i have a 1/10 pan car with traxxas xl5 brushed esc with 550 12 turn stock motor.im using 6 cell 4500mah nimh.it has a 64p 120 tooth spur gear and now i have a 26 tooth pinion and only getting 30.9 mph(im using gps)im planning on getting 7 cell 3500mah nimhwich should give me about 5 mph more but what other pinion size can i use to make it faster, more teeth or less.i also have a peak racing motor 11x2 should i trow that in instead. im hoping to get at least 45 mph and i dont want to go brushless this car is just a stepchild getting used parts.

i tried the traxxas motor and esc out of my slash in my tc4 and i found it was not nearly as fast as the 17 turn it came with. the motor is a 550 and it does have a kinda low turn but it is made for power and the fan in the end of the can is not making it any faster. the 540 you have would be better but you need a smaller spur most likely one in the lower 90's . but be careful check the turn limit on the esc and see if it can take a 11x2 i don't think it can i would personalty start thinking brushless . what is the brand of the car

the spes and no it cant handle a 11x2 15 turn is its limit
Traxxas XL-5 Forward and Reverse Electronic Speed Control with connectors and instruction manual

REQUIRES: Connecting to motor and battery of vehicle

SPECS: On Resistance Forward: 0.007 Ohms On Resistance Reverse: 0.014 Ohms Peak Current-Fwd/Rev: 100A/60A Braking Current: 60A Continous Current: 14A BEC Voltage: 6.0V DC BEC Current: 1A Power Wire: 14AWG/ 5" Input Harness Type: 26AWG/ 9" Transistor Type: MOSFET PWM Frequency: 1600Hz Thermal Protection: Thermal Shutdown Single Button Setup: Yes Motor Limit: 15T (540 Size), 12T (550 Size) Input Voltage: 4-8 Cells (4.8 to 9.6V DC) Weight: 3.07oz (87g) Profile Selection: Sport Mode 100% FWD, 100% Brakes, 100%REV Race Mode 100% FWD, 100% Brakes, No REV Training Mode 50% FWD, 100% Brakes, 50% REV

the xl5 wont handle a 11 turn 540. the stock 12 turn is a 550, which is more like a 19t 540.
get a speed gems 15t. they are pretty good motors for the money. it will be faster than the 12t titan for sure.
also, larger pinion equals more speed. until you over gear the motor and fry it(been there, done that!)
i wouldnt gear up the titan more than you have. it will most likely fry itself.
if you got a decent 15t 540 motor, and a 2s 3000mah lipo then you could do 45mph for sure.
a decent motor will run $30, and you can get 2 lipos and a lipo charger(imax b6) off ebay for $100.