Powernow "Scary Fast"

[86 Quad R]

i had the opertunaty to install one of these on a 05 trx450 this weekend and was very impressed with it.

as a test. i took the bone stock quad out to the back 40 and rode the hell outta it, getting a feel for where its power was. then i installed a full exhaust and carried it back out. the power was gained throughout the revs but very noticable midrange.

after returning back to the shop, i let it cool while doing other stuff and then installed the power now kit. afterwards i carried it back out. the torque on the bottom end was noticable immediately and blended very well with the increased mid range that the pipe had given it.

i returned back to the shop and again allowed it to cool while doing other things and installed a carb kit that has everything to calibrate the carb for any paticular mods. all i can say is "DAYUM IT" !!!!! that thing is "Scary Fast" just like the logo the carb kit accented the power everywhere from off idle to WOT and drastically improved the upper end.

i'd reccomend it to anyone.

[GPracer2500]

FWIW, here are the two dyno tests I've seen of the PowerNow device.

This is a modded 2004 TRX450R using the Keihin carb. Red line--run 006--is with the Powernow installed:

http://i34.photobucket.com/albums/d133/gpracer2500/stock05carbmoddedWppracing.jpg
[testing courtesy of WppRacing (http://www.wppracing.com/) ]




This is a modded 2005 TRX450R with a 40mm Keihin FCR from a CRF450R:

http://img508.imageshack.us/img508/52/powernowcomparend0.jpg
[testing courtesy of Vador]

[86 Quad R]

interesting numbers there. :cool:

all i can elaberate on is the differences that my butt dyno read while doing each and additional addon. i can say that the scary fast did increase the bottom torque of the engine.

as a test. i removed the scary fast last evening, rode it and then re-installed it. the difference was noticable. :)

[mojavedude]

heres something like a power now.
http://www.thumperfaq.com/downloads/JamesNOW!.pdf
did you install the blade on the air filter side of the carb or the engine side or both?

[300exguy125]

are you sure that the you marjed the gaphright because it is saying the the power now is reducing rpms and torgue and hp if i am correct you said blue is with out powr now and red is with powewr now and the grapg shows a decrease in power with the power now maybe its a mistake

[GPracer2500]

Originally posted by 300exguy125
are you sure that the you marjed the gaphright because it is saying the the power now is reducing rpms and torgue and hp if i am correct you said blue is with out powr now and red is with powewr now and the grapg shows a decrease in power with the power now maybe its a mistake

Hmmm....I guess your right. It must be a mistake sense god knows no one would manufacture and market a product that doesn't really work very well. I mean really, since it exists it must work great and be all that we could ever hope for. ;)

I'm being a bit harsh just to make a point. And the point is: sometimes we have a tendency to fall victim to every wonder-gadget or performance product out there. Some things work well no matter how loosely applied. Some things work well only in specific circumstances or when matched with specific parts. And some things are ill-designed pieces of poo that only exist to swindle us out of our money.

I'm not saying the Powernow is the latter. I think it mostly likely falls into the second category.

The graph is labeled correctly. With an FCR carb the test indicates the Powernow hurts high rpm HP (most likely because it's an obstruction to airflow). I've read a fair amount of anecdotal reports that back that up. The test shows the Powernow gained a decent amount on the bottom, lost some through the mid, and lost a lot on the top and into the overrev.

The piston valved carb on a 04/05 TRX450R responds differently (so say these results). It doesn't appear to be nearly as sensitive as an FCR. I imagine this is because that carb has a butterfly in the venturi in addition to the slide. In other words, there's already an obstruction in there.

The testing I posted does not show throttle response and part-throttle characteristics very well. That kind of thing is easier to evaluate through back-to-back seat of the pants testing. Nonetheless, unless I had a particularly sluggish responding FCR, I wouldn't trade the benefits of a Powernow for what it costs (both in dollars, peak HP, and in reduced area under the curve). For the type of riding I do (mostly dunes) I need every last bit of horsepower I can get--all the way to redline.

On a piston valved carb the pros/cons of the Powernow are less clear to me.


