Increasing the speed on a HPI Trophy 3.5

[Mdolman]

What engines are better than the stock hpi engine?

 

[MudSlinger33]

Picco, LRP, novarossi. Just to name a few.

 

[Zdragon71]

Go engines make a pretty affordable .21. I have that same buggy and dropped a stock F4.6 on it and geared it with a 17 tooth bell with stock 46 tooth spur and it hauls butt!!! Around 50 mph or better top end now. View attachment 12204

 

[Mdolman]

Ok thank you for your help, I will probably put a f4.6 in it

---------- Post added at 2:50 AM ---------- Previous post was at 2:37 AM ----------

What other parts will i need to fit the F4.6?

 

[frickenjoey]

Not sure the price of one 100% but there are better engines than that for about the same amount. Keep in mind that a f4.6 is a stock engine out of a Savage and not made for speed. I think you would be short changing yourself with it. In a buggy you don't need that much torque. The tires are narrow and you look traction and then it is all wasted. You want higher RPM, that you will get out of something like and OS .21. If you are looking for top end then bigger is not always better.

---------- Post added at 5:28 PM ---------- Previous post was at 5:19 PM ----------

This would be faster in the buggy than the HPI .28 you are looking at.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXKX8&P=SM

 

[Mdolman]

Does horsepower matter as much as rpm?

 

[frickenjoey]

In a buggy RPM plays a bigger roll is speed than pure HP. I want a mill that will turn out a lot of RPMs to get me down the track. I put a .28 in a buggy and I could break the wheels loose at almost any speed but was still getting out ran by .21's. I had torque but without proper gearing torque will not be faster. It will get you to your top speed faster but the top speed will be lower overall.

 

[Zdragon71]

I agree. The only reason i have the .28 F4.6 in my buggy is because the 3.5 that came in it took a crap and hpi warranty sent me the F4.6 in place of it. If you want speed in a buggy go for higher rpms. The torque on mine is stupid crazy. I have a 17 tooth bell on it to tame it and also installed a Buku adjustable clutch on it so i can adjust it so there is less wheel spin at lower rpm. Like at take off and cornering. I'm just a basher so I'm fine with the higher torque engine but if i ever wanted to race it i will need to install a .21 engine.