hpi2

Can anyone give me some tips on gearing for a electric HPI sprint 2 for racing on asphalt. The car has a internal ratio of 2.4375. I tried a 80/34, it nearly killed it. Tried a 76/31 went a little bit better but when racing in a competition other competitors leave me for dead. Am I going the wrong way with the gearing, any advise is appreciated. I am running a stock motor (Johnson 540) This is the only motor for New Zealand for a stock class whish is set by the New Zealand RC Assocciation.

[&o]

Piero23

give us more info about you car esc, battery, cells, wheels, body

hpi2

Hi Perio23. The speed controller I am using is a Duratrax Intillispeed ST Pro 8 turn limit. There are several automatic track settings you can use with this speed controller, 1/12 On-road, Stock touring, Mod touring, Off road and manual settings. I have got it currently set for Stock Touring. The battery is a Tamiya 1400Mah. The battery is new and had 2 x meetings. The body is a toureza body. I got this from Tower Hobbies pre-painted. The wheels are 26mm wide 4mm off-set with HPI V-Groove D Compound tyres. If you need more infor please ask but thanks for your reply.

Piero23

Well theres, your problem

upgrade if you can to some [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNCR2&P=ML]4200 mah cells[/link]

replace your the tamiya connectors from your battery to esc to [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKX39&P=ML]deans connectors[/link] they have much lower resistance than

stardard tamiya plugs

also im not familiar with that motor you are using if it has a sealed endbell or replaceable brushes, either way take it apart and check the commutator for wear and check the brushes if they are worn and

good pressure

did you break in your motor first ?

once you get that stuff straight work on getting the right gearing

hpi2

Thanks for your reply. The other problem is the regulations which are set by the New Zealand RC Assocciation. The class is open stock touring. The maximum battery is 1500Mah, the motor has to be completely sealed even the brushes. The motor is know as a Tamiya RC 540 Johnson motor. Tower Hobbies and most hobby retailers sell them. I have changed from the Tamiya commectors to the Dean connectors and yes I do agree with you they are very good. As far as all that is concerned I can't change anything apart from the gearing. I guess I will have to experiment.

Thank you for your time to help me.

Regards

David

PS If you can think of anything else I would appreciate your comments.

420Speedster

Well Im no expert but my Sprint 2 came stock with a 87/28 and its pretty speedy with the 17T it came with. I ordered a Team Checkpoint money, I'll let ya know how it does with that as well.

420Speedster

Update-

The money motor is fantastic. More torque and more speed than the 17T. I can barely control it. Still using stock pinion/spur gears.

Makuku68

Pit your original 87T spur gear back on and Change your pinion gear to 32T. Also get an Orion Platinum Edition LiPo battery. BIG IMPROVEMEMT!