Some pics from Donington: Conclusions from the pictures: The suspension is working a lot better. The rear wheel isn't lifting. Not much of a test, but I was pushing on in some of the pictures. The bonnet needs some pins Always check the passenger door is properly closed... lol
So, nothing has happened to the car. I've not looked at it since putting it in the garage. I was filing some paperwork, and realised the engine only has about 3000 miles on it, so I've decided to leave it as is for now. I'll replace the rocker cover and sump gaskets, as well as remove the two port temp sender extender, as that's been a pain from day one. As much as I'd like one of the new generation GTX turbos, I can't afford it at the moment. I'll get the current core replaced with the upgrade to the bearing housing they do. The exciting news is these arrived today: I needed an EGT gauge, and can't use DTADroid to monitor that, as the DTA S40 only outputs that value via CAN, which I haven't built yet. I also needed an AFR controller, to feed DTA. After some research, I decided to go for the new Bosch 4.9 sensor, as it's better, and doesn't require free to air calibration regularly like the older 4.2 sensor. PLX then have this nifty gauge that reads up to 32 of their controllers. You simply join them together using the provided cable, and the gauge reads them in the order they are joined. The gauge/controllers store high low values, as well as provide graphs. The controllers all have analog outputs, meaning you can feed the gauge at the same time as the ECU. You can also set warnings for up to two parameters. As I'm only using two controllers, that's perfect. If it works as well as they say, I'm going to be very impressed. So the planned winter upgrade list looks like this now. Winter Upgrades Refresh sump and rocker cover gaskets. Remove extra oil sender extender. Exhaust manifold - machine turbo mounting surface, replace M8 studs. Either with hardened bolts, or upgrade to M10 at the same time. Fit oil pressure reducer to turbo. Maybe copy Gurd's oil feed solution Fix turbo. Fit AFR and EGT sensors/gauges Fit proper oil pressure sender. VDO aren't accurate, and DTA can read a proper 3 wire sender. I have the sender, just need to fit it and wire it in. Measure bump steer on front with current suspension set up Remove and refit entire front suspension, replacing all bolts where possible. Check all rose joints for wear. Add hole to suspension arm. Using wrong one on fixed suspension arm Bonnet pins Mount tablet to use DTADroid Run DTA cable through bulkhead. Needs the cable chopping, feeding the cable through, and joining together again. Sort out electric cut out switch wiring Adjust brake pedal height, and add pedal covers to allow easy heel and toe. Add extra rear silencer Door cards from plastic Create new cover for fuel pumps/lines where they are in the car. I'm not a fan of having those exposed when I'm in the car. Nice to at some point list: Redo the in car fuel lines in Teflon fuel hose. Should lessen the fuel smell, as they are supposedly better than the rubber hoses I have now. Plus I keep stabbing myself on mine as they're old and frayed. Fix dent from where wheel fell on the car, as well as a few other nicks. See if it's possible to fit a Mk3 ARB to one of the camber bolts. Maybe use AST ARB attachment. Replace fuel fillers. The current ones are for fast fill jerry cans used in endurance racing. PITA at petrol stations. Sort fuel level gauge/sender.
I actually worked on the car this weekend. Well, I say worked... After being dumped in the garage after Donington, I had to move parts just to get to the car. Still there though. Hello stranger: I made a start on removing the turbo. Failed pretty quickly, as I can't get to the water pipe at the back near the bulkhead, nor could I work out how to get to the 4th bolt on the exhaust manifold. It's perfectly surrounded by the oil return, compressor housing and turbo frame. Since discovered it's easier to just take the exhaust manifold off, so will try that next weekend. I did find evidence of a water leak that's new: When I removed the shield between the turbo and the head, it's also clear there's an oil leak from somewhere: That's not a shadow on the exhaust manifold, it's where oil has settled on it. I'm guessing a small leak from the return pipe, which is being sprayed around by turbulence. Costs to fix the turbo are: New GT2860RS core - 380 + VAT = 456 With upgraded bearing housing - 380 + 114 +VAT = 592.80 New GTX2860 with billet compressor wheel - 670 + 114 + VAT = 940.80. That's right, you still have to pay for the optional bearing housing upgrade. Probably not in budget for now.
