Having recently unlocked S2, the Formula XR (aka. FOX) has quickly become my favourite car in LFS.

Judging by the shape of the car, the specs on the LFS website, and the description of the car in the LFS Wiki, it appears that the FOX is based - or claim to be based - on the Formula Renault 2000.

The thing is... the real life Formula Renault 2000 is a lot faster than the FOX.

On Westhill International, the highest speed I can reach is just over 230kph - that's with both wings set to 0 degree to minimise aero drag. On Kyoto Ring, I can get to 235kph with tweaked gear ratios, but that is the absolute maximum.

A real life Formula Renault 2000 produce 196bhp (or 192bhp, according to the British championship tech specs), and the cars can reach up to 260kph in race trim at Monza.

Considering that the LFS website quotes the power figure for the FOX at 190bhp, the speed variance is too much to reconcile. It actually seems like the LFS's FOX is based not on the full-spec Formula Renault 2000, but the British Formula Renault BARC, which use 35mm restrictors to reduce power to 175bhp.

Is something awry with the physics engine?

I think, it is the aerodynamic resistance that makes the difference. Just increase the coefficient and the top speed drops.

(260/230)^0.5 = 1.13^0.5 = 1.06. So, if the aero coeff is 6% more than needed, the top speed drops this much.

Those flaws that are there in the physics engine, have nothing to do with this.

So the question is where does the excess aero coefficient come from?

If the FOX isn't based on the real FR 2.0, then I can understand the difference. It's just that the Wiki says that's what it's based on.

Well , you say it

IS BASED , so , is not the same car , thats the diference
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i hate the new fox, it sounds horrible, and its handling ... lower speed than in patch x

yeah, i like the FO8 and fbm more than the FOX.
what about old formula renaults... maybe the fox is based on an older model. sorta like the f08 is based on the older lola engined f3000 cars.

Quote from detail :

I think, it is the aerodynamic resistance that makes the difference. Just increase the coefficient and the top speed drops.

(260/230)^0.5 = 1.13^0.5 = 1.06. So, if the aero coeff is 6% more than needed, the top speed drops this much.

Those flaws that are there in the physics engine, have nothing to do with this.

I've not doubled checked but that sounds about right. Given how simplified the aero model is, and how little data I suspect Scawen has been given, it's not surprising if things don't match perfectly. Although it's only a case of changing one number to fix the car, if the devs so wish to match up with the Formula 2000. It would help put the FOX more between the FBM and FO8 for sure.

Btw it's not really a problem with the physics engine per se, rather the data being fed into it.

Quote from Gabkicks :

yeah, i like the FO8 and fbm more than the FOX.
what about old formula renaults... maybe the fox is based on an older model. sorta like the f08 is based on the older lola engined f3000 cars.

You mean Lola chassis. Engines were from Judd.

The older FR2.0 cars had engines rated roughly 190bhp. The FOX body shape looks similar to the 2003 chassis.

Looks like at first I wrote it correctly: (260/230)^2 and 27%, not 6%. Anyway, the data fed into the model can easily differ this much.

Personally, I love the fox, but feels a bit tame compared to the fbm. A little more oomph wouldn't hurt I guess (210-215hp?)

Quote from Osco :

Personally, I love the fox, but feels a bit tame compared to the fbm. A little more oomph wouldn't hurt I guess (210-215hp?)

+1

It should be closer to the middle between the FBM and FO8.

If it's being compared to a formula renault, I'd rather it were at the upper registers of being realistic than the lower.

fox should be like it was before patch y.. now its so slow and weird to drive

FBM feels much more nervous than FOX, and guys tends to setup FOX for oversteer but FBM for understeer even though FBM has less power.

Quote from Kazu2799 :

fox should be like it was before patch y.. now its so slow and weird to drive

But do you want it to have a slower revving broader powerband less modified production based engine like the real car has and LFS currently has or like a really peaky full race engine as it was before the update? Part of what makes motorbike engined cars special (like the FBM) is they are allow really light peaky high revving engines without going to full race engines

Quote from Osco :

Personally, I love the fox, but feels a bit tame compared to the fbm. A little more oomph wouldn't hurt I guess (210-215hp?)

I love it too as you know but apart from the ugly noise it makes,it surely needs more power that may come either from a power increase or from changes in aerodynamics.

I just can't see how you can say the FOX feels tame compared to the FBM. Stomp on the throttle in the middle of a slow corner in the FOX, and try to hold it. The FBM is far easier to handle, due to its lower power and softer available tyre compounds. I run the FBM with downforce usually around 5/5, the FOX more like 8/12 - and still the FOX is more twitchy. Drive both cars consecutively with the same downforce levels and tell me which feels tame.

The FOX seems to suffer most at high speeds. It accelerates at lower speeds pretty sharply, but then starts to feel like it's losing power. It's not really much quicker than the FBM at the top end, and so a more aerodynamic body shape seems to be the way to go if you really want the FOX to be faster.

Personally, I like it how it is.

Sam

Didn't do too many miles in the FOX before patch Y but i thought it actually felt better after patch Y unlike the BF1 where ive done over 6000 laps in, maybe only experience can really make you tell the difference.

If you want to make the FOX feel faster drive the FBM for an hour then jump in the FOX. Seems really fast

I did not really notice much difference with patch x of y, car has same character, look and feel to me.

