wheels caught the debris littered across the road and the back-end let go. We slid into a ditch at the side of the road. Luckily the 4WD system allowed us enough traction to pull ourselves out and finish the stage, but it had cost us about 10 seconds. We drove back to the service area knowing our time of 5 minutes 38 seconds (same as SS1) would not be good enough to snatch 3rd place.
We got back to the service area and checked the damage. Luckily it was only superficial, just a few scratches and nothing more. The only real damage we suffered was to our egos! Anyway, on the bright side we did interviewed by a national news channel, not because we were any good, just because we were the only foreigners taking part!...
Here is a link to a video of the full report:
We waited for all the other drivers to finish so we could watch the awards ceremony and then make the 200km journey home, knowing that we had done fairly well but fallen short of our 3rd place goal. And then a glimmer of hope, we heard that the driver in 3rd place had been given a 30 second penalty on SS1 for starting the stage late. However, even with that penalty we would probably still only be equal on points at best. We didn't hold out much hope.
But then out of nowhere a gentleman approached me, shook my hand, and said, "Congratulations"! I looked at him with a bemused expression on my face, and asked as to what the congratulations was for. He told me that we had finished in 3rd place, and he was in fact the driver that we were chasing the whole time! It turned out that he had also had a crash on SS4 and finished only 1 second behind us. That meant we had beaten him on 3 stages, and he had beaten us on 1. Basically, if he had finished 2 seconds faster on SS4 we would have been equal on points, but his total time would have been 5 seconds faster than us. If we had spend 2 more seconds in that ditch we would have finished 4th. Just like the first round of the TRCC, we were 2 very lucky boys!
I must say I have a lot of respect for Stanley Liu for coming over to shake my hand after he found out he lad lost a podium finish to us. That's sportsmanship at it's finest.
We stepped up to collect our 3rd place trophy for the second time in as many races. Unfortunately the announcer still couldn't pronounce our names, but in all honesty we couldn't care less. We set out to bring home another trophy for PB, and that's exactly what we did. It wasn't 1st or 2nd, but considering this was our first season in the TRCC and we were up against an EVO 9, we were happy with the results.
It was also a great result for our team, LTC Racing, who picked up 4 trophies this time around in the street car 4WD MT and 4WD AT classes. An all round fantastic weekend!
Now, back to the technical side of things. Like I mentioned at the start of this post, our clutch and stock 5 speed gear box is letting us down. We have already swapped out the the clutch so that's one problem sorted, but the gear box is most important. The ratios just aren't suitable for rally driving, so when we exit the bends our RPM's just aren't high enough to stimulate sufficient boost. The cheapest and easiest way to fix that is to change the final gear ratio, which is exactly what we'll do before the next round in Taichung.
At the moment we're running a stock 3.9 final, so we're going to change that to either a 4.111 or a 4.444. We have top tuner, Jasper 'The Flying Dutchman' Kopinga doing the math for us as we speak, so as soon as he has worked out what's best we will get to work on changing it. Ideally we will hitting over 3,500rpm on the exits and has instant boost at the pedal.... At least that's the theory anyway!
In regards to coilovers and brakes, we have plans for those too. We're lacking a little bit of grip, so we're going to increase the camber to 3 degrees front, and 2 degrees rear. The next stage will be taking place on flat street roads in Taichung city, so it might also be worth us upping the spring rates for that, but it depends how much time and money we have spend over the next 2 months.
Another issue that needs rectifying before the next round is the brake bias. We're a little bit rear-heavy at the moment, so under heavy braking the back end tends to want to lock up before the fronts. That's because the PB Impreza was originally never intended to be a race car, therefore we installed the biggest rotors that would fit under the 17" wheels, 330mm front and 330mm rear.
We pulled out our brake bias calculation spreadsheet to see exactly how far off the stock setup we were....
As you can see from the table the stock '05 WRX bias is 2.21 to the front, and our current setup is only 1.91 which is quite a big difference. There are 2 ways to correct unbalanced brake bias; one is to down-size the rear discs, and the other is to change the pad coefficient of friction. The seconds option is by far the cheapest and easiest, so on this occasion we will go down that route.
We could either change the rear pads to a lower friction, but this would reduce our overall brake torque. So we might as well take advantage of the situation and change the front pads to a higher friction, therefore increasing torque and balancing the bias to the stock specifications. Now look at the table below, it seems as though front 0.52u pads would give us the exact 2.21 ratio we are looking for...
So that was round 2 of the TRRC Taiwan Rally. The next round should be in September, so we have plenty of time to prepare! Stay tuned...
