OK, so.. Monday morning was the mapping session, which all started off very nicely.
I enjoyed this view all the way from MK to Track n Road in Rainham..
And then after an hour or so of fiddling to get the starting map sorted, the guys started to work on the low rpm / part throttle stuff.. I was JUST about to take a picture of it all when they called me over to say it wasn't charging very well and it all kinda went downhill from there.
To cut a long story short, the alternator wasn't able to keep the battery topped up during the low speed running, so it drained to the point where the fuel pump could no longer supply enough pressure and they were having to run insane amounts of injector trim to keep it rich enough. The alt is driven 0.9:1 off the crank, so meant for a formula car which never idles and is straight up to >5krpm and stays there!
I've tested the battery voltage, but only when fully charged, so the 13V seemed to be just fine. However, after having the fan running for ~30mins or so the battery was totally dead and even with a booster pack linked up to it the voltage could barely reach 12.4V.
We had a chat for a bit, going over possible fixes, then I loaded it back up and headed home.
Not exactly perfect after all the trouble I've had with the Formula Renault electronics.. it seems that everything electronic that came with the engine is fit for the bin and the car will only be reliable when it's all been replaced!
It's not all bad, though.. after some phone calls I have a Brise alternator (120A) on order with a TINY 25mm pulley, which should drive it at ~2:1 off the crank. I've also got hold of a set of 330cc Pico injectors and a 3 Bar FPR so the pump doesn't have to work quite so hard! This should take care of all the electrical woes, and I've booked another mapping session for next Tuesday so it won't be a long wait!
While the car is back in the workshop, I've also made some changes to the suspension. Seeing as the struts weren't made to drawing (which we're pretty pissed off about actually) the front ride height has been way too high, even though the ride height adjustment is set as low as possible. The only work-around has been to fit softer springs, going from 600lb/in to 450lb/in. I've also had to adjust the rear down from 500lb/in to 400lb/in, and have fitted some spring aids to add a bit of progression in now that the initial rates are quite soft.
This is the bump stop that came with the struts - crap, basically. Literally just something to stop metal-metal contact.
The front now has a 43mm long spring aid and 450lb spring, with an option for 500lb
And the rear has a 68mm spring aid and 400lb spring, now 8" long, with an option for 450lb
The result is much better!
It's still 10mm high at the front, but it was 33mm high before so this is much much better.
Next week is going to be a busy one.. mapping is booked for Tuesday morning, then in the evening it'll be at Brands for a first test, so all digits crossed that the electrical woes are over! Then it'll be doing a full day at Cadwell later in the week. :astonished: