sf4018

Normally they would let anyone in after signing the usual waiver stuff, but the rules right now require it to be a private event. The organizers are allowing participants to submit a “guest list” and only those on that list are allowed in. Hopefully that’ll change soon!

Hey all, I'll be shaking down my 420R on July 11-12 at Barber, which will be hosted by Chin Track Days. Would be good to see any other sevens on here at the track! :driving: https://chintrackdays.com/event-details.aspx?q=89cmg2TRuyo%3d Cheers! Simon

Which software/cable you gonna use? The one I bought gave me decent real time sensor feedback but error codes were useless.

Congratulations and best of luck squeegee! :auto:

Pokey - going back to post #199 about the 2 mystery wires, I asked Caterham also about this last year. They said it was used for racing 420R cars for the oil tank temperature sender, but was not required otherwise. I guess they have different ECU programs for different applications. But I had the spare sender (as you do) and so I installed it anyway in the hole near the bottom of the oil tank and attached one of the spades to that, for the second spade I drilled a hole in the bottom flare of the tank and bolted on a ground connector. I'll send a pic if you want. I ran the car with it connected and disconnected and couldn't tell any difference in operation, so they are probably right it's not used, but as OCD as I am it just felt better being connected. When I dug into the CANbus I couldn't find it there either, though I got bored somewhat after finding all the good stuff. About idle - my 420R idles at 950-1000RPM, don't know if that's the best RPM for idle but it seems fine to me.

Make sure the line isn’t pinched off somewhere like the LSD or tranny area, or bent sharply somewhere.

Nice progress, much faster than me! Couple of thoughts... Engine Oil - they recommended to me splitting the oil fill between the engine and the tank, split isn't that important. Maybe add 1 litre to the tank just to stop it sucking in air when you first start it? The running level in the tank is quite low so it's not going to damage anything if you over fill a little. Front Wing - +1 on the Sikaflex 521, seems like the right product for the application.

I built a 420R SV with lowered floor last year, I'm 6'5", 215lbs. SV was the right decision for me, lowered floor was essential.

I'm 6'5", 39" waist, I went with SV and lowered floor, and even that is tight!

Looks like it's pretty fixed except for the transmission slots forward/aft. Maybe loosen the engine/transmission mounts, shift the gearbox forward in the slots of the transmission mounts as far as possible then tighten this then the engine mounts? It may give a little more room. Anyways, good luck!

Shouldn't the rubber on the tranny mount be on top? Maybe the pic is misleading.

cardboard and 2x4, very underrated tools. You're really moving along quickly, congrats!

The Caterham is the one which doesn't overheat after lap 4.

I have a spare space in my garage if anybody needs to store the cobra, GT, 911 or Noble :jester:

Has anyone swapped a gas tank out before? Anything I need to get toolwise that's special before I get the tank?

It maybe the trim for the air inlet box, item 4 on page 31 of the assembly guide?

Beautiful car, best of luck to them for putting this out, hope it's a success. Can tell it's built on a Caterham chassis, all that weight on the rear axle and nothing on the front would make it a bit understeery I would imagine?

I suspect the variances of the chassis/wishbone between cars would make it unlikely that 222 would always make 6 degrees, 040 4 degrees, so it's probably a guess for now then see what you get on the alignment machine.

Castor is the "return to center force" for the steering wheel when the wheels are turning. The car is so light that if it's 4 degrees (that they specify) or 6 degrees (that I ended up with after the build and feels fine) it doesn't make a great deal of difference, it's really personal preference as opposed to right and wrong. The angles are set by the # of washers installed on each side the lower wishbone. I ended up doing the standard 2 on each side (check out the explosion on the Caterham Assembly Guide 1.0 pdf page 7.

Thanks Jim. I think you may be right, ATL wasn't very helpful trying to figure out what options were required, so the best way to go may be to buy the first one through Caterham (it only last 5 years after all), keep the s/n then get replacements directly.

Thanks for the info Mike! So it looks like if I buy through Caterham Parts it will be about $4k but I know (or assume) it will have the right stuff. If I can buy from ATL direct it'll be about $2.5k. I called ATL in NJ and they were asking for a serial number since there are so many variations? Does anyone have an ATL tank for a 420R SV or similar that they could share their tank serial number?

The mystery tube is one of the 2 radiator hoses, it runs from the rear of the engine to the radiator. I seem to remember the manual says install it before putting the engine in, but just put it in after. The 3 other hoses are also coolant but they will be chopped up. There should also be a 5/16" hose for coolant which connects to the water expansion bottle - I didn't get this hose either, but it's cheap and readily available so I ended up buying locally just to keep the project moving.

Greg, congrats! No doubt you've found some already but the build blogs from other builders are really useful and have better pictures and explanations than the official manuals. A couple are: https://caterham420rbuild.com/other-caterham-sites/ https://www.purplemeanie.co.uk/index.php/2017/09/23/build-session-17-5-caterham-420r-water-and-oil-overview/ (The diagram John made for plumbing were really useful). I just finished my 420R SV a few months ago so if you need any help let me know! Simon

Hi all, My name is Simon, I'm a first time poster and a bit of a noob with car building, although I'm learning fast! I ordered a 420R SV a couple of years ago, started building in April this year and about finished up last month, although I still have some Winter projects to do. It's basically a "race" spec car, with full roll cage, fire extinguisher, external electrical cut-off, race suspension, etc. Here's a vid of the first track day shakedown... Next May I'm planning on racing it in the HSR series at Barber. I have all the required safeties for the series except for an FIA/FT-3 Fuel Cell. Does anyone have experience or suggestions with fuel cells that might help point me in the right direction? Is the SV tank bigger than a regular? Thanks! Simon