GTP/GR-C Lap time comparisions

So there has been some drama in regards to the Group C Class and the pace of some of the cars vs real life. I wanted to compile the laptimes of the C9 Sauber at varous tracks both IRL and in the Time trial mode in AMS 2.

1. Why the C9?
Both IRL and within AMS 2, the C9 Sauber was known for being a massively overpowered and overengineered racing car, often domanating events until a accdent, poor pit stratagy, or a mechanical malady took the car out of competition. As such, Reiza has confirmed that they have gently BOP'ed the other Group C cars in order to make sure they can complete in shorter distance races and in online competition.

Therefore, the Lap Times of the C9 is paramount for the class.

2. Why Time Trial Mode?
Austin Ogonoski in the video that stired up this controversy, was done using Time Trial mode, which gives the best possible conditions for the car and track.

Spa
IRL
A C9 Sauber took pole in 1987, with a time of 2:04
Spa 1000 Kilometres 1987 - Photo Gallery - Racing Sports Cars

AMS 2
The world record for the 1992 Layout of Spa, with the C9 Sauber, (as of time of writing), is 2:00.7, about 4 seconds faster with a track in perfect condition

Monza
IRL
A C9 Sauber took pole position at the Monza 1000km with a laptime of 1:31
Monza 1000 Kilometres 1988 - Photo Gallery - Racing Sports Cars

AMS 2
The world record for the 1991 layout of Monza, with the C9 Sauber low downforce model, (as of time of writing), is 1:29.7, about 2 seconds faster with a track in perfect condition

Brands Hatch
IRL
A C9 Sauber took pole in the 1988 , with a time of 1:14 (Note, they're might have been a extra chicane on this layout, someone please confirm?)
Brands Hatch 1000 Kilometres 1988 - Photo Gallery - Racing Sports Cars

AMS 2
The world record for the Brands Hatch GP course with the GTP Corvette, clocks in with a 1:14.3 beating out a C9 Sauber with a 1:14.5
Even if there is a Chicane on the IRL layout vs the AMS 2 layout, we're still well within the expected range of a sim vs IRL laptime

I hope you're seeing a pattern here, at the tracks the C9 actually raced at, the laptimes are very very close, and well within what I would call acceptable tolerances given the AMS 2 laps are under perfect conditions.

Just for fun, I decided to compare the highest placing 962 aswell...
Spa 962
IRL 2:06
AMS 2 2:01

Monza 962
IRL 1:32
AMS 2 1:31

Brands Hatch 962
IRL 1:16.3
AMS 2 1:15.2

Clearly, the Group C cars are well within acceptable ranges, the only odd man out is the corvette, which again, was BOP'ed to meet Group C speed so it wouldn't have to be in a class by itself, so that's somewhat expected. Hopefully in the future, Reiza brings us some more GTP cars, and then we can seperate the classes to bring them closer in line with their IRL counterparts.

 

I mean I appreciate the effort... And you did your research unlike that youtuber who chose a car in GTP BOP IRL vs a car in Group C BOP in AMS2...

But these cars never ran in an era when the track was close to "perfect conditions" and all the other argument ending reasons why cars are faster in sims than in real life... A little more emphasis on those perfect conditions and how they only came closest to it at the end of a race where no engines blew up or major accidents happened dragging dust onto the track... Might help those stuck on the numbers understand...

Completely agree about more Group C and GTP cars... It would be nice if Reiza could allow people to choose from a few physics options for each car... Such as the Low Downforce and High Downforce versions... But with a BOP'd option for both as well for league races that want a close field...

Finally let me introduce you to racingcircuits.info...

Brands Hatch

Sheens or Dingle Dell Corner as it was known was indeed a fast chicane rather than the corner we have in AMS2 from 1988-2002... Without the chicane in 1987 the fastest 962C in qualy was a 1:15.0... It is worth noting though that Graham Hill bend and Westfield were faster corners...

