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Mine had an ATRE and a Gipro gear indicator installed before I bought it. There's no midrange POP on deceleration at 3500 rpm like you hear without it. The gear indicator on the LCD dash always reads "6" which is why the Gipro is needed. I haven't ridden one in a while without it, so other than that, I don't know the differences.
 

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I have both the ATRE/GIPro and a set of Factory Pro mid-range stacks on my '07. I added both while the bike had relatively few miles on her, so I'm not a good one to give you a "before and after" critique. However, I did add the ATRE to eliminate the off-throttle 'pogo-stick' effect that the earlier 14s were noted for, and it did the job admirably. The larger gear indicator was a welcome bonus, and the coolness factor didn't hurt, either. I had a long series of technical conversations with the FP representative about the efficacy of the stacks, and he gave me some good advice in suggesting going with the mid-range set up for street riding. I've had no adverse performance issues, and the install was relatively easy.


DW
 

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I'd be interested in a before-and-after dyno graph for those midrange stacks. For what they cost, it would take a substantial improvement to make it worth my $.
 

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I'd be interested in a before-and-after dyno graph for those midrange stacks. For what they cost, it would take a substantial improvement to make it worth my $.
There's no effen' way I wold have paid full price for them. If I recall, however, they were being offered, maybe on eBay, as seconds or factory overstock by the company. I paid about 1/3 list.

B
 

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The ones I've seen on fleabay go for around $250 a set. That's a lot of coin for something you only see when you clean the air filter. They had better produce some substantial gains.
 

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I was going to get a set last year.Until I heard from different people their worth 1-2 HP.
Craig
 

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Differences in intake length can affect the power output just like differences in exhaust length-witness the machines that feature variable-length intakes to produce power at varying rpm. If the spun-aluminum aftermarket stacks are the same length as the stock plastic , I would doubt there is much of an improvement. If they are different, they could possibly move the powerband around without producing any more peak hp

Years ago, some guys vintage racing an old Norton twin at Daytona were having trouble getting it to run well with open intakes (no filters or anything on the carbs). The machine wouldn't pull max rpm and get up to its potential top speed. They called Leo Goff, the famous Norton dragracer and he told them, "You have the typical Norton midrange miss. Get some velocity stacks to increase the intake length and your midrange will return and the motor will pull through to max rpm." They searched all over town and couldn't find stacks for the ancient Amal carbs. Finally, in desperation, they cut the bottoms and tops off some used beer cans, stuck them on and went out for practice. For the first time, that old twin wound out all the way to redline and they got the speed they geared for on the banking without losing tractability on the infield

I actually tried this and it worked! That was when I found out I needed to replace the all-metal stock clutch with some Barnett fiber friction plates, because when the motor hit 4500 rpm, the torque came on so strong it made the clutch slip, something I had read could happen when you increase power over stock levels.

So when midrange stacks were mentioned for the 14, it tripped my mental trigger. As much as I love my new ride, it doesn't have the grunt of my old one, so anything that might give me some of that is of intense interest.
 

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I think the shorter ones move the power down into the midrange by 500 RPMS.The longer ones raise it but for 1-2 hp in the midrange for $200.I don't know if you could feel it.My bike is a midrange bike with the gears and pipe and map.
Craig
 

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That's what I'm kind of wondering is if they are worth the money. Will they help it out enough to tell a difference. Or are they just a waste of money?
If only for bragging rights, nothing one adds to a 14 is a 'waste of money' .....except maybe stickers.


DW
 

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I have both on my 14, the TRE went on really early in the build and made a difference but I ended up pulling the flies out so it wasnt really needed after that. I got the top end stacks and yes they made a improvement in power above 7200 rpm, picked up around 5 hp from 7800 to redline. If only street riding the midrange stacks are a better choice though. But velocity stacks alone on a relatively stock bike are not going to make a big enough difference to justify cost, they are a tuning tool to get the last bits of power out of your combinaton.
 
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