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:

 

GearRatioBeforeNow
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...

 

Back In Action!

/

Hi Folks, Well, it's been over a year since my last update and a lot has happened in that time. Sadly most of this has had nothing to do with the car and much to do with moving house...

Anyway, having moved house back in August last year and having converted my new garage from a dark dungeon with one power point and one 60 Watt bulb into a lined garage with 5 fluorescent tubes and numerous powerpoint, we are ready to get back to work!!!

Progress in recent weeks:

1. Reconditioned driveshafts using driveshaft boot kits sourced from MNR. Also bought new rear hub nuts from MNR.

2. Tidied up wiring loom at the back of the car in readiness for fuel tank fitment. This mainly involved fitting rivets in the middle of my self adhesive harness clips since I understand that the SVA inspector will insist on mechanical attachment and not just self-adhesive.

3. Designed and ordered fuel tank from Allyfab.co.uk (should be delivered w/b 27/03/06)

4. Added clips to wiring and fuel pipes in tunnel before fitting propshaft.

5. Fitted propshaft which was originally bought ages ago from http://www.autopropuk.co.uk/

6. Sourced propshaft retaining bolts (diff end) from burtonpower.com (M10 x 1.00mm x 18mm set screw - 10.9 grade)

7. Sourced Mikalor stainless steel exhaust clamps (SVA friendly) from burtonpower

8. Sourced M8x50mm socket cap bolts from Namrick to secure driveshafts to differential.

9. Ordered ITG air filters from Steve Turner of Turner Automotive Design Ltd to suit my HIF6 SU carbs.

10. Sourced stub stack rampipes to suit my ITG air filters from Calver Special Tuning. (see Calver Special Tuning) These are the most beautiful stub stack ram pipes I have ever seen. It's just a shame I need to cover them up with my air filter since they are a work of art. I will post a photo when I get a chance. Keith Calver is a nice genuine guy to deal with!

11. Started looking at how on earth I'm going to hide my SU carbs and air filters! I think I have a plan though and will post some pics when I get a chance.