We have received a lot of email and phone calls asking: “What is the difference between E4 models”? “Which E4 should I get”? “I race on Carpet and asphalt. Do I have to buy two different cars”? Do you have all of these in stock?
What is the difference?
The E4 is the original version. It has more machined aluminum parts than any other version, including; Aluminum pulleys, caster blocks and bottom battery door. It has a convertible (1 way independent, 1 way coupled and locked spool) quick change front 1 way and rear ball diff. This version is out of production and will never be produced again which is why we call it the Special Edition.
The E4FS (stands for Foam Spec.) has a 3mm Carbon fiber bottom deck (chassis) and a 2.5mm solid top deck. The shocks have been improved to reduce friction on the shock shaft. The steering is a single rotating arm style to increase Ackerman effect for more aggressive turn in. The battery mount area has been changed to accept most LiPo batteries without any modification. The pulleys have a deeper tooth depth and the belts are wider. It uses front and rear ball diffs.
The E4RS (stand for Rubber spec.) is like the E4FS with these exceptions; 2.5mm bottom deck and a 2 mm top deck with cut-outs. The steering is also twin parallel arm style to reduce Ackerman for a less aggressive turn in. It has a front 1 way and rear ball diff.
Which E4 should I get? Do I need separate cars for Foam and rubber tires?
First of all the E4 cars are unlike anything on the market. As an engineer and full size racecar builder I saw the advantages of centralized polar mass (putting the heavy items in the center of the car) but I had no idea it would make this big of a difference. The car is just amazing. If you like bling and are the type that is going to hop up the car with billet parts then the best kit is the E4. The bright aluminum parts and gold turnbuckles and carbon fiber chassis and steering parts make this car almost too nice to put on the track. Once you do put it on the track you will find that it is very neutral and easy to drive fast. It is also a very durable car. We let a lot of people drive it at several tracks and it took a real beating. To date we have not broken a single part on the car. It is still exactly as it was when we first put it together. After hundreds of laps it still has exactly the same readings on the setup station as it did when it was new.
The E4RS is the production version of the E4. Many of the billet pieces have been replaced with injection-molded parts which is why it costs less. The E4 Special Edition is about $30.00 more. This is less than the cost of 1 billet part. This makes the E4 Special Edition a real bargain.
The E4FS is the most versatile of the three models. The slightly thicker top and bottom decks have a weight penalty of only a few grams but they give you a stiff stable platform that removes one more tuning variable: Chassis flex. It is stiff enough for foam tires on carpet and by simply changing springs and shock oil it grips the asphalt like crazy with rubber tires too. This kit is my overall favorite electric racecar. I can get into the physics of it if someone asks but it would take a long posting that will bore a lot of people. One sweet aspect of this kit is that if the aggressive turn-in of the single arm steering does not suit your driving style, you can simply change to the twin parallel arm steering system (we have a kit with all the parts). It takes a few minutes and the holes are already in the top plate. If you insist on making the chassis more compliant we do stock the thinner E4RS top deck with the machined cut-outs. If you prefer a front 1 way or spool it just takes four screws to change either diff. This car can easily suit any race surface and any driving style preference. So the answer is no, you do not need to buy two cars.
The answer to the last question is: Yes… We have the E4 and E4FS in stock. www.wolfhobbies.com
In fact we are the only source in the world for the E4FS as we purchased the entire production run. We will order E4RS cars as requested.
One other question we see a lot is: “What are the ratings on the springs in the 502134 spring kit”?