sf4018

Here's the slick list I've compiled so far...I'll add the FF tires to the list. I don't have any R60 experience but if they need to be above 95F to fire up they may not work. The R35s are pretty durable and are considered Softs. Wheel Size Use Type Manufacturer Part # Compound Diameter (in) Diameter (mm) Width Width (mm) Notes 13x6 Track Slick Hoosier 43370 R35B 20.5 519 7.0 177 No longer available 13x8 Track Slick Hoosier 43380 R35B 22.5 570 8.0 203 No longer available 13x6 Track Slick Hoosier 43167 R20/R35B 20 507 7.5 190 13x8 Track Slick Hoosier 43380 R35B 22 557 9.0 228 13x6 Track Slick Goodyear 234776 R255/R470 20.5 519 7.2 182 13x8 Track Slick Goodyear 234777 R255/R470 22.5 570 9.2 233 13x6 Track Slick Avon Historic 7.0/21.0-13 21 532 7.0 177 13x8 Track Slick Avon Historic 8.2/22.0-13 22 557 8.2 208

A7 compound is not available for the 185s according to their documentation...no idea what the logic is for that. I raced with a set of As and Rs a few weeks ago in a SpoecE46, turned out which to run depended on track temperature more than anything, the Rs are very difficult to heat up in cooler weather. But I agree As would make more sense for our light cars.

Hijacking this thread...seeing as Nova is going to be a long time before they get going and my stash of ZZRs have been used up I'm looking for different DOT race tires (not street). The table below shows what I found scouring this forum and the internet with the first couple of lines being the old ZZRs for reference. Does anyone have any knowledge about Hoosier R7 vs. Kumho V70A vs. Toyo R888 as far as cornering performance? The UK supplier was convinced the Kumho V70A are better than the Avon ZZRs anyway, which was surprising to hear. Wheel Size Use Type Manufacturer Part # Compound Diameter (in) Diameter (mm) Width Width (mm) Notes 13x6 Track DOT Avon 185/55R13 EXT ZZR EXT 21.0 533 7.3 185 No longer available 13x8 Track DOT Avon 215/55R13 EXT ZZR EXT 22.3 566 8.5 215 No longer available 13x6 Track DOT Hoosier 46302 R7 21.8 551 7.3 185 13x8 Track DOT Hoosier 46309 R7 21.0 532 8.9 225 13x6 Track DOT Kumho V70A 175/55R13 Medium 20.6 522 6.9 175 13x8 Track DOT Kumho V70A 215/55R13 Medium 22.3 566 8.5 215 13x6 Track DOT Toyo R888 185/60R13 Medium 21.8 551 7.3 185 13x8 Track DOT Toyo R888 225/45R13 Medium 21.0 532 8.9 225

I still have the handbrake setup with the smaller rear pads so not a comparison for your system, but AP pads are fine on it, as they all have been. It's just wear rate I'm fighting, they only last 3-4 weekends, probably due to overheating. You won't have that problem. Could be worth trying a lower friction pad as well to see if that works better for you.

Just to muddy the waters the engine braking can be quite significant on the rears, especially if you aggressively downshift to high revs on corner entry. If you don't heel/toe/rev match on the downshifts it can break the rear tires free briefly.

If they end up buying new equipment that's 2026 before they'll start production .

A 3" gap between the brake and throttle pedals is unbelievable, what were they thinking? I don't have a CSR but I had the same throttle pedal, which I couldn't feel on my foot, so I swapped it out with a Loki pedal and added a heavy duty return spring behind it which made the heel toe a ton easier (the Loki pedal arm did need to be shortened though).

Looks like the sale of Avon's assets happened a few weeks ago to Nova, time is money now so cross fingers things should move quickly.

A turntable

I just got off the phone with Caterham, apparently they used to use the green injectors until they changed the fuel pump to the variable flow setup they sell these days, now it's the black injectors. But he said for my fuel setup (external pump with pressure regulator and return to tank) the greens are better (more fuel, more power).

Ok thanks. I'm going to have to retune anyways (I have a custom SBD tune already in their ECU), so does it matter which injector I get? Not sure what the pros/cons of each are.

Ok thanks for the info @KnifeySpoony and @Croc! I think I’m going to give it a go once Caterham tells me if the Throttle Pot comes with the kit. I believe it should be this one https://caterhamparts.co.uk/throttle-cables/4056-throttle-potentiometer-duratec-and-csr-260.html

Has anyone installed this upgrade kit (or any other kit) from Caterham on a 420R to increase the HP? Engine Upgrade Kit - R400 - 210bhp to 220bhp (caterhamparts.co.uk) How hard is it to put this in?

Well the car made it through the race unscathed except for the lowered floor which I discovered has split open below the drivers seat… …I’ll try again next year. Cross fingers for the weather for y’all this weekend.

Great racing between you guys, tons of fun, congrats. Hopefully the driver at the end there is ok.

Here's the 333 tires in action. They are great.

At Road Atlanta this weekend, some notes so far... 333 is about 4mph faster on corners compared to A64 with similar track temps from yesterday. 333 tire wear seems good which is a surprise. 333 tire pressures rise rapidly - cold pressures were set to 21psi, after 5 laps LR=27psi, RR=26psi, LF=26psi, RF=23psi. This was morning 8:30am, so temps were low, air temp 60F. Will try cold temps set to 19psi. Good feel, very predictable. So far I heart 333s.

We’re your target hot temps 25psi still?

Assuming the car makes it through the HSR race in a few weeks it looks like I’ll be able to make it, will register at the end of the month.

The 4.55V vs 4.62V is only ~120RPM delta, it may be a red herring with the TPS being the problem. There are fuel modifiers in the ECU for Inlet Air Temp and Coolant Temp. Would be worth data collection of all the sensors to see if one of them is jumping around when the issue happens.

No, didn't think I'd need to for a 7 lap sprint race, but you're right it would help some.

I have all 3 compounds - A64/24/333. From my experience so far I would select based on track temperature. Here in the deep south, A24 and 333 compounds basically melt in the heat, but the A64 holds up well. All 3 are poor in the wet, especially if there is standing water, in drying/crossover conditions they are good.

Sure it's not the throttle cable not returning all the way? I had to add a spring to the pedal to make sure it returned, the spring on the baffle alone wasn't strong enough.

Thanks all especially @JohnCh for the suggestions and info, so to summarize these are the options... 1. Rebuild engine with new pistons and other internals. 2. Add Roller Barrels or Throttle Bodies 3. Replace Diff. 4. Entry level 5 psi regulated turbo setup with rising rate regulator, small oil cooler, and no intercooler. e.g. Garrett 6262. I think I'm gonna focus on 2 for now, seems the easiest for my limited skill and tool set.

I’m looking to increase the HP of my standard 420R Duratec 2.0 engine by 20-30 HP to be a little more competitive in a race. I have an unlocked ECU and a fuel system that pushes 60 psi of fuel. The tune is setup rich to better ensure engine life and fuel consumption is not a problem (the tank is ~14 gallons). Does anyone have any suggestions or recommendations?