As I just LOVE the XFG - being a hothatch - I did some tests today in order to find out what modifications would slow it down most.

Yeah sorry, despite the title I can't really tell you what makes it faster but I can soothe you with this: Unless you go totally freaky you won't really slow it down with your tweaking. I'm taling about acceleration on a straight and topspeed here.


1. TOPSPEEDS
1.1. Tyre Pressure
----------------

Tested on Kyoto Ring, the topspeeds of two similar setups only different by tyre pressure (almost non vs. fully inflated) were 190 kph (high press) against 186 (low press). As you may never want to run on either of these, this difference can be necleted on other than highspeed-tracks (even there I think).

1.2. Camber
------------

I ran on fully inflated tyres. Once with close to 0° camber on every wheel, once with all I got (negative): no camber 190 kph, full camber 191 kph (less contact area). Kind of obvious, but as you see it's also necletable. The difference even decreases with decreasing tyre pressure.

1.3. Track
----------

Actually I thought heavy "track-ing" of 0.9° on both axles should be THE speed-killer. Nope. NO difference to 0°. Compared with low and high tyre-pressures. Hello???

1.4. Gearing
-----------

You can't really go too tall, only too short.



2. ACCELERATION
2.1 Tyre Pressure, Camber, Track
--------------------------------

Ok, here I went wild: I did all the no-nos for acceleration: low tyre-pressure, extreme camber and track compared to high tyre-pressure, no camber, 0° track.
I did 3 runs for both settings on the drag-strip. The times were always identical to the first decimal. The spread of second decimals was more bound to chance than to the setups.

Then I thought: Well, the low tyre-pressure might support a good start... so I inflated the tyres of the no-no setup - with no effect.

Any combination would give me that time around 16.5.

Given the fact that you hit a speed of around 150 kph after 16.5 seconds, all those settings have no real effect on your speed on the straight.

2.2 Gearing
-----------

Obviously you can choose your 1st too long and you won't have a nice start, or too short and you wasted power. The fifth can also be too short, seldom too long.
But what about the steps? Or the number of gears? Would the XFG be faster with a 6-speed-box?
No.

Did you ever think "hey, why is this guy accelerating just as quickly as me although I have these super-short gearing??"

The XFG (and the UF1000 - and I think even the FOX) appear to have this ultra flat power-curve. Don't believe it? Here's the proof:

I virtually tore out 2 of the XFG's gears - leaves 3 gears (another proof that this 1.3 litre hatchback has a power-curve of a muscle-car). I set the 3rd gear of my "3speed-XFG" to the same ratio as the 1st of the 5speed, the 5ths were the same, the gear(s) between (only 1 in the 3speed compared to 3 in the 5speed) reasonably spaced. I also built myself a 4speed-XFG in a similar way.

Then I accelerated all of them to something like 170 kph, "fraps-ed" it and compared it in a video-editing program.

For the results see the attached table.

So now, what do we learn? Yes, the XFG's power-curve is not THAT realistic and you might not lose a race because of a shitty gearbox-setup.


Hopes this was a bit informative or at least entertaining. I found it at least surprising... although I expected it - otherwise I wouldn't have done it.

I'm impressed by howmuch information you got. Good job man. You deserve a medal, no seriously.resent:

Quote from Bandit77 :

Did you ever think "hey, why is this guy accelerating just as quickly as me although I have these super-short gearing??"

Nope. I usually laugh while accelerating because I'm using manual clutch and most other drivers aren't. I wish there was a "Wave goodbye" button

Interesting stuff though, cheers. I didn't realise the gearing on the XFG was so unimportant, but then I've never touched the setup on it.

I see what you're trying to accomplish with this thread, but can't you just use Bob's Gear Ratio Calculator to get to the same conclusions as you did?

Quote from shiny_red_cobra :

I see what you're trying to accomplish with this thread, but can't you just use Bob's Gear Ratio Calculator to get to the same conclusions as you did?

The gearing was the smallest of interesting things revealed by the OP. Good job Mr. FIA Investigator!

Quote from shiny_red_cobra :

I see what you're trying to accomplish with this thread, but can't you just use Bob's Gear Ratio Calculator to get to the same conclusions as you did?

damn, now that you say it...

Get with the times, that app is long succeeded.

Great thread. I must say i LOVE the XFG too. Fun little car.

~cobra

Quote from Bob Smith :

Get with the times, that app is long succeeded.

Yup, it's now called The Amazing Bob's Super Everything Machine and is powered by a tribe of monkeys fuelled by crack and Red Bull

Couldn't use the old one, even less hope of being able to use the new one

Quote from Bandit77 :

1. TOPSPEEDS
1.1. Tyre Pressure
----------------

Tested on Kyoto Ring, the topspeeds of two similar setups only different by tyre pressure (almost non vs. fully inflated) were 190 kph (high press) against 186 (low press). As you may never want to run on either of these, this difference can be necleted on other than highspeed-tracks (even there I think).

Not completely correct. You forget one thing, LFS doesn't display the absolute/real speed anymore. What you see is actually a calculated speed measured from the output shaft (or on the wheels, not sure on that). The high pressure tyres have a larger radius than the low pressure ones, so if you compare two cars driving with a speed that LFS displays as 160km/h, the one with the higher pressure tyres will be faster.

It's true because when you are inverted, you can control the speed, when not even moving at all.. but it is the same for real life cars too. Ever had the engine on when it was jacked up and in gear? But even a real car couldn't tell the difference, if you put smaller wheels on, your speedo goes out of syncronisation (your speedo goes faster than your actual spead, because the wheels are turning more, within less distance)

Quote from AndroidXP :

Not completely correct. You forget one thing, LFS doesn't display the absolute/real speed anymore. What you see is actually a calculated speed measured from the output shaft (or on the wheels, not sure on that). The high pressure tyres have a larger radius than the low pressure ones, so if you compare two cars driving with a speed that LFS displays as 160km/h, the one with the higher pressure tyres will be faster.

... not to mention centripetal froce, which increases the diameter again.

I could run a test with fully inflated front and flat rear. I almost bet the topspeed will be around 188 - showing the same error from the fully inflated tyres but having the drag of the flat tyres on the rear-axle.