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Building the ultimate GT1


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#1 rvec

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Posted 16 May 2015 - 11:13 AM

 

Building the Ultimate GT1

By: Rich Vecchio    Date: May 16, 2015

 

The Ultimate GT1 just might be the Toyota GT-One. Although the Tamiya kit is a rather complex build, the slot car version looks and runs great! For those of you not inclined to read my long winded dissertation, images of the model and its one to one counterpart are shown below. The salient points are summarized in the section entitled “Summary” below. For those suffering from insomnia, plowing through the many sections jam packed with detail might lead to “safe and restful sleep”. Who needs Sominex anyway? The titles of each section and a brief description of their content are shown in the table below.

Section Title

Content

Summary

Specifications and final test results for the Toyota GT-One build

Background

Development of our True Scale GT1 class including configurations, improvements over time and popular body selections.

The Build

Challenges encountered and overcome building the Toyota GT-One (and there were many, I might add).  Read this section in order to avoid aggravation if one intends to convert the static model kit into a slot car.

Statistics

Analysis and historical results aggregated by race course, make and model for True Scale GT1

History of the Toyota GT-One

Specifications of the actual race car and a short history of Toyota’s obsession with winning  the penultimate endurance race, Le Mans

 

 

Summary    

How can lap times be improved in a well-developed class that specifies a production chassis, sealed motor and a well-known pan configuration? The answer might be body selection. The answer might be the Toyota GT-One.

The basis for this latest build is as follows.

·        Tamiya 1/24 Toyota GT-One plastic model kit

·        Scholer Pantera chassis fitted with new and wider side pans including a notched edge (The chassis was formerly used on my Porsche 962)

·        Hawk 7 motor

The Toyota GT-One made its racing debut on 5/14/2015 at Electron Raceway. The GT-One handled like a dream. The car seldom de-slotted and was perfectly balanced, neither too loose nor too tight. The Toyota now holds the track record for laps (91.3) and the record for fast lap at 4.891. I think the GT-One is one of the best, if not the best body to run in our GT1 class. Both the front and rear track are much wider than the prior record holding Porsche 962 while the height and weight of both bodies are quite similar.

Background

Since its inception several years ago, True Scale GT1 has developed into one of our most competitive classes. Rules for this class dictate a Scholer or Plafit production chassis and a sealed Falcon 7 or Hawk 7 motor. All competitors utilize a similar custom front and side pan configuration designed to improve handling. In addition, the GT1 and Group C bodies specified for this class are very low, and are characterized by a relatively long wheelbase. All of these factors facilitate very fast and very close racing. The latest stepwise improvement in lap times can be attributed to the addition of the Hawk 7 motor as an optional power plant. The Hawk has more snap and better brakes than the Falcon, yielding improvements in lap times of .1 seconds or more.    

With such a well-developed class, how can lap times and handling characteristics be further improved?  The answer could be in body selection. Although the Ferrari Enzo has dominated the class in terms of total entries and podium finishes, other bodies such as the Porsche 962, Nissan R390 and Jaguar XJR12 have achieved a modicum of success (For more detail, read the section entitled “Statistics” below). Could another body be a better alternative?

In the winter of 2014 I had the pleasure of racing with the Arizona Garage Racing club (AZGR). One of the track owners displayed a great looking Toyota GT-One mounted on an H&R chassis. The car’s shape and design was, I believe, way ahead of its time. Recently, while surfing the internet, I found the model for a reasonable price and immediately placed an order. While waiting for it to arrive, I did some research regarding the history of the actual race car. Toyota’s GT-One program was specifically aimed at winning the penultimate endurance race, Le Mans. The effort was, however, short lived, lasting only two seasons (1998 and 1999). Although the GT-One showed great potential, it failed to win the premier event. In 2000, the program was abandoned in favor of an all-out Formula 1 effort. For more information on the GT-One program see the section entitled “History of the Toyota GT-One” below.

The Build

Tamiya makes some of the most detailed static models on the planet and the Toyota GT-One is no exception. Two kits are available, but I would not suggest purchasing the “Full View” model. Box art for both kits are shown below.

Unfortunately, some of the detail as well as the race car design itself would present several challenges. Some of these are summarized below.

·        In the actual race car, the driver’s tub is a part of the aerodynamic design and is in full view from the large openings in each of the slab sides of the car. Using the tub as part of a slot car build was a non-starter because of clearance and weight considerations. Instead, .020” sheet styrene was used to cover the openings.

·        Because the rear deck is so low in spots, the spur gear did not clear the bodywork. A small rectangular cut out resolved this problem. If an inline rather than an anglewinder or sidewinder chassis configuration is used, the cut-out might not be necessary.

·        The wheel openings are very tall and provide ample clearance for the ProTrack tires. However, the rear fenders are too narrow to accommodate the ProTrack tire width. Small cut outs in the inner portion of the rear fender bodywork solved the problem.

·        The body is constructed from relatively thin plastic. This coupled with large wheel openings, leaves the front end vulnerable to impact. In order to bolster strength and rigidity, carbon fiber mesh was affixed to the inner portion of the front wheel wells. In addition, the kit has a belly pan that covers the front end.  The pan may be affixed and then cut to clear the guide flag, again to bolster rigidity.

·        There are two relatively small plastic pieces that extend the bodywork into the inner front wheel wells. These pieces must be trimmed to avoid interference with the inner portion of the front wheels.

·        The rear wing assembly consists of three pieces including two uprights and the wing itself. The assembly then attaches directly to the rear bodywork. As such, it is subject to damage from a rear end collision. To insure a very strong bond, plastic welder was used to attach both the wing and its uprights.

·        The outer skin of the body consists of two major and several minor parts. The rear deck of the static model is hinged and opens to display the mid-engine and rear suspension. For the slot car version of the model, plastic welder was used to mate the rear deck to the front section of the model.

·        The nose of the race car and the aerodynamic air-intake on the roof are white while the rest of the outer skin is red.  I had hoped for white decals.  Instead, masks were provided for a two-tone paint job.  After the fact, I noticed two small masks that looked like “crowns”. Nowhere in the instructions were these shown.  Nowhere on the box-art was the true color scheme reflected. However, images of the actual race car (see images in the section entitled “History of the Toyota GT-One”) show that one of the “crowns” should have been used as an extension of the large front mask and the other should have been used on the roof air-intake. The only mask that I used worked quite well but the two tone paint job delayed the model’s completion.

·        Two small aerodynamic tabs on the leading edge of the front fender are weak. In testing one broke off in a not to violent wreck. One might think about filing the tabs off prior to painting.

·        The model kit came with two sets of high quality decals: The number 1 car sponsored by Zent and the number 3 car sponsored by Esso. Both are replicas of entries in the 1999 Le Mans race. The Zent car qualified first on the grid but did not finish. The Esso car started eighth on the grid and finished second.  I selected the Esso decal set.

My GT-One project began with a Scholer Pantera chassis formerly used on my somewhat successful 962. First, I replaced the Falcon 7 motor with a Hawk 7 power plant. Second, I was never happy with the side pans on this chassis. They were simply too narrow. New side pans were fabricated from one inch wide, .062 inch thick brass plate with a small notch machined into the outer edge to facilitate body mounting. The wheelbase of the GT-One is ever so slightly longer than the Porsche 962; therefore, the front axle required a very slight relocation. The car ran so well in initial testing that I decided to postpone consideration of fabricating a new and larger front pan.

The wait was excruciating while the GT-One received a two-tone paint job, decals and a few coats of Future. Finally, the finished product was ready for testing.  Subjectively, I felt that the GT-One handled better than the 962. The Porsche seemed to be a bit “tail happy”. Below are a few images of the finished product.

     

Statistics

Our GT1 class includes Group C and GT1 plastic model bodies, some of which are quite expensive and hard to find. In an attempt to keep costs down, we allow wide sports cars such as the Ferrari Enzo and La Ferrari to run in this class as well. Many competitors have migrated to the Enzo. In fact nearly two thirds of all GT1 entries have been Enzos. However, other makes/models have achieved a modicum of success.

Initially, GT1 events were held at Electron Raceway, however, in time, the class was added to the mix at STR. Electron Raceway and STR are very different race courses. STR is characterized by very tight turns and long straights. STR also has a “hump” on the pit straight. Electron Raceway is characterized by sweeping turns and short straights. As the saying goes, “different horses for different courses”. It appears that this saying applies to Electron Raceway and STR. Therefore, historical results have been aggregated by race course as well as make and model. Results are shown in the tables below. Race data is provided from my Slot Car Database and includes results from July 2013 through May 2015. My interpretation of the data is presented in bullet point form below.  

STR Headlines

·        The Ferrari Enzo has been the dominant force at STR

o   Only the Enzo has turned a fast lap of under 5.0 seconds (Ron turned a 4.936 with his red Enzo and Bob turned a 4.938 with his black/yellow Enzo)

o   The Enzo holds the record for highest lap count at 92.6

o   Out of 10 races at STR, Enzos won 9 times, finished second 7 times and third 7 times

·        The only other car to win GT1 at STR was the Jaguar XJR12

·        The only other cars to finish on the podium at STR were:

o   Nissan R390 – 2nd

o   Porsche 962 – 3rd

Electron Raceway Headlines

·        The Toyota GT-One now holds the record for high lap total (91.3) and fastest lap (4.891)

·        The Porsche 962 has been a formidable competitor at Electron Raceway

o   The 962 is one of only three cars to break the 5 second barrier with a fast lap of 4.991

o   The 962 notched the highest number of wins (7).

o   The 962 is third in total lap count at 90.0

·        The Ferrari Enzo is a very competitive ride as well.

o   The Enzo is only one of three cars to break the 5 second barrier with a fast lap time of 4.994.

o   The Enzo finished first 4 times and second 8 times

·        Jaguar XJR12

o   In its six outings, the Jaguar XJR12 managed to notch a single win, finished second once and third once.

