Air box cover recommendation for S1

[Certified Lotus]

My S1 did not come with an air box. It has K&N filters installed on each of the webers. While going thru all the "spare parts boxes" I came across the back plate for the air box but nothing else.

It looks like I have three choices regarding air boxes, I can acquire a OEM style cover that is new manufacture, TTR sells a "kit" that includes the cover, hose and air filter or QED sells a cover. Someone had mentioned that reverie sells a cover, but I could not find it on their web site.

In reading all the posts on air boxes for the weber carbs, the main points are to install a larger cover for the rear carb air flow and get cold air from the front of the radiator.

Any comments on either the TTR or QED cover ?

[Certified Lotus]

Wow, 115 views and not one comment ? Did I say something wrong?

[elancoupe]

I have not seen the QED or TTR boxes, so I can't comment.

I do have a deeper airbox on my car, based on a past member's dyno testing. He claimed to see a 1 hp increase from the mod.

I purchased mine from a now defunct vendor - it didn't fit, and needed a ton of work to make it usable.

If you decide to purchase just a cover, be aware that there are several shapes of backplate. EDIT: check out this thread - lotus-carbs-f40/early-air-boxes-and-backing-plates-lots-wide-photos-t19248-15.html

I have a partially modified cover to sell, PM me if interested.

[prezoom]

As a result of dyno testing on an engine equipped with a single down draft Weber, the air box cover should be no closer than 2.5 diameters of the air horn from the end of the air horn. Any closer and the air flow is disturbed and results in reduced measurable horsepower. I am currently constructing a mold for the air box cover to meet/exceed this dimension for my S2.

The engine tested was a Datsun A12, (1179cc), equipped with a single DCNF on a stock intake manifold, using 26mm (class restricted) venturi. At the time of this testing, the engine was making 118 horsepower.


Rob Walker
26-4889

[Certified Lotus]

Thanks Mike. PM sent.
Rob, will you be selling air boxes once your mold is completed ?

[patrics]

Hi,
I have a TTR airbox in my car and wouldn't buy one again - very poor quality.

Haven't seen the one from QED.

Regards
Steve

[JohnDanbyRacing]

We run TTR airboxes and filter, no issues here, performance no different with airbox or open trumpets on a recent back to back test but would not run without a filter for road use.

[prezoom]

My bad, drain bamaged, asleep at the switch, or just a fat finger. Hit the 2 instead of the 1 when I meant to say 1 and 1/2 diameters should be the minimum distance from the end of the air horn to a flat surface. So, for a 40 mm air horn, the minimum distance should be 60mm.

Rob Walker
26-4889

[Certified Lotus]

Rob, thanks for the correction. I was using your suggested distance as a guide looking at other custom air boxes. Now I have a few choices

[Certified Lotus]

I pulled the trigger on the QED airbox as my engine build will require as much airflow as possible to the carbs. Will see how it all turns out.

[vstibbard]

A club lotus Australia member in queensland makes replacement airbox covers for S1 and 2 that are larger than standard.
I will be at my shed later in week and will find a photo of one i had and will post it.
Regards V

[el-saturn]

hi - kelvedon (lotus in UK) have (i suppose) the part you're looking for 36 / 4982 sandy

[Certified Lotus]

A club lotus Australia member in queensland makes replacement airbox covers for S1 and 2 that are larger than standard.
I will be at my shed later in week and will find a photo of one i had and will post it.
Regards V

Vaughn, Greatly appreciated your sending me photos of the airbox. This is exactly what I am looking for. I am very interested in purchasing this airbox cover. Can you send me the details?

image.jpeg (50.77 KiB) Viewed 1455 times

[Stevie-Heathie]

Glen

How did you get on with your QED kit please? I'm considering the same for my S3. I ruled out the TTR version after a negative experience reported in the thread above.

Best
Steve

[Certified Lotus]

Steve, I have purchased four (4) different air boxes and the only one that fits is the original narrow design that came with the car.

All the others interfere with the bonnet edge when attempting to close.

It seems that when "others" built larger capacity air boxes they increased the size of the front part where the air trunking hose attaches, not just the rear of the box. This prevents the edge of the bonnet from clearing and being able to close the bonnet.

I'm still looking for a design that will actually work in an S1.

In the meantime, I have a bunch of custom air boxes that only fit later Elans. They are all for sale.