Product Review Craven Speed “Return of the CAI” Cold-Air Intake system for R53 MINI Cooper S

“Return of the CAI” is a confident and remarkable name for a relative newcomer to a densely packed segment in R53 engine performance...
By Ryephile · Jan 31, 2018 ·
  1. Ryephile
    Craven Speed “Return of the CAI” Cold-Air Intake system for R53 MINI Cooper S

    Product Review by Ryan Malcolm
    Photos by the Author​

    1) Introduction:
    2) Shipment, Packaging, & Parts:
    3) Instructions, & Installation:
    4) Behind the Wheel; Subjective impressions & Objective data:
    5) Conclusions; Likes, Dislikes, & Recommendations:


    “Return of the CAI” is a confident and remarkable name for a relative newcomer to a densely packed segment in R53 engine performance modifications. The first Cold-Air Intakes [or CAI for short] splashed into the MINI aftermarket soon after the cars launch back in 2002. Some early models ranged from quite crude to reasonably effective; however as time went by the lackluster products fell to the wayside as consumers become complacent with the long-crowned kings of the category. Craven Speed’s parent company, DLT LLC, isn’t new to automotive aftermarket, and feels their Craven Speed line has a fresh perspective on the subject. Craven Speed is confident they have designed a segment-busting winner on their hands. I’m always excited to check out new stuff, but with such a product name, what have I gotten myself into?




    A large white cube came barging its way into my laboratory via UPS Ground. I was impressed to see UPS had kept the white finish relatively fresh and clean. Everyone gathered around and asked what goodies had arrived today. Upon opening the very neatly assembled white box we found the container mostly filled with cleanly crumpled heavy brown packaging paper. As with my favorite breakfast cereal, some of the contents had settled in shipment. As we shoveled out the large wads of paper, we found the goodies; a beautifully black powder coated heat shield, a bright red UNIfilter with the “Craven Speed” logo screen-printed cleanly, a baggie filled with instructions and hardware, and a final piece.
    “What’s this?” A Lab-Rat inquired.
    “Ahhh, this must be the tinted polycarbonate box top, complete with protective film.” I quipped
    “The machined edges are well done. It’s very sexy, I can’t wait to see it put together!”


    I was a bit surprised to see the UNIfilter loosely packed within the box. I was hesitant to pick it up as they’re usually saturated with filter oil, which is gross and sticky. To my amazement, the UNIfilter was extremely lightly oiled, almost dry. This will make installation easy, and will definitely make more power at the expense of filtration, but in practice I would spray a whiff more oil to ensure good filtration. The UNIfilter was supplied with a worm gear clamp already installed, a plus. In the long-term, maintaining the filter is really easy. You can find UNI brand cleaner and oil at any power-sports store and a good cleaning approximately every 10k miles will keep this filter good-to-go practically forever.

    The aluminum heat shield piece is interesting. It is unlike any other CAI heat shield I’ve seen to date. It houses a large volume of air, larger than the factory air-box. It’s also beautifully powder coated in a stealthy and rugged crinkle black finish. This piece replaces the lower and upper air-boxes, making the Craven Speed CAI about 1 pound lighter than stock.

    The hardware is separated into two little clear plastic bags. There is a lot of hardware for a CAI; hopefully the instructions will make easy sense of it all. The polycarbonate box-top is nicely wrapped in protective bubbles, making it a safe bet it will arrive on your doorstep in perfect condition. The whole collection of parts for the CAI system feels important and of the highest quality, it is clear Craven Speed didn’t skimp on the little details or on squeezing the last cent out of the design.



    It is becoming increasingly common that nice color printed documents be enclosed with fancy products, and Craven Speed certainly does no wrong here. What doesn’t quite work for me is the lack of pictures. There are two rather small CAD drawings that have assembly lines, but it frankly reminds me of an old stereo manual; the ones that get the really bad rap and end up leaving ADHD people frustrated and throwing screwdrivers at their landscaping. I took the time to read through the words, and tried to reference the “assemble by number” system, but in the end, I tossed the instructions aside and began fiddling through the bags of hardware.

