Great, also known as wheelbase in most models !
Team Magic loves to come up with new things, or sometimes older things with new names . . . Thanks Barry and really glad to know you are on the team !

Now I have two cars, one E4 kit and one E4RS kit, since I run on outdoor really large, low traction asphalt track, RS is the way to go, and I see some points on both cars.
E4:
-Came with anti-squat apllied, huge degree of it, none on E4RS;
-Original Thrust Bearing from diff is crap, got a 930138 Xray really good, like the one came on E4RS kit;
-Original servo mounts is a joke, like told here before, Xray 306200 awesome works, need some 2mm spacers between them and futaba std servos;
-Original battery tray made of aluminium, awesome for lipo, a nightmare for NiCd and NiMh, shor-circuit cells and terminals, nylon one from E4RS lighter and better;
-Front Multi-diff are too hard, breaks more UJ than the 'pulley'd' one on E4RS;
-Rear diff with too hard couples works hard on UJ too, breaks a lot, no mark to hold plates so it slips too much, lost of energy and power, the E4RS outdrives with plate like tamiya ones are awesomely better;
-Rear UJ is joke too, need to replace with 503216-1 7075 ones, with no more bone blade (clips) to broke or came off;
-Rear diff looses easily;
-Front UJ stops breaking with some tips from Wolf, take care of downstop(droop) and too much steering action, and avoid crashs;
-Anyway the V1RRR front UJ fits on E4 all around, has to open outter couple to 8.1mm inside and a heatshrink on the inner, now only pins got broke time to time;
-Original front and rear belts can't hold 7 packs of 4200mah nimh with a mamba 7700kv, so I changed to Optibelt Omega HP 144M3 ones, cheaper and perfect, but the E4RS belts are fine too, front and rear are the same size, only 3mm one and 3.5mm other, but could reverse then with no worries, the side belt ended up with Optibelt one too, not cheaper and do the same job;
-Misses some front belt tensioner, can use the one from E4RS kit, top deck is already drilled for it, all the others are on the car;

E4RS:
-No servo mounts, just tape, don't fool me, xray 306200 too but no need of spacers in this case, chassis holes are placed perfect on this one;
-New shocks looks better;
-No hop-ups, for who never saw the E4 kit thats ok, but like me have both, looks like a start kit, no alu all around (wich is good in some way);
-Nylon batt tray, the best for any sub-c cell pack;
-Front spool have changeable pulley (standard from diff), awesome;
-Antenna mount plastic, not good like alu one on E4 kit, has to buy 3racing ones;
-Front C-hubs mande of nylon, not perfect like alu ones on E4 kit;
-No servo saver, need to buy one separatedly, ended up buying same from E4 kit;
-Rear diff not looses easy like E4 kit one;
-Chassis and "ESC mount" are smartly designed to get some cold air to motor, in this car the motor is hidden in the middle and don't get enough air, small and great idea;
-No more upstop caused by bumper posts like someone told before on this thread, the new posts have smaller bases;

both cars :
-Lack of toe options, need to 3º on this track (180 turns only);
-Internal Ratio is lil dum, 2.0588 ? tried to put 34T (from foam spec) pulleys with the stock 17Ts inside, so can get a 2 radio, easier to calculate on, like on TC5, will see if work on this weekend;
-2.4mm ball diff bearings like told before on this thread, 930120 from Xray are better than stock ones, now running Jt 3/32 (2.4mm) ceramic on rear diff;
-Will find some gear diff that fits rear of this car, FW05 one fit perfect, even same bearings, just didn't see how to 'pulley' that;
-K-factory rollbars awesome, bearing mount too, even being heavier;
-Front posts are too much to the front, almost drill headlights of bodys to put them, and taller than needed, any body left 3 to 4 holes than needed, when rears are smaller, almost couldn't fit a hatch car body (Opel Astra);
-Side cooler from K-factory does nothing and could be under the wheel on a crash, money lost;
-Like told before on this thread, dremeling the outter ball ends on rear prevents binding, a must;

When remember something will post here!
Reference :
Track picture : http://i164.photobucket.com/albums/u...taPanorama.jpg
Main set : Mamba Max ESC w/ 7700kv and LRP TC Spec ESC w/ 4.5T (for now, gonna try 3.5T and 4.0T-orion), 4200mAh and 4300mAh Integy VESC 6-cell packs, Alpha R/C (brazilian) hard tires with soft insert and Mazda 6 body.
Atomic optional front UJ for V1RRR on E4 (KR-022) : http://i164.photobucket.com/albums/u...V1RRRUJ-E4.jpg
Optibelt belts on the car : http://i164.photobucket.com/albums/u...E4/E4opti1.jpg / http://i164.photobucket.com/albums/u...E4/E4opti2.jpg / http://i164.photobucket.com/albums/u...E4/E4opti3.jpg
Opel body, rear posts on the neck : http://i164.photobucket.com/albums/u...E4/TME4-59.jpg
E4 w/ Mamba : http://i164.photobucket.com/albums/u...E4/TME4-57.jpg
Dispensable side cooler from K-factory : http://i164.photobucket.com/albums/u...E4/TME4-53.jpg
Mazda 6 (race) body : http://i164.photobucket.com/albums/u...TM-E4mazda.jpg