25 Feb 2008

Bought the domain midlana.com, the future site for Midlana builders. Granted it’s early but I didn’t want to find the domain gone if I wait. Looking into various forum software packages, I’m not sure what I’m signing up for, probably hours of removing spam for enlargement devices, Nigerian bank offers, and on-line pharmacies, lol.

The garage is filling up, with few nibbles but no offers on Kimini. I realize it could be a long time before finding a buyer; I need to get off my butt and start advertising more seriously. I figured I’d post it here first to give longtime readers first shot at it, but all it proves is that the Internet will beat a path to your door – as long as everything’s free. So I’m going to start showing it at the “Cars and Coffee” event in Irvine, CA, where some very expensive hardware show up, along with some rather wealthy car nuts. That venue should be good for finding buyers.

A buddy said I should have held off buying an engine (which will always be the case.) He said the one to have “today” is a direct-injection turbo engine. The big advantage is that there’s no detonation (no fuel in the combustion chamber until needed), so a turbo 10-11:1 engine has very little lag. Oh well, there’s always something better that’ll come along. Eh, I’m fine with what I’m doing, and like I said, there’s always a better engine next year.

I’m reminded that I’m leaving out project details again. It’s not on purpose, I simply forget to include them. The suspension uprights are Miata all around. While they’re not perfect, the reality is that they’re widely available and affordable. Going through the design process with Kimini taught me how make things easy to build. While Kimini has excellent suspension geometry, it’s because the front uprights were heavily modified and the rears fully-custom fabricated. That’s fine if you don’t mind spending weeks and weeks making them, including using a lathe to fabricate bearing cups to an accuracy of 0.0001″. However…

That said, I’m not sure I like the Miata rear uprights. Even as I work through the front suspension, I’m eyeing them with more of a glare than satisfaction, especially the top mount. In the Kimini book I note how some builders used bolt-on rear spindles – and how much easier that is than making bearing cups. In fact the latest Locost book specifies fabricating rear uprights using bolt-on Ford Sierra hubs. I’d use something domestic, but I’m torn between making the car fast and easy to build and slightly slower to build but having better rear geometry. Of course the question becomes, “How much better would it be?” I’m certain enough of my, um, uncertainty about the Miata parts that I’ve already ordered a different pair of rear hubs that bolt on. This allows making a fully-custom upright with the pick-ups where I want, unlike the Miata parts that force the issue. It’s too early to tell which path will be taken, and so you see some of the endless behind-the-scenes dithering going on. Again, whichever uprights don’t work out, back to Ebay they go.

20 Feb 2008

More goodies. The nose is from Kinetic Vehicles and is their “catfish nose”. Since I don’t have an engine up front I want to run a low profile nose and here it is. The styling is, as I was warned, going to be tricky, since Locosts are narrow vehicles. I’ve made things hard on myself because I’ve pushed the passenger compartment foward. This means the body taper is going to be tough to match up with the taper of the nose cone. The question is, can I make it work or is it going to look bad? Of course the nose can be widened, but the goal is to try to use it as-is. That way I – and other builders – don’t have to mess with composite at all. That said, I suspect it’s going to have to be widened anyway, but we’ll see. If a decent number of people decide to build the car, I’m sure Jack at Kinetic will be willing to build a wider mold, 😉 Designing the suspension around the nose is a bad idea, as compromising proper wheel control to work with the nose imposes a lifelong handicap on the suspension. So, now starts the endless interations to settle on a workable wheel track.

I have some ideas about how the chassis sides will be styled and I think it’ll look pretty sweet – clean, functional, yet bold, if I do say so myself. Of course people may look at it and think, “Ewww”, so we’ll see, lol.

Also received a K20A2 oil pump and pan, necessary as part of converting the K24A1 engine to the high performance version. The transmission should arrive next Monday.

The last picture is my bestest buddy, Cooper, who likes to rest his heavy head on my knee, tug-of-war rope in mouth, all ready to play. He’ll sit there for quite a while, figuring – correctly – that I’m well aware of the message he’s sending.

