aerobod - near CYYC

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 😀

I'm only about 7,000km and 7 time zones away from you, but if the Caterham can be shipped as luggage from LHR to YYC......😁

Sounds good Colin. I have created 2 pages now, the rolling road page and the monitoring page. the monitoring page will also determine the logging channels when not on the rolling road:

In terms of doing the springs with the head in place, after removing the cams (using a jig to hold the timing sprockets in place to preserve timing) and carefully labelling the bucket tappets for return to the same position, an adapter that screws into the spark plug hole and pressurises the cylinder with compressed air (to about 8 bar) can be used to keep the valves in place. Instead of a conventional ‘C’ clamp style spring compressor. A plate bolted to the cam bearing shell bolt holes with a bolt threaded into it to align with and compress the valve springs is then used. Keeping the piston at TDC and transmission in gear to stop engine rotation will stop the valves dropping in if the air pressure is less than required to stop the valve moving when the keepers are removed. Without using this technique or a modification of it (such as the piston at TDC and waxed string stuffed in the cylinder on top of the piston to keep the valves in place instead of compressed air), an engine out job will be likely be needed, as head removal without removing the timing case is likely difficult, then if it is removed timing has to be redone due to the crankshaft bolt being disturbed.

Checked all the sensor and loaded the latest software and my starting map into the ECU today. I made a number of modifications to the mapping: - Retarded all timing by 4 degrees across most of the ignition map from my R400D settings (Thanks Colin T & John C for input). - Set throttle limits at 0.30V for site 0.0 and 4.52V for site 15.0, scaling the other sites from the original SBD throttle mapping on the R400D to maintain the same mapping curve, which had a range of 1.35V to 4.75V. - Adjusted the coolant sensor mapping. It had been accurate in the 50C and up range, but never very good down below. I looked everywhere for the specific Ford sensor calibration, but couldn't find it. Instead, I used the exponential curve that all thermistors follow, and alterned the constants to fit the temperature points I knew to be good. It came out to R=0.000172*exp^(4750/T), where T is the temperature in Kelvin. This then translates to a voltage mapping of V=5*R/(R+1000) foir the 5V sensor supply voltage and 1000 ohm pull-up resistor in the MBE ECU. The mapping then becomes: Temperature (C) Resistance (Ω) Voltage (V) -30 52,431 4.91 -20 24,235 4.80 -10 11,879 4.61 0 6,135 4.30 10 3,319 3.84 20 1,873 3.26 30 1,098 2.62 40 665 2.00 50 416 1.47 60 268 1.06 70 177 0.75 80 119 0.53 90 82 0.38 100 58 0.27 110 42 0.20 120 30 0.15 I also fitted a new wideband sensor to the LC-1 system and calibrated it. I also ran into a problem where the battery voltage stared to fluctuate a lot, even though it was on a smart charger, with the ignition being on for a couple of hours. What seems to have happened is the battery has started to look tired (7 years old at the moment) or potentially a cell went bad during my calibration session. It would drop over 2V very quickly from 12.8V after being taken off the charger and the ignition switched on. I ended up spending 4 hours pulling all the fuses and relays and testing all circuits as far as possible. The ignition off state is at 0.15A draw and ignition on (including running lights) is at 3.4A, but no obvious issues with any of the circuits. I've put the battery on the "Repair" cycle the charger has. Will order a new battery this week if it won't hold a charge or give the correct voltage when under ignition load. I've created a spiffy new ECU data page for my rolling road session, with related functions ordered in groups:

We ran the Canadian Nationals autoslalom in 2015 where we needed ballast to stay above the minimum weight. Had a 25kg tool set in the boot strapped down with no ill effect with the car on slicks at maximum attack (at least my son had it flat out, winning the open class, I was somewhat slower). I would say higher than 25kg shouldn't be a problem, as long as the total payload isn't above the 300kg limit.

I saw that warning Jonathan, I think overall sticking with the current Ford OAT yellow should be fine. It seems that adding phosphate additives to the coolant is not just something Ford is doing, BMW changed it's longtime blue coolant to dark green about 3 years ago, which also saw phosphate additives as the main change. I have donated my spare 4 litres of 50/50 orange OAT to my son for his Fiesta ST200 track car. Interestingly I managed to squeeze in 6.5 litres of coolant into the Caterham to just reach the MAX mark on the reservoir, a lot more than the 5.1 litres listed in the owners manual for an S3 with heater. This is also cold without starting the engine, but elevating the reservoir, squeezing the main hoses to burp the air out and topping up the radiator via the bleed bolt. I was checking under the car to see if I had a leak 😁

Just replacing the coolant in my R400D, had exhausted my stock of the Ford orange OAT (WSS-M97B44-D/D2 spec) and went to buy more from the dealer. It seems that globally they have superceded it with yellow phosphated OAT (WSS-M97B57-A1/A2 spec, which shouldn’t be confused with the previous “gold” coolant to WSS-M97B51-A1 spec).

