Charlie's no budget mid engine build: *Codename:BlakBishop*

[bbunkerc397]

I'd put a klze tt with porsche g50 with custom adapter plate and use corvette suspension.

[wytbishop]

Cool project, have you looked into DDR? http://www.ddrmotorsport.com this car you can buy for 18,000 as a rolling chassis and build the rest.

There are a number of makers of supercar kits that I have looked at. It's not just about having a super car, it's really about designing my own. My very first thought was that I wanted to build something custom so that I could mate a big power ZE to a real transmission but it slowly has evolved into more of a "it's-a-fantasy-so-go-for-broke" monster design.

The original thought was tubular space frame but when I started looking at cars like the Porsche 918 and Lamborghini Aventador for inspiration, I decided that I wanted to do something more challenging.

At the moment the drivetrain plan is a GM LS3 small block with an IPS twin turbo kit making about 660whp @ 8psi and mated to an Albins AGB10 sequential 6 speed transmission. I have accquired models of the engine and all the C6 corvette components. I have drawings of the gearbox and will begin modeling that this week. Once I have all that done I can start to design the subframes and then the main tub. The really hard part is learning the surface modeling software. Once that's done the rest will come together a lot more quickly. I expect the completed design to take another year or so.

From there the question is whether I can get the funding to manufacture a prototype. The current budget based on my parts list and estimates of materials required for the chassis is well over $100k. the drivetrain alone will be $50k-ish. I htink that once I have everything in place I could possibly enter the kit car market with something pretty special. The only carbon fiber monocoque chassis kit car in the world perhaps.

Long way to go though.

[wytbishop]

This is the tranny I found. it's sexy.



I've been chatting with the manufacturer and I'm told that they have used them behind turbo ford V8's in GT40's over 1000hp. Also, they already manufacture a bell housing for the chevy engine block.

[bbunkerc397]

Looks like you got some good ideas, that transmission looks spiffy.

[wytbishop]

So I was browsing the interwebz and ran accross this guy's really impressive build...

http://www.lateral-g.net/forums/showthread.php4?t=20292

The thing that really caught my eye was the fact that he is using C5 and C6 corvette suspension parts and he has all the 3D CAD models of them. I read and found out that he acquired them from the OEM thorugh the SEMA Tech Transfer program.

So I went and signed up with SEMA for a $100 annual membership. but wouldn't you know it they have decided that I am not worthy of inclusion in the Tech Transfer program...so no CAD models for Charlie.

[wytbishop]

So I've been doing a lot of modelling lately. The manufacturer of the transmission I posted above ^^^ sent me some dimensioned drawings. They only have the dimensions necessary for installation. So I took a snapshot, brought it into AutoCAD, scaled it up and took the dimensions necessary to model a decent representatin of it.







Then I found a simple model of an LS3 engine and STi brakes, whipped up some wheels, assembled everything and aligned the diff with the wheels. It has to be inverted to make everything line up and still have clearance from the ground.



I brought in some seats and modeled a manikin about my height...





Then I brought in a wire frame of my car to make sure everything will fit...



It's sort of basic still but I it shows the spacing within about a 1/4" or so. The next step is to locate the pivot points of the suspension control arms and from there I can start creating the subframe and engine cradle.

I also purchased an accurate model of the LS3 from which I will model the exhaust manifolds and intake.

[Daninski]

Where do you plan to install the fuel tank Charlie?

[wytbishop]

It will go in front of the front bulkhead. It will be a big bore engine with a twin turbo so I think I'll need to carry about 70L just to get to the 7/11. Plus it will help with weight distribution.

[Daninski]

Provisions for safety,,,. I'm impressed to say the least with the amount of research and time you've put into this. I was skeptical at first but I can see the commitment now. So when do you start the "Donations for Charlies build" post. I'll donate.

[wytbishop]

My plan has morphed into something reproducable. I think there's a wild chance that I could manufacture a full carbon fibre monocoque kit car chassis. I have friends who are professional money managers. People who know people with money. Once I have a complete design package I will develope a business plan and approach them seeking investment.

But that's a crazy dream.

[Daninski]

Sheet man, dreams becoming reality is what our country is all about. I've never met you personally but from our occasional pm's I do believe in you and that's a fact. I believe in very few people Charlie. Keep us up on your dream soon to be a reality.

[wytbishop]

Thanks man. That means a lot to me. It doesn't cost anything to dream and it keeps my mind occupied.

[Daninski]

If all else fails send the design to China and have them do it for pennies on the dollar. Or not.

[wytbishop]

Progress continues...

I have a rough design for the rear subframe. The process is relatively simple. Place all the things whose position is either known, or which you can decide arbitrarily...i.e. wheels, engine, transmission, suspension pivot points, rear bulkhead. Then you simply create the parts of the subframe in the approriate places to accomodate all those parts while trying to create a structure that is both strong and elegant. It's sort of like sketching with solid models. Now I'm trying to figure out how to use the Invetor simulation environment to do some strength evaluations of the assembly.

I didn't have time to do any renders last night but I'll post some pics of it later this evening.

I also figured out a reasonably effective, albeit clumsy way of creating compound surfaces in Inventor last night which is really helpful in creating basic panels. This makes it a lot easier to develop the panels that define simple areas like internal ducting and stuff. Not great for external panels which are too complex to model this way but good for the stuff under the surface.

[wytbishop]

The subframe...

The upper struts will connect to the roof line at the ahtch opening. Just going by eye I think I will have to add some angle to prevent twisting.


The upper pivots are farther outboard than the lower ones so some artful bends have to be encorporated...


Upper control arm bushings bolt to the frame here...


Transmission mounts to this crossbar...


Here it is around the LS3 engine and Albins gearbox. Note that the gearbox is inverted to create some ground clearance and the intake is turned to face the rear of the engine...


The lower rails will actually extend through the bottom of the tub to tie together with the front subframe and will be braced agaist the back wall. The wall and floor in this model are just for reference.


And i have mocked up inner fenders and panels. If you imagine that the outer fender is in place you see the space where the intercoolers will be mounted. Air will flow into the large side scoops and over the wheel before exiting at the rear of the car.


There will be a mounting plate that sort of surrounds the transmission just behind the differential which will tie the top of the subframe together and provide a mounting point for the coilover shocks. That's next on the list. I have a nice model of an Ohlins shock I want to get in there. It's getting cool now.