Reverie CSR 'ram-air' carbon airbox - anyone tried?

[vertew]

Hi, 

I've always suspected that the internal airbox on the CSR is not brilliant for power, given the high engine bay temps.  Don't know if there's any data on this.  Perhaps when the car is moving quickly, there's enough flow around the engine bay so that the air is shifted and the high temps aren't an issue?  Back when I got my CSR remapped by Steve Geenauld at 'track and road', he mentioned that CSRs could be losing quite a lot of power due to the (standard) enclosed airbox.  My CSR is also marginal for noise on track days and a big part of the problem is induction, so an airbox might help with that too.

I've looked at various alternative induction options and nothing has seemed quite right, but I found this CSR Carbon Induction Kit by Reverie recently, which looks like it could be the best solution so far.  There's also a blog article about the product here.

It took me a while to work out what's going on here, but essentially: 

• the air filter fits directly onto a PX600 backplate (which CSR already has as standard) 
• it also uses a standard PX600 air filter - the airbox just sits around it (would need to confirm depth of std filter to be 100% sure of fit). 
• the airbox extends out beyond the bonnet line, so - yes - this means a hole in the bonnet. 
• the air intake faces forward, so there should be a ram-air effect at speed.

If I can get used to the idea of a hole in my bonnet, it looks like a really nice design.  Also, if existing CSR (PX600 fit) induction parts can be re-used, not a terrible price of around £400 for just the airbox part (as the fitting kit is not needed).  There's a note that ti may be quieter too, which might prevent me getting black flagged (again). 

I've got carbon wings and arches on my shopping list next, so further upgrades will have to wait a while ... but really like this airbox. Would need some careful thought about how to cut and finish the bonnet clearance hole (and some spare pants) ... 

Back to original Q ... anyone got any experience of this?
Perhaps the owner the owner of the 'full race' CSR mentioned in the blog is an L7C club member and could share experiences?
Is there a template for the (eek) bonnet hole?
Would be great to know more about power increases / noise ...

cheers, Andrew.

[SLR No.77]

I’d be keen to find out whether the integrity of the bonnet is still maintained after the hole has been cut, it’s hard to see from the photos how much space there is on the underside of the scoop? Also as far as I can tell the intake is not completely outside the bonnet line which seems a little odd.

Stu.

[Golf Juliet Tango]

It looks like the Arnie Webb approach. (long-standing members will know about K2RUM).

My view, (I'm not a trackday runner, so feel free to dismiss my opinion), is that having that sticking out of your bonnet is horribly ugly.

[vertew]

@Stu - looks like the bonnet cut-out should be around the same size as that required for any deep PX600 size airbox / filter (which aren't that uncommon on a 7). Yes, it does look as though the scoop is not fully exposed.  So long as the motor gets enough cooler air, perhaps that's ok.

@Stephen - I'm not sure on aesthetics yet ... I don't mind admitting that I quite like the look of a protruding carbon airbox (fnarr).  I've asked reverie whether they could share any pics of the installation, with the bonnet fitted.  Having now googled Arnie Webb, wow I see what you mean. Similar approach, though this is somewhat lower profile.

The more I think about it, seeing more pics of the install is probably a pre-requisite, certainly before I get the sheet metal nibbler out .........

[Golf Juliet Tango]

I saw your request for a picture with the bonnet in place whdn I read one of the links you offered.  A very sensible and fairly modest request.  A bonnet from Arch costs less than the airbox.

 

[vertew]

Thanks for the pointer on the bonnet, I thought they were a lot more expensive.  A second bonnet not out of the question then, which give the option of running with / without the airbox.

