HMF slip on power gains?

[stcblack450r]

i have a 2005 450r with hrc kit...would a slip on give it alot more low end power? i ride trails and in the woods so need more torque

[d3ktrix]

It would help a little bit all around.

If you want low end a cam switch would do you best.
That 05 HRC cam is a pure top end cam, not meant for the woods at all.
Switch out for a 02 CRF or Hotcam S1, will greatly increase the low RPM throttle response.

[gcart2]

slip on = noise
full system = noise and power


dont waste your money on a slip on. yes you will get a little power out of the deal. however if you buy a full system you will get professional grade Hp's.

[bama06300ex]

I really dont think a full system will give you much more power than a slip on until you start doing intake, cam, piston, etc. If all you plan on doing is aftermarket air filter (my fav is UNI), powerlid/ no lid, and exhaust, I would just go with a slip on. I like the sound of the HMF. On a dyno a DASA, Sparks, Rossier, will give you more power, but you wont be able to feel it. Good luck.

Oh, and d3trix hit the nail on the head. And a higher comp. piston is where you'll really feel more torque.

[gcart2]

a uni filter, jetting, and lid off is a must. i figured you already had it.

[stcblack450r]

yeah. i have a pro design air filter, hrc lid, and jets. im just looking for more torque

[d3ktrix]

Like said above a full system will do a lot more for you then just a slip on.

But if you get the HMF slip on, it is one of the only aftermarket silencers that you can add a header to later on.

Cam switch will help the bottom end the most IMO.
And you can sell that 05HRC on here and get a nice return back.

I used to have the same setup as you.
05 HRC kit with stock exhaust, then I got the sparks full system. It helped all around but the bottom end was still not woods friendly because of the cam.
Then I switched it out for 02 CRF cam, massive improvement for the woods.

[stcblack450r]

why does it have to be 2002 crf cam? does that cam produce the most low end?

[stcblack450r]

and i dropped my front sprocket to a 13 tooth and that helped out alot for woods riding

[Sjorge450R]

Originally posted by stcblack450r
and i dropped my front sprocket to a 13 tooth and that helped out alot for woods riding

the 02 is known for low end power. The 03 is low to mid.

I run the 03 cause i got it on ebay for i think $13. I love it. I definitely was able to tell a difference after I put it in.

[stcblack450r]

would i have to change my jetting if i put a 02 crf cam in? right now it has the hrc jet kit

[d3ktrix]

Originally posted by stcblack450r
would i have to change my jetting if i put a 02 crf cam in? right now it has the hrc jet kit

Nope you won't have to rejet.

And it doesn't have to be the 02 CRF.

The Hotcams Stage1 is very similar and the 05 CRF is popular with the XC guys too.

This should help you.

From trx450r.org posted by sredish.


The Honda, and Hot cams are drop in cams which mean you can swap them out with out changing anything else. With the Megacycle and WEB cams you may need to change valve springs, cut valve guides, cut valve reliefs in the top of your piston depending on which one you choose.

Honda Cams

Honda 2004-2005 HRC Cam - Part # 14110-NLZ-650
Really strong to top end cam, with a decent mid range, but lacks bottom end.

Intake Lift(inches): .390
Exhaust Lift(inches): .350
Intake Lobe Center (degrees): 110
Exhaust Lobe Center (degrees): 105
Intake Duration (degrees at .040"): 260
Exhaust Duration (degrees at .040"): 260

Honda 2002 CRF Cam - Part # 14110-MEB-670
A good all around cam, strong bottom and really strong mid range with a decent top end as well.

Intake Lift(inches): .380"
Exhaust Lift(inches): .356"
Intake Lobe Center (degrees): 106.5
Exhaust Lobe Center (degrees): 107
Intake Duration (degrees at .040"): 249
Exhaust Duration (degrees at .040"): 272

Honda 2003 CRF Cam - Part # 14110-MEB-770 <-------------Now is 14110-MEN-670
A good mid range cam.

Intake Lift(inches): .380"
Exhaust Lift(inches): .336"
Intake Lobe Center (degrees): 109
Exhaust Lobe Center (degrees): 109
Intake Duration (degrees at .040"): 249
Exhaust Duration (degrees at .040"): 262

Honda 2006-07 HRC & Honda 2005 CRF Cam - Part # 14110-NLZ-610
Really strong bottom with a decent mid range.

Intake Lift(inches): .374"
Exhaust Lift(inches): .313"
Intake Lobe Center (degrees): 248
Exhaust Lobe Center (degrees): 268
Intake Duration (degrees at .040"):
Exhaust Duration (degrees at .040"):

HotCams

HotCams Stage 1 - Part #1016-1
Excellent bottom end and midrange increase.

Intake lift (inches): .378"
Exhaust lift (inches): .343"
Intake lobe center (degrees): 106.5
Exhaust lobe center (degrees): 103.5
Intake duration (degrees at 1mm): 237.5
Exhaust duration (degrees at 1mm): 268.5

HotCams Stage 2 - Part #1024-2
Excellent midrange and top end increase, good all-around cam.

Intake lift (inches): .402"
Exhaust lift (inches): .343"
Intake lobe center (degrees): 106.5
Exhaust lobe center (degrees): 103.5
Intake duration (degrees at 1mm): 248
Exhaust duration (degrees at 1mm): 268.5

HotCams Stage 3 - Part # 1056-3
More top-end power than Stage 2. Will work well for TT and big bore/strokers.

Intake lift (inches): .409"
Exhaust lift (inches): .356"
Intake lobe center (degrees): 116
Exhaust lobe center (degrees): 104.5
Intake duration (degrees at 1mm): 251.5
Exhaust duration (degrees at 1mm): 265

Megacycle Cams

Megacycle X1 - Part # 108-x1
Race profile for increased mid to top end, must use race piston and valve springs. Intake valve pocket may need cut on piston.

Intake Lift(inches): .430"
Exhaust Lift(inches): .385"
Intake Lobe Center (degrees): 102
Exhaust Lobe Center (degrees): 106
Intake Duration (degrees at .040"): 266
Exhaust Duration (degrees at .040"): 282

Megacycle X2 - Part # 108-x2
Strong midrange / all-around. Must use race piston and valve springs. Intake valve pocket may need cut on piston

Intake Lift(inches): .412"
Exhaust Lift(inches): .350"
Intake Lobe Center (degrees): 108
Exhaust Lobe Center (degrees): 108
Intake Duration (degrees at .040"): 260
Exhaust Duration (degrees at .040"): 268

Megacycle X3 - Part # 108-x3
Full race cam max top end. Must use race piston and valve springs. Intake valve pocket may need cut on piston.

Intake Lift(inches): .435"
Exhaust Lift(inches): .385"
Intake Lobe Center (degrees): 104
Exhaust Lobe Center (degrees): 108
Intake Duration (degrees at .040"): 276
Exhaust Duration (degrees at .040"): 276

WEB Cam Inc.

613/812 - Part # 57-102
Performance profile to increase mid and upper end power. Higher compression recommended. Must be used with performance spring kit shortened valve guides and adjustable cam gears.

Intake Lift(inches): .381"
Exhaust Lift(inches): .357"
Intake Lobe Center (degrees):
Exhaust Lobe Center (degrees):
Intake Duration (degrees at .050"): 240
Exhaust Duration (degrees at .050"): 258

493/729 - Part # 55-462
Performance profile to increase mid and upper end power. Higher compression recommended. Must be used with performance spring kit shortened valve guides and adjustable cam gears.

Intake Lift(inches): .415"
Exhaust Lift(inches): .340"
Intake Lobe Center (degrees): 276
Exhaust Lobe Center (degrees): 288
Intake Duration (degrees at .050"): 252
Exhaust Duration (degrees at .050"): 252

208/921 - Part # 57-042
Race profile. Higher compression required. Must use performance spring kit, shortened valve guides and adjustable cam gear.

Intake Lift(inches): .408"
Exhaust Lift(inches): .340"
Intake Lobe Center (degrees):
Exhaust Lobe Center (degrees):
Intake Duration (degrees at .050"): 282
Exhaust Duration (degrees at .050"): 298

Mysto - Part # 57-072
The "MYSTO" cam designed for race use ONLY. Higher compression required. Must use performance spring kit, shortened valve guides and adjustable cam gear. Check all clearances!

Intake Lift(inches): .432"
Exhaust Lift(inches): .350"
Intake Lobe Center (degrees):
Exhaust Lobe Center (degrees):
Intake Duration (degrees at .050"): 293
Exhaust Duration (degrees at .050"): 296

Johnson Cams

400 - 375 (Little Johnson)
Strong midrange and top end.

Intake Lift(inches): .400"
Exhaust Lift(inches): .375"
Intake Lobe Center (degrees): 108
Exhaust Lobe Center (degrees): 108
Intake Duration (degrees at .040"): 266
Exhaust Duration (degrees at .040"): 284

430 - 400 (Big Johnson)
Top end drag cam.

Intake Lift(inches): .430"
Exhaust Lift(inches): .400"
Intake Lobe Center (degrees): 110
Exhaust Lobe Center (degrees): 110
Intake Duration (degrees at .040"): 274
Exhaust Duration (degrees at .040"): 289

[stcblack450r]

thanks man. that helps out alot. this summer when i come home from college i plan on getting a new cam for more bottom end power