I managed to get the ****ing thing off today. What a pain in the ****. The turbo waste gate actuator hits the bulkhead before the manifold is off the exhausts studs. I tried a number of things, but ended up having to remove the actuator. Lot's of 1/16 of a turn of the spanner, take it off, turn it around, repeat. Not the right way of doing it, but I couldn't work out any other way of doing it. I did try to remove the front engine mount to tip the engine forward, but have the front panel for small bumper cars on, and that would have had to come off, which meant bumper off as well. I then cross threaded the top bolt when putting that back in to the engine mount. *sigh* The bad news is the compressor wheel has touched the housing: I hope it's reusable. You might be able to see the edges of the blades are a bit shiny. No real damage to them, but the whole core is being replaced anyway. It'll go off to Owen Developments this week for checking, and they'll let me know. The exhaust manifold will go off to be machined as the surface was damaged when the turbo last came loose. I'll also get the M10 studs fitted that have arrived. Next weekend I want to remove the suspension arms to get the other hole drilled. I have two bosses on my downpipe/exhaust for the AFR gauge. One is about 6" from the turbo, the other under the car where the downpipe joins to the exhaust. I'm going to investigate mount the EGT sensor in the manifold just before the turbo. As it's cast, that may not be an option. If I can't I'll use the first boss after the turbo. The second boss under the car will be used for the AFR sensor. I've bought all the bits to create a new oil feed line copying vw_singh's setup, as it is simple and proven to work.
I removed the suspension arms last weekend. As suspected, the temporary welding done at Donington damaged the nut that was used, so that needs to come out. I've ordered a new captive nut to be fitted as VW still had some. I've also ordered new suspension bolts. The arms are off being drilled and straightened, along with the exhaust manifold, and I collect them on Friday. I heard back from Owen Developments. My turbo was properly ****ed, they can't even find the bearing cage. Unfortunately there is nothing left that is usable, so it's a completely new turbo. I can't stretch to a GTX, so I'll get the same again, but with the upgraded bearing housing. I also ordered some Silver Project front top mounts, which arrived last week. My wife is away for the weekend with the girls, so I have the whole weekend to work on the car. I want to get most of this list done: Refit front suspension, replacing all bolts Fit new top front mounts Fit AFR and EGT sensors/gauges Modify existing oil feed line to take turbo oil pressure reducer. Fit proper oil pressure sender. Fit Bonnet pins Adjust brake pedal height Door cards from plastic Sort out electric cut out switch wiring Mount tablet to use DTADroid Run DTA cable through bulkhead. Needs the cable chopping, feeding the cable through, and joining together again. Possibly create new cover from the plastic for fuel pumps/lines where they are in the car. Once the above is done, and the turbo arrives, I'll trailer the car to Stealth for them to refit the exhaust, turbo, new oil line, sump gasket (rocker cover isn't actually leaking so it's being left), and tweak the map for the new turbo.
Well, that was reasonably productive. It would have been a bit more productive if I hadn't slept for 28 hours over the last two nights... Done Refit front suspension, replacing all bolts Fit new top front mounts Modify existing oil feed line to take turbo oil pressure reducer. Adjust brake pedal height Sort of done Fit AFR and EGT sensors/gauges - Actually all fitted and connected, but the gauge appears to be faulty. Same problem as here. Fit proper oil pressure sender - Fitted, but I made a mistake with the wiring. Simple enough fix. Not started Fit Bonnet pins Door cards from plastic Sort out electric cut out switch wiring Mount tablet to use DTADroid Run DTA cable through bulkhead. Needs the cable chopping, feeding the cable through, and joining together again. Possibly create new cover from the plastic for fuel pumps/lines where they are in the car. Fitting the gauges and oil pressure sender took most of the time, as I had to work out where to run wires, where the units would sit, find suitable plugs, etc, etc. There was no wiring for the oil pressure to the ECU, so I had to create that as well. All good fun though. The car is back on it's wheels and in the garage. I need to sort out the oil pressure sender wiring, then as soon as the turbo arrives, it's off to Stealth for the bits for them to do. One day I'll remember to take pictures a la Nige...
