So,
At this point, I'm sure I'm expected to say something about the changes I've made over winter. most namely, the big change to the Emerald K6 ECU.
This would be the first time it was used on track - we were excited to see how it went!
Dad drove the sighting laps, to help him get a feel for the car and track again. Sighting laps are slow laps in procession, so nothing strenuous. Just getting a feel for the car and track again.
With the sighting laps done, I jumped in for the first session when the track went green.
Low boost, A048's, and I headed out.
All felt good on the opening lap, so I upped the pace a little.
The car felt good, but around half way round my second lap I was confronted with something I've only seen once before on track - my EGT warning alarm
BRIGHT BLUE Light!
Hmmmmmmmmmmmmmmmm, not ideal. The alarm only goes off when the probe reads a sustained 900 or higher for more than 10 seconds.
I backed off and came into the pits, and the peak recall function showed we had seen a peak EGT of 931 degrees.
Feck
Now, what's changed?
On reflection, quite a lot, and it should have been expected.
On the old setup:
Boost at the top end was 17-18 psi - not huge.
AFR at the top end was nearly as low as 10:1 - LOTS of fuel cooling - too much really. Killing power.
Timing on the old map was 25 degrees - lots of advance means cooler EGT's.
On the new map:
Boost at the top end is 22psi - quite a bit more boost = more heat
AFR at the top end was around 11.8:1 - Still a nice safe rich for track use, but nowhere near as much unburnt fuel doing cooling duties.
Timing on the new map was around 20 degrees - Bill wanted the setup to be 100% safe, and was hearing early signs of Knock beyond 20 degrees on the dyno.
So - the new map is excellent. it's much better to drive, on road and on track, but through being more efficient it's highlighting the limits of the setup when pushed to the max - it simply runs too hot.
I had the choice of risk it running hot, or get the laptop out and make some changes myself to see if I could bring temps down.
This is the beauty of standalone - changes are so easy to make and test immediately.
First up, I upped the fuelling to bring AFR down to around 11:1, and I added a cheeky 2 degrees of timing.
I've got the knock light installed now, so I'm able to listen for knock and know if I'm pushing timing too far.
We headed out with the new maps loaded on, and started building up pace. I was happy to report that no EGT warning light came on, and EGT's seemed to hover around the high 800's. Peaking at 898 that session.
Despite adding 2 degrees of timing, I still had no knock showing on the KnockLink, so I decided to be brave and added another 2 degrees of timing for the next session, bringing it up to 24 degrees in total. I also took 4% off the top end boost duty to give the turbo a tiny bit of a break at the very top end. This lowered peak boost to around 21psi from a previous 22.5.
I headed back out, and to my delight EGT's were now down into the ~860 range, which is pretty much where they used to be on the old ECU. I had a VERY occasional flicker from the knock light at around 6800 rpm, but not every time, and very much not sustained, just a single flash once a lap or so.
I'm aware that ~860 in the DP is still hot, but it's around the temp it's run at for the last 3 years, so I'm happy to be back in familiar territory.
With that sorted, and a few sessions under our belt, it was time to make the change to slicks.
The A048's are good - very good. In terms of lap times there isn't a huge difference to the slicks, but there's something about the way the car turns in and feels on slicks that just makes everything else feel rubbish.
We headed out onto the track to get the slicks up to temp:
BigAl as passenger here looking as cool as ever
