Model: (Click to see more) 58380: Keen Hawk
Status: How To Guide
Date: 16-Sep-2007
Comments: 16
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Hey Guys,



With this being my first post I hope you guys find this article useful. For me, I’ve wanted to do a short guide/review for the DF-03 ever since Tamiya release it last year. So after a few e-mail inquires I decided to give it a shot.





Initial thoughts:



Tuning and predicting the performance of your car is all about mastering the mechanical variables on your vehicle such as gear ratios, roll-out ratios, suspension settings, camber and toe-in angles, tires, batteries, motor and the list goes on.



In off road racing it’s not just about tuning your car to outrun your opponents, but it’s also about how to survive the race, it’s actually enabling your car to finish in one piece. That’s when the durability factor comes in. These days off road tracks, especially in the US, are getting insanely difficult with extremely high jumps and bumps on the track that just wrecks your car apart. It takes many practice laps and some plastic broken parts in order for you to get somewhere in an actual race.



So with this in mind, I mainly focused this article on the durability aspect and some performance tuning tips. In other words, what hop-ups to consider that may add durability and performance to your DF-03 chassis.



The advice and feedback I’m about to give is just my best assessment based my experience with this chassis; and what may work on this car to my best knowledge.



Also, I’m sure you guys probably seen and know most of this stuff!



Your comments, questions and flames are very welcomed!











A. Parts for durability:



1) Shock Towers:



I’ve installed:



GPM (#DF3028 ) Alloy Front Shock Tower

http://www.rcmart.com/catalog/images/gpm_df3028_001.jpg



GPM (#DF3030) Alloy Rear Shock Tower

http://www.rcmart.com/catalog/images/gpm_df3030_001.jpg



Aluminum or graphite shock towers are definitely a must for serious off-roading, but keep in mind, (as you might already know) some aluminum parts like this one are slightly heavier than the standard plastic. The weight trade off in a way may be worth it, in my experience very rarely I had aluminum parts break.



If you’re going to choose an aluminum shock tower and aluminum suspension arms, I wouldn’t suggest the ones manufactured by “Yeah Racing”. These for me, in my opinion are over-designed (specially the suspension arms), thus inherently adding unnecessary weight to the vehicle.



If weight is your concern and still desire to have a higher durability shock tower than the stock plastic ones you may want to try these from 3Racing, Square and Top Cad:



3Racing (#DF03-09/SG) SSG Graphite Front Shock Tower (SG)

http://www.rcmart.com/catalog/images/3rac_df03-09sg_001.jpg



3Racing (#DF03-06/SG) SSG Graphite Rear Damper Tower (SG)

http://www.rcmart.com/catalog/images/3rac_df03-06sg_001.jpg



TOPCAD (#DF03101) Graphite Front Shock Tower For DF-03

http://www.rcmart.com/catalog/images/topcad_df03101_001.jpg



TOPCAD (#DF03108 ) Graphite Rear Shock Tower For DF-03

http://www.rcmart.com/catalog/images/topcad_df03108_001.jpg



Square (#SDI-3) Front Damper Stay Tamiya DF03

http://www.rcmart.com/catalog/images/square_sdi-3_001.jpg



Square (#SDI-4) Rear Damper Stay Tamiya DF03

http://www.rcmart.com/catalog/images/square_sdi-4_001.jpg











2) Suspension Arms, Braces, Knuckle Arms and C-Hubs.



I’ve installed:



GPM (#DF3055) Alloy Front Lower Arm

http://www.rcmart.com/catalog/images/gpm_df3055_001.jpg



GPM (#DF3056) Alloy Rear Lower Arm

http://www.rcmart.com/catalog/images/gpm_df3056_001.jpg



FS7051 Five Stars Front and Rear Aluminum Suspension Brace

http://img.inkfrog.com/pix/jr-rc/fs7051akusush.jpg



GPM (#DF3021) Alloy Front Knuckle Arm

http://www.rcmart.com/catalog/images/gpm_df3021_001.jpg



GPM (#DF3022) Alloy Rear Knuckle Arm

http://www.rcmart.com/catalog/images/gpm_df3022_001.jpg



GPM (#DF3019) Alloy Front C-Hub

http://www.rcmart.com/catalog/images/gpm_df3019_001.jpg



As you might already know, aluminum suspension arms are always a good call, for off road racing. But it would be best if you do use the suspension braces with your aluminum suspension arms; since the loading now is mainly transferred to the plastic gear case and the suspension brace definitely helps distribute this loading more evenly throughout the whole assembly. I highly recommend the Front and Rear aluminum set from “Five Stars” (FS7051 Five Stars Front and Rear Aluminum Suspension Brace), but one very important detail is that if you install the rear brace of this brand you won’t be able to attach the rear bumper.



