Cadwell Park 18th August 2016

Before Cadwell I checked the alignment and felt a tiny amount of slack in the steering. Checked Rod ends, Steering U/J, Rack mounts and still nothing. Wedged wood between the outside of the front wheels and the garage wall, the same as when diagnosing the play last year. I could wiggle the steering wheel a tiny amount, the column turned, the UJ turned and the Pinion turned, but the tie rods didn`t. !

The Preload on the rack is set by a cup that sits on the back of the rack and presses it in to the pinion, the play was between the Rack and the Pinion. Even though there is a spring between the adjusting bolt and the Cup, it can only adjust so much.

By loosening the locking & tightening screw #10 , the spring #14 is compressed against the Cup #17. Removing any `slop` between the rack & Pinion. This should not be adjusted unless you are certain it is causing a problem.

Marked up the locking nut and adjusting nut

Loosened the locking nut

Filed the corners of an M14 nut, this then sits snugly into the adjusting socket, without filing the nut a little, it`s a VERY tight fit and I couldn`t get it to fit but a few moments with the file and it went in a treat.

Nut in the socket, 22mm spanner and adjust preload. I added 45 degrees but there was still some play. 90 degrees was just enough. I certainly didn`t want to overdo it, that way you`ll be more prone to it binding when it gets warm, the last thing you want on circuit !

Retighten locking nut.

There is now ZERO play in the rack

I also fitted the Project Mu SAS964 Endurance pads I`d bought.

They list at £660, for a set of brake pads !! I didn`t pay anywhere near that but I was keen to see if they were as good as everyone said.

Initially we were going to camp at Cadwell but we decided to go there and back in the day. A friend of ours was free so Richard and Harry came along for the day. Matt was towing the Golf and I towed the 328, tools, wheels and fuel. Picked them up at 06:00 and set off on the 2 hour drive.

There is a local axle weighbridge on the way that`s unmanned and open 24/7 so we often call that way to get an idea of weights. The combined X5 and E36 combo was a shade over 5 tonne

The Trailer we borrow for the Golf is a single axle lightweight one and that axle weighed in at 1,300 kgs with the rear axle in the E46 just under the limit. Moving the Golf back lowered the weight on the E46 rear axle but makes it less stable when towing, so we`ve found a position that`s stable and legal & stick to that. Ideally, we`d prefer a twin axle trailer, they are more stable when towing but this one suits the few occasions when we want to take both cars to a circuit.

Then it was off to Cadwell for what should be a simple run over. Unfortunately, Matt pulled alongside and gestured for me to pull over after about an hour and a half. The Jerry can box had fallen over onto the E36

We put a strap round it, secured it to the trailer and drove the remaining 30 minutes to Cadwell. When we arrived, the box had totally collapsed. It looks bit tatty but was solid. The mounting bracket welds had fractured allowing it to tip sideways putting a lot of load onto the side of the box, popping the welds and causing the sides to split. I`ve found the tyre rack welds did similar, the vibration when towing causes fatigue over time on parts that aren`t braced enough. The new box / mount will be secured to ensure this doesn`t happen in future.

It was a Javelin trackday so we had a good chat with Colin, Sue, Hayley and Andy when signing on.

During the briefing Colin specifically asked that if people have an issue with another car or driver, they let the Javelin staff know on the day. It`s no good saying nothing then going online a week later moaning about the day because the organiser didn`t do anything about a particularly bad driver. If they don`t know about it they can`t do anything !. All the TDO`s say this but you`d be amazed how many people don`t say anything on the day and then post about a bad event from behind their keyboard when the TDO can`t do anything to solve the issue.

unloaded the cars as the first sighting laps were underway.

I was apprehensive about the first session as it was the first time I`d driven the car since fitting the Diff and rebuilding the gearbox.

All I`d been able to do was turn it around in the driveway and go through the gears with it on axle stands. I knew that until I got that first session under my belt, I wouldn`t be sure it was OK so I went out by myself which is unusual for me. I also wanted to bed in the new brake pads and that`s not really comfortable for a passenger. The gearbox was fine, went through all 5 gears and bedded the pads in until they started feeling hot.

Everything was doing as it should with no unpleasant noises. I was obviously rather happy with this. When I watch the incar back, I pull some very odd faces at times..

Lou had gone out to take some photos and started off at Hall Bends.

