Atom 4 - Pre Spec/Order Discussion

[anx10us]

Another review today.
https://www.goodwood.com/grrc/road/news ... el-atom-4/
It's all looking very positive

Very positive ...

I'll pop my head above the parapet, i'm hopefully going out in the 4 on Saturday (a a passenger), my deposit is already down (20 months to go), if anyone wants me to photograph or video something (assuming i'm allowed), or for me to ask any questions (apart from when is the pricelist out), post here or pm me ...

[cvjoint]

^What type of aerodynamic upgrades are available? What amount of kg downforce should we expect front and rear separately?
What amount of camber/toe/caster change do we expect per inch of bound/rebound from static compared to 3.5R or some older Atom?
What is the torsional rigidity in lb-ft/deg compared to the cup model?

[Hedge]

Right?!

I'm sure Our Henry shall be all over those questions. And Tom.

Best ask Rookie, tbh. That level of detail is right up his (OCD) strasa.

Cheers,
Hedge

[Hedge]

https://www.goodwood.com/grrc/road/news ... el-atom-4/

I quite enjoy reading Frankel's various columns but this particular line caught my eye:

"....the space frame now has thicker pipework, partly to add strength but mainly because the Ariel team think big bore tubing looks really cool"

That's pretty lazy journalism, at best.

Cheers,
Hedge

[Anon]

Phil,

Torque is the turning force an engine can generate, and power is the calculated measure used to compare engines as it crucially covers the rpm at which the engine operates and generates that torque.

High torque at low revs is good for economy and reduces wear on the engine and gearbox. But it is not good for acceleration. You want high power or to sustain torque at high revs so you can run lower gears. Lower gearing gives easier and thus greater acceleration. This is why race engines are tuned for high power at high revs. Think F1 engines revving to well over 10,000 rpm. On track the Atom 4 will not benefit from relatively high torque from 2,500 rpm as it will never be run at that rpm. On track to extract maximum performance you use the lowest gears possible in most scenarios and thus exclusively high revs.

I think you are getting confused between the difference between; gearing, torque and horse power. You said re: torque "But it is not good for acceleration" - this is false. It's the opposite, when an engine has high levels of torque, it will accelerate much faster than a car with less torque - this is basic science. Longer gear ratios will suit a higher horse power car because high bhp engines have less torque at a lower rpm. So reving longer and having a higher rpm with lower valve float will allow the engine to come alive a lot later down the rev range. In contrast, when an engine has high-torque the gearing will generally be shorter with lower rpm because the max power band comes a lot sooner, hence faster acceleration.

You mentioned a comparison to F1 cars. They have lower levels of torque but high bhp so that the engines spin faster due to much longer/higher gear ratios. This makes it easier to drive and requires the driver to keep the engine in the high-rev range and allows much faster top speed.

Basically, it comes down to this, I think (and I don't know until I drive it) the 4 will be much easier to drive and generally much quicker out of corners because you don't have to rev the nuts off it you can be anywhere in the rev range and it will just pull due to the gearing and torque. This is also reflective of all the reviews thus far.

[Winmoz]

This isn’t getting any easier. Have been holding the line all week and repeating the mantra “do not Phone the factory, do not phone the factory” but my resolve weakens with every review I read.




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[anx10us]

This isn’t getting any easier. Have been holding the line all week and repeating the mantra “do not Phone the factory, do not phone the factory” but my resolve weakens with every review I read.

Sent from my iPad using Tapatalk

Do it, I registered on the forum in June 05 with the intention of gathering information before I bought a car, life gets in the way, there was always something that required my attention, finally 13 years later my deposit is down and i'm on the list .. only 20 months to go ...

[Peter255]

I think you are getting confused between the difference between; gearing, torque and horse power. You said re: torque "But it is not good for acceleration" - this is false. It's the opposite, when an engine has high levels of torque, it will accelerate much faster than a car with less torque - this is basic science. Longer gear ratios will suit a higher horse power car because high bhp engines have less torque at a lower rpm. So reving longer and having a higher rpm with lower valve float will allow the engine to come alive a lot later down the rev range. In contrast, when an engine has high-torque the gearing will generally be shorter with lower rpm because the max power band comes a lot sooner, hence faster acceleration.
[snip]

Ha ha. I am not confused thanks. I have postgraduate qualifications in physics.

"High torque at low revs is good for economy and reduces wear on the engine and gearbox. But it is not good for acceleration. "

That is 100% true for our application where we have gears! You missed a crucial part. I did NOT say high torque is bad for acceleration. Torque is all engines have, but it is crucial to consider the gearing and thus the rpm at which the torque is generated. That's the point.

Your rather confused with your latter points tbh. I have no idea what to say to "high bhp engines have less torque at a lower rpm". Err sometimes they do, sometimes they don't.

This is also backwards "when an engine has high-torque the gearing will generally be shorter with lower rpm because the max power band comes a lot sooner, hence faster acceleration." Nope. If the max torque comes in sooner you run longer gears (think Diesel). Or if the power comes in later (think Honda vtec) you run shorter gears to keep the revs up.

But I don't like to argue online so lets agree to disagree.

[Luckky]

I love this forum, lots of people have much more of a clue regarding the subject matter of torque vs bhp, the science of engines etc than I do.

