We’ll start this update with the hope that you have all enjoyed a peaceful and relaxed Christmas time.
As the car has remained in the USA and the bulk of the team are in the UK we have all taken the opportunity to take a bit of a breather. After all of the rushing around in the Californian desert in November it’s nice to kick back for a while and reflect on a momentous year
2024 will stand as the most successful year to date.
Bonneville in particular saw the biggest leaps in performance we have ever achieved and even our ‘naughty’ run at El Mirage saw a huge improvement on the previous year’s attempts.
The plan for 2024 always included returning the car to the UK after the El Mirage event. The decision not to was made for us when the ‘Finishing Straight’ Triumph motorcycle engine exploded. Ian G the rider was very keen to try again and has asked us to crew for him in 2025.
If we were going to make the effort to attend the event to help out Ian G, then it makes sense to have one final try at our target top speed.
This is more serendipitous than it first seems
Jensen C-V8 DLN90C was first registered in the UK on the first of March 1965
Making 2025 the 60th birthday of our car. You can’t help but wonder how many sixty year old cars get to spend their anniversary year running the long course at Bonneville Speed Week!
The destuction of the Triumph engine has given us a number of opportunities.
When we built the bike, there was a lot of untried and untested theories. In the event that things had gone badly it would be really difficult to work out why things didn’t work. So, we made the decision to keep the engine internals fairly standard, this would allow us to prove the efficacy of the fuel injection system.
Thankfully, the EFI worked perfectly. Even beyond expectations on every run the ECU tuned itself for better and more efficient performance.
If it weren’t for an ill-timed gear change the bike would have performed admirably.
As we have to rebuild the engine anyway we are planning on a few improvements to the internals of the engine. We will be using very high compression pistons and we are taking the chance to add a twin spark system, this should improve both power and combustion efficiency, hopefully giving us more bang for our buck!
This combined with the now perfected EFI system should see some hopefully impressive performance on our return to Bonneville.
As the car worked so well in 2024 we have only minor plans to improve things for 2025.
The engine is running better than it ever has, so we plan to leave that pretty much alone.
The biggest issue we were experiencing was due to aerodynamic lift at the back of the car over 170 mph. This caused a lack of traction and less predicatable handling above this speed.
We only exceeded 180 mph after we had removed our flat floor. The front of the car was touching the surface which was why we were struggling to get over 175 mph. This time we are modifying the floor and adjusting the suspension to ensure this can’t happen again. The concept of the flat floor was a good one, but the spring rates and suspension setup was all calculated without this extra weight.
Learning from our experiences we also intend to ensure the revised version has more downforce at the back. Hopefully these adaptations will see us with a more stable car at high speed.