 

To be honest the corvette gtp is simply too fast compared to 962 in AMS2. Eg. at Daytona the corvette is more than 3'' faster per lap. I know that the 962 LH was not the real version that raced Daytona (thanks Reiza for that unnecessary choice) but it does not make sense to have a so fast gtp. It is the same situation of 962 vs Nissan gtp in pcars2, but this is the corvette not the Nissan! A similar problem is between 962 and C9: I know that C9 was faster than 962, but 2-4" per lap in various track is too much.
A bit of bop is needed, otherwise multiclass grids are nonsense.

 

The problem begins when you give room to that YouTuber's comments. He wants to stir the pot with a non argument, as usual, and knows little of what he's talking about. Not the first time he straight out lies, and won't be the last.

Always remember that Reiza is not paying YouTubers to promote stuff, unlike other studios.

 

I also think that if the GTP was bumped up to meet Group C performance the 962 could be bumped up a bit, in the races it's like they are in a lower class.

 

GTP is faster than Group C by default due to the different rulesets, going for an older GTP is the only chance of having parity, otherwise there is no chance, any works GTP from 1988 and onwards will run circles around the best Group C cars (before the 1991 rule changes that is, which brings them closer again).

There is also the fact that Group C ran under a strict fuel limit, something you cannot easily implement on AMS2. I have not done enough testing, but the Corvette should swallow way more fuel, because IMSA did not have such limits and therefor could aim for more downforce and power, while Group Cs were based on efficiency in all fronts.

I do agree that maybe a bit of BoP is needed, as C9 rules the roost, but on longer races things should be more even than what Time Trials show atm.

 

And I was thinking Group C were faster, it's the other way around then.

 

Mainly because of the Nissan VS Jaguar rivalry, which had a 800hp NA Jag vs a 1200 HP Turbo Nissan as the stars of the show. Laptimes plummeted, and then the Toyota came on the scene at the very end...

 

Is there any good reading or youtube channel I can get to know more of GTP and GTO history?

 

Almost all of the races from that era are on YouTube, but not really? Like Indycar, the history of IMSA is dominated by "the thing" that happened. Indycar being the split, and Imsa being almost exclusively used by drug smugglers.

 

Yeah I noticed it's kindda all over the place... I can find some short videos about one car or another but not something about the begining to end of GTP. I've watched a couple of GTP races in the IMSA youtube channel though.

 

mulsannescorner.com has all kinds of technical information on prototypes of various eras. There are various books about gtp racing, unfortunately most are out of print and even used copies are very expensive.

 

+1000 bhp were not a thing anymore after 1987 restrictor rules. But it somehow made them faster as some cars (specially the Nissan) became much more effective in putting the power down to the tarmac. It took them several years, but after it became the car to beat in 1988, the series turned into a brutal arms race between works teams, and privateers (together with the mentioned drug smugglers) were left in the dust. Budgets skyrocketed and the class died by 1992.

They were truly marvelous both from technology, perfomance and brutality points of view. The ultimate example of the GTP class, the Toyota Eagle Mark III, has a strong case of being the fastest road course racecar in the world by 1992. Yes, including the Williams FW14b.

 

I don't think low fuel rules are used for 962 in ams2. At Daytona with 2h20' races, the stints for corvette and 962 are almost the same, so you got about 2' of gap at the end of the race. Please also consider that imsa spec 962 just based on lack of fuel restrictions: 962 got a bit some more downforce in some late version (eg the Busby one), but nothing of incredible. In fact was slower of next gen gtp as Nissan or Eagle, but faster of corvette . The corvette was quite always beaten by 962 in real races and qualify.

 

I agree, the differences are neglectable and the smaller and the more twisty the circuits are the more it evens itself out. I'd say we need one more Group C racer, anything really, maybe the Jag or Nissan R90, even one of the late Group C cars, that'd be fantastic, and of course we need the ZX-Turbo and the Mustang and the Eagle. Seriously, we need that front-engined Mustang One can dream.

 

The 962 was not a consistent challenger against top GTPs because it was still a car that worked best in more streamlined tracks (hence why it did well at Daytona on debut), but on twistier and bumpier places like the many street circuits that featured on IMSA calendar, it was lacking. It wasn't until Andial reworked the engine and Holbert came up with the required chassis and bodywork modifications, that became the car to beat. And that transition took a full year.

