Experiances w/Big Gun Rev Box on CRF450R?

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Spokes574

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Apr 27, 2001
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Does anyone have experience using a Rev box on the CRF450R?
There are claims of 3-4hp gains from just a rev box alone.
If you installed on or have knowledge on a CRF450R please post a repsonse. Big Guns or Max Rev ? what is the diff between them?

Thanks,
Spokes574
 

Rich Rohrich

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Spokes574 said:
Does anyone have experience using a Rev box on the CRF450R?
There are claims of 3-4hp gains from just a rev box alone.
Click to expand...

Only if the Tooth Fairy and the Easter Bunny are working together doing the dyno pull. :rotfl:
 
S

Spokes574

Member
Apr 27, 2001
171
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This is what I learned/gathered so far:
HP gain is about 8/10 HP and very slight inclease in torque - this came from a repreable well known engine builder who tested Vortex ignitions recently on thier new team race bike on a new dyno! So the claims of 3hp is not true.
Advantage is truely some/ not much overev which gives the ability to shift later
Overev studies and testimonials show ~ 30 yards gained before gear tops out
Also slightly improved throttle response from the hotter burn and advanced curve.

For $100: 8/10hp, slight improvement in throttle response, ~30 yards gained per gear
may not be so bad if you have a $100 and plan to hold on to your bike for 2yrs.

P.S I believed in the tooth fairy and Easter Bunny till I was 8! LOL.

Spokes574
 
E

elcamino12sec

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Jan 16, 2006
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I only believe in Santa clause and Frosty the Snow Man? Will the rev box work for me?
I was thinking of riding my dirt bike to work tomorrow in first gear.
 

SFO

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Spokes574 said:
This is what I learned/gathered so far:
HP gain is about 8/10 HP and very slight inclease in torque - this came from a repreable well known engine builder who tested Vortex ignitions recently on thier new team race bike on a new dyno!
Click to expand...


I'd like to know who made these claims.
8~10 rwhp on a stock motor or a built motor?
A rev box giving 8~10 rwhp is in Rod Sterling dyno land.
 

whenfoxforks-ruled

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The last thing I would do to this engine is increase the piston speed, all of them claims they make are by increasing the rev limit, duh, Same reason I don't do the soft valve seats, Don't want to overhaul the engine every week , yet!
 

SFO

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maybe 8~10 hp after the power peak on the back side?
This is the realm of 10hr one weekend motors. Be warned, over rev while nice when racing will over stress all reciprocating components, you are building a grenade.
When you get a fresh motor every weekend it is a non issue. There is power to be had after the peak but it is the costly kind. I have used and tuned vortexs for racing motors as well as having had access to factory yamaha ignitions. We always had two motors ready to go. Making an 8~10 hp claim sounds like the ignition is playing a part of a full range of mods that the ignition can capitalize upon.
 
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Spokes574

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Apr 27, 2001
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HP claims

8/10th's of 1hp, not 8hp to 10hp.

I do agree that the valve seats can be affected by adding rev.
 

SFO

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Spokes574 said:
8/10th's of 1hp, not 8hp to 10hp.

I do agree that the valve seats can be affected by adding rev.
Click to expand...


My mistake... :ohmy:
 
S

Spokes574

Member
Apr 27, 2001
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OK - I ordered a rear sprocket 48-> 49 tooth and also ordered the Rev box to help minimize any loss in gear spread. I will let everyone know next week after I test it.
I will put the sprocket on first, ride, then later put on the CDI box and see if there is any difference. I ordered it on **** and saved about 33% so it did not cost too much and I should get some performance 8/10ths of 1hp and a tad bid of overev.
I am not worry about heating since I have a Boyesen cover/impella and use 75% water & 25% anti freeze with a lot of RedLine Water Wetter product - in addition to wraping one section of the pipe that is near the hose, and use Cyrca front fender for additional air for cooling. I generally never hit the rev limit on my bike anyway since I use the Yoshimira Pipe which gives mid/top ~1/3 more overev than stock. So I should still be good. All mods should work in sync with each other.

Spokes574
 

Rich Rohrich

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Spokes574 said:
All mods should work in sync with each other.

Spokes574
Click to expand...

Dare to dream. ;)
 
S

Spokes574

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Apr 27, 2001
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OK I the CDI box on this past week and here are the results.
-first the bike definitely sounds super crisp on the stand when blipping the throttle
-2nd the bike is a tab bit more responsive and super crisp throttle response on the track
-3rd the bike definitely has more overev - not a whole lot but enough that it is noticable (makes up a little for the extra tooth I added to the sprocket)
-So do I think is was worth the $95 + $5 shipping I paid for it on **** - Yes
My son said its the icing on the cake after I added 1 tooth to the rear sprocket also.

The bike is more two stroke like in terms of crispness and response at the throttle.

Also, I learned that a lot of the aftermarket rev boxes are all made by the same manufacturer and that the resellers just slap on thier sticker on the box. So just buy the cheapest one you can find on **** because they are the same except for JD and Vortex ignitions. As previously mentioned, my mechanic shop dyno the boxes at only 8/10ths of 1hp improvement, but you also get crispness, better throttle response and tab bit more overev.

Here is another note. The CDI box I had took 7+ kicks to get my bike on vs the stock cdi box only tool 1 to 2 kicks. I called the manufacturer and they said that the bike should turn on easier and that I had a defective box and to send it in and another will be shipped to me promptly. I was also told by the vendor who sold it to me that he sells about 35-50 units a month and gets about 2 exchanges a month due to hard starting(defective units).

Spokes574
 

SFO

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Feb 16, 2001
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so, spokes, is there an A/B dyno run?
just curious.
 
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