The TRX450R Kicker Gets a HRC Upgrade
The HRC kit is a factory Honda upgrade kit that is designed for the serious play rider up to a good entry level racer and then some
A quick step back before I get to far. The HRC kit is a factory Honda upgrade kit that is designed for the serious play rider up to a good entry level racer and then some. There is a bit more to it for the 06’ models than years past and seams to make a considerably noticeable difference in performance. A big improvement over the kit’s for the 04’-05’ models. The 06’ HRC kit consists of camshaft, exhaust tip, head pipe and gaskets, breather, CDI sub harness, main jet, needle jet and accelerator pump bypass jet.
Upon installation the quad was sent to the dino for testing and Arlen noticed a nice improvement over the electric start models. The power curve showed that the kick start model was good for roughly 1 hp over the E-start version and the engine revved more freely as well. Which is something I had noted on my initial test of the stock units, so I was happy to here we were on the same page as far as that went. As far as the 50 hp that the factory had claimed....well we ended up close with a solid 49.
As for the ride, the track that I ended up at was a bit far from home and had another product test in mind but I had a chance to compare a completely stock unit with the HRC unit and the out come was a fairly noticeable difference. The HRC kit really woke up the already much improved TRX. I first noticed a difference in the take off but there were two places in the track that it was especially beneficial. The first was coming out of corners. It just naturally pulled through a little easier than the stock unit and would hook up and go upon exit. The other place that the HRC unit would shine was in getting a little extra loft to clear a jump. If a jump was a little close after a corner and questionable with the stock unit, then the HRC unit would certainly have enough to get the job done. And of course any hills that I encountered were conquered much easier too. The sub harness that comes with it is just a small jumper wire and its job is to add an additional 1000 RPM’s. This makes it much more pleasant to ride too, as you don’t have it bouncing off the rev limiter all day long like you would on the stocker.
Without getting to lengthy on the HRC kit portion of this storey, I would have to say that this kit is well worth the money. This is a lot more than I ever had to say about the kit for the prior models.
Let’s put it this way; in stock form this bike has a pretty good power to handling ratio. I’m not sure if there actually is a scientific way to calculate this or not, but it’s a reference I’ve come up with to explain to people how important suspension is compared to power.
What I mean is the quad has a good amount of power right out of the box for the suspension that it is equipped with. So with the addition of the HRC kit it gives you a little more of a thrill factor. Basically once you get the HRC kit installed this quad has enough power get you in trouble but also has enough power to help get you out of trouble as well. And realistically is about all you really need other than the addition of a good aftermarket pipe, in order to have loads of fun pretty much right off the show room floor
All that being said (hopefully it made some amount of sense), we knew that this machine was about to get one of the trickest suspension combinations on the market. So what did we do at that point….Well how about take the engine back to LRD and have Arlen work some magic.
So first of all we made a game plan. We were looking for some more power out of the bottom end and mid range but also needed it to run out good on the top end. Yes, this is a have your cake and eat it too mentality, but I guess that’s just the way I am. Fortunately for me Arlen feels the same way.
Well I made a few phone calls to see what my options were and when I called the folks at Wiseco I was happy to hear they had a bolt on 500 kit in the works for the TRX450R and it sounded like a perfect fit. Unfortunately I wanted something right now and that’s were it got a little tricky. They did have a bolt on kit already for the CRF450 and said that with a little modification it would be usable on the TRX. So I asked Arlen to talk it over with them and when he was done he was convinced that he could make it work. During the modification and installation process he had several choice words about the project but yet again I was fortunate because Arlen is a pretty talented individual and when he was done the jug looked like a factory fit. I have spoke with the guys at Wiseco sense and they do in fact a have this part available now that will bolt directly on to the TRX with out mod.
Next it was the all important decision on the cam. So I called Dan at Crower Power and to see if they were interested in the project and they were all over it. I had them do a regrind on a cam for my 04’ TRX and it turned out to work really well so it was an easy decision to go with them. These guys are cool too and I don’t think that it’s just because I was doing a project quad either. Because the first time I dealt with them I was just a racer looking to better my ATV and after talking with them for a bit I could tell that they were just excited about what they do and what they can make your cam do for you. So I told him what we were trying to accomplish and the specs on the engine and that I would like to use the HRC cam as the unit to be modified. You see Crower Power can work wonders with the stock cam however if they use the HRC cam they have a little more to work with and Dan was pleased to here we had the goods to use. And another nice thing is that they just regrind and refinish the piece that you send them, so you don’t end up with a welded cam. And while I am explaining things I need to let you know that Crower offers billet cams in addition to the regrind cams, so they can come up with a cam for you regardless of your situation, but I wanted to stay with the HRC cam for this particular project just because I was so impressed with the one on my 04’.
So with these two decisions made it was time for Arlen to start on the Head. He decided with consideration of the big mil, it would be best to go 2mm larger on both the intake and the exhaust valves. So it ended up with special oversized Kibblewhite 38mm in. and 32mm ex. valves. Arlen has several tricks up his sleeve that go into the porting process. And unfortunately I am unable to disclose those tricks, for it would mean certain execution. However I can tell you that between his porting room and flow bench he is able to work some kind of magic.
So once we got this thing bolted back together there were a few other decisions to be made. Naturally we went with the LRD Pro4 R exhaust and opted for the Balistic coating that they have come up with. For one it looks sharp, and even more importantly its design can pull some extra ponies out of the engine and another good aspect is that it can take a beating which is important due to the fact that this machine is going to be facing some pretty brutal Off Road racing.
With the exhaust figured out I guess I should think about the intake side of things. With the up grade to a FCR carb that Honda went to for 06’ there was no need for a change in that department. Even the intake boot and air box are both much improved over the prior models. So other than changes to the jetting and needle the only thing that we needed to change in this department was the air filter. UNI was an easy choice for this. UNI has it together in the air filter business and uses a duel density foam combination that has been put to the test by this racer. I have no problem at all with trusting these filters with my engines in virtually any conditions.
"Next I had to think about keeping this thing cool. So I called up the guys at PWR and talked it over with them. They have a great line of over sized radiators for most popular models and fit is top notch as well as the craftsmanship. And we knew this would be an important addition to help make up for the deletion of the oil cooler for the 06' models."
And lastly the extra 1000 RPM’s provided by the HRC Sub Harness was much more than just acceptable and keeps the over rev from getting out of control like some of the aftermarket ignitions.
This machine was together and had a direct trip to the Dino. The Power curve turned out great and appeared to have improvements everywhere we had hoped. The bottom end was awesome and had a 41 % gain at 4250 RPM, climbed smoothly through out the power curve without any harsh spikes and actually had the biggest gains toward the top end at 9500 RPM with a very impressive 71% gain over stock. This really looked good on the Dino and I was pleased with the way the combination that we had chosen worked so well together. Now I could hardly wait to get the suspension on this machine and get it out in the dirt to see how well this thing rips.
Please check these links below to checkout the products available from all the contributors to this project.
Crower Power http://www.crowerpower.com/