    The installation begins by not installing anything, but lifting the bonnet of your R53 and removing the entire air-box assembly; front fascia snorkel, upper air-box, lower air-box, and ECU. The only thing we will reuse here is the ECU; the rest is discarded in the name of performance. If you haven’t seen your transmission in a while, take this time to be a neat freak and polish up your engine bay in this rarely accessed location.

    Before you can put the Craven Speed CAI in your R53, you have to do some pre-installation assembly. There are some brackets, a cross-brace, and battery terminal clamps you need to screw into the heat shield. The ECU gets bolted to the inside of the heat-shield, which is a novel way to install it not using the factory lower air-box. For tools you’ll need a 9mm socket, 11mm socket, and a 3/8” socket. The 11mm socket is a rough-fit for those of you that don’t happen to have an 11/32” socket lying around. Another idea is to just use an adjustable wrench so you’re not rummaging all over the garage trying to figure out which size nut they actually are. Why Craven Speed didn’t unify the nut hardware type among metric or imperial seems like a small oversight to me; the only saving grace is all the bolts are #2 Phillips-head. Another little issue is the two little hardware baggies seemed to have some of their contents crossed; the washers for the ECU were mixed-in with the L-bracket and cross-brace hardware. Small peanuts, but little things like that can make a big difference in installation ease.


    Fitting the completed heat-shield box into the MINI is easy; it just drops right in! Be careful to keep the ECU wiring-harness protective-bellows next to the thermostat clear during installation. I like the battery terminal clamp idea, it’s simple and effective. The whole design seems to have taken a particular liking to the use of flat-nuts; both the battery terminal clamp mechanism and the box-top latches use flat-nuts. The install wasn’t without a snag; I could not bolt the heat-shield to the body near the fuse block for two reasons. The heat shield was pressed against the brake booster and I would have had to bend the heat shield to install it, and there was no hardware supplied to bolt it to the body. I suspect the stock plastic expansion-nut could have been used; however I would have needed to bend the heat shield to match up the mounting holes. For this review, I left it as it sat with a small air gap. The rest of the hardware bolted up flawlessly. It shouldn’t go without mentioning that my battery terminal cable was rubbing against the Craven Speed CAI heat-shield. I would highly recommend slightly kinking the battery cable and using some sort of extra insulator to not chaff the cable insulation. If the battery positive cable was to short against the aluminum heat shield, it might short to the case ground of the ECU and cause a very bad day!






    Upon finishing the install, it was time to key-on and check it out. The engine fired up immediately, revving fiercely and sounding very awake and alive. There were no dashboard warning lights [a good thing!], and there were no vacuum leaks. It’s time for a test drive! The first thing I noticed was how willingly the engine responded to my right foot, and how quickly it revved freely. The growl of the CAI was quite pronounced; very authoritative and not timid whatsoever. When accelerating lightly, the Craven Speed CAI has a distinct sound to it; like a monster sucking huge amounts of air through a 2.5” straw. That all changes when you floor the throttle; the sucking sound changes to a deep growl, and the car lunges forward as if pulled along by a vacuum created from the CAI pulling in the entire atmosphere in front of you. It’s a visceral, spine-tingling experience that makes fun of the stock air-box like a grade-school bully teases a nerd with coke-bottle glasses. This is the loudest, meanest, quickest feeling CAI I’ve sat behind in an R53.



    Part throttle drivability is one aspect I’m not totally thrilled with. While the quick-revving nature of this CAI is fabulous for floorboard-bending redline blasts, light cruising demonstrates some quirky sucking-through-a-straw sounds and enhanced throttle transitions. When moving from off-throttle to light-throttle and back again, there are some awkward reactions that the Tritec engine does that seem to be amplified with the Craven Speed CAI. While some people may prefer this excited throttle feel, those used to a more relaxed pedal interaction may need some acclimation. After several miles of getting used to the newly sharpened throttle feel, it’s relatively easy to teach yourself to not be so abrupt with the throttle pedal like you can be with a stock Cooper S.

