Just returned from a great weekend at Silverstone. We arrived early Friday morning for a day of testing and having never raced at Silverstone before we had a tall mountain to climb!
The morning was spent both learning the track and getting used to the car and it's new suspension. The engine seemed to be running fine albeit a bit spluttery low down and then after about 17 laps we started suffering bad fuel surge. From a brimmed tank ths was a bit worrying. Either the car was drinking an enormous amount of fuel or there was a more serious problem. Either way, wouldn't get through a race with it like this.
We were sharing a garage with several other Clios and their drivers so the conversations began about what could be causing the issue.
In hindsight we probably should have spent more time investigating on Friday but as one of our main priorities was to learn the circuit we spent the rest of the day just keeping the car brimmed.
We came away from Friday feeling much more confident about the track but slightly unsure about the car. The coughing and spluttering had not improved and this was odd as it hadn't run like that at all on the dyno so I was putting it down to the G forces causing the fueling problem.
Our race wasn't until Sunday so Saturday we had a day to wander the paddock and take in some great racing of a complete assortment of cars from 60s classics through 70s, 80s and 90s and all experiencing the highs and lows that racing brings.
This MG was a mate of mine, on it's first outing after spending £10k on a new engine. This shot was at the end of qualifying but in the race the bottom end expired after 7 laps. He wasn't a happy bunny!
Sunday morning arrived and we made the decision to investigate the fuel surge in more detail. Qualifying wasn't until 11.40 so we had time.
We started by removing the in tank pump, as someone had suggested one of the pipes in it could be split hence drawing in air once the fuel dropped below a certain point.
What we discovered in the tank was quite shocking. Years ago I had fitted Demon Tweeks "easy pour" fuel tank baffles. These are small perforated aluminium balls that are designed to be fed into the tank through the filler neck. (although that would take hours!)
What we found was that they had left thousands of tiny punch squares at the bottom of the tank clearly from the manufacturing process of perforating the aluminium.
How the car ran at all was a miracle. The small swirl pot at the bottom of the pump was packed full of them. (no photo unfortunately as I was in shock!)
So with qualifying looming I had to get my arm in to a tank full of fuel and try and fish out as much as I could.
We swapped the pump for a spare although it was an old one which I had been experimenting with installing a Walboro pump in so I was keeping my fingers crossed!
With everything back together we headed into qualifying.
In quali the car ran nicely for the first 4 laps and I was starting to build up speed until it all of a sudden misfired. As it was on the last bend I was able to peel straight into the pits. The misfire wasn't like the fuel surge and my first thought was coil pack.
With cars flying past and the clock ticking I jumped out and changed the coil pack while Ryan my race partner jumped in to do his stint.
Ryan managed 2 laps before the misfire returned and by then quali had finished.
So we qualified a dissapointing 32nd out of 45 when we knew the times we were doing on Friday should have had us up around 19th or so.
Back in the garage more head scratching ensued.
We decided to clean the original pump and put that back in the tank, checked the inline fuel filter and have another look at the coil pack.
After the tank was done, (with a few more baffles and crap removed) I went about checking the connection on the coil pack. That was when I got a huge shock from it which defintely didn't seem right.
With other friends and racers gathered round someone more experienced than me noticed that the car seemed to drop onto 3 cylinders on idle sporadically. We swapped back to the other coil but it continued to do it. Then, just to be sure he went and got his own spare coilpack. Bingo! it worked thank god.
So we made it to the race and the only unknown was whether we would still be plagued by fuel surge before the end.
Ryan started and in 5 laps was up to 26th. As the pit window opened we brought him in for me to do my stint to the end of the race. Driver change was not the quickest as we hadn't had time to practice with all the other dramas going on and then to make matters worse the car wouldn't restart.
After a push start I got going again but we had dropped back down to 36th and were a lap down.
But despite that, the car was running great. I proceeded to reel in plenty of places and ended up battling with the same 2 or 3 cars until the end of the race. (Only later did I discover that they were a lap ahead!) But we finished in 24th and the fuel surge only started to show itself on the last 2 laps. The suspension needs much more tuning as I was being mugged at the corners by slower cars and then just cruising past them on the straights!
Plenty to do before Oulton on the 2nd June!
