Ultima Group C

[CJulian]

HI Guys, It's been some time since I've logged into the PH forum. I wanted to show a couple images surrounding my latest GTR revisions.

This project started out as an accident, literally. I rolled my Ultima back into my Steel gate on my driveway. The damage was limited to the Rear Clip but I was in a position where I ultimately needed to paint the car. Long story short, I took the opportunity to perform a number of Body changes to the Car. Rather than bringing the car into the future I am focused on returning to the past with a very "GTP Group C" Look. The biggest changes, aside from the Body, will be the active tunnel (almost exact copy of the C11) and iterations of the fuel system, among many others.
Enjoy,
Chris Julian

• This first images show the proposed frame changes to allow for a full Tunnel system. I will send images off the body changes soon...

[CJulian]

Hi Guys,

Thanks for the interest. I do appreciate the knowledge and experience that many of the PH members can provide. And I'm sure I will be hassled about the functionality of many of the features I will be integrating into the car. That said, I do have a lot of ideas about where to take this project but It's always good to talk with like minded mates that can offer suggestions, or point out potential pit falls.

As far as the Aero package is concerned, I am trying to closely emulate the aero on the Group C, Sauber C9/C11 race cars. These two cars performed very well, for a number of years. I have not read or heard about any real issues with safety. In the past year I have gathered a lot of info about the Sauber Race Cars, particularly the various embodiments of the C9-C11, and have a couple of great models that display very detailed geometry WRT the underside of those race cars. There were a lot of Aero and body changes throughout the years these cars were raced, including rear wing location (height, position relative to read clip, end plate configuration, etc..). I will do my best to replicate the aero and body geometry as well as provide flexible mounting points for the wing(s), endplates, etc... In the end this will be a street legal car to be driven not only on the track but also on the streets, and highways of California.

I'll have to resize the body pictures, but will send soon.

Best, Chris

[CJulian]

Thanks Paul, Yep, that was one of the first decisions- to relocate the tank(s). I am still torn between a centrally located tank behind the seats, or two tanks GT40 style (next to the driver/passenger). I already have removable Side Pods so access to that area is great, and space is plentiful. The twin tanks would be easier but I have had a lot of fuel issues WRT the dual tank arrangement. It's a toss up for now...... With twin tanks I would manually pump the "reserve" tank into the primary tank that contained the pump(s), filters, surge system, etc.., all within the bladder.

Here's a picture of the rough body work.

I also wanted to thank Lee Benson for his help and suggestions with this project. He was the person that lead me to look at Group C cars in the beginning of the project.

Chris

[CJulian]

OK Lee. Here are a few more pictures of the pre- pre paint. There is still a lot of fine details to work out but these pics should give you a since of the final shape of the Ultima GTP. We are awaiting the polycarbonate headlight lens that will cover 2 or 4, 7 inch round headlights- Typical to that era of race car.....


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I could use some help spec'ing a proper set of exhaust silencers for the car. I am specifically looking for units that can be repacked, and of minimal length. I want to route the muffled exhaust in front of the rear tires (C9 approach) and have an active "Cutout" system for WOE trailing out the back of the car.

Thanking for looking and all the positive feedback.

Chris

[CJulian]

OK, here are further Solid Works Pics. Please excuse the poor body lines. I'll need to hire out a 3D scanner for the final body files when it's ready for paint.

Chris

[CJulian]

If anyone is interested in developing a proper centralized fuel system I could offer the CADD files. I'm still on the fence as I don't want to give up the little space I already have between the Serpentine drive system and the firewall. To date I've lost bearings on two of the aftermarket (Street and Performance) drive pulleys and shredded two Belts. Seems like an alignment issue but, again, without access I may have to pull the motor, or the tank on each new problem......





The volume is ~3750 Cubic Inches, and with a sump system, HP pump, filter, and internal bladder the total may drop below 3500 cubic inches?? That's in yankee units.

Chris

[CJulian]

HI Paul, I agree on both accounts. Primarily the track situation. I'm sure there are ways to increase capacity, and this was just a first pass at the CADD model with some rough measurements. If one was willing to create custom seats, as you might find in older race cars, then the seat and tank could blend together for more fuel capacity. This is yet another reason to pass on the single tank........
One big issue with the side tanks, aside from the fact that you again have two tanks to contend with, is the loss in storage capacity.

Thanks for the reply.

Chris

[CJulian]

Hello my friend, I was anticipating your input and recall the conversation. All I will say in response, and please pardon me if I am not going to try and reply with a long engineering answer.

SAUBER DID IT.

Somehow Sauber was able to create thousands of pounds of down force with their tunnel system on the c9 and c11. Their system has an angle of ~18-20 degrees. I'm sure a closed tunnel is an entirely different animal from a diffuser. Either way, that is why I choose to copy their design and not reinvent the wheel. The two cars are not that far apart and in the end I'd rather have to take out down force to balance the car then try to add more. the other thing to note is that Sauber had a very Wing-Like surface on the front of both the c9 and c11 which I could add to the GTR down the road. I am not too fond of the look so for now we'll leave the front clip alone.

Chris

http://www.mulsannescorner.com/aerodatabasesauberc...

[CJulian]

I like it! I think you should look into the old GTP cars. Those cars had huge tunnels of many shapes and sizes.......

I don't recall seeing these CADD models. What are you going to charge me for the LS engine model? -Mine is very basic. I also have a Bus transaxle if you are interested.

Chris

[CJulian]

Clive, Thanks for the link to the drivetrain comps. I already have that exact Transaxle and when measured against my actual G50/52 Box, the Turbo box is supersized in many directions. The LS3 looks to be a great set of files. Thank you.

Chris

[CJulian]

Here's the LS3 file (w/tweaks) in situ. I will someday tackle modeling the 180 Exhaust.

Thanks Clive

[CJulian]

Yes it does. And the car has all the nice pieces. They must have left a zero off the price. Maybe you are buying the build plans??

Chris

[CJulian]

Yes the rear suspension pickup points seem very fragile but on the track maybe that's all you need?? The transaxle is also a great find. I presume with the HP so low that the torque is also low, hence the small sequential box.

[CJulian]

I would also be interested in understanding what suspension changes might improve handling but retain street-ability in the GTR. Were the wishbones extended and repositioned? This is one are that I have been hesitant to toy with.

Thanks, Chris

[CJulian]

Could someone here post the contact info the outfit that offers the revised front wishbone setup?

Thanks, Chris

[CJulian]

Here's a few recent images of the GTR. Mostly cardboard, wood, and plastic. Your constructive comments would be appreciated.

Thanks for all the support.

Chris

BTW- that's my neighbor that's been carving most of the wood...

[CJulian]

Thanks for the great feedback. I'm definitely looking for larger "round" tail lights and hopefully with modern LED lighting.

also, I had forgotten about the upper body radii. That's a great catch. We did spend a lot of time, and money, trying to retain a "sharper" edge along the entire length of the car. When looking back on the Group C class of cars there is definitely a boxier look to most of the cars.

Any thoughts about the wing mount, end plates? Too wide, too narrow, too high or low??

Thanks, Chris

[CJulian]

Thanks for the suggestions. I like the Alfa lights although it looks like they may not mount on a common plane I'll check it out.........
Chris