Back in after half a dozen laps, bonnet up and check everything over. Nothing amiss so tyre pressures adjusted and back out for a session with Richard. He is one of those passengers who is always looking around, he finds the Throttle trace on the phone and Speed on the PBox particularly interesting at certain points on the track. We did a decent session and everything I asked how he was, he instantly replied “loving it !” which is nice to hear. I was getting a feel for the brakes at this point, they are a little grabby on initial application but are then very progressive in feel and I could modulate them really easily without locking up.

It was time to start getting some miles on the Golf. The weather was ideal, mid 20`s and there were no queues to get on track at all. That was a perfect opportunity to get some laps done and enjoy myself. As there were about 10 people there from Northloop we ended up on track together a lot of the time.

Alastair and I have had some great sessions on circuit together in the past, Cadwell last year was particularly good. He was out by himself at first with the plan that we`d both get some laps in alone and then go out for some sessions together.

James`s M3 was going well but he wasn`t happy with the road tyres, they were overheating. He had some good laps with Matt and they were surprisingly close in places

Braking for the hairpin can be tricky, I need to take it in 2nd which is very unusual on track. 3rd just bogs down but I found that with the adjusted gearselector and shorter throw, I never missed 2nd at all. Usually I`ve had a moment or 2 when it wouldn`t go into gear, but not today. The reduced play in the new selector tower certainly gave me better feel than the old one. Sometimes, parts were so slowly you don`t even realise until you take them off and check for play, this was certainly the case with the selector.

Ian`s next outing is Spa in October and he wanted to check everything out at Cadwell. Fortunately for him the diff failed mid morning. You`re probably reading that thinking `that`s not fortunate !`, Ians next outing is in Belgium, for 2 days. If he hadn`t done Cadwell it would have failed over there instead. Now he has time to get it sorted before Spa rather than having an expensive European trip spoiled due to a mechanical failure. Of course we`d prefer not to have these failures, but there are some times that they are more `convenient` than others. He was able to do some basic inlet temp datalogging and it`s an area he`ll be focusing on to drop inlet temps.

At times, the Golf was almost on 2 wheels through Hall bends.

Then I was given the Black and white flag. A track limits `warning`. Initially I thought it was for taking out a floppy entering hall bends, but when I came in, I was told the rear of the wheel was just catching the floppy on the left on the left hander after this one.

Colin was pretty clear in the briefing, knock over a floppy and the session would be red flagged as the marshalls were under instructions to put them back. The last thing I want to do is cause a Red so I was trying to get close, but not touch them. In this case, I was a little bit TOO close. Matt had been given the same warning, he was doing it through the Gooseneck.

We were checking over the cars after the session and Colin wandered over to check everything was OK and ask how the day was going. He then said “I was also going to give you a telling off for being the first person to get a Black & White, but Matt got it first

Ed was there in his E30 and we had a good lap with Ed, Matt and me following.

I always struggle a little against N/A cars going over the mountain. I have to feather at the crest otherwise it just spins up and that loses boost, taking a moment to rebuild. I`ve since thought it might be worth a light left foot brake instead, but I need to get more finesse with my left foot before attempting that…

Out for another session following Matt. Obviously I had the legs on the straights, but everywhere else we were as close as usual. With the same power to weight, I really don`t think I`d be able to keep up here, he can get on the power that bit earlier than me and it`s more stable under braking. Out data traces are very close to each other although he still carries more speed into corners than I do and is able to hold a slightly higher VMin than me, our exit speeds are similar. I think that`s partly down to how he drives and partly down the the stability and balance of the 328.

I was able to place the Golf accurately on the left before the mountain giving me a really good line through the right hander. I locked up a couple of times on the approach and ran wider but otherwise I could put it just where I wanted

Lizard took his 328 and was piling on the miles. He`d recently had a lot of work done to the car and this was a great test. Nothing amiss and he came away happy.

Lizard and I have often discussed the differences between his E36 328 and Matts. They were out on track together and then Matt let Alex dive for a few laps. Lizard came away with a few things added to the list of stuff to do on his 328…

I was out with Lou and the boost dropped right off, I thought a hose had popped off so came back into the pits for a look. All hoses checked out fine which was odd. Next I checked the actuator arm to the wastegate, that had come loose once before. That was fine too. I don`t think the Actuator should do that though ! The actuator on the Turbo had failed !

I`m guessing the diaphragm has split. It`s a stock part that came with the Turbo and showed no signs of fatigue. It`s just a spring and a diaphragm so they either work or they don`t.

People were saying “Oh, is that the day over ?”