[David aka Blue7]

Sorry but it looks downright ugly, it is a shame to spoil a CSR by fitting that monstrosity ... and lose £400 in the process 

[David.Ashley.Poole]

Hello Andrew,

There is a lot of interesting information on this site (http://csr200.blogspot.com/search/label/CFD) about an attempt to model the flow characteristics with a carbon intake using CFD techniques... but the results were not encouraging.  He did do some dyno pulls with a “PX600 Airbox” installed, when he saw a big loss in power - but this is not what we have on our CSR 260s.   I think that the biggest difficulty in any sort of intake trunking is ensuring that all intakes get the same mass flow.  If this is not achieved the cylinders will be running different air/fuel ratios, and you stand the chance of running one cylinder into lean detonation or worse.  The standard CSR air filter seems to ensure a more or less isotopic airflow around the intakes, and I have never seen any sign that one of my cylinders or plugs has a different mixture from the others.  I think that you could probably get Arch to make you a bonnet with a nice looking scoop on it, but whether it would be better to use it to keep the underbonnet cool and use the present filter or to direct it into an intake trunking is anyone’s guess.  But I would rather someone else experiment with it other than me - new Cosworth 260 engines are in somewhat short supply.

So let us know how you get on, and Good Luck.

 

 

[Golf Juliet Tango]

http://csr200.blogspot.com/search/label/CFD

This is very clear. Thank you.

[elie boone]

I thought  a rough guide for an airbox was 7 x the engine capacity.

[AdamQ]

On my S3 Duratec with Jenveys, my effort to get cold air to the engine eventually consisted of a home-made airbox on a PX600 back-plate going forwards to an in-line K&N air filter above the steering rack and thence to an air intake via a hole cut in the bottom of the nose-cone below/behind the number plate.  There's no hole in the bonnet - it all fits inside - just!  With the Jenveys, it means shorter trumpets (40 or 45 mm I think), but it all seems to work OK ...

FWIW ...

Adam

[7 wonders of the world]

Its not always possible to get everything inside the bonnet depending on your engines spec and what length inlets and trumpets it needs.

If cosmetics if your first priority then you can significantly compromise the performance of a tuned engine, you ideally need to try different inlet lengths on the rollers and see what works for you engine.

[vertew]

Thanks all for the comments ...

@Blue7 - appreciate your view.  My CSR is silver / black and carbon, so already looks a bit 'utilitarian'. Kinda think an exposed carbon air box wouldn't be too out of place.  Definitely need to see pics.

@David - yes, I've seen that blog article.  Fascinating, though the static analysis doesn't model the pulses of moving air as valves open/close (as author acknowledges).  Safe to say "it's complicated".  Certainly don't want to do an damage to the motor, that is a worry.  Nice idea about a custom Arch bonnet intake with the standard induction, I might explore that ... would be lower risk.

@Adam - the CSR200 blog owner did a similar thing, by 3D printing a custom intake.  This took a cold air feed from nosecone intake that feeds that keeps the rads cool.  Did you get a view on power before / after ?

I've got a reply from Reverie.  They say Mountune tested the customer car and got a temp drop of around 20deg with the power benefits.  ITG filter (part of kit) reduced noise.  Also confirmed is the need for a shallower 30mm PX600 backplate (also part of kit), the standard one being 60mm.  I'm waiting to see if it's possible to get pics.

tks, Andrew.

[David.Ashley.Poole]

Andrew,

i have been considering getting a new bonnet for my CSR 260 for some time - and I would if I could match the paint, which is that McLaren Orange and seems to be unobtainable.  My present bonnet is mounted a little to close to the scuttle and has scuffed the paint.  I have considered filing the rear catch mounting holes in the bonnet into a short slot, that would be covered by the retaining plates when they were pop-riveted, but have not yet done so.  But a nice new bonnet from Arch with a stylish scoop may be just the thing...

[AdamQ]

Hi Andrew,

I haven't got any meaningful before and after figures I'm afraid.  The car was mapped by the two Steves without the cold air feed and made 203 BHP and 164 lb ft.  It was subsequently remapped with the cold air feed and made 210 HP and 179 lb ft.  However, the remap was on a different rolling road and other things had also changed (the cam timing was found to be off after the initial RR session) so I think those figures are pretty meaningless to be honest.  Also the bonnet was off for both RR sessions.

Subjectively, before concocting the cold air feed, I did think the car became slightly 'asthmatic' on hot days, particularly after sitting in traffic, and that is no longer the case.  I believe it's also slightly quieter, but I've no data to confirm that.

