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Can-am style, LS6 powered race car
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Author:  kingkyle [ November 4, 2011, 7:35 am ]
Post subject:  Can-am style, LS6 powered race car
Hey Guys,

12.16.11* I've changed the design a few times but this time its set. The plan is to run an LS6 with the C5 auto trans with paddle shift.

I found your site a few weeks ago and its exactly the place to get help and show my build. Many of you will probably tell me i'm crazy for doing this build but I've done other crazy stuff like this in the past. My last project was an LS3 RX7 race car that I raced with NASA. Image

Plans have changed as of 12.1.11 *

My plan is to build a 1,500-1,700lb tube frame chassis race car with a little extra room in the cockpit. I will run 335 rear 285 front slicks.

I need help from you guys regarding Spindle/Hub choices for my suspension. I've been looking at Miata spindles as a base for custom A-arms. I'm thinking the wilwood big brake kit should be good for a car this weight. Let me know if you guys can think of a better spindle chioce for me. The chassis will be pretty straight forward. The suspension is where I need the help.

Let me know what you think!!
Author:  horizenjob [ November 4, 2011, 10:49 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Quote:
Many of you will probably tell me i'm crazy for doing this build


Well, I think you might be out of your depth on this. Have you done any lap time in Formula cars? A Mazda with a V8 is just a tank really.

Quote:
Plus I dont feel like hitting a car that weighs twice as much as me.


Cars that weigh twice as much as you are basically just moving road cones. They really aren't harder to miss then your average cement wall. You're expected to get up close and personal with cement walls so they are probably easier to hit.
Author:  kingkyle [ November 4, 2011, 11:09 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
horizenjob wrote:
Quote:
Many of you will probably tell me i'm crazy for doing this build


Well, I think you might be out of your depth on this. Have you done any lap time in Formula cars? A Mazda with a V8 is just a tank really.

Quote:
Plus I dont feel like hitting a car that weighs twice as much as me.


Cars that weigh twice as much as you are basically just moving road cones. They really aren't harder to miss then your average cement wall. You're expected to get up close and personal with cement walls so they are probably easier to hit.


I expected to get people saying I wouldnt be able to drive the car. For reference here is a video from inside my RX7 LS3 http://www.youtube.com/watch?v=g-6sanQN8hk The car weighed 2700lbs with me in it and had roughly 500whp. The car ran faster times than most formula cars at watkins glen. I totally understand your concerns about most builders not being able to drive their creations.

I also have a pro racing license racing sportbikes. Here is some race footage http://www.youtube.com/watch?v=alQHTtODlso
Author:  Driven5 [ November 4, 2011, 11:14 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
I think your biggest concern is going to be designing around unknown, and potentially rather substantial, amounts of downforce. You'll need to match all of your components to the amount of force that the car will put on them at the also unknown top speed. Consider if your car is capable of a simple 1G aerodynamic downforce, which is well within the realm of possibility. That means your suspension will have to accommodate as little as ~1500lbs in slow speed corners, as much as ~3000lbs on the straights, and somewhere inbetween on medium and high speed corners. The potential ~3000+lb load would probably put me out of my comfort zone with Miata components...And that's aside from finding a Miata brake package to handle such power and speed, as well as 4x100 wheels that will mount 335 and 285 tires. With a car like this, and without having advance engineering knowledge and tools, you're definitely going to want to err on the side of safety. It sounds like you have a lot of reading to do before you start really designing, let alone building, to learn how high levels of aerodynamic downforce effect motorsport design and construction, and the basic methods used to do so.
Author:  JagLite [ November 4, 2011, 11:29 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Sounds like a fun project.

I would suggest going for better hardware for the speed that engine will be capable of.
Corvette spindles, brakes, etc would be a much better set up in my opinion.

I like open wheel formula cars too but they offer next-to-none protection in any side impact.
Depending on how much you value the ability to walk instead of driving a wheelchair....

While many build a Locost with V8 power, it is not designed for the forces that the speed potential the engine presents.
If it is used as a street car it does fine, but once on a track it is seriously exceeding the safety envelope.
Once the car goes OFF the track and hits even a tire wall at speed... or tangles with another car on or off the track, it is like a bamboo bomber.

The original design was fine for the low power engines of the time. But modern high hp engines need much better designed, stronger and unfortunately, heavier frames, suspension, brakes, and everything else.

Your call, your life. Take care...
Author:  kingkyle [ November 4, 2011, 11:57 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Thanks guys.... yes i'm starting to look at the Corvette spindles/hubs. Thats a great idea, great brakes great coil-over suspension options. The parts hold a 3k+ car all day long in race trim. The car wont produce that much downforce. I'm by no means an F1 aero specialist. It might make 500-800lbs of DF @ 150mph. Most of a being drag.
Author:  oldejack [ November 4, 2011, 12:12 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
"Bamboo bomber". .. :rofl:

I recommend looking at a wide 5 setup from the circle track world, a much more capable design for the stresses you're talking about inducing. Miata (or similiar) suspension components are simply too light for the stresses capable of being produced by a 11 1/4" wide front slick if used to it's limit (imhop) not to mention a rear slick over 2" wider.
Add in ground effects and it'll end up like that camera shot that was circulating of when an F1 team (I disremember who it was) tried their first carbon fiber suspension arms :shock:
♫"Dust in the wind. .. all it was was dust in the wind. ..........".♫
Don't forget that you'll NEED power steering to be able to control the thing in the pits. ..
Might want to start a little smaller/lighter for what sounds like it might be your first custom, one off, scratch build but that's just my opinion.
Author:  kingkyle [ November 4, 2011, 12:38 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
See that, I've already found some great options. It looks like mustang II spindles with wide 5 hubs are a good option. They are strong enough for stock car racing and they have a huge amount of parts to go along with them.
Author:  seattletom [ November 4, 2011, 2:09 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Even though you are going to do a mid-engine chassis, two front-engine seven-style cars to look at for ideas are John Meyers' and Dave Kipperman's. Both run big LS engines and big wings. Meyers used a modified Stalker chassis/suspension and has clocked a track speed of 170mph. I believe Kipperman converted his front suspension to Corvette components and has been having a lot of success on the autocross circuit.

