Some pictures and videos of the day. Credit to Liam and Victoria. Early arrival: Ready to go: Action: On board video: [video=youtube_share;DYGtX3AqWtg]http://youtu.be/DYGtX3AqWtg[/video] External video: [video=youtube_share;ZZD6mtmQiZA]http://youtu.be/ZZD6mtmQiZA[/video]
Really appreciate that write up Alex - there's a limited amount of people who delve into their precise setup details the way you do. Insightful info on tyre pressures Thanks man
So, Donington on Saturday. I had loads of plans to do bump steer correction. However, I've just not had the time. The SCCH extenders are welded, but the hubs are still at the welder. I have the 5 stud Mk3 arms, but haven't modified them for the Mk2 ball joints. That's now for the winter break. I did change the crank position sensor, as I'd had a few random misfires, and the diagnostics was showing crank position errors. I'll make up a spare piece of loom to take with in case it's a wire breaking down somewhere. I'll take oil with, and check that on Saturday morning. I need to purchase a spare battery for the GoPro, and I might try and mount one of the spare cameras elsewhere.
What a great day. Well, morning. I went up last night, and stayed at a hotel nearby. I got to the track about 8, unpacked, and went to fill the car up on site, as I'd forgotten to do it the day before. 1.44 a litre!! I decided 25l was enough. Drivers briefing was at 8:30, when I found out that we were doing the international layout, including the Melbourne loop! Awesome, I've never done that layout before. That was followed by the sighting laps, and then it was out for a proper session. There was a bit of drizzle, but not enough to make the track damp. However, it was cool, and I was struggling to get heat in to the rear tyres, which made for a few interesting moments. Apart from that, the car felt really good, and my heel and toe practice has worked, as I was just able to do it everywhere, whenever I wanted to. I started pushing on, which led to a couple of mistakes. Nothing serious, just a few missed apexes, and a couple of bits of grass that need to grow again. I have no idea how long I was out for, but it was probably about 15 or 20 minutes. I'd got a bit ragged, so decided to have a break. A quick check over, and the car seemed fine. i was trying to get Harry's Lap Timer to work on an old phone, but it wouldn't pick up a satellite. I presume it needs a sim card? I used my new phone, and was able to connect it to the external GPS sensor, and then worked out how to add it to HLT, but for some reason no laps were recorded. I'll have to look at why next time. I went out for a second session, and it took a couple of laps to settle. However, after that I really pushed on, and had a good few laps. Suddenly, there was a really loud noise from the back of the car. It took me a moment to work out that I'd used up all the fuel in the car, and the lift pumps were lifting air. A quick cool down lap, and over to the petrol pumps to put some more in. I decided to put 30 litres in, enough for two sessions. That's right, I used half a tank in two sessions!! The car was awesome though, nothing passed me, and I was able to push on. At the limit though, the car didn't feel quite right. I couldn't quite put my finger on it, but it just wasn't right. Braking for the chicane at the end of the back straight, the back would sometimes just step out. I let the car cool down, and then went out for another session. However, the car just didn't feel right. Then I had to brake hard at the end of the pit straight as someone was dithering, and the car went really sideways. I came back in and had a good look around the back of the car, but couldn't find anything. I then remembered Nige recently saying the car just didn't feel right, and it was down to a loose steering rack. All 4 bolts on my steering rack weren't tight enough! The NS ones were particularly easy to turn. They weren't loose, but the weren't tight enough. I then tried to tighten up the NS bolts, and they just turned and turned. Great, the threads are not stripped. However, the bolts are the ones that don't come out, they need to be levered out. As I had a trailer, and the car wasn't going anywhere I decided to try and get the bolts out. Mark (who I was sharing the garage with) offered me a small lever bar, and they both popped out easily. At this point, it started raining. Lots. So I had some lunch, and then went in search of some bolts. I found one place 5 miles away that was open, but when I got there, they didn't have much. I then found a Screwfix, and now have about 150 M8 bolts of different lengths, as Screwfix only seem to sell them in packs of 50 or 100. Back to the track, and the bolts were fitted. However, the track was now really, really wet. The 888s were down to the wear markers, so I wasn't that keen on going out. I wandered around and chatted for a bit, hoping the rain would get lighter. It didn't. So I decided to fit the "wet" tyres. These were the other 888s which had about 2mm to go to the wear markers. Hmmmmmm. However, the desire to test the tight steering rack overcame my nervousness, and I headed out. Very gently. The first thing I noticed is that the steering wheel now sits skew, so the rack has been loose for a while. The second thing I noticed is that 888s are actually pretty good in the wet. I wasn't anything like as quick, but slowly built up pace, until I was going at a reasonable pace. I was able to cadence brake, and locking a wheel wasn't a problem, but I had to be really smooth getting on the power. I did a good few laps, and then the rain picked up. I came in when I suddenly spun the fronts up down the pit straight at about 100mph with no warning. I decided to call it a day at that point. I could have done some more laps, but I decided not to risk it. I want to get the rack fixed properly, and then geometry redone. I do have some videos, and will upload them soon. All in all, an awesome day. I'll be pulling the front suspension completely to pieces over the winter. I have the new SCCH ball joint spacers fitted to a spare set of hubs, some Mk3 arms to modify for the extra caster, and the rose jointed bushes to fit all round. I also have some injectors to fit, and a tubular manifold, but I'll see about doing that. I want to concentrate on getting the Audi ready for racing next year, and have a lot to do to that. I will definitely get the suspension geometry sorted, as I want to do a couple of the Classic VW races if they do go ahead with the open class. My ARDS test is booked for next month.
