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CAI Development - passing the baton

I’ve posted quite a lot on this thread about my experience with the Radium CAI but I’m shortly to switch horses, and so, for the foreseeable, there won’t be any more. (I may well comment!) And regrettably, this is only a tidying up exercise.

I last reported - post #268 - on fitting a proper bell-mouth filter to the Radium intake tube; I discovered that although it increased power over my “Enhanced Radium”, it was not usable because of a weak AFR in the lower rpm range.

In that report I did not give any practical details of how I had fitted the intake, basically because it was not a successful development. I will admit that also I retained a hope that it might be possible to remap the ECU to adjust the AFR, not only to eliminate the above problem but to maximise power throughout the rpm range - within safe limits. I had been reliably assured more was possible from that alone. Further, if remapping could be achieved, it opened the way to adding an improved exhaust system. (I’d been warned that remapping would very likely be needed if an improved exhaust was added to my Enhanced Radium.) So, had remapping been feasible, a bell-mouth/Radium intake, giving pretty well maximum flow, plus a good exhaust, was an exciting prospect. So in #268 I held back details. However I’ve found that remapping is not practicable - not for me anyway. So, in case anyone else might like to use something of my approach, perhaps with AFR adjustment possible in the future, I’m now giving the practical details. I’ve not repeated the material in post #268, which does include links to relevant bell-mouth and AFR information.

Ideally, I wanted to fit the bell-mouth filter (HKS, 3.25” od coupling) to the end of the Radium intake without increasing its effective length as Radium say that the length is optimised. Also, at the same time to mount the combination without any modification to the Evora itself and ensure clearance and free air flow from the bodywork intake grill. And there had to be some flexibility, allowing for engine movement.

Given the size and shape of the HKS filter, even in discussion with some experienced in the field, these requirements appeared unachievable and I was resigned to extending the Radium tube forward and making a cut-out in the lower edge of the plastic air feed from the Evora bodywork intake. However a complete solution turned out to be remarkably simple! (Note that although an entirely usable and practical installation, a little tidying would have been done had it been successful!)

The filter was simply butted to the end of the Radium tube and joined with a short length of the usual silicone hose and large hose clips. (Only gently tightened to the plastic HKS flange.) The Radium tube was rotated about 180 degrees from its usual orientation, and inserted further than the Radium positioning, by the amount of the extra length of the HKS joining flange, into the Radium silicon coupler, which itself was rotated from its normal angle. These realignments positioned the HKS in available space in line with the air fed from the bodywork intake.

See the photos at: http://s1192.photobucket.com/user/Dalphacorp/library/bellmouthradium

The new intake assembly was mounted to the bodywork strut just below the inertia fuel cut-off switch by a substantial hose clip that was drilled to take a single bolt fastening though a further piece of silicon hose, which had been cut and held around the new intake assembly by a spring hooked through the hose ends. The arrangement was entirely secure but allowed flexibility in all axes. The outer silicone hose could remain in place fastened to the strut whilst the intake could be removed - for whatever reason - by unclipping the spring.

The Radium mounting leg projected vertically and reached near to the body work. To prevent contact from potential engine movement, a piece of rubber tube was pushed over it, as shown.

A standard right angle plumbing connector plus a short tube and clips allowed the oil breather pipe to be joined to the intake in its new orientation.

A new aluminium screen was needed to replace the Radium one - the same shape but much thinner and lighter - and, although the photo doesn’t show it clearly, it was in two parts, with the overlap areas largely covered with Velcro materials to join them removably. With the intake in place, the two parts could be installed separately; the cut-outs formed a hole surrounding the Radium tube. The design also allowed the screen to extend rearwards to cover the HKS completely. (No photo available.)

The last two photos show the results from three TDI tests. Comments are in post #268 but I emphasise that none of the three curves applies to a standard NA Evora. The lowest is for the basic Radium intake. The centre shows my Enhanced Radium. The top one is the HKS bell-mouth. (All results were with the Lotus Sports silencer and the 3rd cat in place.)

I wish good fortune to anyone else pursuing this approach.

Mel

 

Edited by mdavies
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A postscript: this won't be news to any fellow enthusiasts of the Radium CAI, but my sadness at parting with the Evora today was lifted a little by the main dealer receiving it.

 

A little surprisingly to me, given that he has driven too many Evoras to count, mine was the first NA with the Radium fitted.  Possibly others have removed them before trading in but I was asked to leave it fitted, although back to the basic non-enhanced version.

 

Anyway, returning from his solo checking run, he said he had been very surprised and volunteered: "That is far and away the best NA I have driven - it goes virtually the same as an S, and the sound is great".

 

I asked whether I could quote that here and he was entirely happy for me to do so.

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Exige S :)

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

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I suppose it's better than NOT being talked about - thank you both!  Shot in the dark Bibs?  Or has something leaked - perhaps I shouldn't have let B&C take that photo. But this thread isn't the place, so...............

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  • 2 months later...

There's also a new CAI from the U.S. Distributor of the Kold Fire tune, BOE. Here's a link to the thread. It's a bit long but this link takes you to where it became available for sale:

http://www.lotustalk.com/forums/f170/boe-evora-cai-123964/index9.html

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I have been running the BOE prototype CAI for a year now on my MY12 S; zero problems and 110% enjoyment.

Edited by Julian73
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  • 4 months later...

The radium CAI seems to be missing from the radium website now.

Anyone know if they have stopped making / selling it ?

Having toyed with selling up and deciding to keep a while longer, I figure a couple of small mods may help.

construction and property consultants : My company

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Did they indicate why? I thought they were popular and well thought of! :blink:

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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Sorry to learn that it is no longer available - it transformed the NA.  Perhaps Radium feel the market has been saturated. Some who sell on their NAs remove the Radium to sell SH.  My NA was sold with it still fitted although I did return it to standard Radium from my "more Radium than Radium" enhanced version. (Too much excitement can be bad for people!)  I am reliably informed that the new owner loves it.

 

Questions were once raised about its effect on the air-fuel ratio. I can vouch for the fact that as described in some of my posts above several tests by TDI showed the AFR with mine was fine, with both the standard and the enhanced versions.

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I was seriously thinking about this after spending hours reading this thread, but then read some less positive things over on seloc and got cold feet. Discontinued part doesn't make me any more confident with it to be honest. I may revisit it as it does get a lot of positive write ups, but will probably try to take a look at the exhaust first.

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Post it in our free classifieds, link at the top of the page :)

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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More noise, but also more power thx to another custom tune. The CAI is shaped like a megaphone, so it really gives a very throaty noise, much more bass than the BOE.

If you have the choice between a Stairway to Heaven and a Highway to Hell don't forget the Nomex®!

Captain,  Lotus Airways. We fly lower! 

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  • 2 months later...

Hi,

 

I may have missed this in the discussion but, what was the conclusion about the BOE Intake on a NA Evora, the Radium Intake seems to have been met with rave reviews, but they are no longer made and as rare as hen's teeth second hand.

 

Is the BOE as good, better or not as good?

 

Considering buying a BOE, just wondered whether it was worth the money or whether it is worth just keeping an eye out for a second hand Radium?

 

Cheers

 

Tris...

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