Also check out Ultima http://www.ultimasports.co.uk/Default.aspx Ultimas weigh in about 2000 lbs., typically use midengined SBC and LS motors with G50/50's, and can carry big wings. They use purpose built hubs and suspension on all four corners.

One other thought, if you are looking at Mustang II front spindles, consider the ones made by Wilwood. Although more expensive, they look to be stronger/lighter than the cheap ones. They offer lots of hub/brake/wheel bolt options and may also have some improvements in their geometry.

Hope this gives you some design ideas. Looks like you are going to have a fun project!
Author:  kingkyle [ November 4, 2011, 2:22 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Funny you mentioned the Ultima GTR, I owned one for 3 years! It was a great car but I had little experience racing or fabrication when I owned it. I sold the thing for penny's on the dollar.... Man if I could turn back time. I'll post some pics of the GTR when I get home
Author:  egoman [ November 4, 2011, 4:00 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
If you look at the stock car stuff on racingjunk.com you can usually find a wrecked late model and use all the front suspension and save yourself a whole lot of engineering.
Author:  horizenjob [ November 5, 2011, 3:14 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
I had to leave, so sorry I couldn't follow up. There is plenty of stuff to draw on, there has been more then one class for V8 powered formula cars. There was F5000 in the seventies, and there was a recent CART class for the entry level cars, I think. Plus there have been F1 and many Indy cars that had V8's. I will include a Lotus V8 formula car picture below. Building a tube frame for this type of thing is sensible. I am using suspension ideas from cars of that era for my own build and combining it with later tube frame stuff which takes the modern roll cage specs into account. That's a big difference between the 60's - 70's cars built with V8's / tube frames and modern stuff.

As an aside I will tell a very quick story. Hypothetically I might know someone who brought his wife to the track for a fun weekend. The car was parked and some checking over commenced. Someone with one of those entry level CART V8's showed up and took the adjacent garage stall. I am unsure of the the car's history but think that's what it was. Wife settles into a folding chair and start reading a book.... Time passes, as it does. Practice approaches and it's time to get ready....

"We're going to fire this thing up, perhaps you'd like to step back."
"No, i'm all set."
"Really maybe you want to move"
"No, I'm OK"

Pause... Grind, Grind "VROOM!" :shock:

One heartbeat later, wife gets huge nose bleed and falls off her chair. There is blood everywhere. Not a good day... So, just saying this is a whole nother level your getting into....

You could buy a car like that easy. Old race cars are cheap.

From your post above, you noticed your Ultima had custom fabricated uprights. That's a good place to start thinking about things. I think there is a lot to be said about just aspiring to designing and building a good upright.

I just made a simple model of a Miata upright and noticing right away it's much shorter in height then my Formula Ford upright is even though the FF uses 13" wheels. I think the bearings are much smaller too, but haven't measured those yet though. On the FF the bottom wishbones and transaxle mounting share bolts. That's not possible with the Miata units.

If you consider looking at fabricating your own uprights you can look into "micro stub axles" for sand buggy type units. That would let you use 930 driveshafts and CV joints and bearings for you car with your design.

Here is the Lotus V8 Formula car. Formula cars are about minimization to be successful. The rear suspension shows how to connect to the frame with minimal points. You just need to be able to put frame where those points are. Not hard after you read the specs for roll cages.
Author:  horizenjob [ November 5, 2011, 3:39 am ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Oh, also take a look at Pook's exo car thread. He's putting a V8/Audi transaxle into a car and I think you can see pictures somewhere in his thread.
Author:  seattletom [ November 5, 2011, 3:50 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Kingkyle, following on one of Horizonjob's comment: "From your post above, you noticed your Ultima had custom fabricated uprights. That's a good place to start thinking about things. I think there is a lot to be said about just aspiring to designing and building a good upright."

Here's a couple of pics of the Ultima front upright which you are familiar with. Note the "NOBLE" mark on the casting. As Lee Noble did the design for the Ultima chassis/suspension (which is very similar to many of his other cars) I wonder if the machined castings are available from Lee or other sources (Ultima?) I didn't reverse engineer all the geometry, but the distance between the ubj and lbj flats is about 6 1/2". These are very light, use standard bearings and ball joints (Ford, I recall) and are well proven in Noble's designs.

Hmmmm, an Ultima chassis with the side pods removed and minimal bodywork would make for an interesting open wheel V8 midi...
Author:  kingkyle [ November 5, 2011, 5:05 pm ]
Post subject:  Re: Mid engine LS6/G50.52 forumula style build
Hey guys,

I think you might have misunderstood, I owned an Ultima GTR but I didn't design the uprights, the car was stock from the factory. When i owned the GTR I was unable to fabricate.

So far I built my chassis table using my motorcycle jig as a platform and a piece of 8x4 MDF.

I've decided to go with F1 chassis dimensions. 10ft wheelbase and 6 ft wide. This will provide a much more stable chassis then a 8x6. I've also decided on Wilwood spindles with wide 5 hubs, thanks to the forum. Also go with a wilwood big brake kit front and rear. The question now is do I buy adjustable A arms and modify or scratch build.
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