Carbon air box (R500) unable to fit under bonnet

Carbon air box (R500) unable to fit under bonnet

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griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
Morning,

Wonder if anyone else has had this and solved the issue.

For trackday noise reduction I have bought the carbon airbox with cone filter under the bonnet. However, once fitted, the cut out in the bonnet sits on the neck of the box meaning I am unable to close it.

Not sure but I believe I have either longer trumpets with the raceline DHTBs or a spacer pushing them out. Rather than change that I think the only other option is to extend the hole in the bonnet by an inch or so to allow it to close.

Anybody else had this and solved it?

Cheers,
Lee

griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
I annoyingly didn't take any pictures at the weekend but the below shows the current filter sitting quite high to others I have seen. Would say I have the carbon bathtub (if that's what it's called), about 2 inch depth that the box connects to. Certainly not flat.


griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
Fair play, will sort some pictures out tonight.

This is the airbox:
http://caterhamparts.co.uk/product.php?id_product=...

DHTBs are raceline versions.

griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
Thanks Greig, that saved me some photos. smile

Alas that airbox will not knock the noise down far enough for me, hence the contained effort I bought. Aimed to add some further noise reduction on the outside and see then how I get on.

Dave, re the filter on the end, it's certainly tight but think I can solve that with a bit of modification, the carbon elbow however is the main issue.

Sounds like a bonnet cut... Anybody done that (well) before smile

griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
Was at an MSV Brands day with a 92db driveby, seemed to be reaching 97db with the open filter.

Garage chum in an R500 I met that day (struggling with noise limits too) had the enclosed version which knocked off 2-3db, and the one you show below which only knocked off 1db.

Given the above it would leave with me another 3-5db to find on the enclosed unit which I hoped to manage through external sound deadening, amongst other things.

Had to keep to 6000rpm limit to stay at 92db (with repacked exhaust so not that), got second black flag when pushing to 7000rpm

What drive by levels were the track days you used to attend?

griggsy2

Original Poster:

126 posts

281 months

Monday 26th September 2016
quotequote all
I saw a previous picture of the car with the box on and specifically asked if they had it, "No". I said in that case maybe the previous owner held on to it, "Likely".

Will keep my eyes open for one in classifieds, can't justify the cost of a new one (£440) on Caterham parts just to test.

Edited by griggsy2 on Monday 26th September 16:43

griggsy2

Original Poster:

126 posts

281 months

Wednesday 28th September 2016
quotequote all
Thanks Mike!

I could, and I expect you are correct, but I believe the mapping was done to take advantage of the extra space provided by the bathtub which freed up quite a bit of extra performance from the engine. I appreciate I will bugger that up a bit anyway by adding the box but aim was just to use that for track days and switch back and forward with the foam filter.

If I can avoid a more permanent adjustment I would like to. Annoying thing is the driveby level is not so easy to test short of going on track and seeing how it goes, unless anybody else has found a decent method.

griggsy2

Original Poster:

126 posts

281 months

Sunday 19th February 2017
quotequote all
After a while I decided to buy a new bonnet to use on track days and cut an extension in order to use the carbon box whilst keeping the bath tub.

A dremel, few files, some masking tape and some bravery later, jobs a good'un!

Just need to get the bonnet sprayed to colour match and striped. smile







Edited by griggsy2 on Monday 20th February 09:20

griggsy2

Original Poster:

126 posts

281 months

Wednesday 12th April 2017
quotequote all
Looks nice but all done now with new bonnet whilst maintaining the bathtub smile



Edited by griggsy2 on Thursday 13th April 08:59