Atom 4 - Pre Spec/Order Discussion

[Hedge]

Well put.

Without having your own insurance, I doubt you'll be able to secure a drive yourself, so I wouldn't hold your breath otherwise. And the mags are going to be having first dibs, after all. As at a few weeks ago, there were only 3 A4's built, so...

I think builds begin around Spring. Which is probably for the best; picking up an Atom in Jan/ Feb ain't a ton of fun, after all.

Cheers,
Hedge

[Anon]

If it's faster than a 3.5R on track I'd be shocked but...pleased! If the chassis is a substantial improvement that means I have an opportunity to upgrade down the line. I'll fine tune the HPD race motor I'm working on in the SRA and drop it in the Atom 4.

So bring on the track reviews.

Why shocked? the 4 has more torque, a lot more and at lower revs meaning you can get on the power faster out of corners, so in effect this reduces scrubbing too much speed in corners. The chassis is stiffer, which means you can get more power down on the track than the old car and making it easier to drive - easier is normally faster for most as I am not a race car driver, I think I need this! And finally, the wheelbase is longer. This is most important I think, it allows the car the settle better and make the car less twitchy esp. over bumps, normally better in the dry. Not to mention, the whole suspension geometry has changed, I have not seen details of what these changes are over the old car but I would imagine they are better. This is not to say you could not setup a 3.5R to resemble the new car depending on the details of course.

So again, why would you be surprised the 4 would not be faster than a 3.5R, this makes no sense to me. Time will tell of course, if I were a betting man, I certainly would not bet on a older design that is for sure.

[cvjoint]

If it's faster than a 3.5R on track I'd be shocked but...pleased! If the chassis is a substantial improvement that means I have an opportunity to upgrade down the line. I'll fine tune the HPD race motor I'm working on in the SRA and drop it in the Atom 4.

So bring on the track reviews.

Why shocked? the 4 has more torque, a lot more and at lower revs meaning you can get on the power faster out of corners, so in effect this reduces scrubbing too much speed in corners. The chassis is stiffer, which means you can get more power down on the track than the old car and making it easier to drive - easier is normally faster for most as I am not a race car driver, I think I need this! And finally, the wheelbase is longer. This is most important I think, it allows the car the settle better and make the car less twitchy esp. over bumps, normally better in the dry. Not to mention, the whole suspension geometry has changed, I have not seen details of what these changes are over the old car but I would imagine they are better. This is not to say you could not setup a 3.5R to resemble the new car depending on the details of course.

So again, why would you be surprised the 4 would not be faster than a 3.5R, this makes no sense to me. Time will tell of course, if I were a betting man, I certainly would not bet on a older design that is for sure.

First, the Atom 4 is heavier. This is the down side of thicker tubing and longer wheelbase. I don't know where else the added weight comes from but it is a substantial increase. Weight is enemy #1.

Second, while it may have more torque, the 3.5R will have more power everywhere in band. Not only is peak power 40hp higher, I suspect power will be higher from redline to where it falls in the next gear in every gear. A driver that can keep the Atom in the meat of the powerband will have no problem pulling away from an Atom 4.

Third, the 3.5R is armored with loads of heat exchangers mounted in high airflow areas. If it manages to run substantially cooler it will stay closer to rated power widening the power gap further. I see that the nose on the 4 has the sides blocked off, great for drag reduction, but could be a decrease in airflow across the main core adding further to the heat rejection deficit. We all know it takes some work to build heat in tires. While heat is built up in tires it is also built in the powertrain. I suspect the performance drop off in the 3.5R will be much more subtle lap to lap.

I do think Ariel has headed the same direction as most auto manufacturers nowadays. It will be a car that inspires more confidence than the outgoing model. It will have features that help day to day driving, like improved turning radius and more attractive dash board design. The price to pay is added weight. But most importantly, let's get to the point here, it's about power and emissions. Honda's new powertrain is built to meet the more stringent emissions standards and in doing so it uses the turbo approach and some cost cutting as we've seen in every VTEC engine 2012 forward. The downsides are reduced head flow, the restrictive single exhaust port head design, laggy throttle response, no variable valve lift on the intake valves, more exhaust heat transfer into the head. So while yes, it will make more power than a K20A in naturally aspirated form, it is ultimately more limited in power output. It already runs ~23 psi.

It will be a commercial success. Confidence and road amenities are what most owners want, followed by good performance/$. The Atom 4 is a champ in all of these aspects. The real question is whether it will be a higher quality car that is faster than the entry level old gen. It is. It will even meet or beat the 310HP non -intercooled outgoing Atoms. Double success. Does it really need to beat the 3.5R? No, I don't think that's the mission statement.

The tough act to follow for Ariel will come later with high end models. What will TMI do in US to make a faster Atom 4 than the 425HP RS? I don't see a way forward as the K20C platform does not have any added tech to surpass that power output. In fact, the RS still has untapped potential via a K20 head transplant. There is a way to get 450hp on pump gas with older Honda K. There is no way with the current K20C.

[s2kseven]

New one is not always faster and better.
1989 my uncle bought a Ferrari F40, 1992 he traded in with Ferrari F50.
He regrets his move. Although his F40 was only 2.9 V8 and the F50 is 4.7 V12, the F40 drives better and faster than the F50. The F40 is lighter and agile. The F50 perhaps one of the worse model Ferrari ever made.

Most of the time new model are much better than the old model. But comparing extreme machine like atom is hard to find the fault. I say, Atom 3 or 3.5 vs 4.0 is very close. Give and take.

[Sir Nick]

Maybe it's just me, but I'm bored with all this tooing and froing now. How about stopping the conjecture and await real world experiences!
I've heard the Atom 5 is a superb car in every way...

[Hedge]

Maybe it's just me, but I'm bored with all this tooing and froing now. How about stopping the conjecture and await real world experiences!

A couple of us tried that already. And that didn't work so well

Cheers,
Hedge

[IanG]

I have also been told The new 5R is out of this world
Artist impression

IMG_0067.JPG (12.43 KiB) Viewed 901 times

[Peter255]

I am eagerly awaiting the options list! Last i heard it was coming soon.

More weight is not good for acceleration, braking or cornering. I am keen to keep the power to weight going up, not down!

Atom 4 is a fair bit heavier, and we need a fair bit more power to off-set that weight. I am sure options will be there.

Exciting times.

[reg]

I'm really not sure who to order the new Atom from now. I was thinking of the Ariel factory, but, there's this guy in the US.....

I thought the reason we all have two ears and one mouth was obvious.

[Anon]

Apologies if this is boring topic, but I am learning stuff here! lol

First, the Atom 4 is heavier. This is the down side of thicker tubing and longer wheelbase. I don't know where else the added weight comes from but it is a substantial increase. Weight is enemy #1.

I am not so sure it is heavier. The spec says 595 kg but I'm yet to see any outgoing car to be this light.

Second, while it may have more torque, the 3.5R will have more power everywhere in band. Not only is peak power 40hp higher, I suspect power will be higher from redline to where it falls in the next gear in every gear. A driver that can keep the Atom in the meat of the powerband will have no problem pulling away from an Atom 4.

Those engines the old K20a and the new k20C1 are very different. You have to rev the bollocks off the k20a engine to get the power which comes a lot later. The new torque'y engine is (from what I have read) instant all the way to the red line. The red line is way less than the outgoing engine, but I know some Honda specialists have found ways to improve this.

Third, the 3.5R is armored with loads of heat exchangers mounted in high airflow areas. If it manages to run substantially cooler it will stay closer to rated power widening the power gap further. I see that the nose on the 4 has the sides blocked off, great for drag reduction, but could be a decrease in airflow across the main core adding further to the heat rejection deficit. We all know it takes some work to build heat in tires. While heat is built up in tires it is also built in the powertrain. I suspect the performance drop off in the 3.5R will be much more subtle lap to lap.

There are benefits to the older port injection with regards to cooling. I guess I remains to be seen in high performance applications and track usage what this looks like on the new engine.

I do think Ariel has headed the same direction as most auto manufacturers nowadays. It will be a car that inspires more confidence than the outgoing model. It will have features that help day to day driving, like improved turning radius and more attractive dash board design. The price to pay is added weight. But most importantly, let's get to the point here, it's about power and emissions. Honda's new powertrain is built to meet the more stringent emissions standards and in doing so it uses the turbo approach and some cost cutting as we've seen in every VTEC engine 2012 forward. The downsides are reduced head flow, the restrictive single exhaust port head design, laggy throttle response, no variable valve lift on the intake valves, more exhaust heat transfer into the head. So while yes, it will make more power than a K20A in naturally aspirated form, it is ultimately more limited in power output. It already runs ~23 psi.

The single exhaust port head is all about cooling and simplicity, but this does limit tuning capabilities here. This is where the direct injection pump will be the limiting factor, simple solution is to increase this to gain more power and more burn. There are cheaper ways of increasing the performance though such as increasing the RPM of the engine. I suspect, once the options are released to get more power will be a combination of this. i.e. just increasing the vale spring pressure is a low cost way of doing such. More expensive ways is to add port injection in addition to direct like on the current engine. I am not a car mechanic, but it will be interesting to understand the tuning options supplied by Ariel.

It will be a commercial success. Confidence and road amenities are what most owners want, followed by good performance/$. The Atom 4 is a champ in all of these aspects. The real question is whether it will be a higher quality car that is faster than the entry level old gen. It is. It will even meet or beat the 310HP non -intercooled outgoing Atoms. Double success. Does it really need to beat the 3.5R? No, I don't think that's the mission statement.

The power is 320hp on the 4 in stock not 310hp.

I know in America, the community is often focused heavily on horse power and number of cylinders. In Europe we are less so because we understand half of building a great car is making it handle. See the BAC Mono, it has way less power than the Atom (280 if memory serves me correctly) but sometimes kicks the Atoms butt on track, including the 3.5R too.

[jaylatti]

Tdi north are tuning the k20c to 400bhp now with just bolt ons

[Peter255]

Simon,

If Ariel say Atom 4 is heavier, its heavier! Why would they over estimate the weight? That makes no sense. They are trying to sell the cars after all!

How can a longer stiffer chassis with thicker tubes and an larger heavier engine be lighter over all?

Ariel used to claim 520Kg for the Atom 3.5. on their website. Now that might be dry weight, but no one has EVER weighed one that light in real life.

Old 3.5 310's were 600Kg+ when owners have tested their cars.

If Ariel are stating 595Kg this time that probably another dry weight so we are looking at 75Kg more weight (using Ariels figures). In reality on the road with fuel the new cars will probably be ~700Kg. Remember there is a larger fuel tank this time too.

I think we are looking at a between 10-15% more weight this time around. But time will tell.

[phil4]

Old 3.5 310's were 600Kg+ when owners have tested their cars.

Yep, MOT chap without prompting mentioned mine was 625Kg. I'm with Pete on this, I think the weights they quote are dry weights (and no optional extras), and completely agree with him that the 4 is heavier, due to engine, size, and tube thickness as mentioned. Extra torque and power should negate that though. Or I could just go on a diet.

[wasp]

If you are interested in comparing weight, isn't it only fair to compare supercharged to turbo as most Atoms ended up with a charger bolted on?

Please don't shoot me down but I believe that the new 4 is 595kg and the old s/c was about 575kg?

Increasing the power in the 4 won't need the addition of hardly any weight for a simple upgrade (to say 360bhp) so the power to weight of a 4 with 360bhp will be better than the outgoing 3.5.

If you then factor in the massive extra torque, it should be ballistic.

That's before you even touch on the other massive list of changes.

I haven't driven in it yet but I believe Hedge because he's been in everything Ariel for donkey's years and knows his stuff and Henry is the most relaxed non-sales sales person you'll ever find and seems only interested in getting you in the right car for you.

I absolutely loved my old 3.5 310, but I do believe them when they tell me it's a massive step forward.

Spring/Summer 2019 can't come early enough for me!

Cheers,
Stu

[Fastlane]

Isn't it the case that the supercharged cars were/are nearer to 330bhp? So, the 3.5R was/is probably nearer to 380bhp?

I doubt the 4 has only 320bhp either, but Ariel have to quote the standard output for emissions purposes I would imagine. Based on what the factory have said, I would say it will be nearer to 360bhp sans cat...