What you have in AMS2 is a 962C in WSPC '87 spec, with a tank limited to 100 litres instead of the 120 litres permitted by IMSA, and a bodywork based on maximum efficiency (based on a concept that by then was 6 years old) instead of having double plane rear wing and diveplanes, like the best 962s at the other side of the pond had.

On these conditions, I expect for the GTP to always have the upper hand if you cannot introduce any sort of fuel quota rules. Which would be unfair on the Corvette ofc, because in all fairness, IMSA GTP cars should have their own class, not share it with Group C machinery.

BoP is a thing to do, as it is already fantasy enough to have these cars racing one against the other. Or maybe Reiza should separate the GTPs and create a 962 IMSA 85 spec to race against the Vette. And throw in a March-BMW!

 

I agree with you, the best way should be a 962 imsa spec, but I still think that 962 performance is worse than expected. If you check some qualifications times of 962 in non-le mans tracks, you notice a gap about 0.5-1.8'' to mercs C9 (just in a couple of races you got 3", but there are also some races in which 962 was faster). In Ams2 I tried 6 different European track and the gap was about 3", that destroy any challenge withing group c.

 

Yes, C9 was state of the art and pretty much unbeatable from 1989 and onwards. If I had the power, I would force the C9 to use more fuel and implement a fuel quota so it's a fair match in races. Implementing a BoP means speeding up the 962 or slowing down the C9 in more unrealistic terms.

Edit: We are racing a fully evolved 1989 C9 against a 1987 962. It will never be a fair fight.

 

Yo

You are exagerating quite a bit here.

First, you forget (or ignore) that GTP was heavely BOPed in engine and weight. The 962 that ran in IMSA was single turbo, and heavier than the group C one. IMSA GTP had an aero edge, specially in the later years, because they were not so limited by regulations in this, but group C was totally free engine wise, being the fuel in the race the only limiting factor. It's no wonder that the IMSA XJR-9 had a smaller engine, and was slightly heavier than the Group C counterpart, and still beat various times the mighty Nissan for poles in 1988.

In 1992, the Jaguar XJR-14 was faster than the Eagle toyota before it was boped, and mighty as the Jag was ,it wasnt faster than the williams. Faster than much of the F1 grid yes, but still seconds slower than the Williams FW14B. The eagle was quicker than indycars though, at least in small twisty tracks.

All this to say that yes, that Corvette is way too fast in game, and it would need to be seriously boped UP to keep up even with the group C 962, not down.

 

I would not call sliding weight scales based on engine size BoP, but yes, they were a thing. I will be honest and say that I cannot recall how much heavier the 962 was at IMSA compared to WSPC.

The Jaguar was not BoPed, the Eagle went 3 secs faster from 1991 to 1992. The Jag still had the lowest weight of the field due to the aspirated engines having a much lower sliding scaled compared to turbos. Jaguar then came with the XJR16 and still could not beat Toyota, its engine being so much more powerful that it could negate all weight disadvantages.

My theory (and I admit I don't have enough proof, it's more of a gut feeling) is that the Eagle Mk III was faster than the Pug 905 due to sheer downforce and roughly 150 HP power advantage. And the 905 on its last 1992 outing it qualified at just over a second above the FW14b's pole at Magny Cours.

Back to the Corvette GTP, even if I am maybe overstimating things, the downforce and power/torque advantage due to no fuel limit cannot be understated. Yes, Group C was free on engines, but the whole bodywork and engine electronics tuning was based on fuel limits, and more perfomance could be unlocked out of it, and the modelling in sim is based around how it was designed and programmed to race in Group C. Even if you then race it without fuel limits.

The Corvette GTP was unreliable and inconsistent. But when well tuned and holding up, it was not slow, and it actually won races. Those real life disadvantages will be always mellowed down in a commercial simracing title.

Nice to see you getting involved in the discussion Richard, really appreciate all your knowledge on historic racing, sincerely