18 Feb 2008

It’s here… a Honda 2.4 liter K24A1 and a K24A2 cylinder head! The engine will come apart, in preparation of getting oil squirters added and honing the cylinders for the new rings (and pistons). Compression will be lowered to 8.5-9.0, for running boost on our crummy 91 octane gas here in California. While lots of people say I don’t need to lower compression, I have a good buddy that built all sorts of crazy Honda engines, all the way up to 1200hp drag racing monsters. He said that all it takes is one long hill and being in the wrong gear to cause detonation (pinging) which will very quickly destroy the engine. The plan is to design every part of the engine for 400hp, but run it at a more “reasonable” 300hp.

A little more infomation about oil squirters, these are oil nozzles mounted in the block that squirt oil up at the bottom of the pistons. The idea is to keep the pistons cool to avoid detonation, yet there’s a lively debate on the forums regarding the need for them. Some people say that switching to forged pistons negates any need for them, while other’s say anything that keeps the pistons cool is a good idea, which I agree with. Factory stock pistons are cast aluminum. This means that as the engine gets hot, the coefficient of expansion for both the piston and cast aluminum block is similiar, so as the piston gets hot the piston-to-cylinder clearance is maintained.

In a boosted engine though it’s common to swap in forged pistons which are far stronger and more resistant to detonation. However, since they are made different, their coefficient of expansion is higher than cast pistons. This can be a very, very bad thing if the engine is run hard (like up a long hill or on a road racing track). The piston keeps getting hotter and hotter and expands faster than the block. Eventually it expands enough to start rubbing on the cylinder walls and once that happens, they get really hot and completely lock up the engine. Sooooo, oil squirters seem like a very good idea to me!

I’m not sure when the engine build will happen, probably in parallel with the chassis build. The goal is to have it done before the chassis is finished. In fact, I’d like to have it done before it’s time to put it on the chassis table, but that’s probably optimistic.

16 Feb 2008

Returned the brake rotors – they’re just too heavy – backing off to “regular” brakes instead of the vented Sport discs. The weight made me give up whatever additional cooling capacity they have. The solid rears are roughly half the weight of the 12lbs vented units. If there’s any heat issues, cooling ducts can be added, upgrade the pads, or go to vented rotors as a last resort.

10 Feb 2008

Found an engine; it’s paid for and will be here in a week or so. Found a transaxle, too.

The brake discs are VERY heavy, 13lbs each for the fronts and 12lbs for the rears. This is due to going with larger vented rotors than solid discs. I had been assured that small solid disc brakes will be fine… so I may take these boat anchors back.

I saved the bombshell for last though it probably won’t be a big surprise to regular readers… I’m going to be selling Kimini.

3 Feb 2008

On the front suspension, I’ve got a good design candidate, though it’ll have to wait for the front nose; only then can the inboard suspension points be fixed. Wouldn’t help to fix them now only to find the nose is in the way.

Regarding the sportbike shocks… the more I think it through the less likely they’re going to work due to the spring rate and shock travel.
With shock travel of 1.5″ (or 2″ if I shorten the bumpstop), the 595lb/inch spring rate’s probably going to be too low. This is what happens due to all the leverages involved and the short stroke. While the springs can be replaced with stiffer ones, the spring rates end up getting ridiculously high… a shame. It’s not a closed case yet, but if you feel they can work in your project, drop me an e-mail else they’ll end up back on Ebay. If that happens, I’m right back to where I was with Kimini, facing the purchase of $300-$500 shocks, ugh, this was supposed to be low budget. Eh, what I’ll do is specify a coil-over shock of common length. This will allow builders to go “economy” or “nuts”, as their budget allows.

1 Feb 2008

Ordered the nosecone and brake rotors so that front suspension design can progress. The nosecone is for determining where the inboard front suspension pivots go. The brake discs are for measuring the thickness at the mounting face, as it shifts the wheel center outward. I feel better measuring them – and every other component – myself. The seats will probably be next.

I got a great deal on a Tilton hanging pedal set, but after seeing how compact, low, and light my brother’s floor-mount pedals are, I wonder if I should go that way. Than again, when I tried them I experienced what other people have said about floor-mounted pedals. The arc of the pedal and foot don’t match, lifting my foot off the floor. Not terrible, but something that would take some getting used to. I have to think about it.