·        The only other cars to finish on the podium at Electron Raceway were:

o   Corvette C5R – 2nd

o   Jaguar XKR GT2 – 3rd

Other considerations (Both Tracks)

·        Jack’s Nissan R390 is a very good ride, finishing second in the last GT1 contest at STR

·        Jack’s Porsche GT1 has never been raced but seems to be very fast in practice

·        Since converting to a Hawk motor, James’ Jaguar XJR12 can run with the best in class

 

 

          GT1 Race Results STR      

Make/Model

Fast Lap/Driver

High Lap Total/Driver

Best Finish

Number of Outings

Wins

Winning Percentage

Ferrari Enzo

4.936/Ron

92.6/Bob

1st

10

9

90.0%

Nissan R390

5.045/Jack

90.3/Jack

2nd

4

0

0.00%

Jaguar XJR12

5.092/James

87.5/James

1st

9

1

11.1%

Porsche 962

5.107/Rich

87.4/Rich

3rd

2

0

0.00%

La Ferrari

5.215/Ron

84.8/Ron

5th

1

0

0.00%

Porsche GT1

5.496/Ron

77.1/Terry

5th

3

0

0.00%

Nissan R89C

5.777/Nick

74.4/Nick

7th

1

0

0.00%

 

 

 

 

GT1 Race Results Electron Raceway

Make/Model

Fast Lap/Driver

High Lap Total/Driver

Best Finish

Number of Outings

Wins

Winning Percentage

Toyota GT-One

4.891/Rich

91.3/Rich

1st

1

1

100.0%

Porsche 962

4.991/Rich

90.0/Rich

1st

9

7

77.8%

Ferrari Enzo

4.994/Bob

90.5/Rich

1st

14

4

28.6%

Jaguar XJR12

5.098/James

88.9/James

1st

6

1

16.7%

Jag. XKR GT2

5.166/Rich

83.3/Rich

3rd

1

0

0.0%

Nissan R390

5.210/Jack

84.4/Jack

4th

1

0

0.0%

Corvette C5R

5.285/Jack

82.0/Jack

2nd

1

0

0.0%

La Ferrari 

5.343/Ron

82.0/Ron

4th

1

0

0.0%

 

Images of some of our GT1 rides are shown below.

 

 

 

 

History of the Toyota GT-One

Throughout its history in Group C, Toyota never achieved its goal of a Le Mans win. A change in the GT1 class homologation requirements for 1998 offered Toyota a simple path back to Le Mans without the requirement of constructing 25 road-going examples. The new rules called for only a single street legal copy. After the rule change was announced, Toyota embarked on an ambitious program specifically aimed at winning the pinnacle of endurance races, Le Mans. The cutting edge machine was dubbed the TS020 aka the Toyota GT-One.

The car was built around a carbon-fiber monocot with an aluminum honeycomb core, which used the engine as a stressed member. While the chassis was designed by Toyota, it was actually manufactured by specialists Dallara in Italy. The suspension included double wishbones with push-rod actuated springs and dampers on all four corners. Carbon-ceramic brakes were also used all around.

The motor selected as the basis for the GT-One was an already existing power plant used in Toyota’s Group C entries – a purpose built 3.6 liter V8 with four valves per cylinder and equipped with twin turbochargers. The motor was redesigned for the GT-One; height and weight were reduced improving fuel economy, boosting power and changing the rev range. In the end, the motor produced 600 horsepower. Not bad for a car weighing in at just under 2000 pounds.

Since the car was intended to be run only at Le Mans, the design focused on reducing aerodynamic drag to the very minimum facilitating the highest speeds possible on the long straight sections of the race course. As such, it featured a minimal frontal area and a relatively long tail. A design feature that particularly stood out was the front wheel-well cut-out, intended to prevent pressure from building up inside the wheel-well. A single, small, aerodynamic air-intake was designed for the roof, again with drag-reduction in mind. 

The initial layout was completed on the computer and the shape was further refined in a wind-tunnel. Production of the GT-One commenced in October of 1997. Testing began in December and three cars were ready for an assault on Le Mans in May of 1998. In addition, two road-going cars were built to meet the homologation requirements. Neither road-going car was ever sold. One was put into a museum in Japan; the other is displayed at Toyota Motorsport in Cologne, Germany.

