Caterham Duratec Intake Plenum
Discussion
Hi Caterham Cats
I'm interested in using one of the Caterham plenums, that they developed for their Duratec 2.0 installations.
As far as I know, they've made 3 iterations :
1) The previous design. Bare cast alloy with an inward curved outer edge towards the TB. Caterham / Cosworth at the top of the casting
2) The current design used on the 360/420. Black plastic moulded, straight outer edge towards the TB,. Caterham at the top of the moulding .
3) The current design used on the 620R. Black coloured cast alloy (?), with intake at the bottom, designed for the SC fitment. Caterham Supercharged at the top of the casting.
If I wanted to used one of these plenums, for a NA Duratec, which is best?
What power levels can these plenums support? For example, would they be OK regards power & drivability if the Duratec was running R500 cams?
As a background, my installation is a S1 Elise, so I have an intake to bulkhead space limitation. Also if ITBs are used, the noise into the passenger cabin will be very high for a road car... more so if the bulkhead needs cutting to fit ITBs / air horns / filter air box.
Thanks for your advice
I'm interested in using one of the Caterham plenums, that they developed for their Duratec 2.0 installations.
As far as I know, they've made 3 iterations :
1) The previous design. Bare cast alloy with an inward curved outer edge towards the TB. Caterham / Cosworth at the top of the casting
2) The current design used on the 360/420. Black plastic moulded, straight outer edge towards the TB,. Caterham at the top of the moulding .
3) The current design used on the 620R. Black coloured cast alloy (?), with intake at the bottom, designed for the SC fitment. Caterham Supercharged at the top of the casting.
If I wanted to used one of these plenums, for a NA Duratec, which is best?
What power levels can these plenums support? For example, would they be OK regards power & drivability if the Duratec was running R500 cams?
As a background, my installation is a S1 Elise, so I have an intake to bulkhead space limitation. Also if ITBs are used, the noise into the passenger cabin will be very high for a road car... more so if the bulkhead needs cutting to fit ITBs / air horns / filter air box.
Thanks for your advice
There are some well trodden routes to tune the Duratec and the Plenum is normally only used with standard, or mild cams. Above 210 BHP the choice is normally ITB. If you want to mix R500 type cams and a plenum, there's nothing to stop you trying it, but IMHO the R500 cam has a overlap that is intended to utilise ITB, and may not work as you intend. A milder cam may work better. The exhaust is also a key part of getting hotter cams to work. The forced induction plenums may be more restrictive in a NA application, so best to use one designed for the intended purpose.
Noise levels will be up if you fit ITB, but there are airboxes that'll keep it bearable, and not much more than a plenum.
Noise levels will be up if you fit ITB, but there are airboxes that'll keep it bearable, and not much more than a plenum.
Hi DCL
thanks for your reply. I really enjoyed reading your build thread, so know you've 'been there, done that' :-)
Regards exhaust, I intend to get one made by 2bular, who make a bespoke 'over the subframe' 4-2-1 manifold for optimum power & heat management (normally in an Elise, the manifold is squeezed under the subframe, which means lots of tight radius, all near the driveshafts). This will require to cut the engine bay to boot bulkhead, which is OK for me, was just trying to avoid cutting the engine bay to interior bulkhead too...
Mmm 210 BHP isn't really where I want to be... In the Elise K Series world, Rover OE plenums are used up to 160... 180 BHP at a push, after that both power & drivability require the switch to ITBs. So I guess the 100 BHP / litre threshold is true for Duartecs too, if 210 BHP is the limit on a 2 litre.
Any more feedback is welcome
Cheers Lotus Loony
thanks for your reply. I really enjoyed reading your build thread, so know you've 'been there, done that' :-)
Regards exhaust, I intend to get one made by 2bular, who make a bespoke 'over the subframe' 4-2-1 manifold for optimum power & heat management (normally in an Elise, the manifold is squeezed under the subframe, which means lots of tight radius, all near the driveshafts). This will require to cut the engine bay to boot bulkhead, which is OK for me, was just trying to avoid cutting the engine bay to interior bulkhead too...
Mmm 210 BHP isn't really where I want to be... In the Elise K Series world, Rover OE plenums are used up to 160... 180 BHP at a push, after that both power & drivability require the switch to ITBs. So I guess the 100 BHP / litre threshold is true for Duartecs too, if 210 BHP is the limit on a 2 litre.
Any more feedback is welcome
Cheers Lotus Loony
Sounds like an interesting project. Going an established upgrade path is safer, but the relationship between induction, cams, and exhaust, is complex and can throw up surprises, so you won't know what works until you try.
Good luck, and let us know what you decide to do.
Good luck, and let us know what you decide to do.
Edited by DCL on Thursday 10th December 11:00
Pumaspeed offer a version of this as well for use in the st150 , it looks to be a vesion of the cosworth inlet .
I looked at the same install a few years ago using a 2ltr duratec and the cosworth plenum ( manged to buy a prototype off ebay from Cosworth direct)
The general concensus then was as above about 210/220 maximum before you have to go with ITB's not sure how you would get on with a 2.5 on a plenum , maybe the bigger capacity will raise the overall output
I looked at the same install a few years ago using a 2ltr duratec and the cosworth plenum ( manged to buy a prototype off ebay from Cosworth direct)
The general concensus then was as above about 210/220 maximum before you have to go with ITB's not sure how you would get on with a 2.5 on a plenum , maybe the bigger capacity will raise the overall output
Thanks Dave for your post
I think that version is simply a Puma branded Chinese knock-off... there's lots out there apparently, some rougher than others.
The 2.5 has much bigger ports, meaning the plenum won't align... trouble is if the 2.0 / 2.3 plenum is ported, the casting wall gets very thin & the theres no grove for the O rings / gasket... they'd need to be machined-in.
I think the more I look into it ITBs will be required on a 2.5, even for a mild tune, as apart from the Ford OE manifold, theres no alternative.
I think that version is simply a Puma branded Chinese knock-off... there's lots out there apparently, some rougher than others.
The 2.5 has much bigger ports, meaning the plenum won't align... trouble is if the 2.0 / 2.3 plenum is ported, the casting wall gets very thin & the theres no grove for the O rings / gasket... they'd need to be machined-in.
I think the more I look into it ITBs will be required on a 2.5, even for a mild tune, as apart from the Ford OE manifold, theres no alternative.
From the sound of it you are probably already aware, but Mountune produced a plenum for the 2.0 duratec as well. It was a limited run though and built to order. Might be worth speaking to them to see if they are planning another run any time soon. Or check on the fiesta ST owners club to see if anyone has one for sell.
Having said that.. the Mountune kit was 'only' good for 200bhp so may not be up to your task. Although they were working with the OE unmodified head so that was probably the limiting factor.
Having said that.. the Mountune kit was 'only' good for 200bhp so may not be up to your task. Although they were working with the OE unmodified head so that was probably the limiting factor.
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