The turbo is here, and the car is booked in to Stealth. I'll drop it off on Saturday and hopefully collect it next week some time. I asked Owen Developments to return the old turbo as I wanted to have a look at it, and had thought about making some sort of an ornament out of it. The hot side was well and truly knackered, the turbine had rubbed all the way around the inside. It's now in a skip. lol The replacement PLX gauge is on it's way back but won't be here until next week, so I'll need to tidy up the wiring before dropping it off.
Picked up the car on Friday, all running well. I'd asked them to check for oil leaks, as there appeared to be a few. They replaced the sump plug washer, oil cooler seal and diff drive flange seals, as well as new turbo seals all round. I can no longer smell oil when running the car, so that's good. The big fix has been the oil pressure reducer to the turbo. The car doesn't smoke at all now, even when cold, so very pleased with that. The replacement PLX gauge turned up during the week, so I've fitted that, and finished the wiring for the wideband lambda. It appears to be working well. I need to update the ECU settings so that it can output the values on the data stream for logging. Before Bedford, I need to torque up the suspension bolts, and I also want to run a cable through the bulkhead so I can run DTADroid at Bedford, and empty the catch can. Other than that, the car is ready. I've picked up some 5mm spacers that I'm going to run on the front to start with, and then try the 15mm spacers to see the difference. I've also picked up some ATS DTCs with 205/50/15s from Gurds, so will then try them to see what the difference is. I currently run 195/50/15s on similair wheels. The car felt much more docile today on the short drive. I suspects that's because the suspension isn't changing geometry every time I accelerate or decelerate, but it will also be because of the smaller spacers meaning less scrub. I'm really looking forward to Bedford now. To Do for Bedford Move gauges to ignition live pin Phone Mounts Measure brake pad wear Print off set up sheets Done Fit MFA temp sensor wire on back of head Torque suspension bolts Secure PLX and GPS units with velcro Tidy up PLX wiring, including shrinking heatshrink! Run DTA cable Empty catch can
Spent a couple of hours on the to do list. Knocked a few items off, added a few more, should get most of them finished tomorrow. I can't do the phone mounts as they haven't arrived.
Bedford With the rebuild of the turbo completed, it was time for the first track day of the year. Having fixed all the issues that had been found last year, I was really looking forward to this. I didn't fancy the M1 on a Monday morning, so booked in to the Travelodge with Nige and a few others. The car was ready, but I didn't manage all the extra jobs I'd planned like door cards, wiring changes, etc, but the car was ready to drive. I packed up on Sunday morning, ready to go. Sat nav mentioned a 10 minute delay, so I left a few minutes early, and got there just before 5pm. Some roadworks, but otherwise a quiet drive there. Nige arrived a bit later, and parked up next to me: One of the main reasons for staying over is I find I have very little time to catch up with people on the day, and it really adds a lot staying over and having a catch up with people the night before. We had a good meal, and then a fairly early night. For a hotel I slept quite well, and was ready to go quite early. The weather was perfect, cold and clear. Although defrosting a track car was a new experience! lol As I was parked in a corner, I fully expected to be parked in the next morning. I was correct. However, it turned out to be Ian with the Mk5 GTi he'd just bought. Literally just bought. He'd picked it up on the way down to Bedford, arriving at the hotel at 1am, and heading out on track 8 hours later. Hero! We headed over to the track. I wanted to warm the car up a bit first as I'm always marginal on static at Bedford, so I parked in the car park, started the car and then unloaded it. There was apparently someone in an XR3 that was doing noise testing, but I couldn't find them, so went back to the gate. I scraped through at 99.2dB. I was asked if I'd been before, and as I had with no issues, they let me through. I then went over to the drivers briefing, and had breakfast while catching up with Gurds, Ram, Eddie, and met Henry and his friend Luke. Drivers briefing done, I headed back to the trailer to squeeze all my tools in to the car, and then went to find the garage I was sharing with Dex. The first sighting laps were already underway, so I