Dec 2017
23Dec
Merry Christmas
20Dec
Fan car
Look at this Aerial Atom Aero-P project! Its pretty insane. A pair of high speed electric fans creates negative lift, through a sealed floor using a rubber skirt. How good would that be? No wings slowing you down through aerodynamic drag. Instead, you've got to try and drag a rubber skirt around, thats being drawn down on to the ground. Hmm, maybe its not so clever after all.https://www.totalsimulation.co.uk/return-fan-car/
19Dec
Diffuser done
I've extended the diffuser, and I'm just waiting for a few more parts to arrive before I start bonding parts together. I tried cutting the carbon sheet I bought earlier in the year, using a slitting saw in the angle grinder, and it cut the carbon leaving a really clean edge. Very impressed. I watched several of the Easy Composites training videos on the cutting and handling of carbon, and they're very informative.I've also read a very interesting paper I found on t'internet, titled, An experimental study of automotive underbody diffusers. It goes to great lengths to explain the results from testing several different designs, from a plane / single channel diffuser, to one with multiple channels (like the one I have), across various angles and ride heights, and I've some more ideas now on how to further increase the downforce, which are all explained in the paper.
In the picture above, you can see I've extended one side. I've used the original splitter plate that was attached to the underside of the diffuser, and created the original two channels. Its been moved to the outside, as it has a 90° edge and is the same profile as the rest of the diffuser. I shall extend the splitter plate downwards, to sit 40mm above the ground, and I shall create a new splitter plate to fit back under the diffuser, to give me three channels each side of the gearbox. The Paper explains the benefits of three channels over two or four, so we'll have to see how much downforce the modification brings.
I'll be adding a splitter plate along the sides of the floor on both sides of the car. This will also need to sit 40mm above the ground, ie along the entire length of the floor, so the splitter plate will help channel the trapped air, through the diffuser. Finally I've a couple more ideas to work out, to increase the air flow even further. Note: 40mm is the minimum ride height allowed in the UK, therefore this applies to the entire underside of the car, when it is static. When it is moving forward, clearly with downforce acting on the car, the car will sit lower, which aids downforce up to a point.
14Dec
Diffuser mods
Over the Christmas Break I'll be extending the width of the rear diffuser from 600mm to 1040mm, which is a 70% increase and should help produce even more down force at the rear of the car. I'll be joining the carbon sheets to the diffuser using 2" carbon tape (CF-TP-50), and (AT30-S-0115) AT30 Epoxy Hardener with (EP-L2-05-A) EL2 Epoxy Laminating Epoxy slow cure epoxy resin, from Easycomposites.
And I've finally managed to draw the shock absorber spacer in Sketchup. Looks simple enough to do, but it needed drawing in a specific order for it to work.
08Dec
Upgrades time
I've fitted both the remaining Bosch potentiometers to the front suspension dampers. Now I can get the wiring started.
I'm getting a pair of 15mm aluminium spacers machined for the rear dampers, to locate the springs further down the damper bodies, which will hopefully prevent them from touching each other. As the suspension is compressed, the rocker arms on the rear suspension rotates the tops of the dampers inwards which is what's causing the interference issue between both the springs. The Eibach 750lb springs are a bit fatter than the 650's I took off, and sit much closer together. [Basically, the Intrax dampers are too large for the gearbox mounts, if Ohlins or some other dampers were fitted, with smaller diameter springs, then we wouldnt have this problem]
Pete Goulding has bought an X-47 hybrid turbo to replace the X-27. He is hoping to see 340BHP, and is now planning on also replacing some of the intercooler pipework. It will be interesting to see if the turbo produces the manufacturers claimed power, as it is supposedly running 1.9bar pressure at peak power, which is 0.7bar more than I'm running, to produce 313BHP. But as a comparison, the SBD EcoBoost is also running 1.9bar to make 350BHP, so maybe there is no getting away from having to run that level of boost, to climb above 320BHP.
Christmas is fast approaching. I really needed to replace my AWS race suit, as I've used it every year since 2002, and it was looking rather tatty. A quick trip over to Grand Prix Racewear at Silverstone last weekend, and I came away with a very snazzy OMP 3-layer race suit, in navy blue, and when I tried it on, it fitted so well, so I'll have to lay off the mince pies over the holidays or I wont be able to fit in to it at Combe in March. I took advantage of their Black Friday 10% discount, and I hope it lasts as long as the AWS one did. At least I now have a spare dry race suit to take wit me, for those weekends where we get rain both days. :D
03Dec
Linear potentiometers fitted
I've fitted two of the linear pots to the rear dampers today. It took a while to work out the easiest way to do this. The pots are only 750mm long, so unfortunately they're shorter than the dampers, hence the little brackets on the rocker arms to attach the pots. I've placed a mounting bracket at the base of the dampers, which is a very solid place to bolt it to, so there'll be no movement or flexing there. I'm looking at using either mini Sure-seal or Deutsch DTM connectors on the loom, I'll make a decision this week and get some ordered.
01Dec
Linear potentiometers wiring conundrum
All the springs are fitted and the car is back on four wheels again. Now I can concentrate on the wiring in the linear sensors for the dampers to record the suspension travel. The Bosch sensors came with short leads fitted with ITT Canon connectors, however I've drawn a blank finding any compatible/cheap sensor loom plugs that can be used to connect them up, so I'll just cut them off and fit 3-pin mini sure-seals.But how to wire them up? There are a pair of pressure sensors used to monitor the front and rear brake pressures, that can be read using Life View. These are located in the front crash box, next to the master cylinders, and both sensors connect to the chassis loom down by the drivers feet. If I unplug the pressure sensors, and instead plug in two of the linear potentiometers, the ECU will show the spring movement, for the bpf and bpr channels.
Another sensor I can sacrifice is the steering wheel angle sensor. So I can run one rear damper sensor cable, to the steering wheel angle sensor input, and again that can be read in Life View. That leaves just one more input to connect the fourth Bosch sensor, and I dont have anything suitable that I can re-use.
This way, the ECU can be used to show several of the sensor movements, without having to get the ECU reprogrammed. Also I only have two spare analogue inputs left on the Syvecs X10 expander, and with the ECU still locked, I'd not be able to read the data off the X10 anyway, so it'd be pointless connecting the sensors up to the X10.
But, the downside of re-purposing these sensors, is that I lose visbility of steering wheel angle and brake pressures, which I need for analysing my performance when on track. So in order to log suspension movement, I'm going to have to look at a 3rd party data logger, and at the moment the AIM Evo4 with Glonas/GPS @10Hz appears to be the best bet. However, I'm then stuck with two sets of logger data, that cant be compared back to back, as they're both totally different systems to one another, and then there's the issue of synchronising the data.... If only the ECU were unlocked and we had full access.
