Cars acceleration is not up to the mark in beamng drive

Ok, so I got this car where the spec state Acceleration from 0-100 in 4.5 s but when driven in beamng - it drives very slow. Definitely not 4.5 s.

But in automation test track - the car show accelearion of 4.5 s and its really confusing me as to what is wrong.

Also it tends to oversteer a lot, no matter what setting i choose. Can someone look into the car and help please?

Here’s the .car file.
Viper - (23.6 KB)

Automation to BeamNG doesnt translate exactly but I would say that it’s pretty close to 0-100Km/h (Definitely not mph) are you quite sure you dont have little confusion there?
Either way as I tested it’s still in the ballpark around 4.7 sec.
Many factors contribute to this, including the boost that is not exactly smooth in automation-Beam conversions (you can see the boost jumping between 0.4-1.1 bar constantly)
Launch: Best performance Worst performance

  1. TCS on Clutchdump, TCS kills the power almost instantly
  2. TCS on idle to full, long clutch slipping -> TCS kills power when you get on to boost.
  3. TCS off idle to full, long clutch slipping -> slips a bit when boost comes on, might lose grip on full throttle shift
  4. TCS off Clutchdump & throttle modulation slips for a bit, but accelerates well, might lose grip on full throttle shift
  5. TCS off Clutchdump & full throttle. Never gains grip.

I tried it on automation TT in BeamNG TCS turned off. Only situations where I found oversteer being an issue in any way.

  1. Evardsen Esses. Long sweeper towards Brians bend. 2nd gear trying to accelerate = Driver error: Too much throttle,
    Adjusting rear tire size,
    Increasing rear rim offset might help,
    softer rear ARB might help
    Increasing rear downforce.
  2. Evardsen Esses. Long sweeper towards Brians bend. Upshift to 3rd while on power = Driver error. Powershifting during turning disrupts the balance of the car leading to oversteer.
  3. Evardsen Esses. Long sweeper towards Brians bend. Upshift to 3rd while offpower. = Driver error
    Car might become unbalanced unless the throttle modulation isnt very smooth.
  4. The Slingshot. Car becomes unbalanced, Due to the high speed and hight front downforce the front end has very good grip, but rear downforce is not strong enough. The car is possible to drive trough on full throttle, but it requires very steady and smooth steering.
    Icnreasing rear downforce
    Increasing rear camber
    Increasing rear tire width
    Softer rear swaybar
  5. After any sharper turn while exiting to straight / acceleration zone and upshifting 1-2 or 2-3 the rear might get completely loose so fast that driver isnt fast enough to counter it. = Driver error: Let the car settle properly before shifting
    Also softer rear supension can counter this to a degree.

I tested the car in beamNG, and with a clutchdump and TCS on, I get 5.17 seconds, which is not that far off. If you use arcade transmission I suspect that might be why it’s slow off the line due to the pretty crazy turbo lag.

As for your handling issues, I’d suggest using larger wheels and/or raising the car a tad. The car’s body tends to scrape on the ground under load.

1 Like

Thank you for the detailed review. Appreciate that. I tried increasing the rear setup as

Increased rear tyre size
Increased rear downforce

However I still couldn’t achieve a stable handling.

Also turbo lag is a point to be noted, but i’m not sure how this can be minimized.

Test Track in BeamNG (Hirochi Raceway)
Screenshot of the time trials

The best time I could achieve on my car is 1:53:067 (3rd)

The first 2 places go to a car which is naturally aspirated, has a lower acceleration 0-100 km/h in 5.8 secs (Meijer Hakone - Credit goes to this car developer for superior handling). Car file attached. Meijer Hakone - (23.2 KB)

Its unbelievable that this car on a straight line is faster than mine. (tested this in the first check point). Im trying to beat this car. My car has everything better than this but still can’t beat it.

Test track in Automation Game:
Point to be noted : If I test both the cars in the Automation Game test track, my car easily beats it by a huge margin. His car was slower than mine by atleast 4 seconds.

In my very educated questimation would call Turbo as your largest downfall.

Void, Check next response
The turbo doesnt seem to work exactly right in Automation BeamNG conversions. often giving less boost than it’s set up to deliver. I have had many cars where I set boost pressure to be 0.5 Bar, or there about, but only get 0.0-0.3 Bar and often not at all.
How ever I did notice that your boost is set to be around 1.2 Bar, and you get 1.0 quite easily, and almost allways more than 0.7 bar.
This will drop your engines power output by certain amount.

