KnifeySpoony

So I'm still trying to diagnose my part throttle misfire. I went and checked continuity on various things - coils, injectors, sensors, etc. Using the continuity check on my multimeter everything was ok with a BEEP. However I realized that it will beep with anything less than 120ohms. So looking at the actual resistance, I noticed that all of the coil (and I think injector) grounds are consistent at 44ohms. Other various grounds were sub 1ohm. Is this normal?

Any comment on difference between the 333 and the A24 compound? Is the 333 in between the A24 and A64 or is it even softer than the A24? This is what Avon says, which is a little vague, but suggests that the A24 is still softest. Medium Hard (A64) - A Circuit spec compound also ideal for track day or dry weather fast road use. Medium Soft (A24) - Ideal for sprint / hill climb use. Medium Soft - Extreme (333) - A thermally optimised compound specific for circuit use. Developed for no compromise maximum performance and reduced lap times.

Yeah but then you have to change the diff all the time which is a massive ball-ache on these cars lol.

I am trying to troubleshoot an apparent misfire, and apparently this can be caused by a bad coil driver in the ECU (a not uncommon issue it seems). Hoping I can borrow an ECU briefly to test. I have a 420R with roller barrels, but I can save your tune, swap to mine, then swap back using easimap. I am in Newark. EDIT - I have one in my possession thanks to a very generous forumite

Roller barrels?

Do you mean using a noid light (I literally just learned that these exist)? Any of these cheap sets available on Amazon will do I presume - where are there multiple lights in a set - different connectors?

I take credit for these 420 models with the race style nosecone. I ordered my kit with the nosecone in 2020, never having seen one with that feature (although a few had spec'd the 620R nosecone for their 420s). Now we have TWO models with the 420R race nosecone. I consider myself somewhat of a trendsetter...

Thanks all - I'm lazy and I hate wrenching/troubleshooting (although I did build the damned thing), so I try to gather as much information as I can and do the least amount of faffing about. Try to do the easier and/or high probability things first. I think I am going to start with continuity checks on coil wires to ECU and O2 sensor to ECU. I still think that there may be some link to open/closed loop running. I just can't see how the car is doing PRs on track but can barely make it to the track...

The problem did not follow the coil - it stayed with cylinder #4.

Did a trackday at Laguna yesterday - Once again the car was fine on track (new PR actually), however the part throttle issues have deteriorated significantly. It's extremely unpleasant/challenging to drive on the street at this point. It does it even when cold, and doesn't like to rev at all on light throttle in neutral; sputters and coughs bad. I checked the plugs again - they all look fine and all look the same- don't see anything obviously wet - does this mean it's NOT a misfire then? The most rearward cylinder exhaust primary is a little cooler than the other 3 but not cold. While idling (which is smooth, btw), I unplugged each coil plug one by one: the front three cylinders this produces an immediately rougher idle. Unplugging the rear cylinder created no change in idle, however revving is even worse. I swapped coil harness and no change. Swapped coils between 2 cylinders - same behavior. The picture is confusing me more and more... One thing that I noticed is that immediately coming off track with the car very hot, it runs fine around the paddock - However in stop and go traffic on the way home with equivalent water and oil temps, the car was almost undriveable. Any thoughts?

Turn left at alices and go down 84/la honda to the coast for some nice sweepers. Even more fun uphill. For a much tighter (but bumpier) route, turn left on Pescadero rd. TBH I'm mostly up there on a bike; I don't drive much on the street. I just ride a bit then pose at Alice's, do some carspotting for a few hrs.

Coolant level in my 420 fluctuates a bit cold to hot as expected but I am not losing any coolant over time.

Maybe I'll see you guys up around Alice's way.

Needs more sidewall. Gorgeous though.

Oh ok, I had assumed you were loose in the seat. You're talking 3mm, just wear slightly thicker trousers...

I'm slim and pretty much have to wedge myself into the s3 carbon seats. I wonder if you actually have sv seats? Have you measured?

I typically get a little over 6qts out during oil changes. That does leave a bit unaccounted for, but I assume you had a lot of blow by before the rings were seated. More importantly, how much did you have to add back in to get the level you were at before draining?

You said it idles well, but how does it pull under load?

I can't help but think that it will twist somewhat with body roll - but maybe the central Aframe bush is soft enough to deflect that much easily. Maybe I should put a gopro underneath my car and find out. Better to check on a car with soft rear spring though.

If you are really trying to get it that precise, you will need to loosen then retorque all the bush bolts after any ride height adjustments in the future, or even as the car settles initially. I think trying to guess the weight and final ride height of your car at this point is wishful thinking...

In addition to localizing the DeDion tube fore/aft (where rigidity and strength is welcome), doesn't the A frame need to twist as the car rolls? Where the A frame meets the tube, there is no spherical joint- it's rigidly mounted. So it seems the A frame is flexing and thus adding to roll stiffness of the car. Correct me if I'm wrong.

Mine is a 2021 kit so I assume the current race a frame would fit. Perhaps not worth fitting as prevention, I'm not sure. They also have "race" DeDion tubes. I'm not sure how the construction differs on these. Swapping an A frame is very quick. De Dion swap not a huge deal either but have to deal with break lines so not as quick a swap. I do a fair number of days at Sonoma which is quite bumpy and I'm not afraid of curbs, so I'd rather have a small hassle now to prevent a huge off into a wall...

Bumping this, as I just realized that caterham makes a "race" version of the a frame that is brazed apparently. Not sure what makes it stronger. Wondering if anything knows anything about this part and if it's worth upgrading to it for cars that are heavily abused on track. https://caterhamparts.co.uk/a-frames/7849-race-a-frame-brazed.html

why not just wait to torque the appropriate fasteners after the car is complete?

its a reverse McF1