aerobod - near CYYC

To confirm if the wheels have sensors, on BMWs if they have rubber valve stems they don't have sensors. If the valve stem is all metal then the wheel likely has a sensor, unless someone has changed the valve stem to an aftermarket metal one.

It is easier to lift the front first. I use an alloy jack that isn't too wide with a rubber ice-hockey puck between the jack and cruciform to protect the powder coating. The axle stands just fit either side of the jack on my S3, I use slit 1" heater hose on the tops of the axle stands to protect the powder coating when supporting the correct support points on the lateral chassis tube. Once the front is up, I lift the back under the De-Dion a-frame mount and place another pair of axle stands under the rear support points, again using heater hose to protect the powder coating.

Motul RBF 600, if the car is being tracked. Readily available and a reasonable price for the performance. In Canada any track I have been to requires brake fluid to be less than 6 months old, so I just change it before the first track day each year. If changing at least once a year, wet boiling point is not too important, but the dry boiling points are: Comma 4 - 265°C Comma 5.1 - 278°C Motul RBF 600 - 312°C Castrol SRF - 320°C SRF is excellent but is typically more than twice the price of RBF 600.

195/50-15" tyres may fit without adjusting the stays. Here is my R400D with that size of tyre, no rubbing, although I have to tilt the wheel a bit to fit the tyre under the wing when changing it:

There is a standalone barometric pressure sensor for the MBE ECUs that SBD sells. It is not the same as the Ford MAP sensor that is used by Caterham, that can be used outside the plenum or when there isn't a plenum, as a baro sensor. The MBE baro sensor has quite robust terminals and wiring pigtail supplied with it, I've had no issues with the one I fitted to my 9A4 ECU, it transformed the drivability of the car in the 1,000 to 2,000 metre altitude range I typically drive the car at: MBE Standalone Baro Sensor

What I have done with the sensor connectors on my R400D that have enough slack is created a loop from where the wires exit the connector, back to the body of the same connector and then used a tie wrap to hold the wire against the connector. Any vibration of the wire should then be away from the crimp or solder joint stress point.

Glad you got it fixed, another good piece of diagnosis for those troubleshooting in the future.

It is difficult to tell without a wide band lambda reading, as the TPS voltage change would cause a throttle map change and consequent fueling change, which could cause a rev change.

I think it is a bad TPS or wiring to the TPS that is the problem. If you look at 9m21 the TPS voltage goes from zero throttle (4.62V) to about half throttle (2.33V) and back again to zero throttle in less than 100 milli-seconds. There are also other spiky changes in the TPS voltage in other areas, such as here: Perhaps these are extremely rapid throttle blips, but it seems to have the characteristics of a noisy TPS input.

From a logging perspective, I would use automatic logging to collect all common parameters, then have a look at all logged parameters when the "cough" occurs. I think the voltage drop could be the cause or effect of the problem. If the ECU reset counter increments when the cough occurs, the ECU has effectively rebooted for a fraction of a second which can cause the cough, the voltage supply, grounding, ECU issue or disturbance from another source such as an intermittent short of a component could cause the voltage drop that leads to the reset. If there is no ECU reset, the engine speed spikes may be caused by incorrect sensor input under certain conditions, for example the lambda sensor or TPS sensor - this should be evident on the values for those sensors. A voltage spike could cause rapid change in the injector voltage compensation value, causing the cough. I think the correlation of the cough "spikes" across the different logged parameters will tell a lot (all electrical parameters echoing the same spikes at exactly the same time would point to an electrical problem, spikes out of sync from a time perspective would point more to a non-electrical issue).

Hi vertex, do you have an MBE lead and Easimap available? It would be easy to datalog the battery & charging voltage over all conditions if you do.

For those who live in a climate that sometimes requires quite cold starts (below freezing), I can recommend this battery: Yuasa AGM GYZ32HL battery. At 500 CCA and 32Ah capacity, it significantly outperforms the Banner battery, which I had taken to carrying an additional booster pack with in spring and autumn for reliable starts. It also has a reputation for robustness and long life from Harley owners (commonly used as a motorcycle and recreational vehicle starting battery). I paid the equivalent of £145 for it delivered. It is a tight fit in the Banner battery tray depth wise, but is a similar height and a bit narrower, I decided to make myself an exact fit tray and reused the top clamp used on the Banner battery.

Hi John, i don't think altitude affects my plug choice or starting ease to any significant degree since I installed a barometric sensor and swapped the ECU from the Caterham supplied MBE 992 (as it doesn't compensate for altitude with the locked map) to the 9A4 with my own modified map based on one supplied by SBD. - James.

