aerobod - near CYYC

I’ve had plated bolts corrode before when using washing-up liquid to ease rubber installation, sodium chloride and citric acid are some of the common ingredients in it. I usually use a rubber lubricant.

Hi Jonathan, It isn't the Brise starter, it is the standard compact one from Caterham, but I can't remember the manufacturer and the sticker is difficult to see with it installed. The ECU has no problem, it shouldn't drop-out unless the voltage drops below 5V for 100ms or so. The sampling interval on the MBE ECU is 83ms, so it typically will capture transients down to about half the sampling interval, or about 40ms. The inrush voltage dropping in to the 7V range for tens of milliseconds is normal, though. Standard car starters can hit 500-1000A briefly. Effectively the battery is short-circuited and the current is only limited by the battery resistance until the motor is fully energised as the motor turns and the stator and rotor windings have opposing voltages established, it then draws of the order of 200A while cranking. A new battery will potentially show a lower voltage than a more "mature" battery that is still in perfect condition, as the internal resistance is lower, so the initial current spike is higher. My 8.5V drop captured with ECU logging is fairly consistent and normal from my review of recent Easimap logs, but if I put my Hantek USB oscilloscope on it, I would expect a bit more of a drop captured due to it's higher sampling rate.

With a brand new battery that has been charged to full capacity before use, the initial voltage before start on my Duratec drops to 8.5V for 80ms, before cranking at 10.5V before starting. The ECU logging captures this, but it is a bit quick to see on a voltmeter.

The recommended tyre temp range of 60C-90C hot would give a cold pressure range at sea level and 20C ambient of 15PSI cold for 90C at 22PSI hot to 22PSI cold for 60C and 27PSI hot.

The repositioning of the air temp sensor worked well. When it was in the backing plate it would be about 45C above ambient with the car idling for 10mins or so, then only slowly drop to 30C above ambient while driving with the engine up to temperature. Moving the sensor so it is actually outside the bonnet but inside the filter protrusion next to the trumpet bellmouth, dropped the temp to 30C above ambient for an extended idle with an up-to-temperature engine, but it drops to about 18C above ambient after a couple of minutes of driving. I think the value now it is quite representative of the average air temperature in the throttle body inlet tract.

I agree with Peter on this, entirely normal based on not just the Caterham, but any non-synchro gear in a car gearbox. If the input shaft is still spinning due to just having moved the car forward, a grind is possible. It also can vary with oil temperature and viscocity which can affect when the shaft stops spinning.

Last weekend when doing the throttle body balancing and adjustment, I noticed the air temp data showed it rising to 60C due to the proximity of the air filter backing plate to the engine. Even with rubber isolation washers and 30 mins of driving around, the temp only dropped down to 48C. I decided today not to be lazy about sorting a better location for the sensor, especially with more mapping and the rolling road session coming up, I want as accurate temperature input as I can get. I picked up some PVC threaded 1” water pipe fittings, machined them to make a suitable stand-off tube and cut a 32mm hole in the air filter backplate: The end plugs were drilled, the one that was shortened for the sensor end, the other slotted to pass the cable through with the minitimer connector left in place. The main body was enlarged inside to allow space for the connector and a spacer was created to optimize the distance from the backing plate: The position is very close to the trumpet inlet, but not too close to affect the bellmouth flow: The PVC should provide good thermal isolation: I’ve recalibrated by Lambda system, updated the maps from data logged last week and fuel data provided by Neil from his engine, created a new target Lambda map that should be close to the needs of this engine and switched on adaptive Lambda. Hopefully I will get at least 200km of moderate load running-in tomorrow to populate the adaptive maps, then more analysis, followed by another few hundred km over the next week or so, before another oil change to synthetic 5w50 for the rolling road session.

The main thing is not to put balance weights close to the inside edge of the rear wheel barrel if your wheel width is such that the deDion ears are inside the wheel. 8" wide wheels certainly have the problem. I normally put 40mm or so wide painters tape around the inside of the barrel in that area with "no weights here" written on it.