Please keep up the banter to keep me entertained until my delivery date comes around!

The only thing I’ll add is that we all know there will be an optional remap / power boost (I had this confirmed when I went down) so if the base 4 isn’t scary enough, I’m sure the options will help, I’m just buying one to scare myself stupid every time I get in it...

[phil4]

I think you are getting confused between the difference between; gearing, torque and horse power.
[snip]

Ha ha. I am not confused thanks. I have postgraduate qualifications in physics.
[snip]

Maybe we should just make it easier for people with postgrads in non-physics subjects...

Power - how fast you hit the wall.
Torque - how far the wall moves.

I know, I know... it's wrong. And here's someone who somehow sounds dead boring to me to explain why I'm wrong:

[Luckky]

I think you are getting confused between the difference between; gearing, torque and horse power.
[snip]

Ha ha. I am not confused thanks. I have postgraduate qualifications in physics.
[snip]

Maybe we should just make it easier for people with postgrads in non-physics subjects...

Power - how fast you hit the wall.
Torque - how far the wall moves.

I know, I know... it's wrong. And here's someone who somehow sounds dead boring to me to explain why I'm wrong:

So we are good towing a caravan with the 4?


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[HenryJS]

Aero upgrades will be available - measurable down force in the real world is yet to be tested, but let me assure you - it is far, far greater than the current ones (which, whether you choose to believe it or not, DO provide down force and settle the car down a lot at high speeds )

I'm not about to put any suspension geometry details on a public internet chat forum - that's commercial suicide. We don't give that out to anyone which is part of the reason why there isn't anything like an Atom... We are more than happy to give out Setup advice, to change your camber etc, but not how the car works!

The Cup Car was never tested for torsional rigidity. However the Atom 4 has a 15% over the Atom 3.5. There is a difficult line between stiffness and compliance. too stiff and the car wold feel horrendous on the road, to soft and it would be wallowy on a race track.



I also don't see the obsession with comparing a standard 4 to a Cup Car or 3.5R... Comparisons need to be like for like really.

So:
A standard 4 is faster than a standard 3.

A standard power 4 with big brakes, bilstein adj shocks and a couple of other small items that you may or may not want is faster than a 3.5 310 with similar spec.

A standard power 4 with the above and some other nice-ities, wheels maybe, ohlins shocks, etc etc is probably faster on the road than a 3.5R. However - it being a road, there has been no racing!

A 3.5R vs a std 4 with adj dampers, wheels etc etc on track hasn't been tested. I suspect they would be similar. A big bore 3.5R might be a different story. who knows!

A 4R with all the trick bits on it (wings, carbon wheels, carbon panels - essentially the '4' version of the '3') will be much, much faster round a track than a 3.5R. (however this is yet to be manufactured)



My simple understanding of BHP vs Torque:
BHP is product of torque and revs.

so actually BHP doesn't really matter. As torque is measure of how much force something turns with - after all, we use a torque wrench to do up nuts and bolts to the correct tightness, not a BHP wrench although, a BHP wrench does sound handy?

[reg]

Aero upgrades will be available - measurable down force in the real world is yet to be tested, but let me assure you - it is far, far greater than the current ones (which, whether you choose to believe it or not, DO provide down force and settle the car down a lot at high speeds )

I'm not about to put any suspension geometry details on a public internet chat forum - that's commercial suicide. We don't give that out to anyone which is part of the reason why there isn't anything like an Atom... We are more than happy to give out Setup advice, to change your camber etc, but not how the car works!

The Cup Car was never tested for torsional rigidity. However the Atom 4 has a 15% over the Atom 3.5. There is a difficult line between stiffness and compliance. too stiff and the car wold feel horrendous on the road, to soft and it would be wallowy on a race track.



I also don't see the obsession with comparing a standard 4 to a Cup Car or 3.5R... Comparisons need to be like for like really.

So:
A standard 4 is faster than a standard 3.

A standard power 4 with big brakes, bilstein adj shocks and a couple of other small items that you may or may not want is faster than a 3.5 310 with similar spec.

A standard power 4 with the above and some other nice-ities, wheels maybe, ohlins shocks, etc etc is probably faster on the road than a 3.5R. However - it being a road, there has been no racing!

A 3.5R vs a std 4 with adj dampers, wheels etc etc on track hasn't been tested. I suspect they would be similar. A big bore 3.5R might be a different story. who knows!

A 4R with all the trick bits on it (wings, carbon wheels, carbon panels - essentially the '4' version of the '3') will be much, much faster round a track than a 3.5R. (however this is yet to be manufactured)



My simple understanding of BHP vs Torque:
BHP is product of torque and revs.

so actually BHP doesn't really matter. As torque is measure of how much force something turns with - after all, we use a torque wrench to do up nuts and bolts to the correct tightness, not a BHP wrench although, a BHP wrench does sound handy?

But what about 800HP, the high speed entry into the apex of Turn 4 at Willow Springs, tensioner failure, generating clean air in London and the outrageous reduction in the size of mint aero's?

[jaylatti]

Can you back that up with butt dyno data logging plots ?

[Som]

When are we likely to see some video footage of any review done so far? Or by YouTubers?
Generally such reviews follow the written reviews within a week or so.