unpacked quickly and headed out for my laps. Back in, I checked tyre pressures, and torqued up wheel nuts. I'd put two phone holders in the car, one for DTADroid, and one for Harry's Lap Timer. Unfortunately I had no data at the track so couldn't load up HLT. First session!! After all the issues last year, I was a bit apprehensive. Gentle out lap, everything felt good. I got stuck in a bit of traffic, and when I tried to pass a Clio on full throttle, I instantly had a misfire. Changed up a gear, and the same again. Hmm, that feels like the engine's cutting due to boost spikes. Gentler on the throttle, and that worked fine. It missed once more in that session, and was then fine for the rest of the day. The map will need a tweak for when it's cold. The logs show boost hitting 1.5 bar, which is where the overboost limit is. I then did a few hot laps, and came in. Checked tyre pressures, all fine. The car had been perfect. Here's a video: [video=youtube;uHJr-1T7m5w]https://www.youtube.com/watch?v=uHJr-1T7m5w[/video] Er, now what? I'm so used to having to fix something I felt a bit lost! lol Chatted to a couple of people, decided the car was cool enough, so went out for a session with Aman. This session I started to push on a bit. However, there were no more misfires. I had a good few laps with nothing coming passed me until my second last lap when a Porsche appeared in my mirror down the back straight. And he had the legs on me. Humph. I pulled in and let him past. Oh, a 991 Turbo S, that's OK then! lol He had the legs on me in a straight line, and a little in the corners. Red mist descended a bit, and I started to overdrive, missing apexes. Going down the short straight just before the pits the car got very out of shape under braking. I put it down to overdriving, but it felt a little odd around the next few corners, a bit like the moving sub-frame bolt. I came in next lap, and left the car to cool down. Video of session two: [video=youtube;EMk6KQorBfs]https://www.youtube.com/watch?v=EMk6KQorBfs[/video] While it was cooling, I checked the tyre pressures again. Fronts were 28, but the rears were still only 25. I decided this was as good a time as any to rotate them. However, undoing the OSF wheel, there was play in the suspension. Not again! Fortunately it was an easy fix. I'd had both suspension arms off over the winter, and forgotten to torque the center bolt on the arms. Tightened them up. I also wanted to test different front wheel spacers to feel the difference changing the scrub makes. Obviously I'm changing the track, as well as scrub and also pushing the wheel out further from the hub, which will increase torque steer. Suddenly it was 12 o'clock, so I jumped in for a quick pre-lunch session to test the changes. On the out lap it was clear there was a load more torque steer, and the car was less stable under braking. The rear would really want to move around if I wasn't braking in a straight line. Apart from that, it felt solid and stable. I did a full lap, but wasn't convinced about the spacers. A couple more laps should see me to lunch. However, it was not to be. On the next lap, coming out the hairpin after the long back straight, 3rd gear let go. You can see that here: [video=youtube_share;RgfxEYfydPA]http://youtu.be/RgfxEYfydPA[/video] Straight back to the pits, and onto the trailer. When I got there, it turned out Ram had lost a stud from his turbo. As he was using the same as me, I offered to let him take one off my car. The good news for me is they were on too tight, so they were unable to undo them. It looks like the upgrade to M10 with Nordlock washers has worked. Fortunately they managed to find a place nearby to get spares. They replaced it, but the gasket was damaged, so that was the end of his day too. After lunch, I spent the afternoon chatting, and had a pax lap with Dex. The MX5 goes really well, and the mid corner traction was impressive, meaning Dex was on throttle much earlier than me. Nige just managed to find time to take me out for a lap in his. This was very interesting, and we were both looking forward to the comparison. It's really easy to tell how much more development has gone in to Nige's car than mine. While mine sat in the garage for 4 years, Nige has been constantly developing his. There are two main differences: power deliver and stability under braking. Nige can just plant his foot to the floor mid corner. As mine is mapped to make much more torque than his, I have to really modulate the throttle on mine, or it will just spin up the wheels and understeer wide. I prefer my set up, but I can see the benefits of Nige's as it's much