Birkin42

I've seen Ryan preform a number of times and his abilities on a bike always blowns me away. His feature Video Manifesto is pretty good too. He has a new video coming out, or is just out. You should also check out the insane off road unicycling of Kris Holm. He can do some pretty awesome stuff on just 1 wheel. Makes me feel useless on 2 wheels but I have fun none the less.

On the same theme, check out Ryan Leech and Hans Ray. Both great mountain bike trials riders.

A couple of years ago I brought a Birkin rolling chassis minus tires, wheels and shocks into Ontario from the US. I had the sell disassemble the chassis into 'parts' and small assemblies that could be listed as 'parts' on the invoice and then had him do an itemized list of all the 'parts'. It cost me a few $'s to get this prep work done and packaged. The deal on the chassis was too good to turn down since the former US importer was clearing out remaining stock. It took some time to get it all prepped but it made it in with no hassles. I took the paperwork myself to a Canada Customs office and didn't use a broker. They waded through the paperwork for about 15 minutes and then said it would cost X dollars which was mearly the taxes. I stop sweating at that point.

Our roads in Ontario are bascially white right now and my blue truck looks like a salt lick. Definitely a good time to have prized cars stored away. Your Birkin is a bit older then mine, but I would assume the pedal assembly is more or less the same. With mine you swap the pads on the pedals side to side, flip them over as well as move them up and down so that you have a fair bit of flexibility to space the pedals as you like as well as set their height. Thought this might help if you didn't know the flexibilty that Birkin designed into the pedal assembly.

With the individual UNI filters it doesn't look like you have any kind of filter for the air inlet to the float bowl and air jets. That is the round hole just between the trumpets. I believe air is taken in here to feed the air corrector jets as well as vent the float bowl. I would think it would be a good idea if you try to keep dirt out of here. I also believe it is important that any pressure drops from filtration be about the same between the trumpets and this breather to not through off the jetting. I have not worked with DCOE's for quite a few years now, but this is what I recall and thought you may want to investigate this further. Sounds like you are having fun with your new car.

I guess right hand drive cars are comparitively not to hard to add the second bike engine since it ends up in the passenger footwell. It would seem a lot more challenging in an left hand drive car with pretty much all bike engines having the drive chain on the left side, though I figure just a matter of time before someone does one.

Picking the right hosts is going to be critical if the show is going to capture the magic of the BBC version.

I too, like many love the XI. It's great to see one brought back to life. It will be interesting to see what WCM XI will be like.

Looks like BMW is doing a bang up job on styling, just like their recent road cars. I think for 2009 all body work appendages will be banded. Hopefully the cars should look a lot cleaner. And Nick said it was the prettiest car he's ever seen and he can't wait to race it.

Most bicycle shops also stock housings in bulk and can sell it by the foot. Get the best teflon lined ones they carry. Don't forget to ask for the metal end caps for the housings as well. I'd go with Shimano teflon inner cables like Dave recommended. I find they are the best, at least for bicycles. The teflon Shimano cables have a thin black/graphite coloured coating over the stainless steel cable. Jack

I know a bunch of guys with Birkins run wheels from Kodiak Racing http://www.kodiakracingwheels.com/. They offer made to order 3 piece wheels with machined aluminum centers and spun rims with offsets to suit. They look pretty decent and I think the costs are pretty reasonable.

I'm using RPF1's on my Birkin, though it is not together yet. Crazy light wheels (9.5 lbs) at a pretty decent price for the 15's. The 16's are a bit heavier. Personally I prefer round to retangular lights, but that's totally a personal thing. The one thing I love about 7 type cars is that by nature they allow each person to customize it to make it their own.

I would think that losses are a combination of those created by things that are not torque/hp dependant and those that are. For example, losses due to seal friction and circulating fluid would be primarily dependant on temperature and speed, but not on torque or hp. Then there is the losses due to things like the gear mesh which will differ with torque transmitted. How much is due to each type I'm not really sure. I would think though that if you add 62 hp or 53% increase to an engine that the drivetrain losses will increase somewhat. I don't think they'd go up by 53% as well, but I wouldn't be surprised to it increase by say 20% (speculation on my part).

Sounds like I need a trip to SoCal. We hit a high today of about 0 degrees F and it's suppose to dip down to about -10 tonight. Then again we are suppose to get up to about 45 on Sunday. I wish the weather would make up its mind. I've ridden my sled in -40 temps before no problem, but you obviously have to be dressed for it. Don't think I'd fit in my Birkin with all that gear on though. Time to get back to work on the car. It's comfy in the garage.