I'm not suggesting that those two graphs are the end-all be-all last word on the Powernow. Dyno evidence is powerful (no pun!) but rarely cut and dry unless the results can be duplicated. If I had 5 or 10 different tests that all showed substantially the same thing then I'd be willing to close the book on the Powernow's affect on HP. I don't have that. But still--these tests are easier to hang your hat on then "the Powernow was the best thing I've every done to my quad!" type of comment. [that was NOT directed at you, 86 Quad R]

[OutlawBill]

This does look good http://www.thumperfaq.com/images/powernow_dyno1.jpg

[OutlawBill]

1/2 throttle

http://www.thumperfaq.com/images/powernow_dyno2.jpg

[wilkin250r]

Originally posted by GPracer2500
The graph is labeled correctly. With an FCR carb the test indicates the Powernow hurts high rpm HP (most likely because it's an obstruction to airflow). I've read a fair amount of anecdotal reports that back that up. The test shows the Powernow gained a decent amount on the bottom, lost some through the mid, and lost a lot on the top and into the overrev.

And this is EXACTLY what I would expect from the Powernow.

Plus, as GP alluded to, the dyno graph doesn't show the whole picture. The main goal of the Powernow is throttle response, which won't show up. An improvment in throttle response will feel like a huge boost in low-end power, because the power comes on strong and quickly.

Like any other product, it's going to have benefits and drawbacks. If you're looking for improved throttle response, then Powernow is probably a good product for you. But you should probably expect it to hurt top-end performance a little. For tight racing and trails, the benefits would probably far outweigh the drawbacks because of improved acceleration out of corners, but probably not an improvement for wide-open areas and dune riding.

[GPracer2500]

Hey, Outlaw---where'd that testing come from? Those are big increases. I'm sure you can really feel something like that in the lower throttle openings. I wonder what if feels like going from 1/2 to full throttle? Must be like not a whole lot happens, I guess [shrug]?

Here's another 1/2 throttle test I ran across. This is 03 WR250. They normally have 37mm FCRs--I assume that's what this has although I don't really know.
http://www.dirtbikemagazine.com/archive/dynocharthalfthrottle.jpg
[test from DirtBike Magazine (http://www.dirtbikemagazine.com/detail.asp?id=404)]

I generally don't trust magazines, but this looks legit to me.




I wonder what one would do in a CV carb like the Z400 has?

[OutlawBill]

http://www.thumperfaq.com

[86 Quad R]

Originally posted by wilkin250r
An improvment in throttle response will feel like a huge boost in low-end power, because the power comes on strong and quickly.

If you're looking for improved throttle response, then Powernow is probably a good product for you. For tight racing and trails, the benefits would probably far outweigh the drawbacks because of improved acceleration out of corners

this type of riding conditions is what we do most of in these parts and the type of power delivery that the powernow gave this quad is exactly what it needed. the torque that it made with the crack of the throttle, regardless of the speed or gear i was in was amazing.

i spent quite a bit of seat time with each test. riding through varying terrain, ranging from snaking wood trails to rolling open pasture with good terrace rows to jump.

i really cant comment as to how it effected the WOT power because that not how its ridden and problably wont. although i am now curious to perform further testing with it.

[OutlawBill]

WOT riding should not be a problem for the Powernow it is used by top Honda and KTM desert racers.

[GPracer2500]

Originally posted by OutlawBill
WOT riding should not be a problem for the Powernow it is used by top Honda and KTM desert racers.

Or maybe they're just paid to put Powernow stickers on their bikes. ;)

I'm half joking.

[chris46250r]

I gave my ididntseeanymorePowerNow valve away. Wasn't worth the time to put it in.IMHO.

[250r4life]

Originally posted by GPracer2500
Or maybe they're just paid to put Powernow stickers on their bikes. ;)

I'm half joking.

why would you be half joking GP? give me enough money and i'll put tampon stickers on my bike :devil:

[Aceman]

Originally posted by 250r4life
why would you be half joking GP? give me enough money and i'll put tampon stickers on my bike :devil:

Where did I set my wallet?:devil:

[wilkin250r]

Originally posted by 250r4life
why would you be half joking GP? give me enough money and i'll put tampon stickers on my bike :devil:

No false advertising here. If I'm forking out cash, you had better be actually USING those tampons... :blah:

[250r4life]

Originally posted by wilkin250r
No false advertising here. If I'm forking out cash, you had better be actually USING those tampons... :blah:

hey now...



:devil:

[250r4life]

Originally posted by wilkin250r
No false advertising here. If I'm forking out cash, you had better be actually USING those tampons... :blah:

hey now...



:devil:

[250r4life]

Originally posted by wilkin250r
No false advertising here. If I'm forking out cash, you had better be actually USING those tampons... :blah:

hey now...



:devil: