Bob Woods in Texas

I am a Professor of Mechanical Engineering at the University of Texas at Arlington. I have been the faculty advisor for the Formula SAE racecar team since 1982 and have been involved in several aspects of racecar design including suspension design and handling.

I will be building a GT40 using the Tornado Super Pro Package. I will start a build log entitled "Tornado GT40 in Texas". I have prepared a document of my story about the GT40 which is reproduced below.

My Story and Plans for the GT40

Some would say that the GT40 was the most famous and iconic racecar of all time. Some would say its design and aesthetics were timeless and that it would be just as stunning of a car if produced today as any car, a timeless beauty. I agree with both.

I have always been fascinated with the GT40. That and the Cobra, but the GT40 was more of a dream car for me. I have always wanted one, but I was just thinking about the original cars and they were way out of my price range. I didn’t really know too much about replicas at that time.

I guess everybody knows the story that Henry Ford II wanted to buy Ferrari, but when the deal fell through, he wanted to beat Ferrari at Le Mans. For this, he developed the GT40. The first two years of the GT40 were not so successful. On the third year of the GT40 effort, Carroll Shelby took over management of the GT40 team. In that first year at Le Mans, 1966, they placed 1-2-3. A GT40 then won Le Mans four years in a row, 1966 – 1969.

The chief engineer for the Carroll Shelby GT40 development was Carroll Smith. Whereas I have met and visited with Carroll Shelby on several occasions, you couldn’t say we were friends and he never spent the night at my house. However, Carroll Smith was my best friend starting in 1993. He was the chief design judge for the Formula SAE competition and we met several times at the annual FSAE competition, SAE annual meetings, Long Beach Grand Prix, and he visited Arlington several times (and yes he did spend the night at my house several times). We had numerous conversations about racecars over the years and developed quite a respect for each other. We had just agreed to write the “Design to Win” book together a few months before he died in 2004. I didn’t know he was the engineer for the GT40 until we became friends. He signed a copy of a book about the GT40 history with the following inscription.

So by now my interest in the GT40 was heightened, but I still didn’t think one was within my reach since the actual GT40 that won Le Mans in 1968 and 1969 recently sold for $11M.

One of my friends, Randy Johnson, bought an original 1969 GT40 MK1 that has a race history with Wilson Fittipaldi, the son of famous racecar driver Emerson Fittipaldi, but not at Le Mans. This car, P1083, was the last GT40 to be constructed and sold as a completed racecar with specs identical to the 1968 and 1969 Le Mans-winning car.

When I went to his house to see it, as soon as I opened the garage door, something snapped inside of me and I knew I had to have one. You might have seen pictures of the cars, but if you have never seen one in person, you cannot imagine how absolutely stunning they are. Here is what I saw.

The 40 in GT40 represents the height of the car, 40” tall. When compared to a sleek low-slung Ferrari, the Ferrari looks big.

So that was in April 2013 and I have been obsessed ever since. I started reviewing the replica market and was pleased to find out that one was possibly within my budget (if I stretched a bit).

GT40 Replica Kits

Some of the cars built today are so-called continuation cars and are as close as possible replicate the original, and some are a faithful look-alike with almost all of the original features but updated as a street car instead of a pure racecar. The original cars were a monocoque. Most of the current replica cars are monocoque. A few companies (most of which have come and gone) built space frame cars. Tornado Sports Cars in England makes a steel frame kit that I have selected. They have been in business for 27 years and I think they will continue. I have ordered their Super-Pro Package that includes every single thing required to build a complete car (including brake fluid and touch up paint).

Engine, Intake, and Exhaust

I have several interests in building a car. First, I want the small block Ford engine with performance upgrades, the 8-stack throttle bodies, and the “bundle of snakes” exhaust system that pairs cylinders from both sides of the engine to create a 180 degree pulse in two collectors. Thus there are two 4-into-1 collectors that take pipes from both sides of the engine according to the firing order. This produces the most wonderful exhaust note. I plan to use the D&D “Bobcat” motorcycle mufflers (that I actually designed and are named after me). That muffler increases power and makes a good sound on big bore Harleys and I think it will work here.

I will have Charles Eller of Arlington build my engine. He is an accomplished engine builder and has built several similar engines for my friend Arnold Petsche. It will be a small block Ford 302 bored and stroked to 363 cubic inches starting with a new DART 4-bolt main casting. I will use an 8-stack EFI manifold from Borla. The Borla (formerly TWM) intake manifold has 8 throttle bodies that have the injectors shooting directly down the intake ports whereas others shoot the injector stream against the intake wall. Notice below that the injectors are on the inside of the throttles pointing down the intake.

I will use the PE3 ECU from our friends at Performance Electronics. It is what we use on the FSAE racecars with great success. This unit has 8 peak-and-hold injector drivers and 4 coil drivers that I might use later with two of the Bosch coils that have two high-voltage outputs per channel and I will use a wasted spark. However, I will start out with a traditional MSD ignition system.

Here is what it will sound like. [ame=""][/ame]

Suspension and Steering

My second interest is to modify the suspension. I suspect that the suspension systems in the 60’s could be improved with our understanding today. Those cars basically had to go straight at over 200 mph and occasionally turn a corner. I will be interested in a car that handles well with spirited driving on the street as well as the autocross track. Of interest in my design will be the camber curves in roll and heave, roll center location, scrub change, bump steer, etc. Since the geometry of the suspension and steering is not published, I will have a group of my students measure the x y z coordinates of the suspension system on Randy’s original GT40 using a Faro Arm. With this coordinate measuring system, you simply touch a location with the pointer, press the button, and the x y z locations are recorded. You can then import these coordinates into SolidWorks and eventually draw the complete suspension in 3D. Once you know the coordinates, you can put the coordinates into a suspension analysis program to determine all of the suspension performance factors.

When my car arrives, we will repeat the process on the Replica car (since they might have changed some of the suspension and steering geometry for production).

Knowing both of these benchmarks, I can then see if I can modify the frame, A-arms, uprights, and steering system to get better characteristics for the street and autocross. I have considerable experience in suspension design.

Wheels and Tires

The original GT40s used 15” wheels and high aspect ratio tires. For autocross and the ability to stuff the upright inside the wheel, I will use 17” wheels. The Tornado GT40 comes with 3-piece wheels made by Image in England that simply bolt together (from the back side). I have ordered 8” for the front and 10” in the rear. I will accept whatever offset or backspacing they provide because if I want to have more backspacing (especially for the front); I can order new inner and outer rims and bolt them together.

I will use 245-45R17 in the front and 275-40R17 in the rear. This will give me a tire diameter of 25.7” front and rear. I will start with BF Goodrich g-Force Sport Comp tires since it was hard to find both of these sizes from a single manufacturer.


I will have leather interior for the seats and dash. My car will be a left-hand drive car. The shifter will be located on the left hand since it is better to send the shift linkage through a rod to the transmission. If I placed the shifter in the middle it would have to be cables and they have too much friction and compliance.


I have selected an upgrade to the transmission that will hold the power better and has a close-ratio gearing. Well, actually it is close ratio for the first three gears, but not so much for fourth. According to the drag coefficient (0.39) and the power that I will have (475 HP), the car should be capable of just over 200 mph; however, it will be over-revving the engine slightly just as the car in the above video does. If you listen closely to his shift rpm and his top speed rpm, you can hear him lift the throttle a little to keep from over-revving at top speed.

My BMW M5 has better spacing in the gears and has six speeds. With the Dinan upgrade, it should be good for just below 200 mph.


I will paint the car in a more metallic version of Guardsman Blue (which is a period correct color for Shelby). I probably will not put the traditional twin stripes down the middle, but I will have the Ford GT40 logo along the bottom. My car should look like the one shown below.


Here are some typical car parts being prepared at Tornado in England. My package will arrive in December. They claim that it takes about 350 hours to assemble everything. Since I will have a month off around Christmas, I should make good progress. Let’s see 350 divided by 24…

This is my package as it left the Tornado factory in England. It has a big crate for the frame and body parts and a box full of all of the other parts.

Below is my garage that I call the “GT40 Factory”. It is somewhat small, but I think I can do everything I need to in it. The tape on the floor is the footprint of the GT40. My daughter had a professionally-built sign prepared for me. It is as spectacular as the car inside the factory.

When my friends and family that criticize me for driving an expensive German BMW sports car and worry about what this one will cost, I will tell them that I am just buying an OLD FORD. And when they ask “what does it cost?”, I will say “It is not what it costs, but what it is worth”. It is worth it for me to have the car of my dreams, get to engineer and select all of the technical details of the car, get to build it myself, and then drive it… priceless. I honestly don’t know which part of this journey I will enjoy more, but I suspect it will be the driving.


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Jim Craik

Lifetime Supporter
Welcome Bob,

Yes indeed, you have a caught the bug, big time!

I love the 302 based motor, its hard to beat the sound from a small block.


Brian Magee

Welcome Bob,

Just one small point I noticed. Wilson Fittapaldi is Emerson's brother, not son. Christian, who raced Indycar is Wilson's son. Sorry to be 'pickie'.


D. Nye

Lifetime Supporter
Welcome to the site Bob, you do have the bug big time. I hope you take more than 15 days to build your car, enjoy this time. As a mechanical engineer I appreciate your thought process and your plans. Looking forward to reading your build log.

Dr. Woods, First and foremost...WELCOME. Thanks for your superb introduction to the forum. It conincided very well with my morning cup of tea and was a great read. Like many others, I'll look forward to your build log when you get started. One small correction, the car that recently sold for $11 million was not the actual car that won Lemans in 68 & 69 that was serial # 1075. I believe the car that sold was # 1074 or possibly a sister car of 1075. I've heard 1075 could fetch over $20 million if sold today. Regardless, lets not quibble over a few million! : )

Enjoy your holidays and all the best to you and yours.

That car is beautiful. It looks identical to Randy's 1083. Is it for sale?

I hope I don't end up with 600 HP from a 363... I don't think the transmission will hold it; however, I am doing everything that might make it happen.

The GT40 enthusiasts from Dallas met at my shop for a visit Saturday. Just as this forum, it is great to get information and hear opinions from knowledgeable people.

Here are John, Gary, Sam, Darrin, and Marc.


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I know most of those guys. You should raise your standards!!!

That is a fun group. They are a wealth of knowlege when it comes to these cars.

The 1083 replica is forsale. I built it and had a great time in it. I traded it to a guy for an SPF gt40 and some cash. He has had it now for a few years. He sent it back to me to freshen up and get ready to sell.
Hi Dean,

I thought I did raise my standards by inviting these guys over!

Thanks for the information about the 1083 replica. That is very interesting. I have told Randy about it.

Have you been to a Post Office lately? The government isn't known for taking the best pictures, but still some of those faces look like a poster there.
Welcome to the group....