HRC vs. stock...the same?

[35charlie]

I put an HRC kit in my R a little while ago. It has probably 3-4 days solid riding on it before the kit and another 5-6 after. After putting it in, the first thing I noticed was I was stalling it less when idling around. The motor also had more torque down low than before when slowly climbing steep sand hills. This is contrary to what most have been saying about it.

My brother just bought his and it's totally stock as of now. He's running 21x12x8 haulers and I've got 22x11x8 (almost the same profile but mine are just a bit more squared off). We're both running a 13 tooth.

Yesterday we raced on the beach, on the flats and up a moderately steep bowl. The results were almost dead even. He's maybe 15 lbs lighter so we switched bikes. Almost the same results give or take a bike length. We both thought mine pulled a bit of a holeshot but the midrange just wasn't any better. I'm totally puzzled considering the higher volume of air my motor should move plus that huge jetting change.

I'm wondering if mine needs a different main jet. I'm using the 185 that comes with it but always run at sea level in the sand. The thing starts and runs great and doesn't have any flat spots in the acceleration. It seems all it does is make more noise than a stock one. Any ideas? I set the valve lash, which required changing a couple shims, when I put the cam in so that should be ok. What else is going on here? Did my brother luck out with a kick *** stock one? For what it's worth, my uncle has a completely stock '01 400ex that was stonger than several others in our group from day 1.

[Pappy]

ill geuss and say that without a pipe the hrc kit isnt giving up all the power you should be seeing.

[MY450R]

if your beating him by a bike length then thats a lot
depending on how far you race 1/2 a length is good also

[Bretmd94]

How much psi are you running. Both of you are using giant rims for 4 stroke bikes. I run 21x8x8 haulers. You will have more sliding and spinning with yours but its definatly hurting your drag times a lot.

But seeing as your brother has the 12 inch rim you should have the advantage.

In top speed most bikes are really close. My 450r is dead even with my friends raptor going down the beach all out, and i dont have the 13th sprocket. But i destroy him when dragging.

I raced another 450r with an hrc kit and some exhaust that wasnt sparks, and i thought i was going to be able to beat him with my sparks, exhaust and air filter kit. Mainly because he was running 10 inch haulers. Unfortunatly for me we were dragging on wet sand, and he proceeded to take the hole shot every race and i couldnt catch him. So be happy, and work on launching.

[35charlie]

We're running 3-4 lbs in them. The 11" and 12" is the spec'd tire width. They're both mounted on 9" wide rims. When mounted, the tires are nearly the same profile. We've run 21x12x8's Edges on 350x's for years. My other brother also runs them on his 350'd 250x.

On the beach we were racing until about 3rd gear rev'ed out or maybe just into 4th. The point is we were basically side by side from lauch on. I would have thought with the kit supposedly adding 10-15% power increase I should pull away right from the line and stay in front. We did trade bikes in all situations to eliminate rider error.

I guess if all the extra noise is just going to buy me a bike length, what's the point? Perhaps it isn't the fair way to judge the power difference. I'm really looking for hillclimbing power where the engine slugs down some into the midrange as the tires are digging. As long as it doesn't sign off then, I guess I don't care much about the drags.

I think my brother is still planning on HRC'ing his. If he does, we'll re-run and see if he walks away from me or if there's little difference. The problem is I didn't have a good "before" with mine alone, other than seat of the pants.

Thanks for the input.

[jmoney45]

I had mine for a couple months before the hrc kit and here is my impression of it. Down low I feel almost no difference. I still think I need a pipe to get me going more off the bottom. In the midrange I can feel a bit of a difference. Seems to pull a little harder but not a ton. Up top is where I notice the most difference. It seems to pull harder when the revs are high. I think the only way to really feel a difference with this kit is to rev the motor and not lug it around. With a full pipe I've heard you get a bigger boost down low. I'm gonna try that next but honestly it pulls pretty good with just the hrc kit. Would be nice to have more low end so I can easily pull second gear starts.

[lukester720]

The difference should come from about 3rd gear on, at that point you should begin to walk away from him. From some of the more recent dyno sheets i've been seeing the hrc loses a little bottom end compared to stock up to about 6000 rpms then the hrc jumps about 4 to 5 hp over stock at this point. a stock piped 450r vs a hrc, piped 450r the hrc is actually about 2 hp shy of the stock 450r all the way up until about 6000rpm's, thats a comparision using the same pipe in a controled dyno run to ensure accuracy.

With the mods in my signature I was beating a guy that i outweighed by about 35 pounds who was riding a stock 450r by about 4 1/2 quads on a hardpacked dirt 300 to 320ft flat drag track. We raced a few times not just once and we switched quads and he was about 5 quads in front of me with him on my quad. This is of course before I lowered it and changed tire pressure for drag racing, i was spinning bad.:cool:

[35charlie]

Hmm. I still did notice a low end increase, (right as you let the clutch out). I was stalling it less with the kit. Who knows, maybe it's an illusion or I got more used to the quad.

As for the drag tests, I would think over 6000 rpm power would help in all gears, causing my lead to increase each time I rev'd up. Maybe I'm shifting too soon and afraid to really wind this thing up, causing me to lose in the lower rpm's what little I gained in the higher ones. I usually just shift when it seems I'm no longer accelerating quickly.

I'm heading to my brother's place tonight to help him finish his kit install so we'll know next time we ride what difference there is.

[BSTURDIVANT]

Out of 4 supposedly identical bikes 2 early builds and 2 later- 2 were stronger all around until we found that Honda failed to adjust the throttles to full open. Take the side cover off and adjust the cable at the thumb throttle so the carb opens fully!

[trost66]

Originally posted by lukester720
The difference should come from about 3rd gear on, at that point you should begin to walk away from him. From some of the more recent dyno sheets i've been seeing the hrc loses a little bottom end compared to stock up to about 6000 rpms then the hrc jumps about 4 to 5 hp over stock at this point. a stock piped 450r vs a hrc, piped 450r the hrc is actually about 2 hp shy of the stock 450r all the way up until about 6000rpm's, thats a comparision using the same pipe in a controled dyno run to ensure accuracy.

With the mods in my signature I was beating a guy that i outweighed by about 35 pounds who was riding a stock 450r by about 4 1/2 quads on a hardpacked dirt 300 to 320ft flat drag track. We raced a few times not just once and we switched quads and he was about 5 quads in front of me with him on my quad. This is of course before I lowered it and changed tire pressure for drag racing, i was spinning bad.:cool:

[trost66]

How do you like your sparks exhaust. Also did the sparks cam a make big differtence on the bottom. Just puchased the exhaust and was thinking about getting the sparks cam. Thanks for you time

[lukester720]

I'm really happy with the sparks pipe, chm is also a good pipe company and there stuff can be bought for some of the best prices in the pipe business. Comparing the sparks cam to the hrc cam the sparks has better low and mid and the hrc has the sparks by about 1 hp on top. The thing about this is that the sparks makes the power to get you out front early but the 1 hp advantage the hrc has on top(from about 6000 to 6500rpms up) isn't really enough to make me want to have it. The sparks is definately the best all-around out of the 2 IMO.