I've tried 6 different plugs in my R400D now, running each for at least 1,000km and come to the conclusion that there is no ideal plug, it depends whether you want the best start and pull from cold or the best high rev hard use plug. The following plugs start on the button in all temperatures above 0C, but tend to melt very slightly on the sharp edges during flat out track use and feel a bit sluggish at high revs, all are heat range 6 on the NGK scale: NGK TR6AP-13, 1.3mm gap (double platinum tipped electrode and ground contact plug) NGK TR6GP, 1.0mm gap (single platinum tipped electrode plug) NGK TR6, 1.0mm gap (copper electrode plug) These plugs all require a smidge of throttle for about 5 seconds when starting a cold engine below about 15C and a bit of nursing for the first 2 minutes of warm up, but feel much better on the track after continuous thrashing, they are all copper centre electrode plugs: Champion RS9YC, 1.1mm gap (6.5 heat range on NGK scale) Autolite AR103, 1.0mm gap (7 heat range on NGK scale) NGK BR7EFS, 0.9mm gap (7 heat range on NGK scale) I've currently gone back to the BR7EFS, as the quality of the Autolite and Champion plug construction seems to be lower than NGK and what I thought was a misfire at low loads with the BR7EFS plugs due to them being a bit "cold", turned out to be a failing coil pack. From a price perspective, most of the plugs cost me CAD$4 to CAD$6 (£2.50 to £3.50) each from local sources such as Canadian Tire (the Halfords of Canada) but the AR103s were $10 (£6) each online and the TR6AP-13s are about CAD$9 (£5.50) each online.

The new coils seem to be running very well, as smooth as the old coils when the car was brand new, but the part number mystery continues. The bags on the new parts indicated 4M5Z-12029B (DG541), but when I took the coils out of the bags the part number printed on them was 4M5E-12A366-AA. They are all brand new and shown as the same fitment as the original 4M5G-12A366-BC, I'm not sure if the parts are revised, older, equivalent or exactly the same with different part numbers printed on them.

My first switch failed in less than 2 years / 12,000km from new, contacts were burnt from arcing. I put in a 30A relay with a rating of 200,000 cycles, it dropped the current to 0.16A from 3.8A through the brake light switch. Just fitted the relay into the pedal box with short pigtails to the switch.

I just received a set of new coils today, I had a spare of the old ones, but the old part seems to have been superseded, so I thought I would put in the new part number across the board, assuming overall enhancement (perhaps a bit of a stretch) as the part has evolved. $38CDN (£23) each for the Ford / Motorcraft part. Original part number was 4M5G-12A366-BC, new one is 4M5Z-12029B (DG541).

Might be a coil pack going out. On my R400D I had a small hiccup in acceleration especially at mid revs and mid throttle, felt almost like turbo lag, just annoying to begin with a year or so ago. The past couple of months it has quickly worsened to the point that the car would sometimes misfire on light throttle after hard acceleration. Checking the plugs would never show any variation between cylinders, they all looked perfect. Also checked and wiggled all wiring in the ignition, TPS, CPS and other sensors with no effect. Once it became repeatable and started to do it at idle, I put an infrared thermometer on the primary exhaust pipes and found that #1 cylinder would cool rapidly while it was misfiring. I swapped the coil pack on #1 and the problem has disappeared.

Or a standardised units pedant would use Joules for stored energy :)

What is the general experience on how long an Acoustafil blanket lasts? I've had mine in for 3 years and 15,000km, the exhaust seems to be a bit noisier than it was. What would be a good repack interval?

In terms of removing the nose cone to check the oil in the tank, I have found that the right sized coin for the dzus fasteners works wonders, enabling the removal without getting down on the ground, just a reach under the nose cone and a twist with a coin, you can soon get used to finding the slot by feel. A Canadian quarter fits exactly, as should a US one. Probably could find a washer for an M12 bolt that fits well too.

If it is the triangular standard Duratec dry sump oil tank, the baffle approximately halfway down the tank has about a 40mm hole in it with a radius on the edge. When the engine is fully up to temperature and idling, the oil should reach the bottom of the radius, 5mm below the baffle surface.

The inherent Duratec resonance centred around 2,500 is normal from my experience due to the balancer shafts being absent in the Caterham implementation. Making sure it doesn't excite other elements in the car to amplify the sound is the trick.

As there has been an ECU change and a difference in behaviour between the two ECUs, I would check that the 'Tacho Setup' in Easimap for the map you are currently using is showing an appropriate 'Tacho Duty Cycle' value for the new ECU (assuming the 'Tacho pulses per Cycle' are correct as the tach is normally showing the correct rev value). 75% is the norm. Also, depending on the current ECU vs the old one, there may be some signal output voltage level differences that may require a pullup or pulldown resistor to get the correct voltage level at the tach. When I switched from the standard 992 ECU to a 9A4, I needed to put a 1K pullup resistor on the speedo feed.

On my R400D, I've only recently found an optimum plug that will run well on track and around town and also start well in cooler temperatures below 10C. I found the NGK BR7EFS very difficult to start when cold. Plugs tried so far: NGK TR6AP-13, 1.3mm gap - original fitment, engine feels flat at high RPM on track NGK TR6GP & TR6, 1.0mm gap - same as TR6AP-13 NGK BR7EFS, 0.9mm gap - hard to start when cold and some low-load fouling Champion RS9YC, 1.2mm gap - generally good, but slight low-load fouling and occasional throttle needed to start Autolite AR103, 1.0mm gap - currently the best compromise for my car, with minimal low-load fouling, but start easily and no issues under high load.