I am no expert on Torsen/Quaife LSD diff's, but having looked at both, they are designed very differently. If I am not mistake, the Torsen uses 45 degree helical gears arranged with their axis 90 degrees to each other and uses the friciton in the gear mesh to create the torque bias. I believe this system has the problem of acting like an open diff if no traction is available from the other wheel. I'm pretty sure a Quaife has shallower helical gears with their axis parallel to each other and uses the friction between the idler gear and the carrier to positively drive the wheel with the most traction. I believe a Quaife do not transfer all power to a wheel with no traction. The negative I have heard about Torsen's is that they can create push or understeer when powering out of a corner since the internal friction in the gearsets causes the diff to acted locked and hence does not want to track a circle but wants to go straight. I am not sure if a Quaife has the same issue but I would suspect it would to some degree. I think any LSD in the end will create some handling issues but in turn will provide much better drive out of corners. Whether this trade off is worth while depends on personal preference and how easily your car can light up an inside wheel. Jack

I would definitely agree that a lower viscosity would be a good idea at the type of temperaturs your are going to hit in Cincinnati. Do you drive you car in the winter for enjoyment or is this your preferred approach to maintaining the car over the winter? In southern Ontario, the roads never become salt free until the spring so driving a pride and joy is out of the question until the salt has been washed away, at least for me. I also believe that unless you are getting the oil, exhaust, etc up to proper operating temperatures, you could be doing more harm then good since moisture, unburned fuel, etc will build up. Personally I prefer to put it into hibernation for the winter. If you can do this in a climate controlled enviroment, even better. My 2 cents worth. Cheers, Jack

Birkins come stock with Outlaw 2800 calipers which don't have dust boots. Almost all sport bikes (motorcycles) come with calipers without dust boots and they never seem to have a problem. I think as long as you are using the car in gerenally good conditions on the road and track, you will be fine. If you intend to drive it on muddy roads or in the winter, then the dust boots would be a must. Wilwood does offer some of their calipers with an option for dust boots. They don't offer any with a 3.25" pitch that I'm aware of though.

Hi Skip, I don't have a Caterham so I can't confirm if they will fit. I have a catalog from Outlaw that shows the M-16 so I thought I'd pass on some info in case it would be of some help. It looks like it is designed as a direct replacement for an OEM Ford caliper with a 3.25" pitch on the hole pattern. They offer 2 versions, 1 for 0.50" wide disc's and one for 0.81" wide disc's. They are not hand specific so only 1 P/N for both left and right. They use 1.50" pistons for all 4 locations. They use Performance Friction 754.16 pads or Hawk HB237 pads. They both seem to offer 4 compound choices. I would think that Caterham offers a number of brake options for the various versions of their car over time. Not sure if they all used the same mounting pattern for the caliper. Too bad they didn't use a 3.5" pitch on the mounting bolts as this is pretty common in North America and you'd have a ton of choices of caliper makes and models to pick from. Hope this helps. Jack

I looks like it all arrived all in good shape. My Birkin was delivered with 2 fork lift size holes through the side of the car. At least the shipping companies insurance coughed up the money for the repairs but it sure was a hassle getting it sorted out. Seeing how hard it was to bring a kit cars like this into Canada, I was just glad that I was able to bring it in, fork lift holes and all.

That looks like a pretty nice setup Dave. I was originally thinking of doing a flat filter in a custom air box for my S2K Birkin, but this looks like it will work well for me and should be a lot easier to make. Using the roof of the nose cone for the top of the air box is a great idea. Now to see if I have the vertical height for a round filter. Can you let me know what make/model filter you are using and what its dimensions are? Probably a good place to start. Jack

Bike transmission, particularly for litre class and larger have very close ratio gearboxes with a very tall first gear. My last street bike, a Honda RC30, had an 81 mph first gear. Bikes with a high CoG and a high power to weight ratio really can't use a low or normal first gear so the ratio make sense for bikes but are not really suited to BEC's. I doubt anyone makes different ratio's, and if they did, I don't know if the trany could take the extra torque that it would general. Would be nice though. I'm surprised that you can get a 3.08 gearset for Toyota rear end. I figured they be higher ratios based on a small high reving engine and a relatively low top speed. I've heard of overdrive gearboxes that can be added on to domestic rwd cars. They speed up the output for more relaxed cruising. Don't know what ratios are available and I don't know how big and heavy they are. You could do a chain or belt drive which might be lighter, more compact and could be placed in the offset from the engine output to the car centerline and then straighten out the drive shaft. The company out in BC Canada that puts Hayabusa's in Caterhams uses a chain drive in this manner. http://www.super7cars.com/Gallery/?album=Our_unique_drive_system_and_reverse Jack