Thanks for the emails Neil, I was going to compare them with my logged data tomorrow. The weather would be good for putting some running in km on the car tomorrow, but I don’t want to rush the analysis and also promised that SWMBO and I would go out somewhere, too (but not in the car!). I’m currently set for sequential injection once cam sync is achieved, batch (paired) before sync when the engine starts.

Hi Neil, I can do adaptive tuning with the MBE, but I need to determine if the new Lambda sensor is giving correct results first. I do have a cam sensor fitted, haven’t checked the data yet to see if cam sync was achieved on target.

Still lots of mapping adjustments to do, also need to determine if my new Lambda sensor is faulty as it would suddenly go from rich to maximum lean, but I could still smell excess fuel. Only one small leak requiring the clip on the main hose at the back of the head to be tightened more. After the first start I shut the engine down quickly from what I thought was excessive top-end noise, but it turned out the throttle bodies allow quite a banging noise out of the intake at low throttle openings, probably due to the late valve closing. Took about 5 brief runs for about 20 seconds at a time to fiddle around with the throttle mapping at sites 0 and 1, as it would not rev initially due to being either too rich or lean just off idle. Did the 20 minute initial cam and ring running-in as specified by the manufacturers, then did all the throttle air-flow balancing (only needed to use th3 bleed screw on #4 to make 0.5kg/hr adjustment, setting all to 9kg/hr after setting mechanical idle at 1,200RPM, then re-activating ECU controlled idle to 1,000RPM. Did a 6km brief drive to log some data with medium load up to 4,500RPM. Did the first oil change and cut the oil filter open, a few bits of old RTV debris and tiny specks of what looked to be machining debris. Probably the amount expected, typically like this every couple of filter pleats: The finger filter also trapped a few bits of larger debris: Overall on track, need to have a look at the logs and make adjustments before more road use and the upcoming rolling road session.

Parameter R400 @torque peak R400 @power peak R500A @torque peak R500A @power peak Power output (bhp) 180 210 240 258 Power output (kW) 134 157 179 192 RPM 6300 7600 7165 8200 Torque (Nm) 203 197 238 224 Observed injector time (ms) 12.94 12.50 - - Observed ambient pressure (bar) 0.891 0.889 - - Injector time at standard atmosphere (ms) 14.71 14.25 9.60 9.36 Injector flow at 100% duty (g/min) 172.6 172.6 310.0 310.0 Lambda 0.86 0.82 0.86 0.82 Injector duty cycle (%) 77.2 90.2 57.2 63.9 BSFC (g/kwh) 239 238 239 248 Total air mass flow (g/min) 6651 7407 8857 9432 Volumetric Efficiency @ 40C intake temp(%) 89 87 108 101 Thermal Efficiency (%) 35 35 35 33 Using measured parameters on the old engine and projected parameters on the new engine based on other people's info and projections from the existing engine, this is my best guess at the engine parameters at the moment. My general conclusion is that if BSFC is a little optimistic, then the published Caterham info is over starting the power output of the standard engines (which has generally been the caes). Also, the Caterham peak torque RPM for the R400 plenum engine seems to be a bit low, my previous data logging suggests it should be more like 6,700RPM instead of 6,300RPM, which would change the BSFC to 237g/kWh at that engine speed, logically making the BSFC lower at peak torque than peak power, which is the way it should be.

With Sat being start day, I wanted to just double check the fuel injector timings I had built into the new map. Compared with conventional high output naturally aspirated engines, I keep coming back to what seems to be very efficient BSFC figures for the Duratec in R400/420R and R500 variants. Looking at logs I have taken over the years and checking BSFC at peak specified torque and power, I end up with 235g/kWh at peak torque (with Lambda=0.86) and 240g/kWh at peak power. I’m also adjusting for my altitude with typical 0.88 bar pressure, normalizing back to 1 standard atmosphere. One would expect 250 to 300 as a typical value. I will have to keep a close eye on Lambda values before taking the engine to high loads, but so far all the calculations seem to be lining up.