    I used my Auterra OBDII Scan-tool with dynamometer calculations to do some sensor observations. The Craven-Speed CAI consistently demonstrated at least 10°F lower intake air temperatures than stock, with quicker temperature recovery after a heavy-footed stomp to redline. The dynamometer calculations showed comparable gains to the very best competitors to the Craven Speed CAI; clearly this CAI deserves to be recognized as a top-shelf performing piece. The kicker isn’t just that the Craven Speed CAI performs excellent; it provides caffeine-enriched throttle response and hardcore sensory enhancement to go along with it.

    The only maintenance item with any CAI is occasionally refreshing the air filter. With the Craven Speed CAI, they chose a UNIfilter. I can’t lie, I’m a fan of UNIfilters. They’re a popular brand in dirt bikes and ATV air filters, and if that is any indication these filters stand up to harsh environments. Cleaning takes about an hour total, though most of that time is spent waiting for the filter to dry. Removing the filter entails removing the pretty tinted polycarbonate top cover. To do that you have to loosen the four Phillips screws and rotate the flat nuts 90 degrees in order to simply lift off the cover. At this point you just loosen the worm clamp on the filter and pull it off the heat shield. After that, you will have to run out to your local power-sports dealer and pick up a UNI brand cleaning kit, usually under $20. Spray the foam filter with the cleaning solution, rinse it with water, and let it air dry for a while. When it the filter is dry, spritz on a light coating of filter oil. The UNI filter uses very viscous and tacky oil that is specially formulated for the foam.




    The Craven Speed CAI is an exciting, value-rich addition to the R53 aftermarket catalog. While there are some little quibbles regarding assembly and installation, the sensual and performance gains are worth it. I may caution this CAI is not for everyone; those not looking to maximize their aural experience may want to look elsewhere. For those that are interested in getting the most out of their supercharged setup, this is your ticket to success, loud and proud.

    1) Excellent torque gains across the RPM band
    2) Expensive feeling fit-and-finish; no corners cut on materials
    3) Lighter than stock!
    4) Spine-tingling acoustic concert for the hardcore enthusiast
    5) Huge UNIfilter lasts forever with easy regular cleaning and flows mega air

    1) Requires patience and problem-solving during assembly
    2) Demands caution of battery terminal during installation, additional insulation needed!
    3) Spine-tingling acoustic concert might rate low on S.A.F. [Spouse Approval Factor] scale


    To Craven Speed, I would suggest a quick re-sort of the hardware bags and perhaps adding labels saying what hardware goes to which part of the assembly. A few more pictures in the instructions would work miracles for assembling the box painlessly. One step further would be to offer an assembled heat shield!

    To the Reader, if you’re looking to buy a CAI, put Craven Speed’s CAI on your short list. It’s not without flaw, but no CAI on the market is. The combination of light-weight, high-quality, large power gains, and amazing acoustics make for an irresistible package. The pricing is on-par with its competitors, which is completely fair given the quality pieces making up this CAI.


    Response from CravenSpeed

    What is in a name anyway? This is our sequel, so we named it like one. We did consider some other names such as; “Son of The CAI”, “The CAI Who Shagged Me”, and “I STILL Know What CAI Did Last Summer.” Good to know that the protective film was not a turn off for you, it is really the best way to keep the top from getting any scratches. You have talking Lab-Rats?!

    Hitting the filter with oil is important, after all, it is the oil that does much of the filtration. We do have UNIfilter spray oil sold separately, and batteries not included.

    The good news is that it is intuitive to assemble when you see the picture of the finished box. We have revisited the instructions after reading your comments, and simplified them quite a bit and we are adding some nice photos too. We also rearranged the bolts in a way that makes more sense. Look for an instructional video to be ready to help with installation soon.
    These tips also will be included in the updated instructions, along with a replacement bolt for that plastic one. The heat shield piece in question is aluminum, like the rest of the box, and will bend to match up when properly bolted.

    Just so we are clear, Craven Speed would never tease a kid with glasses, we all were that kid.

    I do not know what else to say. We are all so glad that you enjoyed your time with our intake on your MINI. Of course, as with anything, there are flaws. Albert Einstein said, “Anyone who has never made a mistake has never tried anything new.” When we innovate, we err. It does seem like we are close enough to be content this time around! Time to move on to the next project.

    Original Source

    Written by: Ryephile, Apr 23, 2009,

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