I agree the car still feels underpowered. It is nearly impossible to spin this car with a good setup. 10-15 hp extra would be very nice.
Also drag may indeed a bit on the high side; compare it to real life big estate cars with about 190hp will al do about 230km/h on top. In fact i owned once one with only 165hp which got to 235km/h(on the speedo 245 but that is not true speed)

Quote from Bluebird B B :

I did not really notice much difference with patch x of y, car has same character, look and feel to me.

I agree the car still feels underpowered. It is nearly impossible to spin this car with a good setup. 10-15 hp extra would be very nice.
Also drag may indeed a bit on the high side; compare it to real life big estate cars with about 190hp will al do about 230km/h on top. In fact i owned once one with only 165hp which got to 235km/h(on the speedo 245 but that is not true speed)

Comparing a single-seater race car with substantial aero downforce, against a normal road car isn't really a good comparison. The downforce and wings cause more drag than an ordinary road car.

However, as I said before, a real Formula Renault 2000 car with 196bhp can clock almost 260kph at Monza. I can't imagine the FOX doing that sort of speed in any configuration.

The aero drag probably needs to be tweaked down a little. The engine power is pretty close to the real thing, so the issue must be aero drag.

Drag is always going to be on the high side for single-seaters. The BMW-Sauber F1 has almost 1380bhp per ton dry, and can only reach about 225mph, whilst (to use a really clichéd example) the Bugatti Veyron has roughly 530bhp per ton dry and can break 250mph. The simple design of a single-seater means that it will not be that fast at the top end, but, having said that, the FOX does feel a little slow at higher speeds - for what it is. But look at the shape of the thing - it's hardly the most aerodynamic body in the world, and the undertray will produce downforce whatever you set the wings to; so comparing to road cars isn't really a fair test.

As pearcy says, though, driving it after the FBM removes any feeling of the FOX being 'too slow'.

Sam

Quote from Dark Elite :

I just can't see how you can say the FOX feels tame compared to the FBM. Stomp on the throttle in the middle of a slow corner in the FOX, and try to hold it.

A diesel may be faster than a smaller petrol engine and it may well let you spin out more easily but you just can't get away from the fact it's duller, less responsive and isn't as fun as a small screaming engine. Same applies with the FOX and FBM.

Quote :

The FBM is far easier to handle, due to its lower power and softer available tyre compounds. I run the FBM with downforce usually around 5/5, the FOX more like 8/12 - and still the FOX is more twitchy. Drive both cars consecutively with the same downforce levels and tell me which feels tame.

The angle of the endplate tells you nothing about two completely different wings, your test is completely irrelevant.

Quote from ajp71 :

A diesel may be faster than a smaller petrol engine and it may well let you spin out more easily but you just can't get away from the fact it's duller, less responsive and isn't as fun as a small screaming engine. Same applies with the FOX and FBM.

Quote from Thread Title :

FOX too slow

Well, that depends on your definition of 'tame'. I took it to mean how easy the cars are to handle, in which case, the FBM is considerably more so. If you mean which one is more shouty and sharp, then - although I think the FOX is noisier and more pointable, personally - it's more open to discussion.

Quote from ajp71 :

The angle of the endplate tells you nothing about two completely different wings, your test is completely irrelevant.

However different the two wings are, the parameters we're given for setting them up are similar - that is, the allowable angles are similar. We can, in fact, set the FOX's wing angle to be completely zero, while the FBM's minimum is 1/4, but the basic ranges aren't too far apart from each other. This means that however different the wings are on each car, they still can't be adjusted greatly differently - and so the feel of the car is, in fact, limited by where the comfortable area of wing angle is. If the FBM is stable at 5/5, it's hard to make it any more twitchy, whereas if the FOX is stable at 8/12 it is very easy to make it feel a lot more tail-happy.

Sam

Quote from Dark Elite :

However different the two wings are, the parameters we're given for setting them up are similar - that is, the allowable angles are similar. We can, in fact, set the FOX's wing angle to be completely zero, while the FBM's minimum is 1/4, but the basic ranges aren't too far apart from each other. This means that however different the wings are on each car, they still can't be adjusted greatly differently - and so the feel of the car is, in fact, limited by where the comfortable area of wing angle is. If the FBM is stable at 5/5, it's hard to make it any more twitchy, whereas if the FOX is stable at 8/12 it is very easy to make it feel a lot more tail-happy.

The angle of the wing end plate is still only a fine adjustment to the balance of the overall aero package, which is completely different on each car. Before you can then take balance into account you have to rule out chassis, suspension, weight distribution and tires to name a few. You simply cannot compare the two cars like that. The FBM has a shorter wheelbase so should in theory be more twitchy and keener to change direction (I think it is) than the longer wheelbased car, if you can't setup the FOX to be near competitive from a twitchy tail happy set to boring colossal understeer you're doing something wrong.

FO8 is nice step forward for racers after FOX

Quote from samjh :

So the question is where does the excess aero coefficient come from?

If the FOX isn't based on the real FR 2.0, then I can understand the difference. It's just that the Wiki says that's what it's based on.

It could also be the tyres which generate way to much heat. At max pressure zero toe-in or out, they get hot just by driving straight. So much rolling resistance must have an influence on top speed. I estimate once this is corrected, top speed will increase 2-6 km/h for the fox.
Topspeed near 240km/h on normal track like kv national sounds a lot better