450r Rev Box

[joe1l]

I was browsing around online today, and I came across this new
REV BOX (http://www.procomengineering.com/ATV/trx450r.htm) for the 450r, I wouldn't mind a few more revs out of my bike, the only thing, is that I haven't heard of this company. Does anyone know anything about them?
Joe

[Honda]

Nope! I ain't heard of em, I be skeared until proven to be effective.

I need a higher revvin Box too! Not sure about that rectum'fier thingy though.

:p

[joe1l]

It would be nice to have it rev to 10K, I talked to them on the phone, they sound relatively cheap, but won't available for 2 more weeks.

[Honda]

I thought stock rev was like 9800 RPM?

I think 11,500 would be nice!

:macho

[joe1l]

I heard that the rev limiter was set to 9250? What ever it takes so that a guy on a YFZ is staring at my LED brake light!!! :blah: 11,500 sounds nice, but I'm really looking for reliablity in the long run, if 11,500 is possible with out causing too much harm, then I'm all for it!:D

[Honda]

What is the YFZ's Rev Limit?

[mephyst]

Wow, that would be pretty sweet. I thought 450's didn't need rev boxes or something like that.

[quadrcr161]

i dont know if it would work, if you look at a dyno plot you start loosing power after a certain rpm. if thats the case, why would you need to rev to 11k?

[joe1l]

YFZ's can rev to 10,100. The more rev you produce the faster top speed you will have. Even if you are not at max hp, your speed will still continue to rise. Your max speed is dependent upon your max RPM.

[quadrcr161]

it still might rise, but your dropping HP and torque, look at all type of racing and its meant to shift at the top of your curve, anymore and its not doing anything. i can rev my CRX higher, get nowhere, and risk floating a valve or i can shift below redline at the peak HP and pull through another gear harder. personally i think its a wast.

[dn1911]

excellent point couldn't have said it better awsome posting

i wouldn't worry about it unless you have used dyno tuning to determine that u could benifit from extra RPM. my guess is that you won't so why increase the wear and tear on you engine when its not needed

[joe1l]

I think the dirtbike revs to 12k, so I really can't see a little extra reving being too much of a problem, but I see the concern about floating a valve. I would like to see an even 10,000 or 10,500rpm. Many people are noticing that after a few mods like intake and exhaust, the rev limiter is getting hit too fast. To me the extra revs would only help me out in 5 gear on long drags....sometimes a just a few rpm will hlep you win a race.
Joe

[crashsmith]

You would need the over rev for things like cams -bigger carb-porting which all aid breathing - good breathing means more HP her!her!her!
All this changes your HP graph and will alow it to run useful revs atpeak.(may not be reliable though).
Food for thought.

[86atc250r]

The 400EX revs to 9200 RPM

The 450R revs to around 10,100

The YFZ revs to around 10,700

[2004TRX450R]

Originally posted by joe1l
The more rev you produce the faster top speed you will have. Even if you are not at max hp, your speed will still continue to rise. Your max speed is dependent upon your max RPM.

This isn't necessarily true. Mechanically it is but wind resistance and terain has a lot to do with it too. If you aren't makeing any more power then you may and probably won't be able to reach the rev limiter in 5th anyway. Where are you drag raceing that you are going that fast? Must be on flat ground.

[joe1l]

Where are you drag raceing that you are going that fast? Must be on flat ground.

5 mile long flat sand trails, we drag down them, 5th gear wide open. I always end up hitting the rev limiter on my 250R on it in 6th gear, I can't see this bike being much different. Normally I gear up when I ride there, but it is not uncommon that I hit the rev limiter. I plan on adding a cam and doing some porting in the future.


The 400EX revs to 9200 RPM
The 450R revs to around 10,100
The YFZ revs to around 10,700

I had no idea the 450 revs to 10,100. Every where I asked people came back with numbers like 9250, 9500, 9850....etc. I really wish I knew what the the true rev limit was. If it is 10,100, then I wont mind so much!

[crashsmith]

Originally posted by 2004TRX450R
This isn't necessarily true. Mechanically it is but wind resistance and terain has a lot to do with it too.

What I was implying is true. The more the engine CAN rev the higher the speed.( with the identical gearing each time)
If the engine is hitting the rev linmiter at ie. 10,000rpm and the power in theory, due to all the mods would peak off at 11,000rpm then you would go faster.
What if (like some of these guys are doing) putting on 13 front sprockets. theire top speed would be down. give the engine more hp at higher RPM- up the rev limit and they might just get back to or even higher than their original speed with stock sprockets.
Hope it makes sense!

[Bretmd94]

I know that with stock exhaust i was never hitting the limiter.

Now with the sparks system it hits it in less than a sec. I was hitting it all day at the dunes now. If it can go higher with out having a valve come loose im up for it.

I had a valve become un-seated on my old craptor. It was not good. :eek:

[Barely legal]

The TRX revs to 9850 and the YFZ revs to 10,750. Mine revs to 11,800 now. :)

[joe1l]

Barely legal, how do you like your Procom CDI, they are the same company that makes the one for the 450R that I was looking at. Does your bike feel any different at lower RPMS, or does it just rev further now?
Joe

[86atc250r]

Dirtwheels said 9850 - but it's been actually measured at 10,100.

Be careful revving that YFZ past 11,000 - Keith Little had a small problem with his recently. Nothing new engine cases and a rod won't fix though.

[joe1l]

Nothing new engine cases and a rod won't fix though
:eek:
Yeah that sucks!

[86atc250r]

I had a friend that was flattracking his heavily modified 300EX last year and I watched as it chucked the rod -- pretty ugly scene - sounded like it threw the chain - but it threw sparks from the front of the engine, so I knew something else was up... Took a pretty good sized chunk out of the front of both case halfs.

His next engine had an aftermarket rod :)

[Guy400]

I watched an alcohol funny car throw a rod through an aluminum Keith Black block. The piston slapped the valves and knocked 2 of them through the valve cover, when the piston smacked the head it put about a 4" crack from the chamber ceiling to the exhaust port and the hole in the block from the exiting rod was big enough to literally put my hand inside...lmao:D

[86atc250r]

Last time I was at the machine shop, there was an Arias aluminum block there with a hole the size of my hand - Appeared it wasn't the first time it had happened by looking at the previous welds :)

[Barely legal]

Originally posted by joe1l
:eek:
Yeah that sucks!

I guess all the bikes should be blowing up too then.

[Barely legal]

Originally posted by joe1l
Barely legal, how do you like your Procom CDI, they are the same company that makes the one for the 450R that I was looking at. Does your bike feel any different at lower RPMS, or does it just rev further now?
Joe

It didn't change the powerband at all, just added upper RPM's to it. I use it sometimes when I don't want to shift before going into a corner when someone is coming, or in a drag race. It just gives you some leeway but usually the YFZ can and should be shifted around 10,000.

[86atc250r]

I guess all the bikes should be blowing up too then.

Touchy, touchy....

Just a heads up...

[bran_bro]

I am looking at getting a higher rev box too. Something that no one has mentioned is that the aftermarket rev boxes not only give you a higher rev limit, but they also enhance the torque curve, some are programmable, etc. So getting a new box actually has more than one function.

[chris29]

Hey guys theres a little wire you can cut on the 450r rev box to give it a little more rev's. I done it on mine and it works out pretty well for not having a aftermarket cdi.

[bran_bro]

the green wire is only valid on 06/07 models. It doesn't help out the 04/05 guys.

[sean3393]

thread is 2 years old, lol. Green wire mod didn't exist when this thread started.