Fortunately, I`d taken a spare Turbo and Actuator…

Changing the Turbo is something I`d only do if we were in Europe for a couple of days, it`s not really worth attempting on a UK day but the Actuator is dead easy to swap.

Unfortunately, everything was Rather HOT ! It`s held on by 2 M8 bolts, but one of them is awkward to get to and even with gloves on, the heat made it difficult. Probably took around 20 minutes to swap and then I was back out again.

The actuator preload on the wastegate was slightly different and midrange was lower than before. I wasn`t about to start tweaking the boost delivery, it was pulling so well I could leave it alone. I did use the wheel mounted `boost button` to check it gave full boost which it did. I`ll modify it before the next outing.

Had a break for lunch. Everyone was just sitting around catching up and enjoying the sunshine. It was almost a shame when the track reopened and we had to go back out. Almost…..

Duncan was out in the MK1 although he had a few small issues, my angle grinder and flapper wheel soon sorted them out and he was able to get some good laps in over the day. Anthony had a few niggles with the EVO, he was struggling to find a copper banjo washer, but I had one in my spares kit and he was soon back out lapping.

Alastair had a weird knocking from the rear, we think it`s an inner CV so his lapping was cut short. A shame as we were about to go out together.

When I fitted the Turbo I said I`d be thrilled if I could keep up with an M3 on acceleration. I didn`t think that was achievable but it would have been nice. I`ve now been on track with plenty E36 and E46 M3`s and the golf is noticeably quicker on the straights. Some friends keep asking why I don`t up the boost, I still run between 0.8 and 1 bar. Basically, I don`t need to. The delivery is so good right now, I don`t want to muck it up. I`ve found a nice sweet spot where it`s fast enough that I don`t want more power (Yet), but manageable enough that I can actually use what I have. give me a couple of years and I might want more but right now I`m really happy with what I have and I know I`m not making the most of what I have.

Coppice felt really stable and yet again I came away thinking I could carry more speed in that I did. Matt was flat through there but we`ve discussed it afterwards. It was something I experience at the ring. If a corner is flat, you just keep it pinned. If you approach too quick and need to slow down, it`s very easy to overbrake and go through with a lower apex speed than when you had less power. I`m slowly addressing that issue but for obvious reasons, I`m doing it incrementally.

Peak GPS speed was 120 before a dab which isn`t bad at all.

Matt had reprogrammed the Raspberry Pi and I`d bought a new EGT Probe. We powered it from the Booster pack so it was completely self contained and logged EGT`s without a problem. I don`t believe I have an issue but wanted to know temps weren`t getting dangerously high on high boost and high revs.

I was running the Pilot Sport Cups and even though they squealed more than slicks it was a good way of testing out the new diff. I had a nice session after lunch with Cat as my passenger. Usually Matt takes the seat but as he was out driving she made the most of it. This lap shows how early I can get on the power and also shows EGT (Exhaust Gas Temp) from the probe placed in the collector just before the Turbo. Peak is around 800 Degrees .

 

The afternoon progressed without issues and I managed to take out a load of passengers. My lines and speeds were very consistent which is always a goal of mine. I want to be able to drive the same lines each lap then when I try something different I know what it`s doing and why, rather than every lap being different which makes comparison and subsequent improvement almost impossible.

There was a Red flag mid afternoon when an Audi TT had an off entering Hall Bends. The driver was OK, but the car had damaged the armco and it took a while for them to repair it. Even after the Red the traffic was fine and everyone drove sensibly.

Some days you come across drivers who are either really aggressive or don`t use their mirrors. Today just wasn`t one of those days. I never came across anyone like that and at appeared nobody else did either.

Final hour and I took Tim out before coming back in for Richard. This is a couple of laps with Tim, not super quick but with a LOT of data overlaid. If you aren`t interesting in looking at the data then you probably won`t enjoy these, but if you are I suspect you`ll watch it, pause it and watch it again to see what the boost, throttle, inlet temps, afr etc are doing.

 

A great session to finish the day and then back in to take Richard out for the last 20 minutes. Seeing the Chequered flag at the end of the day when the car is performing well is always a nice sight. I`ve had some pretty good days this year and Cadwell was another cracker

Loaded up and strapped down, said our goodbyes and had a nice run home. That 2 hour drive gave me time to reflect on the changes I`d made, the brakes and Diff in particular.

