What's up with the Caterham engines in AMS2? Will the real 360R please stand up?

Note: All of the following doesn't really take licensing issues, etc. into consideration. But it would repair a few niggling inconsistencies among Caterhams in AMS2.

AMS2 includes four Caterham Sevens, including 3 race-spec models and 1 road model:

Caterham Academy (1.60L; 121HP/158 Nm in AMS2 UI). Open Differential.

• Powered by a 125-HP 1.6L Ford Sigma engine without modifications. Earlier Academy cars had fixed-cam Sigmas, but regulations currently permit only sealed Ford Sigma TiVCT engines. The Academy in Automobilista is identified as having a TiVCT engine, so we can assume the one in AMS2 also has variable camshafts. Caterham Academy models also have a full windscreen and are NOT badged as a 270R, as they are in AMS2. Finally, the 270R factory race series cars have upgraded springs, wider front track, and have their windscreen and lights removed. Therefore, the Academy car in AMS2 should have all 270R badging removed. Academy liveries are badged with "Academy Championship" and have plain dashboards.

Caterham Supersport (2.00L; 122 HP/162 Nm in AMS2 UI). LSD

• The AMS2 UI initially listed the engine displacement of the Supersport as 2.0L (i.e., the Duratec), yet it produces horsepower equivalent to an unmodified 1.6 L Sigma engine. [Note: This displacement error has since been rectified; the UI in AMS2 lists the Supersport as having a 1.6L engine.] 1.6 L + 120ish HP + full roll cage + no headlights + no full windscreen = 270R with Avon ZZS tires and rear swaybar as used in the Caterham 270R Championship. However, the 270R retains the open differential from the Academy, so the Supersport in AMS2 (with its LSD) is definitely not a 270R.

• The Supersport's badging incorrectly identifies itself as a 360R in the showroom and on its dashboard. Among road-going Caterham models, the road-spec 360R is indeed the current replacement for the previous road-spec 2.0L, 180-HP Supersport R. The Supersport in AMS2, however, is definitely not a 360R, but rather it should be a race-spec, Supersport (or 310R) with its 152-hp Ti-VCT Sigma engine and LSD. Caterham often considers the Supersport and its successor, the 310R, as the “sweet spot” in its lineup and one of their favorites. Unfortunately, the UI in the original Automobilista (and AMS2) erroneously places a 120ish-hp Ti-VCT engine in the Supersport. Race-spec Caterham Supersports were initially equipped with the fixed-cam 140-hp 1.5L Sigma while later models received the 152-hp Ti-VCT engine. Given the Ti-VCT listing in the Automobilista UI, the Supersport in AMS2 should be given its proper 152 hp rating.

Caterham Superlight (2.00L; 177 HP/175Nm in AMS2 UI)

• This model also incorrectly identifies itself as a 360R in the showroom and on its dashboard. R300 engine specs combined with a six-speed sequential gearbox were combined to create the Superlight R300-S, the (technically identical) predecessor to today’s 420R race car. Similarly, the current race-spec 420R is badged as a 420R despite its 360R engine specs. In short, Superlight R300 + six-speed Sequential gearbox = R300-S. The only difference is the R300-S Championship cars were shod with Avon ZZS all-season tires, whereas today's 420R gets proprietary Avon racing slicks.

Caterham 620R (2.00L; 300 HP/ 282 Nm in AMS2 UI)

• Powered by a supercharged 2.0L Ford Duratec engine. In 2015, Caterham states this model should have 310 to 315 HP. Close enough.... The 620R in AMS2 is equipped with a standard Caterham roll bar; sadly, the street/trackday 620R is not part of any factory Caterham race series.

