Williams Renault FW18 (F103RS)
Williams Renault FW18 by Black Hole Sun
Black Hole Sun describes the Tamiya F103RS Williams Renault FW18, where it fits in the F103 family, along with a review, re-build and track test.
It has been some time since I was thinking about getting this Formula 1 chassis for my collection because it was a reference into its category during its almost 15 years of existence in Tamiya's offering. After reviewing its predecessors, I wanted to know about the generation that seem to be the achievement of the dynasty. So when the opportunity popped up, I clicked :)
The F-103 chassis family
As mentioned in the foreword, the F-103 chassis was the ultimate weapon in its category for many years. Several versions existed, and it all started in 1993:
|58126 Lotus 107B (1993)
||58130 Sauber C12 (1993)
||58142 Ferrari 412T1 (1994)
Photos © Tamiya
Only 3 models used the orginal F-103 basis, but in 1994, new variants were released, among which the F-103L version to fit the longer Formula Indy bodyshells:
|58134 Newman Lola T93/00 Ford (1994)
||58148 Rahal-Hogan Lola T94 (1994)
|Photos © Tamiya|
Following the same idea, Tamiya will later release the F-103LM version for prototypes bodyshells from the world famous 24h La Mans race:
|58247 Audi R8R (1999)
||58258 F-103LM TRF Special Chassis Kit (2000)
Photos © Tamiya
Let's get back to 1995 when my model F-103RS version was released, mainly introducing an improved rear suspension system:
|58156 F-103RS Chassis Kit (1995)
||58179 Williams-Renault FW18 (1996)
||58198 PIAA Nakajima Reynard 97D (1997)
|58213 Ferrari F310B (1998)
||58229 Toyota GT-One TS-020 (1998)
||58230 Porsche 911 GT1 (1999)
|58235 Mclaren Mercedes MP4/13 (1999)
||58253 Toyota GT-One TS020 (1999)
|Photos © Tamiya|
Then, the F-103RX version was released in 1997: it mainly brought a modified front drivetrain that most drivers disliked. Almost 10 years later, the F-103GT was released: this 2006 version is specific since it was designed to fit the Touring category bodyshells. This allowed the F-103GT chassis to race in the 4WD Touring category whenever the rules allowed it.
|58194 F-103 RX Chassis Kit (1997)
||58367 F103GT Direct Drive (2006)
||58376 Advance Courage LC70 Mugen (2006)
Photos © Tamiya
The F-103 last appearance was in 2008 with the release of four models in limited edition: the first three were using the lastest chassis evolution called F-103RM. This last evolution brought an adjustable rear drivetrain ride height and an lighter damper stay. These models came with unofficial Formula 1 bodyshells, probably for licence cost reasons. Nevertheless, the "M Body" is a McLaren, the "T Body" is probably a Tyrrell and the "L Body" is probably a Ligier. Last but not least, a special 15th Anniversary limited edition was released at the end of the F-103 chassis career:
|49498 F-103 RM M Body (2008)
||84031 F-103 RM T Body (2008)
|84032 F-103 RM L Body (2008)
||84056 F-103 15th Anniversary Chassis Kit (2008)
Photos © Tamiya
This impressive dynasty and how long it lasted are proof of its commercial success. The F-103 chassis was the king of the tracks in its category, especially starting from the F-103RS version released in 1995. Its resurrection under the F-103GT version in 2006 is more trivial: at the highest racing level, the F-103 chassis had already very serious opponents. But this Touring version definitely proves that the F-103 genes were good enough to decently race it against 4WD opponents. As for the 2008 versions, they mostly look like a last tribute to a chassis that made history.
My Williams-Renault FW18 when it arrived
A few days after clicking, I was pleased to open the parcel:
You can only see part of what I received since the parcel also contained the stock wheel set, the battery tray missing parts, the sticker sheet and everything required to transform the chassis into an F-103GT. The overall condition looks pretty good but a full disassembly is required, both to check every part is there and to rebuild the chassis as stock.
The F-103RS chassis
With their F-103 chassis, Tamiya introduced several major improvements over the previous F-102, from the chassis plate to the front drivetrain, the differential and the suspension.
Let's start with the chassis, below is a photo of the F-102 followed by the F-103:
Obviously, the F-103 is narrower than its predecessor, either at the front where the front arms are bolted or at the servo location, the battery tray and even the rear end T-Bar shape (the T-Bar is the part located under the motor, heading forward inside the chassis plate). Moreover, even if photos can't show this, the F-103 chassis is much stiffer than the F-102's: this is a radical change compared to previous versions of the chassis dynasty started 7 years before with the Road Wizard.