Since fitting the 6-Pots, I`ve always had more than enough braking. What I`ve been doing is trying different compounds to get one that I like the feel of and wears well. The Performance Friction 08`s are excellent. Not too sharp on initial application but modulate well. I was going to try some Pagid RSL1`s but then these Project Mu came up. After bedding in, they felt really good. Slightly sharp on first application but then really communicativ. I was able to stand on them but also feel when they were about to lock up.

The big issue was wear. How would they fare against the 08`s or RS-29`s I`d tried before.?

Whilst there are a couple of decent braking zones at Cadwell, pad wear was disappointing and averaged at 150Miles/mm. I really need to see how they fare at the Nurburgring at the end of September before making a conclusion, but at this rate they are no better than the PF08`s. I don`t know if the lack of proper bedding in and cooling down contributed to the wear but I`d hoped for less wear if I`m honest. Fortunately I paid a fraction of what they should cost so even if they wear the same as the PC pads, they are still cheaper but perform just as well.

One thing I had noticed was some high speed vibration. Took the wheels off to investigate and the amount of rubber pickup stuck to the inside of the wheel explained the vibration!

I split open the Actuator when I got home to see what was amiss.

The Diaphragm was intact

The plate on the end of the bar had fractured and dropped off. Obviously a fatigue failure but I don`t know if it was a time related issue or something else. I`ll ensure I have another spare so if it happens again I`ll be OK.

Plate Diff vs ATB.

That was the big question today and results were very interesting. I`ve thought about it a lot since Cadwell and will try to capture my thoughts here.

First lap out and I was driving it just like the Quaife. That made it understeer more. I`ve been driving with a quaife for 8 years and it`s hard to suddenly change the instinctive habits I`d formed. I went into Barn, felt the front washing wide, feathered the throttle and it kept understeering instead of tucking in. I then put my foot on the throttle and it pulled the front in nicely. This was repeatable and if I got onto the power I found the front end bit and pulled the Golf through the corner. If I didn`t apply power it understeered.
I instinctively know how much lock to apply for a corner and how much to unwind to run out to the exit kerbing but I was ending up 1m to 1.5m away from the edge of the track and wasn`t sure why. Then I realised the diff was still pulling the car and I needed to unwind the lock sooner and by a larger amount to allow for the effect of the Diff. It only took a few laps but at times I forgot and didn`t run out wide at the exit of a corner.

When accelerating over bumps the car was much more susceptible to bumps on the tarmac. I could certainly feel the wheel moving around more in my hands when on the power. It wasn`t a big issue but I can see it making it a little bit more exciting in the wet.

I could get onto the power far earlier when going through Mansfield. Where RWD cars could gap me in the past, I was able to keep up with them on exit.

This datalog comparison from Cadwell last year and this year, Pilot Sport Cups both times clearly shows with the BLUE line (Plate Diff), I`m able to keep onto the power and accelerate once past Apex. The RED line is the Quaife and even though I go in slower and get on the power earlier I have to lift to reduce understeer on exit. Once I get on the power I`ve lost 6mph that I never get back and I`m able to carry that down the entire straight.

That datalog alone isn`t as black and white as it appears. Like all data, it can be chosen to reflect what you are trying to prove but it`s the best exit from each day showing what I felt in the car that the Pate Diff enables me to get on the power earlier and keep on it. There are some laps with the plate where I needed to lift but none are as much as the Quaife was.

The Cups overheat after half an hour or so but with the Kaaz I found they didn`t wash out as much when on the power exiting a corner. Mid corner on part throttle was as expected but once on full throttle the diff helped negate the effect of the overheating.

If I went into a corner too fast, getting on the power couldn`t save it, the diff could only do so much. I found this exiting onto Park straight, I`d go in too hot and getting on the power just made it understeer more.

Understanding where getting on the power will help or not is something I think I understand but I`m not 100% sure yet.

Would I go back to the Quaife ? For a dedicated track car, No, I`ll stick with it. For a road car it`s a different issue. The Kaaz clunks and bangs when maneuvering at low speed and would get tiring on the road. It was bad enough in the paddock ! For a road and track car I`d probably stick with an ATB to be honest. The difference isn`t night and day. The plate diff does help get on the power sooner but not by a massive margin.

The next outing is Destination-Nurburgring at the end of September where I hope to get in 2 days of quality lapping. The Golf is ready to go now but I`ll give it a once over just to check nothing is amiss.

Cadwell was one of those days where you look back and wish all trackdays were like that. Courteous drivers, as much lapping as you wanted and ideal conditions with a car that didn`t really miss a beat.