sf4018

Hoosier F2000s were the best for me, fit perfectly.

Just my 5c about the Hoosier R7/A7s...I raced with R7 on a much heavier car but the air temp was 58F - I couldn't get them fired up. Spring time in Georgia they were great. Conversely the A7s melted after 2 laps in the Georgia heat. Point is the ambient and track temp is as big a factor, not just car weight. I won a SVRA race last summer on R7s in the Caterham 420R at Summit Point, they worked great, just ~0.5 slower than some F2000 grooved slicks (R35) I used for qualifying. My 420R is now retired from racing and is converted back to a street car, so I have the R7 set for sale if anyone is interested

This set will be perfect for track days or race sessions. The tires have been scrubbed for 30 minutes from new in the summer. 2 Fronts: used 13x6” Silver Apollo Wheels. Tires - Hoosier R7 185/60ZR13. 2 Rears: used 13x8” Silver Apollo Wheels. Tires - Hoosier R7 225/45ZR13. 4 x 108mm (4.25”) PCD (fits 2018 Caterham 420R). Set is balanced. These tires are track only, not street legal. The tires are about 2 years old. I can include 2 x 0.25" wheel spacers for the fronts if desired - it was needed on my 420R to clear the cycle wings, though your car may not need this. Wheels are 2 years old and have had a few sets on them prior to these, they are in good condition but not new, most of the wear and tear is on the inside rim not the outside. ZIP is 35213. Make me an offer.

I had to lookup what R117 compliance is - turns out the UN is now getting involved in tire specifications for the EU, as if the EU didn't already have enough regulation.

The problem with the fuel pump module is it's guessing the amount of fuel needed, there's no feedback loop to correct any changes in fuel quality, fuel pump efficiency, etc. I had the same problem as you some years ago on track before the FIA fuel tank/ECU changeout project. I believe the racing 420Rs use an always on external fuel pump with return to tank through a pressure valve, which I basically copied. That said if you don't want to change out the fuel system I reckon swapping out the fuel pump would be a good first step as Croc and MV8 have alluded to. Maybe the pump has lost just a few percent of pumping efficiency but maybe that's enough to send it over the edge on this flaky system.

Correct.

This set will be perfect for a racer who needs a backup set for rainy qualifying or race sessions. 2 Fronts: used 13x6” Black Apollo Wheels. Tires unused Hoosier W2 185/65R13. 2 Rears: used 13x8” Black Apollo Wheels. Tires unused Hoosier W2 205/60/R13. 4 x 108mm (4.25”) PCD. Set is balanced. These tires are track only, not street legal. The tires are about 2 years old. Wheels are 4 years old and have had a few sets on them prior to these, they are in good condition but not new. ZIP is 35213. Make me an offer.

Purchased in 2022, used for 3 years, but no longer needed. Part number 380X0006A. It works great, has some imperfections of the polished chrome as shown in the picture but otherwise normal condition. For reference the new part is this. https://caterhamparts.co.uk/silencers/6839-exhaust-silencer-7-duratec-side-exit-polished.html?search_query=380X0006A. New price is $740 + whatever import duty is applicable. asking $290 obo + shipping. Current ZIP is 35213.

I had a series of blown coils a few months ago - turned out to be a frayed wire on the ECU harness where the harness rubbed occasionally against the drivetrain below. The frayed wire was for coil #1. For some reason that occasional grounding out caused the coil to blow (I went through 4 coils in one weekend before figuring it out). I repaired and zip tied the harness to make sure it doesn't touch anything, didn't have any more issues after. It may be worth checking out the loom wiring for wear.

I've a had an engine loom wire that fed to a coil fray and fail due to rubbing of the harness on the engine, it was really hard to find since it was intermittent and also underneath the loom. I would verify the loom is in good shape physically and electrically between the coil and ECU. Maybe you've done that already.

Try bleeding the brakes and see if any bubbles come out, maybe the fluid is boiling. If so, check the specs for your brake fluid. The fluid I use has a boiling point of 310C for racing. If you have a handbrake check the rear pads for wear, that may be another reason for drop in fluid level, the standard rear pads wear super fast on track.

No, should not need to do anything with the prop or diff. Verify Your angles and clearance under the chassis is sufficient though. You’ll need to take the starter motor off the front left of the engine. It is close though.

Pull the engine with transmission attached, the disconnect will be between the back of the gearbox and driveshaft. I know it feels like you'll be undoing months of work but it's not as bad as you think, about 4 hours. Most of it is draining and pulling out the hoses.

The 1/4" spacers did the trick. I could only get slotted spacers at the local parts store so centering was a rough guess and there was some vibration but it was ok. But the 5 race laps I put in the R7s seemed good, held up to the intense heat (95F) well. It held up better than I did, I pitted after 5 laps as the mustang in front was dropping oil, I was completely covered in oil by the time I came in and about to pass out from the heat.

R7 update: It takes 100 clicks on the fronts to get the correct rake (due to the very narrow rears), but there's enough ride height to get by without having to lower the rear suspension, so that's good. The bad news is I need to add 1/4" spacers on the fronts, there was a significant amount of tire rub on the corners with the wingstays.