Need engine for traxxas 4tec.

[romahahaha]

Hello everyone!

I just bought traxxas 4-tec with os max 15cv engine in it. I'm planning to replace it with original 3.3 traxxas engine. Is it a good idea? I know 4tec with 3.3 traxass can reach speeds of 70 mph. Should I leave os max? What speed can it reach? Also, I I have a brand new LRP Z.12R spec.2 engine. Is it a good engine? Is it faster than max and traxxas?

 

[Scrogg]

The LRP should be a great choice for that car if it has the proper carb and crankshaft style. I'd run what you have. I highly doubt a stock O.S. Max .15 can hang with a 3.3, the LRP should be a close match though.

 

[romahahaha]

The LRP should be a great choice for that car if it has the proper carb and crankshaft style. I'd run what you have. I highly doubt a stock O.S. Max .15 can hang with a 3.3, the LRP should be a close match though.

will I be able to get it up to 70 mph?

 

[bigt]

os 18 cx rx is a great engine for the 4-tec. i dont know if you will be able to 70 but anything over 50 for a onroad car is on the edge of out of control.

 

[olds97_lss]

Most mfr speed claims are based on really over gearing a rig for typical use and running in a straight line on a very long stretch of really smooth ground. If you run on a street, in a parking lot, any little crack in the road at 50+ will send your car sailing.

For power/RPM's, the 3.3 is a close match to an OS18TZ. The TZ just runs/tunes better and has a better power curve.

My guess would be that the LRP 12R will have more peak RPM's than the TRX3.3, but it will lack in power. Which means it will be better to gear lower and rely on the engine to get to your peak speeds with the gearing giving you needed torque to shoot from corner to corner while racing.

The 3.3 will be a definite improvement in power and rpm's over the OS15CV. The OS15CV is a beginner tuned engine. Great for a general basher, but it won't crank out the rpm's of more performance minded engines.

 

[Scrogg]

In short, Traxxas LIES a lot! Every 2 wheel drive truck I've seen with a 3.3 in it starts to literally fly and backflip way before 50mph. 40 mph is a handful.

 

[romahahaha]

Thank you all for your responses.
I'm not going to race with it because I got rs4 for racing. I just want to have another car that can reach speeds over 70

 

[ohsnap]

If that's the case you may want to look at 1/8th scale on road cars with a good .21 motor like Serpent (Vectors, 95x or 966) or Mugen's MRX4 or MRX5.
These tend to stick to the ground at higher speeds...

http://www.serpent.com/product/903009
http://www.mugenseiki.com/menueefi.htm

If you want to stick with HPI, they have or had the Proceed...
http://www.hpiracing.com/kitinfo/801/