WRC engines

Please discuss here all your remarks and pose your questions about all racing series, except Formula One. Both technical and other questions about GP2, Touring cars, IRL, LMS, ...
Joined: Sun Dec 21, 2003 5:22 pm
Location: Monza, Italy


manchild wrote: So if the WRC cars with some 300-350 HP can afford to go 250 km/h without spoiling acceleration than why couldn't gr.B cars with 600-650 HP make average of 200 km/h?
As a start the Lancia S4 didn’t have 600 hp, but in the order of 450hp. Then these 4WD transmissions had very low efficiency (remember that 4WD means 3 differentials sucking power + obviously the gearbox) and in the order of 30%, if not more, was lost well before reaching the wheels, so we are talking about 320-330 hp at the wheels, being optimist. That still more than what a current WRC has, again at the wheels, but not by much because the initial deficit, at the crankshaft, is vastly reduced thanks to the lot more efficient current transmissions.
Lower weight still allows the Group B to win in straight line acceleration but the power advantage isn’t probably enough to balance the poor aero and beat a current WRC top speed. I would be surprised if an S4 could touch 230 km/h actually.
Anyway I focused on top speed because it’s the easiest way to see it, if top speed is 230 it’s plain to see that average speed can’t be 200.
But even if top speed was lot higher that would mean nothing, the FXX top speed, electronically limited, is 345 still it, with 800 hp, weight 1150 kg, latest generation slick tyres, carbon brakes, capable of 0-100 km/h in 2.8” and producing an amount of downforce close to its own weight. can’t go over 150 km/h average at Fiorano.
Anyway if it could help you, I made a simulation with Bosch Lapsim (you can download it for free at the Bosch website), just to see how 1 parameter can affect the performance I used as car the F1 example car included with the program, as track Imola (from a lap I made in Gp4 and exported via f1perf) and I just changed the weight of the car from the 600 kg of the example, to 1000 kg (that is probably less than a S4 weighted since it was 900 dry + 2 people), keeping everything else, max power included (900 hp) equal. The laptime passed from 1’19”79 to 1’29”74, just the 400 kg more of weight mean 10 seconds, then we should change power, aero, cg, height etc etc.
manchild wrote: I can't say yes or no beacuse I wasn't there so only thing that would convince me are offical informations. :lol:
The problem is that you will always find someone in some forum saying that “a friend or a friend of my friend meet Toivonen’s aunt and she said he did it”.
Just look at the opinion you posted from another forum, it’s already different from the other story, there it was a race, here it’s a test, there it was Cresto, here it’s a “passenger”...
Personally, also because otherwise I would be a philosopher and not an engineer... I trust physics law more than anybody opinion, and physics laws say a HUGE no to the possibility that an S4 could set a 1’18”1 in a complete lap at the Estoril track used for 1986 Gp.
These laws usually don’t lie and don’t try to over hype a presumed event in a useless attempt to say that Gr.B were more exceptional than they actually were, and don’t get me wrong, Gr.B were exceptional cars.
Just I think that, if the reason for all this story is an attempt by someone to justify his love for rally at the expense of F1 (and that’s the way it’s often used in forums), then it’s the wrong approach because he doesn’t help rally this way, it just makes other people reluctant to believe other facts once they notice that this one isn’t true.
Besides, I never understood why one can’t appreciate F1, rally, motorbikes etc etc at the same time without trying to contemporarily diminishing other people passions.
Spencifer_Murphy wrote: Besides Jeremy Clarkson is quite accurate when he jokingly says "Everyone of the 246 Billion facts on the internet is wrong".

To setup a website now is so easy and you can post all manner of "facts" without proof. So sooner ot later, more people who make similar themed websites will visit yours to gain "information, data & facts" to fill up their website. Soon this incorrect "fact" spreads.
Yep, the best thing about internet is that everybody can share his knowledge, the worst thing about internet is that every idiot can share his idiocies... Sometimes to distinguish amongst them is easy, sometimes not, especially because more often than not the idiocies have more defenders than the facts do.

Joined: Tue Jan 24, 2006 11:58 am


Well said reca.

Joined: Fri Jun 03, 2005 9:54 am


S4 officialy had 550 HP and it is a common fact that official HP is always lower than actual one (like F1 teams saying in 2004 that they have over 800 while actually it was over 900). If Audi had way over 600 HP and 205 T16 over 550 than there is no reason to think that Lancia had 450.

Anyway, I've sent some emails to reliable sources so I'll inform you once I get the answers. :wink:

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Joined: Sun Apr 11, 2004 10:29 pm
Location: London, England, UK


F1 cars in 1986 had turbos and only turbo (no supercharger) and I think there was still great turbo lag because turbos back than didn't have variable geometry (I could be wrong).
Oooops, sorry lol :oops: I got my dates mixed up. I thort we was talking about 1987...but then by 1987 Gr. B was aready banned. So we cuddnt have been talking about 1987 could we?

Sorry...must make sure my head is screwed on correctly next time :!:
Silence is golden when you don't know a good answer.

Joined: Sat Feb 25, 2006 3:25 am
Location: Eskilstuna, Sweden


This discussion has mayby been taken to far? I sure agree with Reca.
Taking average speed in to primary consideration, I'd say there's no more to debate.

It would have made a quite amazing story, though. A bit like a legend, right? Mayby the same way some see Gr B rallying?

As to
manchild wrote: F1 cars in 1986 had turbos and only turbo (no supercharger) and I think there was still great turbo lag because turbos back than didn't have variable geometry (I could be wrong).
I for one, really would like to know if VNT (or VAT, VGT) was ever used in F1, or rally, for that matter.
The design itself doesn't handle heat very well, so I'm really curious if it could fuction in an elite motorsport environment.

Sorry about the OT.

Joined: Fri Jun 03, 2005 9:54 am


Hehe, this is the talk going on all racing forums around the world.

Perhaps I should have mentioned that during all this talk here on f1t I had in mind original configuration of Jerez and fact that it was a short circuit with a lot of slow turns which could dave suited more cars with better acceleration than the ones with huge top speed and downforce. In very slow corners dowforce of 1986 F1 couldn't have advantage over traction and handling of gr.B cars. What I'm trying to point out is that on karting track Ferrari Enzo would be beaten by 100 cc karting and in 1986 Jerez was big version of karting track with many turns that can be taken much faster by power-slide of 4WD cars than what F1 cars could have done.

Gray zone shows 1986 version of shorter Jerez


Grahame Ward wrote:In December 2 1985 I had the privilege to be taken to see the Lancia Rally headquarters in Torino. My sincere friends at Lancia, including Enrico Ferrero and Emanuale Garibaldi arranged a visit to these premises at the old Abarth factory at Corso Marche 38 in Torino...

...In a set of tests carried out in early November, Lombardi stated that the S4 had been timed at 2.8 sec from zero to 100 kmph and other figures showed that the car accelerated as quickly as a Cosworth engined Formula One car up to 400 metres, despite the rally car weighing 990 kgs.

That was official 1985 data given to person from public (not 1986).

http://www.lanciaaustralia.com.au/pages ... allyhq.htm