Sorry for the slow reply Dermot. In searching the web I found the primary reduction for a Hayabusa is 83/52 and 6th gear is 24/23. I found this for both 1999 and 2008 so it looks likely that they never juggled the ratios. For reference, the bikes final drive ratio was 40/17 in 1999 and is now 43/18. All the model years seemed to have used a 190/50-17 rear tire. Top speed at red line in 1999 was 199 mph. Based on this and your requested 140 mph at 11000 rpm with 22" OD tires, the required diff ratio would be 3.087:1, not taking into account tire slip. Funny how that worked out perfect with the 3.08 ratio that is typically run, though I believe Demon's typically run tires that are a bit larger then 22" I believe. Hope this helps.

Hi Chuck, I had Peterson put a AN-16 fitting on the tank for both the inlet (scavenge return line) and outlet (feed to pump). I believe the -16 inlet was the stock size but the outlet is normally -12. Peterson offers a number of different size fittings for their pumps so I went with -16 for the pressure stage inlet, -12 for the 2 scavenge stage inlets, -12 for the pressure stage outlet, and a single -16 for the combined scavenge section outlet. My pump is internally manifolded like yours but has a block off plate for the 2nd scavenge stage so it has provisions for separate return lines. Going to the -16 lines for the pump in and scavenge out may be overkill, but given the pump flow, I wanted to play it save. Now I'm dealing with trying to get a lot of large hoses into a very cramped area. I am in the process of trying to determine what I want to do with oil cooling. I have waffled all over the map on this but am currently leaning towards an external air/oil cooler mounted in front of the rad with a thermostat to control the temperature. I think you could run this with or without the stock coolant/oil cooler. I think I'm going to try an figure out how to do this so that I can go either way without significant harware changes. I was thinking of a Mocal Laminova coolant/oil cooler but am concerned about the capacity of the coolant system, the pressure drop on the oil side and packaging issues. To connect the pump pressure feed to the motor, I had a few thoughts. First you need to decide if you want to bring it in through the pan to the port in the block where the stock oil pump connects. Going this route solves a lot of problems around the stock cooler/filter, but I believe I won't do this as it complicates the custom oil pan further and adds another oil line connecting to the pan prone. If you are not going to use the stock cooler/filter, the easiest thing is to make/buy a blocking plate to seal off the annular ring and provide a fitting to the center pressure port. I think you can buy all the stuff you need for this from Mocal and possibly others. You will need to block off the outlet port. If you want to make it yourself the female thread in the block is M22x1.5 and the thread for the stock oil filter is M20x1.5. If you want to keep the stock oil cooler and filter, I would recommend a sandwich plate from Canton/Accusump (not sure if it has a big enough port) that provides a single port to the annular ring and with this you will need to block off the feed hole coming up the block from the stock oil pump. If you want to keep the stock oil cooler but not the filter, you could either use the same Canton/Accusump sandwich plate and with this use a remote filter blocking plate in place of the filter. You will need to pipe the inlet/outlet together. The other option is to buy just the remote filter blocking plate, plug the pressure feed port (center) and connect your pump feed to the annular ring connector. With this arrangement, you are now pumping the oil backwards through the stock cooler. To get the oil into the pressure port in the engine, take the stock fitting that goes through the stock cooler and drill some holes through this and turn a portion of the threads down. I can send you a sketch of this. I did the math on this and it should not present a flow restriction. The last thing you will need to do is block the oil feed hole coming up the block from the stock oil pump. Kind of sounds complicated but I don't think it's too bad. There may be a way you can drill a passage in the engine block to solve this, but personally I'd prefer not to modify the engine block in a way that is not reversable. As you can probably determine I am still trying to sort the system out. Any thoughts you'd have on this would be welcome.

Though the front nose on my Birkin is only held on with 4 M6 screws, I guess there is enough frame behind it to attach to for the front down force load. Now the rear frame in my Birkin barely looks strong enough to hold up the fuel tank and the optional spare wheel. I can't see it holding any significant load from a rear wing. Wonder what he did? It's surprising how a few add-ons really change the look of the car. Doesn't look half bad (for a track day car).

Thanks, I'll keep in mind. Right now I'm still heavily into chassis & suspension work so I'm a little way off on getting to things like lighting.