A few years back I used to use fresh 888s as my race wet tyres, were ok. New Kumho 700s in soft k6 compound are good in wet too. Its just when the tread depth gets liw they start to get slippery. Proper race wets have to be tried to be believed.
888s surprised me, I'll be honest. I have some T1Rs, and even in this level of wet, the 888s were far better than the T1Rs ever were. I'll be moving those wheels on.
Session one uploading now: [video=youtube;IPC3JLYgFuo]https://www.youtube.com/watch?v=IPC3JLYgFuo[/video]
First one done, second one uploading now: [video=youtube;FaaL_qidLQA]https://www.youtube.com/watch?v=FaaL_qidLQA[/video]
Having actually watched the second video now, I realise I need to fix my fuel gauge. I was running low a few laps before I noticed!! I'll probably need a light somewhere, as I didn't notice the lift pumps this time, which I've always done before. I was having too much fun. I've also never done a 20 minute session before, and the car was still ready for more. I'm very pleased with the reliability.
I bet it takes some abuse over 20 minutes on track!!! Is your fuel gauge on the Mk2 clocks or is it the one on the right of the 3 in the stereo slot?
Yup, 20 minutes is a lot for such a high power output. However, reliability is there now. It's the one on the right of the 3 in the stereo slot. It's been faulty ever since I bought the car. Plan now needed.
I went back to Bill's again yesterday, as I wanted to get closed loop fueling tested. I'd set it up already on a map, so it was just a matter of uploading it and testing it. I'd planned to upload it before leaving, but was running late, so left it until I got there. Uploaded the map, and went for a quick drive. I could instantly feel the difference, and the engine sounded different too. As I've only got the update rate set to 1Hz at the moment, the AFR would start at on the main map of low 10s, and then lean out as the closed loop adjusted it. I'm logging the changes and applying them, but there's a fair way to go. Back to Bill's and on to the dyno. I was expecting around 320bhp. However, it made 347!! To say I'm delighted is an understatement, as there's more available. Eddie reckons another 30bhp with timing and fueling improvements. 350bhp on Bill's dyno equates to around 380bhp on Stealth's. As can be seen from the graphs, peak boost is at around 19psi (1.35 bar), which is up a bit from last year. The AFRs are around 11/12 most of the time, a lot better than last year On the drive home I logged more changes, and applied them as well. As I drove home I played around a bit. It's noticeably more eager at the top, and sounds much crisper too. Graphs, cos pretty: When the car was originally mapped, it was mapped very conservatively, as there was no feedback at all, both on ignition and fueling, and also using TPS vs RPM, with no MAP corrections. To be honest, it didn't need them, it was making plenty of power, and it still doesn't need them. Despite this, I'd like to revisit a lot of this as a learning experience, just to see what's possible. I'd like to play with closed loop boost control, MAP compensations of spark, using MAP as load, etc. Unfortunately, this car's not going to get a lot of attention now. I need to spend what time I have on the Audi. I have my ARDS test booked for next month, and then I start racing next year.
I've not moved the car since the last post. However, the Audi won't be ready for Donington next weekend, so I need to take this one. There are two things I want to do. 1. Check the oil level. 2. Replace the drivers side steering rack bolts. Tom has sent me some to try. I love this car.