Also I noticed your Turbo setup. which is using as large turbo as possible, this leads to large turbo lag.
Also yuor turbo “intake” (AR ratio) is very high, which does increase the power output, but means that the turbo spools up later, and then “kicks” in. which isnt really an issue of you are going for straight line performance, but it suffers massively in any situation where you arent using full throttle.

If you have driven 80’s or early 90’s Turbo Saab. Especially if you have tried to overtake a car with it.
The passing procedure goes.

  1. Drop to a lower gear.
  2. Plant the throttle to floor.
  3. indicator on.
  4. Check mirror.
  5. Check blind spot.
  6. Change lane.
  7. Brace for boost.
  8. Boost comes on you start to overtake the car in front.

The turbo in your car works just like that.
Also as @TrackpadUser mentioned lifting the car a bit shouldnt hurt it, as I do remember seeing some sparks every now and then when driving it, which does indicate that the bodywork is hitting the ground at least occasionally.
This leads to the car unloading the weight from the tires on to chassis, which in turn means reduced grip.

Turbos not getting up to boost can be due to low FPS. Try to set BeamNG to garbage tier graphics and don’t have a frame limiter on, see if you get to boost then on a simple map.

Thankyou @Killrob
I have to test could that be related,
If that is just FPS issue the boost should come on, but top speed stay the same, and if that happens it is only FPS issue on my end.

At a quick glance from the Viper car, I’d say the problem is most likely brake balance. Your rear brake force is much higher than grip, especially relative to the fronts. This will cause a car to want to come around under heavy braking, and pivot while mid-corner braking.

edit 1: I’m guessing the apparent slowness 0-100 is lack of powerband. That speed is covered in 1st gear

@JOVA1982, that passing procedure instruction was precious. Early Dodge turbos, too. We dropped 2 gears to pass. But if you were brave, and had enough road to stay in it, hehehehe

I haven’t driven it, yet

@JOVA1982 , @Killrob, @TrackpadUser, you guys are awesome. I will have to try these based on your advise

  1. Reduce turbo little bit to see if that can compensate lag (still trying to achieve the acceleration of 4.5), reduce ar ratio
  2. increase height,
  3. @Obfuscious - The rear grip is a slighly curved line, the break force is just above that line

The other question is , the steering graph tends to show over-steer for most of the speeds no matter what.

Since you’ve added fatter rear tires, I believe you. But the original Viper posted has a heavy rearward brake bias. Don’t get me wrong, I actually like just a little rearward brake bias. Just not as much as shown in the available download.

edit to add: your front brake power is through the middle of the line. If rear brake force is above the line, it’s rearward biased. the thing (for me) to consider is: when I’m overbraking it, how do I want it to act? The answer for me is rotation, but it will vary by driver. If you’d rather just have it slide to the outside, then more brakes up front.

Edit2:Having driven the Viper posted at top, I thought the chassis was decently set up. I can’t fault the brake setup, they felt good even going deep into corners. In fact, the only oversteer I really noticed was 1) every time I shifted, and 2) every time the turbo kicked in. Whee! You could use a less aggressive shifting trans (adv auto or dsg) to help this a bit,

I tinkered a bit and came up with this, it’s a little bit faster with 30 less hp.
Viper - R1 by (23.7 KB)
It also doesn’t get stuck in a gravel trap, hehe. I tried to keep the “feel” original, that turbo still kicks hard and it can be a little hard to modulate out of low speed corners.

I think the build is hamstrung a bit by the turbo size, which in Automation is based on bore size. As an inline engine, only one turbo is granted; in an undersquare engine it’s just not enough to feed that exotic cylinder head. Further, that long stroke is keeping you from spinning the engine high enough to take advantage of that exotic piece. Turbo motors don’t like overlap, so I backed down the cam. Ditto timing, and I bumped compression ratio. The result is a 1.8 that gets serious at 6000rpm (300+ hp), and stays rowdy to its 9300 rpm redline. Peak of 388 at 7700.

As to how you’re being beaten by the Meijer car, weight and cornering speed. That car corners at 1.2g, and carries 500 fewer lbs. And, it’s so easy to drive my grandmother could hot lap that thing.