Differential 3.92 -> 3.36

Also changed the diff yesterday from the 3.92:1 to a 3:36:1 I got from a fellow locost builder. This should make the car much more usable with a theoretical top speed close to 140 MPH and improved intermediate gear speeds. Cruising should be more comfortable with 70 MPH being around 2800 RPM in top gear and it should do over 80 MPH in 3rd.

Here are the in-gear theoretical speeds at 5500 engine RPM before and after diff change:


1st3.32129.3 MPH34.2 MPH
2nd2.08746.5 MPH54.3 MPH
3rd1.39669.6 MPH81.2 MPH
4th1.00097.2 MPH113.4 MPH
5th0.833116.7 MPH136.2 MPH

I've given the speeds at 5500 RPM but even with the standard hydraulic valve lifters, it is possible to run to 5800 RPM which pushes theoretical top speed beyond 140 MPH. However, the drag coefficient of the Lotus 7 type car was never great so I'm not sure how fast it will actually go. I'm pretty confident it will go beyond 120 MPH but I wouldn't like to say any more than that...


DVLA Inspection & Registration

As advised by the local DVLA inspector Kenny whilst at my SVA test, I submitted my DVLA paperwork to the DVLA office in West Campbell street in Glasgow. This consisted of a V55/5 and a V627/1 form primarily with the original SVA MAC certificate, certificate of insurance and proof of ID. This allowed Kenny to arrange an inspection appointment with me for 12:40pm on Wednesday at my home. After the inspection I should be able to go to the DVLA office again with my chequebook and get my road tax and numberplate certificate. The good news is that I am off work from Thursday to Monday but the bad news is that the weather is expected to be crap over easter weekend... Surprise surprise...

Okay, so I’ll get wet - big deal...