Radtec should be specific over which blue coolant they recommend. Blue G48 which was the old BMW spec is slightly different to blue G11 old VW spec and quite different than Asian vehicle blue POAT spec.

I've had red (Ford red OAT) coolant in my R400D for 11 years and 39,000km / 24,000 miles. It is stored for 6 months of the year without being started. Still on the original radiator, if not the original engine. Just switching to Ford yellow OAT with the new engine due to the Ford red being discontinued.

I will bond my strengthening strip to the flange as well as the bonnet side to hopefully alleviate both vertical and horizontal cracking.

I would try and buy more to keep the mix at 50/50. You may find that it takes more than 5.1 litres once you have purged all the air from the system. Before starting it is worth elevating the reservoir as high as possible, if you have a heater opening the supply valve, and squeezing the top radiator hose until there is no air coming out of the top radiator bleed screw/bolt, if you have one.

If they supply 5 litres of concentrate as opposed to pre-diluted, it should be enough for 10 litres of coolant at 50/50 mix with distilled or de-ionised water.

I'm planning to replace the steel backing plate behind the hook with a larger and longer aluminium one that is actually a bit thinner (1.6mm), a bit of epoxy on it, too. The issue of adding to the thickness behind the hook is that it is already kept from the proper position by the rivet body that contacts the Dzus fastener for the nosecone. The plate should increase the strength of the bonnet material where the plate is added by about 2.5 times what it is now.

As usual, always another issue to deal with. This time I have noticed cracking where the bottom flange ends on the bonnet due to the fatigue forces on the spring hook. Looks like I need to create a longer backing plate for the hook and put a couple of rivets further back on the bonnet through the extended backing plate, where the flange can add support:

Sounds good using the roll bar instead of the jacking points for tie down to get that extra load on the rear tyres, Neil. I will see what straps they have for the tyres, I'm OK going through the wheel rims if they can't easily fit under the front wings, as that is what I do on my track wheels when the car is on the trailer due to awkward strap angles if I go over the tyres, the scuffing is already well established!

Hi Jonathan, I just checked how much coolant and distilled water I had left in the containers to double check. I certainly used more than 6.0 litres. I’m thinking either the radiator capacities can vary (I have the old style R400D radiator with the M10 bleed bolt in the top), or the Caterham quantities don’t include the amount in the reservoir.

Thanks for that Colin. Without the mapping box, I will be restricted to Live Mapping mode only. I think R79 has a few enhancements over earlier versions to smooth the mapping process, such as colour intensity in the active map indicating the cell that is closest to the engine speed and throttle position, so the injection time or ignition advance can be quickly jogged to the modified value with either the course or fine change keys. One question I don’t know if you can answer (maybe @7 wonders of the world or someone else will also know the best answer) is the best place to tie down the Caterham while on the rolling road. I think the Dynojet 248E is a 2-wheel dynamometer, so I was planning to strap through the stationary front wheels, but other than around the tubes where the strengthening plates for the rear jacking points are, I can’t picture anywhere else to tie the back down to.

9am on the 2nd of May is the appointment time for my rolling road day. Of the 2 rolling road operators who weren’t phased by ECUs they haven’t dealt with before, both having experience of at least 10 different ECU manufacturers, one tapped out today after talking with his friend in Australia who described the MBE ECU as ‘a nightmare to tune, better to swap in a new standalone, mate”. This operator wanted to learn the MBE and do the tuning with his computer gear. The company I picked is not phased by me bringing my computer gear along, then working with me on tuning. They currently have a Dynojet 248E rolling road that is good up to 1200bhp and fairly common here in North America for tuners.

I was on the team that configured the WestJet 787s when working there until 2018, they have the pallet capacity with their daily LHR-YYC flights, a Caterham should just fit on to a PLA pallet, but I don’t know if your allowance would stretch to that size, as it has a capacity up to just over 3 tonnes 😀