Hrc Kit

[blasterboy93]

I have an 07 450r. I invested in the hrc kit for my first year on it since I quit racing my blaster. I would like to know the best slip on system for motocross racing with this kit.

[exrider12]

Hmf iron man

[blasterboy93]

thanks i appreciate it

[blasterboy93]

id still like other opinions to gather my decision off of

[conley 450r]

HMF full sys

[Purcell450r]

I have the the HMF sport slip-on on mine, don't need full system with the HRC head pipe.

[quad2xtreme]

I posed a similar question and was told the same...HMF with the HRC headpipe works really well.

Was also told that all the other full exhaust systems wouldn't offer any performance over the HRC headpipe and stock exhaust unless you start doing engine mods above and beyond the HRC kit. In many cases, you will actually get worse performance.

[Purcell450r]

I just know the sound coming from the stock exhaust with the HRC end cap, sounds god awful if you ask me.

[venom450r]

HMF/HRC is a very nice setup for the money.

[BlaineKaiser450]

Originally posted by quad2xtreme
Was also told that all the other full exhaust systems wouldn't offer any performance over the HRC headpipe and stock exhaust unless you start doing engine mods above and beyond the HRC kit. In many cases, you will actually get worse performance. whoever told you that has no idea what they are talking about. it may not be a MASSIVE gain, but you should get 3-4 horsepower with a slip on. Id do an HMF Ironman by the way

[blasterboy93]

any jet changes?
and what fuel is being run?
i use the vp110 and noticed a major gain.

[smw450r]

i wouldn't recommend running any racing gas unless your at least 12.8/1 and above what kind of compression are you running?

[smw450r]

what year model is your's? and what kind of piston did you run and compression

[blasterboy93]

i have the 07 kick. and i run stock piston

[smw450r]

well i wouldn't recommened the racing fuel, for the stock piston, it doesn't really increase horsepower with that compression, but if your crazy about running it at least mix it with 93octane, don't run it straight it will eat up the walls of your cylinder

[blasterboy93]

i ran it straight this whole last season and all winter so far and no sign of problems yet.

[quad2xtreme]

Originally posted by BlaineKaiser450
whoever told you that has no idea what they are talking about. it may not be a MASSIVE gain, but you should get 3-4 horsepower with a slip on. Id do an HMF Ironman by the way

pretty reliable sources who do this stuff for a living...guys who own dynos...

what I said was I was told that an HMF slip-on will offer some improvement over HRC canister.

ALso said that unless he goes into the engine doing mods, there isn't any reason to buy a full exhaust as it won't result in any improvements over the HRC headpipe and the HRC canister or the HMF.

[blasterboy93]

im assuming im gonna have to make a jet change if i get the hmf slip on. i practice at NEMX every saturday and i can hang with any quad up there. i realize that this is not all quad and it has alot to do with my experiance and abilities but i do not wanna go backwards in performance because it runs like a champ.

[veenser2000]

If you are running race fuel without the higher compression you could be losing power as it takes more energy to burner higher octane fuels than it would to burn say 91 octane. People always think it is the race fuel that adds power but it actually just prevents your motor from predetonation and motor knocking.

[blasterboy93]

i was running pump 93 and it ran good. then a friend of my families that races drag cars said theres a gas vp 110. when i put it in it ran noticeably better, more snap, and a vetter pull on the top and bottom end.

[blasterboy93]

with the HMF ironman will it slip right on to the HRC header pipe?

[440ex2001]

Originally posted by smw450r
well i wouldn't recommened the racing fuel, for the stock piston, it doesn't really increase horsepower with that compression, but if your crazy about running it at least mix it with 93octane, don't run it straight it will eat up the walls of your cylinder

Why would it eat up the cylinder walls?

[smw450r]

i had a mecanic tell me that a few years back i couldn't actually tell you the reason, but if the motor ain't built for that ocaine it's only a matter of time, just think of it this way run jet fuel in your car and see how long it last jet fuel is only around 114 ocaine only a little higher than vp110, but in my opion it's just a waste of money racing fuel ain't cheap, but if you got the money to run race gas i would spend the 200 dollars and make it worth it run a 14.1 or 13.5/1 compression piston and your notice a huge difference over the stock piston

[droppedmazda]

jet fuel is oxidated so it burns way hotter than race fuel. so if he were to run jet fuel it would hurt the cylinder but synthetic race fuel is not goin to hurt it with the compression that they have stock. i run race fuel straight and it hasnt hurt mine.

[250R]

Lets clear up a few things.

1. The higher octane in race gas allows the fuel to burn much more slowly than a pmup gas, whcih in turn allows it to resist detonation. If you do not have the compresion, it does you no good and can actually slow the bike down. It is not going to "eat up your cylinder walls".

2. Jest fuel is nothing more than a high grade kerosene, you must be talking abouit aviation fuel, which is more like 100 octane. It is formulated to burn at high altitudes and is not well repected for land going stuff.

3. You probably WILL see a gain in switching over to an oxyagenated fuel, I know VP has 2 types, one for 2 strokes and another for 4 strokes (UV4 I think). If your bike is jetted spot on right now, you will typically have to step up a jet size.

[chayes627]

250R is spot on with what he has said about the fuels

[blasterboy93]

i looked up some info on the vp 110 and it is formulated for the stock piston compression which is 12:1