In addition to suspension braces it would also be a good call to purchase an aluminum front lower section gear box cover, an item I’ve yet to purchase. The original plastic one over time will show stress marks (in my case) at the suspension shaft supports, and will eventually fail after some serious jumps.



GPM (#DF3008 ) Alloy Front Gear Box Lower Mount With Screws

http://www.rcmart.com/catalog/images/gpm_df3008_001.jpg



In regards to knuckles and C-Hubs, these always cracked when they were plastic, especially in jumps, so definitely a must have! For me, these parts almost any brand has done good job on the design.



By the way, you can purchase a full “Hop Up Kit” from “Top Cad” and it will bring most or all aluminum parts needed for $99.99 plus shipping. Design wise this company seems to have done a good job, in the sense that they are not over designed. If your on the budget, these are it man!



TOPCAD (#DF03100) Alloy Complete Set For DF-03

http://www.rcmart.com/catalog/images/topcad_df03100_001.jpg











3) Aluminum Shocks or Dampers



I’ve installed:



Tamiya (#53926) RC DF03 Alum Oil Damper Set

http://www.tamiyausa.com//images/product/720/53926/header_53926.jpg



In off road racing, this is one of the critical mechanical variables in your vehicle. Tuning and setting up the shocks is very dependant on track conditions, for me, it has always been a trial and error until you achieve a comfortable set-up. Once again, it takes a few test runs and patience to figure out the best combination between springs and oil and decide whether to manage jumps and or rough terrain.



In regards to the stock ones provided by the kit, in my opinion, they’ve always performed well (not excellent) under some what rough conditions. But definitely the aluminum ones will handle better in jumps, they are less prone to bending making them more predictable. Plus the easy adjustability is a plus. I would recommend the ones from Tamiya, hands down, these are among the best I’ve seen manufacturability and quality wise, though with a heavy price, you will not be disappointed. Still, I haven’t tried in person other companies; it might be worth a shot to check out “Yeah Racing” and “3Racing”. They seem pretty good too.











4) Chassis



I’ve installed:



3Racing - Graphite Conversion Kit (DF03-15/WO)

http://www.3racing.com.hk/images/DF03-15WO.jpg



A topic of much debate for some people, but these are my two cents. I purchased the 3Racing graphite fiber chassis conversion and here are the Pros and Cons in my opinion:





Pros:



-Added rotational torsion stiffness along the car’s longitudinal axis, it’s a definitely a plus for added performance.



-The servo stands provides better cable strain relief for the servo than the stock one.



-It provides better ventilation for the battery to cool down.



-Adds a lot to the “Bling” factor!





Cons:



-Prone to painful scratches, After an $90 dollar investment, it will hurt if you scratch it bad. I’m currently planning to manufacture a custom under-cowl for it with a battery access hatch.



-Compared to the stock plastic tub, the tub provided better protection against FOD (Foreign Object Debris) because you can install a Velcro seal between the body and chassis.



-You still have to remove the body in order to access the release pins of the battery hatch.



-It is heavier than the original plastic tub chassis.





You can see in detail the assembly of this chassis below:



http://www.3racing.com.hk/manual_moives/DF03-15.avi



Overall, if you’re on the budget, maybe have it for a later purchase. For me, I think its not an immediate performance item. But it’s worth a shot, if you can deal with the cons.











5) Other critical items:



Universal Shafts and Differential Joints/Drive Cups:



I’ve installed but not pictured:



Tamiya (53791) RC Universal Shaft Assembly - DF02

http://www.tamiyausa.com/images/product/720/53791/header_53791.jpg



3Racing - Heavy Duty Front Differential Shaft (DF03-08/HD)

http://www.rcmart.com/catalog/images/3rac_df03-08(hd)_001.jpg



3Racing - Heavy Duty Rear Differential Shaft (DF03-03/HD)

http://www.3racing.com.hk/images/DF03-03HD.jpg



Definitely a must when it comes to handling in the dirt, the universal shafts are less prone to pop off and provide a continuous drive to your wheels no matter the angle of your suspension arm and steering angle.



For the DF-03 chassis, Tamiya uses item 53791 Universal Shaft Assembly it’s actually for the DF-02 but will work on the “Keen Hawk”. These shafts (so far) with the proper maintenance shouldn’t give you any problems.



