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conebasher

Project E-Mod MGB-GT

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I had some doubts about how much power it has but I just uncovered a dyno graph from the same engine and even though they revved it to only 5500 rpm' date=' it made 250 hp and 272 ft/lb at the wheels. My exhaust and intake should flow better and I will be revving to 7000 so it should be ok. I am tossing around car names, Big Ben is pretty good but it makes me think of Gentle Ben the bear, and this car is probably not going to be gentle. ;)[/quote']this thing started life as Dr. Jekyll, but now he's looking like Mr. Hyde ;)

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How about "Frankenclarkson", given it's disheveled English heritage. Might even catch the attention of the Top Gear folks.

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I have been messing with the steering. The Jag I got the front suspension from had the steering rack behind the wheels but I have no room there so I had to mount the rack in front. By a stroke of luck, the steering arms from the MGB bolted right onto the Jaguar knuckles without any modification. Here is the rack bolted in front of the suspension and the new tie rod ends attached to the MGB arms:Posted ImageWhen I measured how sharp the wheels turned, I found that they turned 25 degrees in either direction (50 degrees total) which is probably enough for anything but the tightest turns. The restriction was the tie rods hitting the upright pieces of the crossmember:Posted ImageSo I notched and welded the upright pieces, now I get 32 degrees of turning angle:Posted ImageNext thing I worked on is Ackerman, which is when the inside tire turns sharper than the outside tire, reducing scrubbing and making sharp turns easier. Currently, the car has zero Ackerman, which a little toe-out could cure but that is sort of a band-aid fix. By moving the steering rack back, I can get some Ackerman but then the tie rods run into the upright again, reducing my turning radius. Here is a shot of the rack moved back 3/4", which gives me 24 degrees of turning. I think I am going to notch the upright further so I can move the rack back.Posted Image

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Where are you getting your steering angle requirement numbers from? Carroll Smith said a proper race car shouldn't need more than 18-deg. But that's wide race track environment. Maybe 24-deg is good for autox, given your short wheelbase.

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I have a feeling there's going to be some healthy counter-steering with this machine. 90 degrees of steering is likely enough. ;) I've never complained about having too much steering angle available, but I certainly didn't like hitting the steering limits in otherwise recoverable slides.Is it possible to add some kind of mechanical stop in the rack? Ideally I'd like it to stop so that the tie rod could never contact the structure. That way if you hit a bump at steering lock you can't possibly bend the tie rod.

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Where are you getting your steering angle requirement numbers from? Carroll Smith said a proper race car shouldn't need more than 18-deg. But that's wide race track environment. Maybe 24-deg is good for autox' date=' given your short wheelbase.[/quote']One of the CP guys sent me an e-mail asking about my steering angles. He said his car gets 21 degrees and it's not enough for tight elements like pivot cones or even pulling into the grid spot. The Solstice and S2000 seem to turn sharper than the Boxster around the pivots so I would rather have too much steering angle than too little. 24 degrees may be enough if I get the Ackerman that I am seeking.

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I can find out what we run in the fsae car tomorrow if you like. We see way tighter elements than any scca auto-x. I do know that due to the fact that we don't typically see speeds in excess of 100k, we have 70% Ackerman geometry but our designed average track speed is 60km/h. Cory does have a good point that the more counter-steering lock you can get the better though. Looks really good!

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I dug out S2000 specs for reference.Inside wheel max angle: 34 degreesOutside wheel max angle: 29 degreesThat's with a wheelbase of 94.5", front track width of 57.9", and rear track width of 59.5". (Track width = from center to center of the stock 205/225 tires)I've never hit the steering stops while on a 'good' lap, even in the tightest St. Andrews hairpins. I generally only hit the stops when I'm so sideways that a spin is almost inevitable. (so about once an event? :P)I threw the above numbers in CAD:Posted ImageBigger version: http://i56.tinypic.com/331m62q.jpgIt looks like the S2000 does not have 100% Ackerman or the two lines at 90 degrees off the front tires would intersect along the rear axle centerline. At low speeds and full steering lock the front tires are trying to turn on different radii, so they'll both be scrubbing somewhat. Add in some rear wheel slip angle and the math goes beyond my level of interest. There's a pretty healthy debate in the racing world about what degree of Ackerman should be used. I think that slower speeds generally call for more Ackerman.

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This is getting way cool. It wont be long and Nasa is going to be putting up posts:) rofl. I am quite pleased to see all the real science and race stuff being posted. The beast has sure become a club icon. Keep your specs Mark, you may have a lineup of people ordering clones. I sure cant wait to see it fly, in a good way:)

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i don't know what you actually need. just wanted to make sure your sources are good for your assumptions.it's good to know the suspension numbers for fsae have remained relatively static. it's reassuring to hear that there wasn't a epiphany moment where all the specs were questioned and changed.there is generally a compromise with installation stiffness when trying to get large wheel cut angles. that's why the f1 guys will design completely different steering parts specifically for monaco. it's one of those headache guesstimate balances for the rest of us.

