https://trackdaytoy.comA blog about my experiences with a Caterham CSR trackday toy.https://trackdaytoy.com/2026/10/titan-lsd-rebuild.htmlhttps://trackdaytoy.com/2026/10/titan-lsd-rebuild.htmlLast time I was on track, I felt I was struggling with traction when accelerating out of corners. Curiously, much of that grip seemed to return when I ignored my instincts and simply floored the throttle. My…https://trackdaytoy.com/2026/08/a-new-generation.htmlhttps://trackdaytoy.com/2026/08/a-new-generation.htmlSo I ended up as a gokart dad. For some years now, my son and I have been busy competing in karts. Or, he has been competing and I've been wrenching. I drove myself in the beginning but when I realized how…https://trackdaytoy.com/2017/12/brake-pressure-sensor.htmlhttps://trackdaytoy.com/2017/12/brake-pressure-sensor.htmlLogging driver inputs is a way to get quicker, they say. I don't doubt that for a second. For me though, more frequent driving would probably be more effective. But that didn't stop me from putting in another…https://trackdaytoy.com/2017/12/front-suspension-travel-sensors.htmlhttps://trackdaytoy.com/2017/12/front-suspension-travel-sensors.htmlFor a while I've had suspension travel sensors on my rears . Now finally I have sensors on the fronts as well. The rears with 3D printer mounts. Variohm PZ12A 75mm linear position sensors. (100mm on the rears)…https://trackdaytoy.com/2017/03/airbox-static-flow-cfd-analysis.htmlhttps://trackdaytoy.com/2017/03/airbox-static-flow-cfd-analysis.htmlI did back to back testing on a rolling road with and without my Pipercross PX600 airbox. It turned out with the airbox fitted the engine lost almost 20 rear wheel horses! I desperately need to find a new…https://trackdaytoy.com/2017/02/cool-spark-plugs.htmlhttps://trackdaytoy.com/2017/02/cool-spark-plugs.htmlFrom recommendations I've always used NGK BR7EFS spark plugs - with heat range 7. After a rolling road session I was told to use a cooler spark plug as the insulator nose was chalky white all the way up after…https://trackdaytoy.com/2016/12/diy-duratec-balance-shaft-delete.htmlhttps://trackdaytoy.com/2016/12/diy-duratec-balance-shaft-delete.htmlSome Duratec blocks are equipped with a balance shaft . As most sports car owners are more concerned with weight and rotary mass than ride comfort that is something that needs to be removed. A balance shaft…https://trackdaytoy.com/2016/11/vct-delete.htmlhttps://trackdaytoy.com/2016/11/vct-delete.htmlUsing aftermarket cams on a VCT Duratec head requires that the VCT valve is removed. Unfortunately this opens up an oil passage which must be blanked, and doing so without eliminating the oil supply to the no…https://trackdaytoy.com/2016/10/duratec-front-pulleys.htmlhttps://trackdaytoy.com/2016/10/duratec-front-pulleys.htmlSome of the more recent Duratec versions uses a larger front pulley trigger wheel than before. The trigger wheel diameter must match the style of the engine front cover, at least if you plan to use the…https://trackdaytoy.com/2016/03/damper-position-sensors.htmlhttps://trackdaytoy.com/2016/03/damper-position-sensors.htmlI've written before - I have a thing for measuring things. I also have a new set of adjustable Penske dampers and wanted to see how their behaviour changes when turning those adjusters. So, I've bought a pair…https://trackdaytoy.com/2016/01/penske-dampers.htmlhttps://trackdaytoy.com/2016/01/penske-dampers.htmlWhen I bought my car it was equipped with Caterham CSR race spec dampers, non-adjustable Bilsteins. They're now 10 years old and not serviced once, and therefore I now think I finally got an excuse to replace…https://trackdaytoy.com/2015/12/pushrod-strain-gauges.htmlhttps://trackdaytoy.com/2015/12/pushrod-strain-gauges.htmlAs I have a thing for measuring things, this summer I did an attempt to put a strain gauge on one of the push rods. A strain gauge is like a thin film with an embedded wire. You can glue it on objects and when…https://trackdaytoy.com/2015/11/new-lsd-from-titan.htmlhttps://trackdaytoy.com/2015/11/new-lsd-from-titan.htmlMy car was fitted with a limited slip differential when I bought it. I've never known what kind of LSD I had, and I've never had any problems with it. One time long ago I asked Caterham what type it was and…https://trackdaytoy.com/2015/11/rear-wheel-bearings.htmlhttps://trackdaytoy.com/2015/11/rear-wheel-bearings.htmlI was told the bearings had this number printed on it: "4EO 407 625 A SKF BAF-0076 C ITALY A 23 3 3347". Which after some Google magic indicated they originally belong to an Audi A6C6 2,0 T / 2,4 / 3,0. For us…https://trackdaytoy.com/2015/10/unsprung-weight.htmlhttps://trackdaytoy.com/2015/10/unsprung-weight.htmlIn order to get an estimate of the chassis unsprung weight, I weighted some parts. First I tried to put the wheel on a scale with the push rod disconnected but the result was a bit off (~18kg for the fronts).…https://trackdaytoy.com/2015/08/3d-printed-gopro-mount.htmlhttps://trackdaytoy.com/2015/08/3d-printed-gopro-mount.htmlI've tried various generic GoPro mounts over the years but they all have had problems with vibrations and wind in high speeds, and I've always ended up with securing the camera around the roll bar with…https://trackdaytoy.com/2015/08/bronze-bushing.htmlhttps://trackdaytoy.com/2015/08/bronze-bushing.htmlAnother try with the front lower rear a-frame bush. Now in oil filled bronze bush, thrust washers and a custom made crush tube. This solution feels rock solid without any play at all! Ahhh inner peace,…https://trackdaytoy.com/2015/08/3d-printed-moulds-for-polyurethane.htmlhttps://trackdaytoy.com/2015/08/3d-printed-moulds-for-polyurethane.htmlFor a couple of years ago I bought Powerflex polyurethane bushes and replaced the rubber bushes in the front suspension. I was never really satisfied with the small bush in the lower rear a-arm as it felt like…https://trackdaytoy.com/2015/07/bad-earth-troubleshooting.htmlhttps://trackdaytoy.com/2015/07/bad-earth-troubleshooting.htmlMy engine has been a bit "moody" when idling. It can idle smooth, and then suddenly change idling speed. Some of the dash gauges has also been flickering a bit. It haven't bothered me much but today I took my…https://trackdaytoy.com/2015/07/custom-moulded-ear-plugs.htmlhttps://trackdaytoy.com/2015/07/custom-moulded-ear-plugs.htmlI hate ear plugs. The sensation of being inside a bubble playing a video game has got me avoid them except when using power tools in the garage. I ride a motorbike to work everyday, and now when I'm getting…