Also, notice that the older Thunder Shot / TA-01 Universal Shafts are compatible with this chassis as well. They may not look as nice, but they may go for half the price.



4135028 RC Universal Shaft: 58075

http://www.kimshobby.co.kr/images/product/kimshobby/4942.JPG



There are also other brands you may want to consider like:



GPM (#SDF3268C) Steel F/R Universal Swing Shaft (68mm CVD Design) For DF03

http://www.rcmart.com/catalog/images/gpm_sdf3268c_001.jpg



3Racing (#DF03-18 ) Swing Shaft For Tamiya DF03

http://www.rcmart.com/catalog/images/3rac_df03-18_001.jpg



TOPCAD (#DF03113) Universal Joint (Heavy Duty)

http://www.rcmart.com/catalog/images/topcad_df03113_001.jpg



TOBEE (#43370) DF03 Strengthening Universal Joint 16mm Wide

http://www.rcmart.com/catalog/images/tobee_43370_001.jpg



In regards to the differential joints or differential drive cups, with the use of a low turn brushed or brushless motor, the stock ones will wear fast or even fail. So I do highly suggest to install hardened steel ones like the manufactured by 3Racing or Square brand.











B. Parts for “Bling Bling” and some improvement (I’ve purchased):





Yeah Racing (#DF03-013BU) Alloy Gear Cover For DF03 (BU)

Just pure “Bling”, no performance gain on this one.



Yeah Racing (#DF03-014BU) Alloy Main Drive Shaft For DF03

“Bling” the stock one will work just fine!



Yeah Racing (#DF03-034BU) Alloy Spoiler Stand -10 deg (BU)

It may help when your car rolls over, but for me its just “Bling”.



GPM (#DF3003F) Alloy Front Bumper

This is just “Bling”, actually I don’t think its good idea to have an aluminum bumper, most of the shock load will be transferred to the gear case! He He…..



GPM (#DF3003R) Alloy Rear Bumper

Same comments as in DF3003F, but very important to keep in mind that this part is not compatible with PN# FS7051 Five Stars Rear Aluminum Suspension Brace.



GPM (#DF3018 ) Alloy Motor heat Sink Plate With Screws

The stock one will perform pretty much the same, the word heat sink in this case for me is a selling gimmick. Any brand will do the same.



GPM (#DF3048 ) Alloy Steering Assembly With Collars

Maybe consider this one in the future, since the assembly will definitely be more robust. But will not give your car immediate performance increase.



GPM (#DF3049) Alloy Steering Plate With Screws

Same comment as in PN #DF3048



GPM (#DF3201R) Alloy Rear Body Post With E-Clip & Screws

Yes! lots of “Bling Bling”!



Tamiya (#53941) DF03 Alu. Turnbuckle Steering Rod

More Bling, the stock one will do the same, though this one is a lot easier to adjust.



Tamiya (#53943) 3x46mm Hard Turnbuckle Shaft Set

Its good to have them, a lot easier to adjust.



Tamiya (#53944) 3x50mm Hard Turnbuckle Shaft Set

Its good to have them, a lot easier to adjust!



Tamiya (#53948 ) Alum One-Piece Propeller Cup Joint For DF03

It is definitely a good call to have them if you want to avoid the stock ones to wear out over time.



Tamiya (#53949) Lightweight Battery Stopper Pin For DF03

More Bling! but keep in mind that if you buy the graphite fiber conversion kit from 3Racing, you won’t be able to use this part!



Tamiya (#53924) RC DF03 Heat Sink Bar

Though it is good call to have them installed, I’ve yet to measure any noticeable temperature differences. For me, it just looks cool.











C. Gearing Tips





Gearing wise, I haven’t looked into any new spur gears from GPM and Kawada, but here is a quick tip to keep in mind when you’re preparing for the race:



The combination of:

Low Spur Gear with High Pinion Gear = High RPM Output thus Higher Top Speed, but slower Acceleration.



The combination of:



High Spur Gear with Low Pinion Gear = Hi Torque Output thus Lower Top Speed (Lower RPM ) but a much higher and faster acceleration.



A lot of people overlook these things (i.e. also Roll Ratio) and blame the performance of the car on the design and brand. When actually the problem is the driver’s understanding of the mechanics behind the car. These factors play a crucial role on the performance of your car when it comes to racing, aside of tires, motors, batteries, etc.







Comments

joelvardy

16-Sep-2007

Great review m8.. even nicer car!

MvT

16-Sep-2007

This baby should have been in cold! at least I think that is what it has cost you to mod it like this Would be a pity to paint the body, cause else you not see all the beauty underneath it! Sorry about the 1st empty comment... I have a tricky finger! nice one mate!

