Akina/Haruna Downhill

I can try out the na side of things to see where the balance may lie. I did find it interesting that the turbos in this configuration still came up trumps! Wonder what the average speed is… How long was the course?

It’s about 7,8kms iirc

OK so the average speed of the fastest cars on this downhill is just a shade under 100km/h. (I’m interested to see if there’s a certain threshold where the different types will have a certain advantage.)

Also, if anything the NA engines aren’t too far off being competitive on this track, just a little off the pace. I chucked in as light an NA engine as I could to achieve the perfect power:weight ratio while keeping the tune of “spartan sports car”, and came up with a fairly respectable time in the 4:49s:


In addition here is the NA engine I used:


Of course changing the engine means I have to retune the gear ratios, so now it’s a 6 speed to take advantage of a (paradoxically) narrower power band, and my front wheels have widened a little too.

OK, 2nd attempt. Lower weight. Lower power. Slower time.
Same issues with power and traction so RWD still didn’t work.
I did go back and widen the tires to 245/40R15 all around. It didn’t help. (last attempt was 215’s) With 16’s, I can get 4:93.89, but meh. I suck at this car building thing.

PLEASE tell me I got it right this time?

4.0L NA V8 AWD
280HP/Tonne
308HP:1100kg

Downhill time: 4:54.41

SME-Hatch-D-v2.zip (32 KB)

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Maybe RWD should get a boost? Considering almost noone uses it now :stuck_out_tongue:

[quote=“Dragawn”][size=50][/size]

Maybe RWD should get a boost? Considering almost noone uses it now :stuck_out_tongue:[/quote]

I’ve gotten a RWD with a pushrod to 295 seconds. :laughing:

If I recall correctly I got a rwd car to the 291s, and elsaico also got a fwd car to 291!!! I’m sure I can take just a little more off the times but I suspect to give equivalent times the limit will have to be bumped up by about 15-20bhp/tonne.

@cobaltgirl: you can probably find time if you were able to widen the rear wheels to 265mm. The gearing probably should be taller too, a car like that should be geared to about 270km/h top speed. And check the balance of your cambering too… I find there’s a heap of time to be gained in negatively cambering both front and rear… But it has to be balanced as there’s a tipping point where it’ll make the car unstable, which the cornering g value does not reflect!

[quote=“strop”]If I recall correctly I got a rwd car to the 291s, and elsaico also got a fwd car to 291!!! I’m sure I can take just a little more off the times but I suspect to give equivalent times the limit will have to be bumped up by about 15-20bhp/tonne.

@cobaltgirl: you can probably find time if you were able to widen the rear wheels to 265mm. The gearing probably should be taller too, a car like that should be geared to about 270km/h top speed. And check the balance of your cambering too… I find there’s a heap of time to be gained in negatively cambering both front and rear… But it has to be balanced as there’s a tipping point where it’ll make the car unstable, which the cornering g value does not reflect![/quote]

I assume this means I made a car which passed the scrutineering?
strop, I’ve already tried most of that. Camber should be good. I am pretty sure it’s below -2.0 on both front and rear. It isn’t past the tipping point, as Tameness is still at nearly 60. I will play with that some more, I guess. Suspensions are confusing to me, which is probably why my car is stock suspension. :wink: I do have the aero slightly front-biased to counter the heavy nose. I could do wider tires, but I *HATE *fender flares, so, yeah. Personal taste, if you will. I also had the gearing much higher at first, but it only got slower. I did the click-by-click on gear spacing even. Higher was just worse. MPG below 10 (not that I really care about it much in the game), All the stats (except sportiness) got down in the low numbers, and times got slower. I messed with the downforce as much as I could and ended up going back to the 80+ kg. The biggest problem I had is weight balance, which is why this motor is only a 4L (homegrown), where the original motor was a 5.7L(SBC350). I played with a 5.4L 327, but it had the same problem…too heavy on the front without the power. Maybe this just isn’t my thing. Still, 295s is semi-respectable, I think. And it’s a $970 engine (which isn’t really all that great for 1994)! Maybe you can give it a go with what I used, and teach me a thing or two. hahaha

You definitely got the power to weight ratio right, and everything else looked legit as per the restrictions on page 1 (assuming all tech is set to 2000 and earlier!)

It also seems like you’ve definitely considered most of the things that I mentioned… the bad news is that the way I understand it, generally the wheels that carry power should be wider, and the wheels that steer should be narrower (at least, matched to load). Widening the rear wheels to 265mm will probably actually slash 3s off your time, so apart from that your car is already relatively well optimised.

I tend not to pay attention to the tameness:sportiness ratio when tuning, because it doesn’t fully reflect what time the car will put out. There’s a correlation, sure, but when getting to the fiddly parts I’ve noticed that certain tipping points where the times suddenly blow out for whatever reason aren’t necessarily reflected in those values. Everybody has a different style when tuning their suspensions, and I’ve found my most competitive tunes are the ones I’ve used in every simulation before this one: tending towards softer front and stiffer rear (with a few exceptions)… but I also tend to be fond of power oversteer, which isn’t always the fastest way around a track. That said, it’s worked for me elsewhere and it continues to work for me now so I’ll stick to what I know!

Now, I decided I’d go back to the RWD cars and see if I couldn’t make them better, having learnt what I have during my stoush with Dragawn. The results show that the restrictions are actually not too bad at all, though the estimate of the benefit of an increased 15-20hp/tonne may be accurate.

First up is the RWD turbo, with a power:weight ratio of 329.1bhp/tonne:


And here is the RWD NA, with a power:weight ratio of 300.0bhp/tonne:


As you can see they’re pretty even, though I don’t know which is the faster as I only spent about 15 minutes each tinkering with these, as my platform was already pretty well set. Note the different tyre widths on each car! There may be room for a few tenths extra here and there but most of the basic tuning has been done and they both go well into the 289s, which is pretty close to the 288.11 I got with the AWD.

Next I’ll see how the FF format stacks up, it takes a tameness penalty from the transverse engine layout! As mentioned before ElSaico managed a scary 292, but I’m going to give it a real shot this time!

p.s. if you like you are very welcome to pm me your files to see if there’s any more to be squeezed out. I’ve had some success with a couple other users’ files.

Okay, as promised, here is my shot at FF domination! The platform is based on the Swift, but the year is set to 2000, and it has a carbon skin over its AHS steel frame. It has basic entertainment, a perfunctory amount of sound insulation, and standard safety. The engine comes from 1999, a tiny 1.5L AlSi block and headers with turbo limited to 0.83 bar, that can easily rev well past 10000rpm (but I limited it to 9500rpm because after that the power drops off too much for there to be any point anyway).

This gives the car a power:weight ratio of 329.9bhp/tonne, and it does pretty well for an FF car:


Of course, I had to do a comparison with the NA engine, and I must admit, I wouldn’t normally drop a 1.8L V8 that revs to 10400rpm (sounds more like an F1 engine doesn’t it…) in your regular CRX… but the block blueprint was lying around, so all I had to do was reduce the bore and stroke a bit and fiddle with the timings and mix, and it only costs 770 bucks and 73 hours to put together! In all honesty I still have a lot of room to move in terms of lightening the engine and optimising the power curve, but this’ll do well enough as an estimate.

The NA version of the Swift Touge Edition has a power to weight ratio of 299.87bhp/tonne :stuck_out_tongue: Funnily enough, while the Turbo did far better on 14 inch wheels, the NA version prefers 15…


Again, times of 290-291, which is, to me, about expected.