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I moved the steering rack back 2 inches and now have good Ackerman. I had to re-route the oil line under the engine and notch the upright pieces but now I have 28 degrees of steering in each direction. The car has a 91" wheelbase and the limit for steering angle is the tires rubbing the lower control arm. By adding wheel spacers, I can get more steering angle, but I don't think I'll need it. BTW, the steering wheel turns only 1 3/4 turns lock to lock, I that's kinda fast for a sedan. Posted ImagePosted Image

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I need a hydraulic release bearing so after making the appropriate measurements, I ordered the Tilton pieces from www.fasttoys.net. Here is the aluminum piece that replaces the front bearing plate on the T5 tranny:Posted ImageThen the release bearing spins onto the aluminum piece and is adjusted to provide the right gap between the release bearing and the fingers of the pressure plate:Posted Image

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I ordered 4 K&N air cleaners for the Stromberg 175CD carbs but the rear air cleaners interfere with the roll cage tubes, so I decided to build my own air cleaner housings for dual oval air cleaners. I started by cutting two pieces of plywood to the same shape as the air cleaners. These acted as a template for the housings.Posted ImageThen I cut some aluminum a little larger than the plywood:Posted ImageAnd clamped it between the two pieces of plywood:Posted ImageThen I hammered the edges over:Posted Image

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And was left with half a housing, which still needs some holes drilled and some sanding to look good.Posted ImageAnd once I made a second one, I had a completed housing. I may still use this technique to modify the original round air cleaners and use those instead of the oval ones.Posted Image

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Dude: Posted ImageYou probably already know this, but you can get simply amazing results with even a cheap Princess Auto style polishing kit. These covers will be very visible, it's worth the time. Keeping them shiny is a pain, but it's worth it.

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Dude: Posted ImageYou probably already know this' date=' but you can get simply amazing results with even a cheap Princess Auto style polishing kit. These covers will be very visible, it's worth the time. Keeping them shiny is a pain, but it's worth it.[/quote']I think I'm going to try and do something with the other covers because I know the air cleaners are so visible. We'll see, first I'm going to get the car driving.

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I would say to clean them up then send them away with the car when it gets painted. Nothing like some nice colour matched accents in the engine bay... They turned out really profesional looking too!

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We'll see' date=' first I'm going to get the car driving.[/quote']Stop being so practical! Shiny covers are way more important than a car that moves. ;):P

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Got the brake lines all in today. Thanks to Westcan Hydraulic on McPhillips, I have the coolest braided stainless lines ever. The car moved forward and back under it's own power but I did not drive it because I didn't have a video camera to record the momentus occasion-tomorrow, I drive the beast!!

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Is an absolute testament to your mechanical skills that you could take a giant mix-match of parts from all different kinds of cars, machine them to work together and come out with something was driveable on the first time out. Congratulations!

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Congrats on it driving for the first time and not appearing to have broken anything. I know how it feels to drive a car you built for the first time and it is amazing! Sounds amazing, and looks like way too much fun! Great design and fabrication work!P.S. I love the ridiculous marks left by the rear r-comps!

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Ok, I joined the forum so I could track the build of this car and all I can say is I finally found some one crazier than I am. Looks like it will be one fine car once done. Lots of fun figureing how to package every thing in such a small car, ain't it. Might just have to drag our cars out so we can have a battle of the "B's" when your done.Good luckBrianCanoe B.C.

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Ok' date=' I joined the forum so I could track the build of this car and all I can say is I finally found some one crazier than I am. Looks like it will be one fine car once done. Lots of fun figureing how to package every thing in such a small car, ain't it. Might just have to drag our cars out so we can have a battle of the "B's" when your done.Good luckBrianCanoe B.C.[/quote']Did you see the blog? http://ultimatemgbbuild.blogspot.com Your car has monster horsepower compared to mine but on an autocross course, I might be able to keep up. We have a big vintage sportscar event every year, you should come out for that. I think it's August 6/7 this year. For those on here not familiar with Brian's build, click here: http://www.solobc.com/phpBB3/viewtopic.php?f=10&t=27

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After driving the car, I realized that the seating position wasn't comfortable and moving the pedals is not an option, which leaves moving the roll cage back-how hard could that be? I moved the cage back and there were some side benefits like the fuel filler hose is now straight and the tubes that run over the doors no longer hit my head with a helmet on. Here are some before pictures:Posted ImagePosted ImageAnd after:Posted ImagePosted Image

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I put hood pins on the car and drove it for the first time with the hood and fenders on-my goodness, that hood seems to go on forever. Here's a few pics:Posted ImagePosted ImagePosted ImagePosted Image

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Does that mean it's time to move the shifter again?

No, I was too close to the steering wheel and shifter, too so it seems to be good now. Moving it is easy, I just have to drill some holes in flat steel. Now comes all the little jobs like hooking up proper throttle linkage, making a firewall, sealing up all the gaps, etc. I will be replacing the plugs,wires,cap and rotor soon and then will be putting it on the dyno-which should be fun.

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