By narrowing the chassis, especially at the front, Tamiya designers intended to improve the suspension efficency. As the chassis is narrower, the front arms are longer and this helps improve the overall suspension precision and efficiency. The difference in front arms length is depicted hereafter:
|F-102 front drivetrain
||F-103 front drivetrain
You can also notice that reducing the chassis width implied another major evolution: the steering servo is now placed vertically, allowing to perfectly center it in between the wheels and the chassis for a better weight balance (despite the higher center of gravity). On my model, the servo stay is a carbon structure (3Racing part): in stock form, the servo has to be double-sided tapped against a vertical plastic part.
The most important improvement on the front drivetrain is the simpler build: on the F-102, the front drivetrain is made out of 4 parts (1 upper arm and 1 lower arm by side) held by a plate, 4 screws and nuts. On the F-103, only 2 parts are used (1 upper and 1 lower part for the whole drivetrain) held by 2 screws and nuts. Apart from being simpler, the whole drivetrain is lighter due to eliminating half of the steel screws and nuts.
Next improvement, the front wheel suspension: on the F-102, the spring is located on the lower side of the wheel axle, sandwiched by the upper and lower arms. On the F-103, the spring was moved below the lower arm:
|F-102 front suspension (view from behind)
||At full load
|F-103 front suspension (view from the front)
||At full load
The advantage of this solution is to move the spring weight at the lowest (even if we're talking about a few grams only), but mainly to make spring changes easier. On the F-102, you need to disassemble the wheels and the arms to perform this operation. On the F-103, you only need to remove the wheel and the C-clip holding the spring. In theory. When biulding the front drivetrain, I found this operation rather complicated and unfriendly (you need to compress the spring while fitting the C-clip at the same time), but this may be a question of practice.
Next major improvement, the rear drivetrain suspension was radically changed. The F-102 chassis features the same system the Road Wizard introduced back in 1986:
With the F-102, likewise its predecessors, the rear pod movements are controlled in two different ways depending on their kind:
- longitudinal movements: these are the rear pod movements oriented from the rear to the front of the chassis (and vice versa). They are controlled by the damper joining the rear pod to the battery stay upper deck.
- side movements: these are the rear pod movements from left to right (and vice versa), typically those occuring in curves (also called chassis roll) that directly influence the front drivetrain steering response. These movements are controlled by how strong you tighten the T-bar screws to the battery stay.
With the F-103 chassis, the system was totally changed:
On the right side manual excerpt, you probably recognize the chassis roll adjustement through the T-Bar screws. However, the damper now connects to the rear pod through a friction plate partially acting both as a chassis roll control and longitudinal dampening. This friction plate is also the main difference between the original F-103 chassis (below left) and the RS version of my model (below right):
Basically, the system was simplified, by reducing from 3 to 2 friction disks and offering a much more precise setup thanks to the adjuster nut that replaces the previous 2-position clip system. Below are the parts making the RS version friction plate system:
In concrete, setting up the front drivetrain response is made like with the F-102 and predecessors, by tightening the T-Bar screws. Likewise, setting up the dampening effect is mainly made through the damper itself: these two elements determine the chassis overall handling. The friction damper settings (as well as the grease viscosity applied to the disks) mainly serve to more precisely adjust the settings to perfectly match the track conditions.
Apart from its precision, the main advantage of this solution is that adjusting the friction damper system will jointly affect the dampening and the chassis roll. Once you have found the best dampening and front drivetrain response settings, you don't need to change them since the best chassis balance was found. However, since grip and surface quality change from track to track, it is very helpful to be able to adjust both the dampening and the chassis roll in equal proportions depending on track conditions (or temperature that impact grip).
Last improvement on the F-103 chassis:
In fact, apart from the differential housings, everything else is strictly the same. Which means the differential first seen on the GroupC chassis (my Jaguar XJR-12) that was borrowed by the F-101 and F-102 simply received a slimming treatment on the housing side to reduce weight.
To conclude this part of the review, here's the chassis ready to run:
The Williams FW18 bodyshell
As you could see at the begining of this review, the bodyshell came painted without stickers applied. As for the rear wing, I found it couldn't serve anything since it was broken:
|The broken rear wing
||The replacement part
It definitely looks like a weak point and it means the model was hit by the rear. However, it is quite unpleasant to discover the problem afterwards because the seller didn't mention it (and photos didn't show anything).
Let's get back to the bodyshell: in addition to a not that fantastic paint job, the main issue is that it was already painted. With this kind of decoration set, you should always stick to the manual instructions, especially when they recommend to apply some stickers before painting since they make the limit between colors. Despite my best efforts to mask the mistakes by cheating as much as I could on stickers placement, some mistakes couldn't be fully hidden:
The solution is to scratch the white paint from the inside of the body and to reapply the blue paint after masking the whole bodyshell:
Unfortunately, the result is not perfect: I first tried the 87118 Polycarbonate Body Cleaner but it seems this product doesn't work for me, whatever the bodyshell. I was only left with the scratching technique, which is not the best possible solution. Nevertheless, the final result is quite correct.