Toyota fielded a team of three cars for the 1998 Le Mans contest. The best of the three Toyota GT-Ones qualified second. Unfortunately, this car was involved in an accident early on in the race pinning Toyota’s hopes on its remaining two GT-Ones. The better of the two ran second until the final hour when it succumbed to a transmission failure. The remaining GT-One ended up a disappointing ninth.

Not to be deterred, Toyota refined the GT-One design and entered a three car team in the 1999 Le Mans race. GT-Ones qualified an encouraging first, second and eighth. Unfortunately, tire problems and relatively high fuel consumption doomed the 1999 effort. Some have reported that the Michelin tire failures were a result of sharp gravel that made its way onto the racing surface. Unfortunately, tire failure on the Toyota GT-One often resulted in damage to the mechanical linkage rendering the cars inoperable. That is exactly what happened after 90 laps when the first GT-One was lost due to an explosive tire puncture. About half way through the race, a second GT-One tire puncture led to a high speed accident which destroyed the car. The remaining GT-One soldiered on, running near the top of the field. In the final hours of the race, the remaining GT-One was in second place and closing on the lead BMW. After all of the hard work and disappointment endured for over a period of more than two years, there was hope that, at last, the GT-One would conquer Le Mans. Then, with a bang, another tire failure led to another disappointment. The remaining GT-One was, however, able to limp back to the pits where a new set of tires was installed. The unfortunate incident relegated the GT-One to second place, dashing Toyota’s hopes for a Le Mans victory. After the 1999 season, Toyota withdrew from sports car endurance racing to concentrate its efforts on Formula 1, thus ending the era of the GT-One. Below are images of the 1998 and 1999 team as well as the road going version.


  • Metalflake King likes this

Rich Vecchio





#2 rvec

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Posted 01 June 2015 - 04:49 PM

Sorry, The images have disappeared. I'll reply again when I get the problem fixed

Rich Vecchio


#3 rvec

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Posted 10 June 2015 - 09:34 AM

Images have now been restored. Enjoy!

Rich Vecchio


#4 Metalflake King

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Posted 03 September 2015 - 02:17 PM

Awesome thread Rich!  Thanks for all the info on this car and how it worked as a slot car body.  I have the same Tamiya kit and am in the process of building it on a B&E chassis for a Hardbody class at The Race Place in NJ.  Could you kindly show some pics of the body modifications you mentioned to allow for proper fit? Thanks.


Max Mohring

#5 rvec

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Posted 03 September 2015 - 03:45 PM

Awesome thread Rich!  Thanks for all the info on this car and how it worked as a slot car body.  I have the same Tamiya kit and am in the process of building it on a B&E chassis for a Hardbody class at The Race Place in NJ.  Could you kindly show some pics of the body modifications you mentioned to allow for proper fit? Thanks.


Thanks, The following image shows the cut outs for the rear wheels and for the gear. It also shows that the ears have been cut from the front wheel covering. My friend Ron covered the gear. He found a plastic model tire and cut it in half. He sanded the tread and ridges off and glued it to the body hiding the cut out and yet leaving the gear in place. Some other things that might work would be on of those old fashioned plastic change holders oval in shape and hollow in the middle. You might think of some other things. You might not have to deal with the gear problem at all because of the in-line configuration of the chassis.

P1010781.JPG

Rich Vecchio


#6 Metalflake King

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Posted 03 September 2015 - 04:46 PM

Thanks Rich.  The cutouts look like they belong there.  Very nice job. 


Max Mohring

#7 James Wendel

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Posted 03 September 2015 - 04:58 PM

Update - The Toyota GT-1 track record was broken 8/27/15 and is now held by James' Jaguar XJR at 4.868

Just in the interest of full disclosure.  :D 

 

Hey Rich, I have been working on my T/A chassis and hope to have it ready for your next Triathlon.  :good:


You can't always get what you want...

#8 rvec

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Posted 03 September 2015 - 07:51 PM

Update - The Toyota GT-1 track record was broken 8/27/15 and is now held by James' Jaguar XJR at 4.868
Just in the interest of full disclosure.  :D 
 
Hey Rich, I have been working on my T/A chassis and hope to have it ready for your next Triathlon.  :good:

James is correct, his Jaguar XJR turned a 4.868. Jacks blue Enzo is next fastest with a 4.888 and my Toyota GT-One is third fastest with a 4.891.

Glad to see you are working on a Trans Am chassis for the next race.

Rich Vecchio


#9 rvec

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Posted 03 September 2015 - 07:55 PM

Max,
Thanks and be sure to post an image of your finished work. Also, I follow your hard body racing in the NE. I see you put together a Lola T-70. I think you are using an H&R chassis. What motors are you using. Below is my rendition. The body is a Tamiya slot car body. The chassis is a Scholer. The motor is a Deathstar.

P1000519.JPG

P1000520.JPG

Rich_Lola2.JPG

Rich Vecchio






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