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The 60hp ninja 400...here it is!

6K views 34 replies 13 participants last post by  BMHS 
#1 ·
People have been asking in the past on here about getting a ninja 400 to 60hp and what it takes to do that. Well I finally found the secret sauce to that! Turns out all you have to do, is sit on your ass for a few weeks and wait for the weather to cool down a bit, and then take it to the dyno! LOL No other modifications needed!

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Believe it or not, the 2 curves represent the same bike (mine) in the exact same form, on the same dyno, with the same settings on the dyno, but taken about 6 weeks apart. The pink was my final tune, done sometime in September, before racing at Daytona. That was the fuel map I made for VP MR12. I then ran 2 races and a few practice sessions at Daytona using the same fuel, then parked it in the garage. Even left the MR12 in the tank, which you're really not supposed to do because it can clog up fuel filter and injectors. I finally got the motivation to flush it all out, thinking for sure my fuel system is messed up by now, so I took it to the dyno and ran it until I got rid of all the MR12, then flushed it with regular 93 pump gas. Nothing at all was changed on the bike and now I got almost 3 hp more! lol

I like to think that MR12 is like fine wine and it just gets better with age...but in reality that's that exact opposite, and the only difference here was the environmental conditions. Today was a cooler and humidity lower than several weeks ago. Not sure by how much, but I would say around 10-15 degrees cooler. Not sure about the difference in humidity though. So far for that SAE correction factor, right? :rolleyes: ;)
 
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#4 ·
Yeah that CO air will do it...although I wouldn't have guessed such a large difference. I figured about a 4-hp drop. When I raced at High Plains with MRA, one of the local guys there told me all the bikes there are about 10% down on power from where they should be. I can't remember the elevation at HPR, but I think it was somewhere around 4500 feet? Maybe a bit more?
 
#12 ·
I'm kind of lost on this as well. Getting it to 57-60 hp is really impressive, but I'm not clear on what was done to the bike? Is there a more detailed description of how this was achieved?
 
#19 ·
Yes, most likely in my racing thread for 2021 that I started about a year ago. I've always been transparent with my mods and even most people I race with all know what I've done...unlike so many others who seem to hide things.

Akrapovic exhaust
aRacer ECU custom tuned per individual cylinder by me
custom airbox made by me using the Norton stacks (I've used the TST stacks in it as well which gives me a bit more power in the mid-range but less at the top end, right now I still have the Norton stacks in it)
bored throttle bodies (done by Norton)
race cams (from Norton)
thin head gasket
ported head and valve job (done by someone I wouldn't recommend...I'm pretty sure this actually hurt my output instead of help it, cuz with all the mods I had, I should've seen another 2-3 hp, but the porting job was total ****)
 
#20 ·
Come to think of it now, one change I did make was swapping the wheels to the forged aluminum MOS wheels. With the rear wheel being 2 lbs lighter and have less rolling resistance in the bearings, I imagine that accounts for some of the power gain, but not sure how much. Now I need to do that test some day when I get a chance. Do some back-to-back runs with stock rear wheel and the forged rear wheel. I'm sure @jetpilot01 would be interested to see those results as well :)
 
#23 · (Edited)
A lighter rear wheel assembly DOES does change the indicated power on a Dynjet dyno, or any other dyno that uses a "sweep" technique versus a steady rpm to measure power. This is a moment of inertia effect.

You can also change the indicated power by changing that gear you have the bike in for the dyno run. 3rd or 4th gears give lower power readings than 5th or 6th gears. Again, this is a moment of inertia effect.

Steady-state dyno (i..e dynos that hold the engine rpm steady to get their readings) do not exhibit these MOI effects. However, acceleration on the road or track DOES result in the MOI effects, so lower MOI is indeed helpful in the rear world.

Jim G
 
#28 ·
On higher HP bikes, often the power output is restricted in the lower gears, so dyno runs have to be done in a higher gear to get a true reading.
I doubt that's a factor on the 400, but I don't know for sure.
 
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#29 ·
SBK1198,
I have look at & test bike engines on about 5 different chassis dyno's. Not one of them had a correct SAE correction that worked. I never found one that used humidity in the calculation. I always did my own correction using a Meriam barometer, digital thermometer in the carb or throttle body, and a humidly gauge in the dyno room. Not once did it ever agree with the Dyno Jet, SuperFlow, or whatever brand dyno. At Kohler, in the engine lab, we corrected/certified the SAE correction data every morning, because our dyno runs needed to be certified to the Feds, for emissions & power ratings. The engine dyno's were eddy current pumps with highly accurate load cells that are controlled to 1 RPM, and repeatable to 5 RPM. That said, it's too bad all of us that are interested in engine performance can't find reliable/inexpensive place's to test are engines that really work.
Brian
PS, Maybe we should all get electric bikes, forget that thought.
 
#30 ·
That's good to know. I have looked into the SAE correction factors before and the info I found also agreed with my test findings and what you said, that it's not 100% accurate way of normalizing dyno results, but it will bring values closer together. Still better than leaving results uncorrected, but not a completely accurate way of normalizing.

I am not opposed to electric bikes, but they need to improve the battery technology and the costs to get lower :)
 
#32 ·
sbk1198,
The fact is that we should all thank Kawasaki for making a 400cc race bike, and then hanging lights and turn signals on it. If you look at the 300, and compare it to the 400, frame engine gearbox, this bike is a bargain. It's raced all over the world, it has tons of speed parts available. It just won the WSB 300/400 championship, with YSS suspension components by the way. What's not to like. For a $5000.00 bike, it handles really well. If you push it, sure it needs some new parts, but the foundation is there. If Kawasaki brought out a $7500.00 model with great forks & shocks, bigger brakes, I'm guessing that very few would buy it. We all seem to have our own ways of doing things, but that's OK, we are all on 2 wheels with a great little FAST bike underneath us..
BMHS
PS, I'm actually considering selling my 2018 Z900RS Café this Spring, because this 400 is such a HOOT to ride.
 
#33 ·
Yep, it's a great little bike for sure! I have no regrets. The Z900RS is a cool looking bike too. I like the retro look but with modern technology.

By the way, you know you can just click "reply" and automatically quote a message rather than type out who it's being addressed to like a letter :)
 
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