more forgiving. Where I want to really work on mine is stability under braking. If I'm not careful, the back of my car will move around, whereas Nige could break at any point. More time is needed to understand how that affects the handling in other situations, but I could feel Nige was able to carry more speed in to the corner because of his confidence in the rear of the car. This was also the first chance I'd had to use DTADroid in anger. It was faultless all day. I did forget to turn on the 10Hz GPS logger, but I'm very impressed with the logs taken at 1Hz. My intake temps are a little higher than Nige's, so I'll be looking at venting the bonnet at some point. However, the main concern is that I appear to be getting oil surge. This is clearly visible in this screenshot: The bottom graph in the white is the oil pressure. The vertical line shows maximum speed down the back straight. There are three oil pressure dips in the graph. The one just to the right of the vertical line is the chicane on the back straight. The one on the far left is the new left right chicane, and the one on the far right is the hard change of direction after the hairpin. It seems to be on direction change, but I'll look further at that when I have some time. So that's it for now. I have a spare gearbox, but I don't know if I'll have time or money to get the diff in the spare box. I may just fit the spare box with the open diff in for Curborough, but I know I'll find that massively frustrating. We'll have to see how things go over the next few weeks. Finally some pictures from the on site photographer. I bought them as I knew none of our group were taking any. I may have been trying a bit hard: There's an apex there somewhere!
Nice report Alex. Pity the gearbox decided to grenade as everything else seemed to be working well for you. Very interesting data about your oil pressure there. It's something I'm quite concerned about and was thinking that most people place one baffle plate close to the pickup where as the other sits quite far away. This would lead to less available oil on left handers over rights. However, this would only apply to home made baffled sumps. I'm pretty sure you have a schrick deep sump? Maybe add half a litre of extra oil? Gurds
Good write up, cheers for that. Car looks great in the pictures. Are those 888's you're running? Tried Yoko 48's? I found them to have a much stiffer sidewall that the 888's which reduced flex and helped feel. The tyre pressures you mention, are they hot or cold pressures? I find on the Rado that most track tyres really don't get into a sweet spot until about 30 to 33 psi hot, max. On the fronts, on a normal day I'll usually get an increase of about 8 psi cold to hot, about 3 or 4 psi on the rear. Have you played around with rear pressure at all? I'll start my rears off cold from anywhere between 26 psi and 40 psi. I generally up the rear pressure the warmer it is. Although it sounds bonkers starting the pressures off that high, when there's lots of rear grip it really helps the front of the car turn in and the rear to swing round. Basically just another way of shifting balance from understeer to oversteer. Worth experimenting with if you haven't already. Don't try it for the first time in the wet though!
Thanks Gurds. Yup, I run a Schrick sump. I forgot to check the oil level at all, so have no idea where it was. It should be at normal level as Stealth did a full oil change when they fitted the turbo. If it is, I'll try a bit more next time and see how it is. Thanks for that. I've never run A048s, they are on the list to try, but I've got two nearly new sets of 888s to get through first. Tyre pressures above are hot. I start at 24 cold. I found the car started to slide around when hot pressures went above 30 at previous track days. I'll try higher pressures again at the next one. I probably need to start the rears higher, as I struggle to get heat in to them.
The easiest way to get more heat into the rears, short of adding weight over rear axle, is by sliding the rear or lowering the contact patch. Increasing pressure generally results in both
Great report, enjoyed reading that There is another reason for me mapping mine this way. Whilst it makes it extremely driveable in the wet OR dry, I also wanted to limit the torque spike to protect the drivetrain. I run the odd kerb and I didn`t want to be putting huge torque through at low speeds and damage a CV or Gearbox. I agree, it could be increased slightly to keep the delivery I like AND gain a bit more lower down, but I`m very mindful of the extra loads going through the drivetrain now I`m F/I