I had, but I’m skepticsl about remote optimization of timing without a tuned ear for pinking working directly with the engine. I feel that I can get the fuel mapping as accurate as they can, as I saw considerable improvements over the SBD R400 plenum map by doing my own on-road tuning when I originally bought the 9A4 from them. The people I’ve been talking to are fairly skilled tuners with plenty of high-horsepower European car tuning (one company also has done a number of Bonneville Speed Week Cars). On balance I was thinking it would probably double the rolling road cost by using SBD, but I don’t know if it would be any better result. The tuners I’m talking to have experience with lots of different ECUs and are not phased by an ECU they haven’t worked with before. There may be some MBE experience locally I haven’t found, as there are quite a few Radicals around at the local tracks that would also have an MBE ECU.

Lots of great info there Colin, thanks for that. I’ve talked to 2 rolling road operators so far. They will be learning the software and having to use me for a guide on many features. As I have a wideband system on my car, I’m going to do some prep adjustment at medium loads and 4 degrees of timing retard across the board as you suggest. The timing map is from the R400 map developed by SBD that I used on the engine before upgrade to the R500A spec, so if fairly safe. Both operators are BMW and Porsche tuning specialists, they both advised medium load running-in on the road if possible before a full load rolling road session if the fuel settings and timing are conservative, which should be the case after about 20km of logging (based on my R400 wideband logging and adjustment of the SBD maps on the road originally). I will hopefully pick one of the 2 operators next week, my current favourite downloaded Easimap while I was on the phone with him and I emailed him my current chip and template files. He promised to study the software on the weekend and tell me on Mon if he could do the tuning at a reasonable cost, but he would want to operate Easimap. The other operator said he would look to me to operate Easimap using my laptop and tell me what to change, with a CAD$250 setup fee and about 5 hours of rolling road time for a total of $1000 or so. I was planning to do an accurate alignment of the TPS on the weekend. I’ve currently got the throttle bodies set at 0.05mm open when against the throttle stop, as measured with a feeler gauge. The SBD alignment method is to wind the idle screw fully out (about 3 turns currently), rotate the TPS to read 0.25V, then wind the idle screw in until the TPS is set to 0.30V. The full throttle voltage will then be read and set for throttle site 15.0, before scaling the values at the other sites to give the 0.3V to Vmax range, but I will keep the current curve the same shape between the new limits. I’m also going to check other sensor values, load the latest template file and fit and re-calibrate a new wideband lambda sensor, too. i will need to get the initial startup 20min run at 2,500 to 3,000RPM (with no engine load) finished before throttle body fine tuning, as no idling or rev deviation is allowed during that period, based on Kent and Wossner instructions. The 2ms injector value at 1000RPM and site 0.0 is a scaled value from the old injectors on the R400, but it may be overridden by the idle target electronic control, in the old R400 incarnation it idled smoothly at 1000RPM +/-25RPM with 0.97 to 1.01 lambda. Your technique of switching off the ECU controlled idle to set the mechanical idle high should determine if this needs to be addressed.

As I prepare to start my hybrid R500 Duratec (I'm calling it an R500A - 'A' for Aerobod), I'm trying to finalise the basic fuel and ignition maps to get them as close as possible before the rolling road session and allow me to do the basic ring and cam initial running-in that the manufacturers have sopecific requirements for. With that in mind I have created these maps from an adaption of the original R400 maps and various other sources.and was wondering if anyone has any comparable maps they could share or comments on the values I have set, so that I can refine my initial maps as much as possible. These maps are for Bosch "Green" injectors, part #0-280-155-968 @ 431.1cc(310g)/min @ 3 bar, together with 48mm Jenveys with 90mm trumpets and R500 equivalent cams (Kent D-TEC35). Injector latency map: Throttle voltage to throttle site mapping: Primary fuel map: Primary ignition map:

I’ve seen a steady 60C at. -5C ambient in my R400D oil tank when heading to events on dark spring mornings, but not as low as 41C. With the new R500 equivalent engine build I’ve put in a 12% lower speed water pump pulley to reduce over cooling, besides the lower risk of cavitation.