Good luck with whatever you decide to do!

Adam

[David aka Blue7]

Apologies for thread hijack.

Andrew, re your scuffing bonnet problem, I had the same issue with my last CSR and a similar problem again with my current CSR.  Not only is the bonnet a tight fit between nosecone and scuttle, it also rubs on the coil cover, especially the Cosworth badge mounted on the cover.  My solution to both problems was to fit Caterham's cycle wing rubber edge strip (product code 76110), to the front and rear edges of the bonnet, which has resolved both issues ... well the Cosworth badge had to be shaved down a bit with a belt sander plus another tweak to pull the coil cover down.  You may find it cheaper on CBS but I bought the Caterham product here:

https://caterhamparts.co.uk/brackets/307-edge-trim-sva-cycle-wings.html

David

 

 

[Manstein]

I was aware of your bonnet rubbing the coil cover Blue but didn’t realise it was a tight fit fore and aft. Must be lucky with mine all seem to have clearance or perhaps CC’s builders got it right for once!

[David aka Blue7]

The last CSR was the worst.  Apart from the damage to paintwork along the edges, it causes the most annoying buzzing vibration as though something at the back of the dashboard was loose ... it had many a thump with clenched fist to no avail.  I eventually stopped, removed the bonnet and the vibration ceased.  It is probably caused by the nosecone being fitted too far forward rather than a bonnet that is slightly too long.  Buying a new bonnet will not resolve the issue unless you request a made to measure bonnet.

The paint matching issue should not be a problem, you just need a decent skilled person to match the paint.  Paint codes are pretty much useless because the original paint fades over time and the colour changes.  When I had my wheels sprayed blue by Wheel Specialist, they had about twenty samples that were close to and looked like Plasma Blue, it was hard to choose and you needed to be outside in the sunlight to get a good match.

 

[vertew]

There are some more pics of the CSR with the ram-air airbox on the Reverie site here (looks like a couple of airboxes tried).  The images look small, but are actually high-res, so worth downloading.  Thanks to Simon (MD of Reverie) who provided the pics.  He mentioned that the ram-air airbox, was fitted to a race-winning CSR prepared by Boss Racing.  He doesn't have a pic with the bonnet fitted ... I'll drop a line to Boss Racing and see if they have any.

To be honest, my road-going the CSR 260 has more than enough power out of the box, but if they're some relatively easy bhp to be had by addressing an issue such as high intake temps, with a straightforward(ish) retail mod, then seems worth looking at.  I'd j-u-s-t about count cutting a hole in my bonnet as 'straightforward' if the aesthetics are ok.  I'd hope that my MBE ECU (which has been remapped though with std induction) would have enough flexibility to deal with a slight induction improvement and safely deliver some extra bhp.

If an induction mod requires another remap, or other parts are needed (like experimenting with different trumpets) ... then this is all probably edging into too difficult/pricey area.

On the bonnet scuffing ... I've had that too, as well as bonnet vibrating against the carbon coil-pack cover, which caused the really attractive buzzing noises. I've replaced the foam tape on the nosecone and scuttle with slightly thicker foam + also added that same foam tape down each side of the bonnet.  The combination of all of this seems to have lifted and cushioned the bonnet enough to stop the buzzing.  Think the scuffing is better too, though time will tell.

@David - love that McLaren Orange colour.  I was looking for a CSR in that colour, but couldn't find one, then a silver turned up (that I also like a lot).  If was ever to respray mine, I'd find it hard to resist the orange though ........

@Adam - best of luck with your induction mod too - sounds like you've done a great job with it!

tks, Andrew.

 

[vertew]

Amazing what you can find on google ...

I know beauty is in the eye of the beholder etc ... but I like the look of it, even though this is a race, not a road car.  The CSR is already festooned with slats, vents and carbon bits, so one more might not look out of place.  It does look as though the bonnet hole might have been sized for a different airbox, so could possibly be made to be a closer fit.  Anyway, that does seem to solve the mystery of what it looks like !