Lotus Elise S1 Honda Conversion Build

[Mudgey]

If you only use 6th for cruising then I would recommend fitting the Honda TSX 0.659 6th gear, it'll bring the RPM's down by approx. 18%, doesn't sound like a lot but assuming your 6th is currently a 0.78 you should then be looking at 3300rpm or so at the same road speed.

[Will_S]

Mudgey said:

If you only use 6th for cruising then I would recommend fitting the Honda TSX 0.659 6th gear, it'll bring the RPM's down by approx. 18%, doesn't sound like a lot but assuming your 6th is currently a 0.78 you should then be looking at 3300rpm or so at the same road speed.

I built a spreadsheet to calculate all of this the other week, adding ratio data from a few Honda gearboxes, and agree changing 6th to 0.659 would take 6th at 3000rpm from 61mph to 68mph. That should definitely help, as you say.

(To do this I need to take the engine and gearbox out again. Perhaps at this point I supercharge it.)

Maybe the answer would be a 4.39 final drive from a 2.4 Type S (Anyone know if they are directly swappable?) & 6th from that gearbox, added to the UKDM Civic Type R gearbox. Labeled 'Custom' in my spreadsheet:


click to view full size if required

TheRocket said:

Good to see it up and running Will. I know what you mean about short gearing, on an SC car 1st is a bit of a waste of time and 6th is really a bit short too, I actually have a 3.9 F/D to go in my car but never got around to fitting it but I can also understand what Dan says on an N/A car it will be too long. I think Essex Autosport may have had some longer 6th gears made for the k20 but had some problems with them so they never actually used them.

Cheers!

That was my thinking too, that 1st and 6th would be too short when supercharged. Where did you buy the 3.9F/D? PM me if you ever want to sell it. I think my plan is still to supercharge the car. I've seen some of Dan's awesome N/A builds producing upto 300bhp, but I'd prefer to supercharge on the basis that should anything go wrong with the engine, I can replace it with another stock K20 engine. (They'll handle 400bhp stock?) Then bolt the supercharger back on, and be back driving without time/cost of a specialised engine build. Ignoring the main issue of supercharging, which is heat management.

I also prefer the 'normal' type superchargers over a Rotrex type as I like the supercharger whine. The noise my other car makes as a result of the supercharger is intoxicating. I have a spare Eaton M112 supercharger, but this is overkill. How difficult would it be to have a custom inlet manifold made?! Is it just the same as making a custom exhaust, with an attachment for the charger? Otherwise it's a Merc Racing one, maybe with a TVS charger.


Anyway, that's all for the future. Going to enjoy driving and getting to grips with what I've built.

[TheRocket]

Spitfire engineering (http://www.spitfireengineering.com/) had a batch made but I don't think they have any left but worth checking with them, I'm hanging on to mine for now just in case I change my mind and end up keeping my car but will keep in mind and drop you a PM if not.

I do know what you mean about Dan's builds they are very nice and coming from BEC's previously I love the idea of a high revving N/A motor, the SC cars are probably less refined (and definitely heavier with the SC and all it's gubbins) in some respects and heat is an issue, especially for intake temps which pegs them back a fair bit from their full potential, as you say though the induction whine is quite addictive too and in theory the standard engine can take it though mine has upgraded internals for longevity.

Enjoy yours as is for now, SC is there for when you get bored

Edited by TheRocket on Tuesday 28th February 15:08

[Will_S]

Had the alignment checked and adjusted today.



Balast added for my weight in the driver's seat, then the following settings:

Front Toe: 0.5mm Out
Rear Toe: 1.2mm Out (factory spec)
Front Camber: -0.1º (factory spec)*
Rear Camber: -2.25º

This has been a good starting point, and created a nice neutral car. Feels much like my Boxster S, after I'd had it set up by Kenny Brown (in Glasgow). Well balanced, and predictable. A nice long drive with the roof off in the sun this afternoon has confirmed the new settings are a great improvement.

• I'd like the Front Camber to be set to -1.0º, then maybe -1.8º as per the 340R track spec. Unsure if -1.8º is overkill for predominantly road use. From reading on various Lotus forums front negative camber makes the biggest difference. I'll remove some of the shims on the front to increase the negative camber to -1.0º, and have it re-checked (and probably front toe adjusted to bring it back to spec) when I have a few spare hours.

Struggling to get a photo that actually shows what the purple colour looks like. It looks purple, but photographs dark blue or black: