Rotrex supercharger questions/advice

[Bas_Himself]

Hi guys,

i'm new on the forum so I'll introduce myself briefly. My name is Bas, I live in Belgium, 34yrs old and recently bought a 2009 Atom 3 (Honda K20 SC). I also have a R35 GT-R which i'm planning to upgrade in the next two years.

I'm really happy with the Atom; drives fantastic, closest to driving a motorcycle without having to dress up in leathers

Although the power is mindblowing, i'd like to improve the performance. I mailed Komo-Tec (germany) to inform about the options. They advise an upgrade to 400hp with the Rotrex SC, and to what i understood from the mail, upgrade short block (i assume rods and pistons).

I saw this kit includes an intercooler which is mounted in the original air intake located next to the drivers head. I found some video's from a 400hp Rotrex charged Atom and i'm missing the squeeling high pitched sound from the original SC. Maybe this sounds crazy, but for me that's part of the charm. Not sure though sound is missing because of the video-quality or the different SC design.

Does anybody here who upgraded to a Rotrex SC can tell me something more about it? How does it drive? How does it sound? Pro's-contra's?

Curious about your experiences! Many thanks in advance for your advice gents!

[thomas_fr]

Also interested to get feedback from an Ariel with a rotrex

[speedmachine]

Hi Bas,

Welcome!

I know of one, it was a dutch car and the engine blew 2 times, apart from that, it was pretty fast, allthough on track he couldn’t keep up with me, for what it’s worth.

It did not had the wine as the stock cars, but it did had some extra charging noise, just different.

I didn’t really like that they have to cut in the panels to get it to fit, but it was fast and thats the point.

There are quite some belgium drivers, if you like I can introduce you to some

Have fun

[dreamscape]

3 members of the german club AACG have a Rotrex conversion.
All was done at KT and costed a fortune.
Even the installation of the TTS supersport kit at KT costs 3K more than in the UK!
For almost the same money you get the engine rebuild in addition at TTS.
The 475HP Atom has achieved a 10.5 seconds time on a 1/4 mile event.
The + 500HP Atom destroyed the lap record on a TV test drive.

However, as far as I know, only the TTS Kit Atom with 330 HP runs without issues ...
And yes, the Rotrex does not make that howling sound like the jackson racing SC.

[Bas_Himself]

Hi Bas,

Welcome!

I know of one, it was a dutch car and the engine blew 2 times, apart from that, it was pretty fast, allthough on track he couldn’t keep up with me, for what it’s worth.

It did not had the wine as the stock cars, but it did had some extra charging noise, just different.

I didn’t really like that they have to cut in the panels to get it to fit, but it was fast and thats the point.

There are quite some belgium drivers, if you like I can introduce you to some

Have fun

Hi Speedmachine! Yes i'd like to know them. Maybe we could create some kind of Ariel-club on Fb or something Would be nice to find some people closer to home in this small community of Atom drivers!

[Bas_Himself]

3 members of the german club AACG have a Rotrex conversion.
All was done at KT and costed a fortune.
Even the installation of the TTS supersport kit at KT costs 3K more than in the UK!
For almost the same money you get the engine rebuild in addition at TTS.
The 475HP Atom has achieved a 10.5 seconds time on a 1/4 mile event.
The + 500HP Atom destroyed the lap record on a TV test drive.

However, as far as I know, only the TTS Kit Atom with 330 HP runs without issues ...
And yes, the Rotrex does not make that howling sound like the jackson racing SC.

Thanks for the informative reply Dreamscape. I saw the KT500 Atom movie already on Youtube. It's just insane
For me 'issues' are no option. If the car and engine get upgraded, they must run perfect. The howling sound would be hard to miss. It's just part of the Atom-experience. Before i'll take the plunge i'll inform about prices both with Komo-tec as with TTS. Maybe the car keeps it's value (and howl) if i would go for the 3.5R oil-and intercooler. Anyway, first things first, next winter we'll be doing the GT-R's engine to start with

[HenryJS]

Bas,

Our experience of Rotrex Supercharged Atoms here at the factory isnt amazing - mostly they come back with issues - its usually a combination of running poorly and down on power.

When they do come back to us for a service and they are working properly, they dont feel as fast as a factory fitted roots type supercharger.

Our recommendation to fix these issues has been to remove the rotrex unit...

The car will not keep its value as well if you fit a non standard supercharger, particularly one from TTS. I would advise that you avoid TTS at all costs.

If you want more power - go to the 3.5R upgrade, and if you want more again, oversized forged pistons and upgraded rods is the way to go. you can get up to 365bhp this way.

Henry

[Bas_Himself]

Bas,

Our experience of Rotrex Supercharged Atoms here at the factory isnt amazing - mostly they come back with issues - its usually a combination of running poorly and down on power.

When they do come back to us for a service and they are working properly, they dont feel as fast as a factory fitted roots type supercharger.

Our recommendation to fix these issues has been to remove the rotrex unit...

The car will not keep its value as well if you fit a non standard supercharger, particularly one from TTS. I would advise that you avoid TTS at all costs.

If you want more power - go to the 3.5R upgrade, and if you want more again, oversized forged pistons and upgraded rods is the way to go. you can get up to 365bhp this way.

Henry

Hi Henry,

tried to PM you but for one or another reason the mail stays in 'outbox' and refuses to transfer to 'sent messages' so I assume it never left


Thanks for replying to the topic. So i understand you work at the Ariel factory/headquarters? Do you guys also upgrade Atoms (such as power upgrade 3 to 3.5R) with or without engine rebuild? If so, could you give me a rough estimate to upgrade to 365hp? I assume pistons and rods to manage the extra torque, but do you also install a different crankshaft for a bigger stroke?

I saw a pricelist from a few years ago and remember all parts needed came at +/- 10k GBP ex VAT. without engine internals (I assume it's only parts, so no labour).

Kind regards,

Bas

[John Scherrer]

The 300 to 310 was an ECU remap ..

The 310 to 350 is the 3.5R upgrade that Henry discussed in this post :-

viewtopic.php?f=3&t=17097&p=288441#p288446

To go to 365, they'd probably strongly advise that you'd need better pistons and con rods - I don't think Ariel offer that themselves as an option, but if you push enough ££ / Euros in their direction they might be able to do that work too?

[autobackup]

BAS

A PM remains in your outbox until the intended recipient retrieves it!

He/she gets a notice from the forum advising them of a waiting PM

[HenryJS]

Bas,

Message me on henry@arielmotor.co.uk

and ill take you through the options - or give me a call and we can go through it all!

[cvjoint]

I plan to install a Rotrex at the end of the race season. I'm not impressed at all with the Eaton unit used on these from the factory, it's really old and has low power output. If there was an option for a TVS 1900 or larger Eaton then it may become attractive. As it is, I'd say the output is capped at 10 psi/300 whp. You may extract more for short durations like in a drag race, but to get more PSI it has to work in a very inefficient range. Think that the Corvette ZR1 uses a 2650 unit for just 14 psi. If you look at that map, it's already pretty inefficient at that point. It also takes over 100hp to spin it in that application.

When driven hard for extended periods of time the Eatons transfer a lot of heat into the intercooler and that water remains pretty hot.

While the newer/larger Eaton units are quiet with optimized ports the mp62 is not. I can't stand the sound of it although I see many like it.

I understand older C38-91/92 Rotrex blowers have some reliability issues when used with Honda K, but it is unfair to say that is across the board. For example, the more commonly used C30-94 is bulletproof.

Though Eatons will likely last more miles than Rotrex, Atoms are rarely driven 100,000+. There is a performance penalty to pay for Eatons. I would use them only for 350hp and lower setups and Rotrex above that. For over 350hp builds, you may get a dyno queen Eaton mp62 that you can feed through an ice box, but it's not going to be a solid performer on track.

[HenryJS]

cvjoint

Agreed! For big power applications the Jackson Racing Unit is at its limit at 350-360bhp.

It was a conscious decision to not use any other units - as the Jackson was compact, relatively easy to install, and we didn't need to change too much hose routing on the car. Plus - 300bhp in something that weighs a several hundred kilos was enough

its not actually the Rotrex Blower unit that is the problem - its the APPALLING installations... fitted properly, and not just rammed in there - with a neat panel, or just the existing panel trimmed neatly for the unit, wired and plumbed correctly - it would be a great asset. But we haven't seen one yet that has been done properly / nicely / doesn't wreck the look of the car / make it slower due to bad running.

I'm not saying dont fit one - I'm saying be careful who you get to fit it.

Maybe one day someone will get our guys to fit one to their car! It wont be cheap... but I hope it would work!

[cvjoint]

cvjoint

Agreed! For big power applications the Jackson Racing Unit is at its limit at 350-360bhp.

It was a conscious decision to not use any other units - as the Jackson was compact, relatively easy to install, and we didn't need to change too much hose routing on the car. Plus - 300bhp in something that weighs a several hundred kilos was enough

its not actually the Rotrex Blower unit that is the problem - its the APPALLING installations... fitted properly, and not just rammed in there - with a neat panel, or just the existing panel trimmed neatly for the unit, wired and plumbed correctly - it would be a great asset. But we haven't seen one yet that has been done properly / nicely / doesn't wreck the look of the car / make it slower due to bad running.

I'm not saying dont fit one - I'm saying be careful who you get to fit it.

Maybe one day someone will get our guys to fit one to their car! It wont be cheap... but I hope it would work!

If I was Ariel I would have picked an Eaton too. In my C7 Z06 it outlived the engine, GM recycled it and just gave me a new engine. That's how durable they are. Plus it was quiet and civilized and one of the higher efficiency late model blowers. The bearings are good enough so that they can spun way out there in the inefficient range so even the aftermarket guys have a hard time breaking them.

Unfortunately with Rotrex you do have a wide range of experiences. The original Jackson-made Rotrex kit for the S2000 was one of the best. When he left, under the same Kraftwerks brand we got a re-engineered Rotrex kit that was the stark opposite, half the parts missing in the box and the ones that were included would fail in the first few miles.

The TTS kits strike me as some of the best out there. I feel like you guys are spoiled with quality craftsmanship in the UK.

Price to play and looks aside, the new C38R coupled with a high quality air-to-air HE would be light and literally double the output of an Eaton.