To clear up inconsistencies in badging, here are conversions of the four Caterham models in AMS2 (3 race-spec models & 1 road model) into current Caterham nomenclature:

1) Caterham Academy = Academy. It is not a 270R. Why? Full windscreen + headlights = Academy.
2) Caterham Supersport = 310R (almost). It's the LSD that makes the Supersport the predecessor to the 310R. However, there is still a power difference between the 120ish hp listed in the UI and either yesterday's Supersport or today's 310R. While the fixed-cam Supersport yields 140 HP, the variable-valve Supersport/310R is rated at 152 HP, so the 120ish hp figure in both Automobilista and AMS2 is simply too low.
3) Caterham Superlight = 420R. The race-spec Superlight R300 (i.e., R300-S) with the 6-speed sequential gearbox is technically identical to today’s race-spec 420R, minus the the current use of racing slicks.
4) Caterham 620R = No change needed, it's a 620R, which, with its standard roll bar, should be considered a street & trackday car—just don't drive it at night!

 

Really interesting, I've always been slightly confused by our Caterhams, something seemed off on the specs list, but I enjoy driving them too much to care. I wonder if the South American market is different possibly, someone might know the historical reasons behind it.

 

I assume that most of the apparent inconsistency can be attributed to the cars being, for lack of a better word, ported from AMS1. When originally created, its Caterhams were based on race-spec Supersport and Superlight models. More recently, however, Caterham revised their naming structure into 270, 360, 420, etc. (to reflect various power-to-weight ratios), and S vs R trim, for example. As a result, the race-spec AMS1 cars have been shoehorned into AMS2 based on current road-going Caterham nomenclature. It is not my intent whatsoever to blame either Reiza or Caterham for any confusion--for it is confusing. If nothing else, the Caterham inconsistencies in AMS2 presented quite an interesting puzzle to sort out.

 

You sir, know your Caterhams well. I like that

 

Actually, I thought I knew a thing or two about Caterhams until I started finalizing my ideas about this thread. As the saying goes, if you really want to learn something, try teaching it....

Here's a hominid-era schematic illustrating the official Caterham race series, three of which (in bold) are available in AMS2. Evolution from previous-to-current Caterham nomenclature (e.g., from R300-S to 420R) included where appropriate.

 

After finding additional information, I was able to finally sort out the array of Caterhams in AMS2 (see revised posts, above). In brief, ignore most of the dashboard labels in AMS2, as the sim features the Automobilista-era Academy, Supersport, and Superlight R300-S (all in race-spec) as well as the road-spec 620R. Any Caterham badging and/or engine-spec inconsistency in the AMS2 UI stems primarily from muddling the various permutations between road vs. race-spec models and/or “S” vs. “non-S” Supersports and Superlights—which is a very easy thing to do. Overall, Reiza did a great job with the Caterhams; the minor errors pointed out here are primarily with livery and dashboard badging—just minutiae, really. Thanks to @Coldsalmon for driver feedback related to the Supersport. FWIW, my NAMeS mod now includes several revised Caterham AI files to reflect these updates.

 

It's really fun investigating the cars and seeing all of the differences. Caterham has lots of lap data available on their website, and there are videos of the races on YouTube so you can see how the cars handle around the track.

Comparing real life lap times to sim cars is interesting, even if it isn't particularly useful for gauging realism. The Academy is a couple of seconds slower than its real- life times; I think this is due to the tires having a bit too little grip. The Caterham Academy feels a little more grippy in other sims like AC and rF2.

The Supersport's lap times are right in the range of the 270R. This makes sense to me, since it seems to have the specs of a 310R with the 125hp engine of a Roadsport.

Here's the Caterham lap records for comparison to AMS2 time trials: https://cms.caterhamcars.com/wp-content/uploads/2022/10/Caterham-Lap-Records-end-of-2022-season.pdf

 

Thanks for the additional info. Just for the sake of clarification, the Supersport is differentiated from the Academy, Roadsport, and 270R (all of which have an open diff & unmodified 1.6L Sigma engine making around 125 HP) by the presence of its LSD and an upgraded 140-HP 1.6L engine: Camshaft Kit - Sigma 140hp. Its sucessor, the 310R, puts out 152HP thanks to variable-valve (Ti-VCT) technology. Looking over the Championship regs, there are some different exhaust parts on the Supersport/310R to complement the engine upgrade--and the option for a lightened flywheel. Other than the flywheel mod, no other engine changes are permitted, at least for the factory-sanctioned series.