spesler
Member
Although those S4 numbers are probably measured at the engine. Either its 4.4 second time is generous (including rollout and under only very specific conditions) or these dyno readings are a little high.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
GoFundMe to Dyno the AWD (non-Performance)
- Thread starter Wildbill
- Start date
No because every dyno is different, they are simply a comparison tool. In this case you're comparing two different cars. Usually you're comparing you care before and after modifications. Take these two cars to a different dyno and you will see different numbers but similar curves.
Also there are drivetrain losses, the motors are not direct drive, there is a reduction gear which will have losses as well as anything from the motor to the tarmac (joints, tires, hubs, bearings, etc) but the loss is certainly less in an EV than a standard ICE with a spinning transmission..
ℬête Noire
Active Member
They tried that in the Roadster and unfortunately the "world of difference" was the transmission blowing apart.
It's likely possible to add a a transmission. However the question though is more about feasibly in price, durability, and overall performance due to overall weight increase and mechanical losses in the drivetrain.It could be sort of an awkward experience, too, where the [undoubtably automatic] shifting is likely to be occurring. I don't know the exact gear ratio assumed in this dyno run but IIRC it's generally assumed to be about 9.3? So peak torque at about 4800 motor rpm divide by 9.3, divide by 790 rotations per mile for stock tires, x 60 min/hour = 39MPH. Usually you'll let it run up a bit past that but not sure how that'd feel having shifting happening at that threshold around 55-60mph? From there you could easily do a 3.5:1 gearing or something that would move peak HP up around 105MPH. That means you'd have the acceleration punch to eat up pretty much any road course out there but the weight compromise, on what's already a pretty heavy vehicle? It's certainly have more top-end than the vehicle would ever have been envisioned to handle, as given the low Cd 200mph should be reachable?
Hmm.
In any event for "normal" use, for a street vehicle, this seems entirely unnecessary. I find the 70mph to 90mph entirely *cough* adequate for passing on 2 lane highways....and that's in the non-P.
P.S. As far as we know what the 2020 Roadster is doing is just making the gearing a lot taller and throwing a lot more motor behind it to keep the acceleration at the bottom end a bit above the P100D. It's got so much motor that lower gearing wouldn't be usable due to tire limits.
Last edited:
ℬête Noire
Active Member
Curious that the P has the slower onset on the curve by about 400RPM (2500 vs 2100). An artifact of the testing equipment, that it's not really measuring accurately & consistently down there?
I have no idea why I read this totally backwards. We're saying the same thing, and apparently I didn't realize this. To make matters worse I reversed tall/short gear ratios, which just makes me an idiot. Sorry.
Last edited:
ℬête Noire
Active Member
I read your post completely wrong. I have no idea how I did this, or WTF came over me. I apologise, and I accept my thumbs downs.
ℬête Noire
Active Member
Wow! Thank you for doing this? What kind of P3D was it, a + or a -?
Do we know what the differences are between the P3D- and the P3D+? If so, please point me there. I haven't found them.
Knightshade
Well-Known Member
The extra stuff on the + is right there in the configurator-
- 20” Performance Wheels
- Performance Brakes
- Carbon fiber spoiler
- Lowered suspension
- Aluminum alloy pedals
- Increased top speed from 145mph to 155mph
- Track Mode
Is this part of the explanation why the M3P doesn't seem to quite kick/jerk very hard off the line vs at 20-40mph or a model S?
Fascinating! Thanks for posting. It lines up nicely with what some prediction engines (like this one on Wallace Racing), which shows about 475-480HP for an ET of 11.8 in the quarter mile, with trap speed of 115. Those prediction engines might slightly overestimate HP in an EV vs. ICE due to the gear shifting needed in an ICE and the flatter torque curves of EV, but it's still really really close. NIce job!
Same here, I have noticed the Model 3 P takes a fraction of a second when you floor it...gets rolling then rolls all the power in. Maybe this is to help save a little wear on all the drive components? Maybe a Ludicrous mode in the future that will throw all the power out from the start.
SageBrush
REJECT Fascism
ConcordeSST
Member
All I meant was the suggested retail price listed in the press release I linked to. I wasn't trying to start a debate on total cost of ownership. I was just pleased to see that the Model 3 LR AWD compares favorably to the sportier Audi S4 when I've always heard that it was intended to compete with the A4.
Knightshade
Well-Known Member
Heard from whom?
The A4 is much nearer the RWD Model 3LR performance-wise than it is the AWD Model 3.
ConcordeSST
Member
From Elon. Yes, I realize now that he was likely referring to the RWD. That tweet just stuck in my head and I was pleasantly surprised. That's it. Nothing more.
Last edited:
AlanSubie4Life
Efficiency Obsessed Member
The dropoff at the low end is just an artifact of the dyno. Not sure why it behaves that way but it does.
I posted a VBOX run in another thread. The low end of the dyno curves are just not accurate for whatever reason (actual torque is obviously pretty constant all the way down to near 0mph based on the instrumented run - acceleration is constant pretty much from 0mph).
Does anyone else feel like the first 0-10mph are limited in the M3P?
ℬête Noire
Active Member
Yes this is what my pant seat dyno says, too. Good to see some more objective measurement to back that up.
Thinking about it more my guess is that because these dynos are built for ICE and on ICE everyone's torque & HP suck down low, and have ways of mitigating that with that via gear shifting, dynos weren't built to capture that stuff because you're revving and dropping the clutch etc. Maybe they're measuring using inductance and that requires a certain RPM to work accurately and then the instrument triggers and there's a delay, perhaps to let everything settle and get to where the engineer designing it was confident of an accurate measurement happening or maybe it's using a running average to smooth things out a bit.
In that case the reason for the start being further right with the P in normal mode is that small delay allows it to get going faster before the reading kicks in.
What supports this is you see how in chill the D and the P start their climbs much closer to each other, and both are to the left of the D in normal mode. In chill they aren't getting as far out ahead as in normal mode because their acceleration is attenuated.
Last edited:
Similar threads
- Article