For decorating this bodyshell, I used a new technique my friend Jérémy taught me for applying stickers: to get rid of air bubbles, but more especially to apply stickers on difficult shapes, you can heat them with a lighter. Below is a sticker applied "normaly" the best I could and the same one after receiving some heat from a lighter:
Obviously, the sticker on the left won't stay long whereas the one on the right perfectly covers the shape of the part. This was not exagerated: the sticker on the left was applied using a tooth pick and it was pretty much fitting the part nicely. But the photo was taken about less than one hour after applying it.
The technique is to place the sticker as usual and to make it fit the surface shape as best as you can. Then, use a lighter to heat the sticker: quickly pass the flame close to the sticker and immediately stick it so it retracts on the surface. The heat makes the sticker softer, allowing it to better stick to surface shapes. When cooling down, it recovers its natural rigidity, but now perfectly molding the surface.
Caution: heat the sticker, don't melt it. The lighter flame needs to pass quickly a few millimeters away from the sticker: if the movement is not quick enough, the sticker will melt. I recommend you first make several attempts with leftovers in order to get the correct technique.
The cockpit and the driver were left to be painted: I could choose between Jacques Villeneuve and Damon Hill. I chose the one who won the 1996 drivers championship with this Williams Renault FW18:
My model is now finished: let's see how it performs at the track.
The AMRCL (France) on-road track was open only for 3 days when I brought my Williams FW18 to this new track. Before the first wheel turned, I shot a few photos:
The model really looks nice on the track and I was impatient to test the famous F-103. So, after switching on everything and a last checkup, my Williams made a first lap with caution. Second lap, the long straight line was again at sight so... throttle... BRAKES!
I hadn't been driving a Formula 1 for about one year, at least nothing modern :). But above all, despite the chassis photos showing it, I didn't mention the motor is a Sport Tuned: I knew I was probably optimistic, but I wanted to test the F-103 chassis with 'some" power. Result: the grip on our track, the tires and my driving skills are clearly not good enough to control a surface-to-surface missile. A basic Mabuchi 540 immediately replaced the Sport Tuned in order for the driver to regain more control over the model.
With the Mabuchi 540, the F-103RS chassis can be controlled, at least considering my driving skills and the track grip. Without surprise, the handling is very much like the F-102's of my Footwork FA-13, but with more directivity and precision at the front drivetrain, as well as a more stable rear drivetrain.
As I wanted to understand the overall F-103RS handling, I performed a weighing session once I got back home:
|Williams FW11B||1987||670g||1080g||+ 1.89%|
|Footwork FA-13 (F-102)||1992||740g||1150g||+ 8.49%|
|Williams FW18 (F-103RS)||1996||800g||1210g||+ 14.15%|
The "empty" weight is the complete model without the battery pack, the weight "on track" adds the battery pack. The difference is the weight difference between a given model and the Road Wizard's I used as a reference since it is the first modern Formula 1 from Tamiya. Unfortunately, I don't own an F-101 chassis to complete this comparison, but I guess it should weigh about the same as the F-102.
Obviously, the chassis gains weight at every new generation, but not loosing vivacity as far as I can feel it at the wheel. In fact, the weight gain mainly seems to improve the chassis stability: the handling stability difference is quite sensible between the Road Wizard and the F-103RS. Of course, the chassis plate stiffness, the suspension, the tires (especially their age) and the overall chassis design certainly have direct influence: nevertheless, I think the weight difference is probably the most significant parameter for the much improved chassis stability, again, not losing raw performance using the same motor.
To conclude, the F-103RS chassis is a pleasure to drive with no more than a standard Mabuchi 540: to use a better motor, you'd better seriously consider to upgrade the tires and run on a high-grip track surface. Not to forget being a pretty good driver.
Naturally, the chassis has a serious propensity to oversteer that you can correct by adjusting the chassis roll: this is typical of the chassis dynasty started with the Road Wizard.
Moreover, drving an F1 chassis is somewhat specific: the front drivetrain is amazingly precise (thus the "natural" oversteer) and the rear drivetrain is very stable when accelerating (which may sound like a paradox). In fact, the main point in driving an F1 is the curve entry: whatever the speed, the front drivetrain will go where the driver tells it to go. The rear drivetrain will follow as long as the grip allows it: whenever it loses grip, the car spins, meaning the driver was too optimistic. However, whenever the curve entry went well, the curve exit will be perfect since the rear drivetrain will perfectly handle the motor power when re-accelerating (as long as the motor power matches the track grip condition).
More photos on the gallery.
RC Formula1 Comment
A great article thanks Pascal! And thanks for providing permission for us to reproduce it in full. You can see the original article in French here (there is also an English version). You can also see more articles on modern and vintage Tamiya RC models (in English and French) on the Black Hole Sun website.