Kokuzu

16-Sep-2007

Chris,
if i ever need some detailed analysis about a car's possibilities and hopups - I knock on your door. Nice article!

Vin87

16-Sep-2007

Nice article! Makes me want to hop up my DI. However with the price of all those hop ups one could maybe better buy a TRF501X

technical.burP

16-Sep-2007

This must be the most expensive Keen Hawk or DF-03 based car I have ever seen! Amazing though. It looks really nice.

astute77

17-Sep-2007

Wow! Is there anything left of the original DF03 kit after all those upgrades? Seems like you could save some bucks by not bothering to buy the original kit, and just assembling all the hopups!

backtomyroots.

18-Sep-2007

Excellent write up & article. I'm no buggy guy - but you may be swaying my opinion !

Jetalone

18-Sep-2007

Thanks for all your complements guys! I’m glad some you have enjoyed the pictures and the review!




Addressing some of your comments, “Vin87” has a good point, if you purchase part by part individually from GPM, as I did, it could get as expensive as purchasing a TRF501X.



Still, an option to consider and save a bit of money, is to purchase a full “Hop Up Kit” from “Top Cad” and it will bring most or all aluminum parts needed for $99.99 plus shipping.




As “Astute77” mentioned, yes, there is little left from the original kit, just the gear cases and the gear themselves, aside of the body. I agree, maybe just buy these parts separately and then the “Hop Up Parts” will indeed save you bit of money. I’m going to have to do the math and verify this.



In regards to the body, well, it’s been transparent all this time, not necessarily to show the “bling” underneath, but mainly because I haven’t decided what paint color and scheme should I use LOL!. Plus, for the photo shoot, it was my original intent to have it transparent.



I will be posting soon some color scheme options I’ve been working on digitally.

19-Sep-2007

Which wheels and tires are those? Part #'s and avaliablity would be nice.

Jetalone

19-Sep-2007

In response to “Chad’s” inquiry :



I’ve totally missed the details on the wheels, they are as follows :



Rims - 50566 RC 1/8 Opel Calibra Wheels - (1pr)

Tire In-serts - 53203 RC TGX Shaped Tire In-serts - (1pr)

Tires - 50839 RC GP TGX Rally Block Tires - (1pr)



If you guys are interested in purchasing some “stylish” rims for your 1/10 scale buggy, the 1/8 scale on-road car rims are the ones for the job. Do a search on e-bay under “Tamiya TGX Wheels”, regularly they for go $8 a pair, which is not bad at all. It seems at this moment Jason, aka JR-RC, has up for sale some really nice black eight spoke rims (PN 50864), check them out!



You may also find some of these items at:

[Click here]

[Click here]

Wrc action

21-Sep-2007

Yeah very nice wheels, can I have some dimensions please as they look really promising for my Pajero T3,also wat is the overall width of the model as I would need it to fit under my pajero shell, My DF03 is the donar chassis cheers Ryck

Jetalone

21-Sep-2007

In response to “WRC Action’s” inquiry :



Sure! No problem, dimension are as follows :



Rims - 50566 RC 1/8 Opel Calibra Wheels - (1pr)

Inner Tire Rim Outside Diameter - 2.04 in or 51.91 mm

Inner Tire Rim Width - 1.15 in or 29.30 mm



Tires - 50839 RC GP TGX Rally Block Tires - (1pr)

Inner Tire Diameter - 1.97 in or 50 mm

Outer Tire Diameter - 3.15 in or 80mm

Outer Tire Width - 1.35 in or 34.25 mm



I believe these “TGX” or “1/8 Scale On-Road” rims have the same dimensions that the Manta Ray and Dirt Thrasher buggies have on theirs. Keep in mind that these rims will not fit DF-03 tires.

4-Oct-2007

How do the rear GPM suspension arm compare to the originals which seem to have a distinct toe in and narrower track than the front. Are the GPM identical or are these perameters different

Jetalone

5-Oct-2007

In regards to “Rob H’s” question, taking some quick measurements and comparing these suspension arms side by side, the GPM arms have the same geometric dimensions for those parameters as the original ones, thus the toe-in and track are the same.



It may seem that way in one of the pictures, on the fourth one, top to bottom, top view of the car; but these wheels being narrower than the stock ones and the rear turnbuckles being inadequately adjusted at the time pictures were taken, it gives this visual effect. Good observation Rob!!

9-Jan-2008

Road Burner

1-Aug-2008

Nice review! I want to get one now!


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