Tirpitz's 62bhp ZXR400L4

Who's zxr400 is kicking out the most BHP? show off your mods and your dyno printouts.

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Tirpitz
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My Bike: Kawasaki ZXR400L4
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Tirpitz's 62bhp ZXR400L4

Post by Tirpitz » Fri Oct 21, 2011 9:17 am

11000 miles
A16 Exhausts carbon fibre road legal end can (with baffles in)
Everything else totally stock
Shell standard unleaded petrol in the tank
Silkolene PRO4 10w-40 in the engine
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ZXR400 L4, purple / black / pink
Hel braided hoses
Pirelli Diablos
Ohlins steering damper
A16 carbon fibre exhaust can
Nitron Sport shock

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Mori Man
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Re: Tirpitz's 62bhp ZXR400L4

Post by Mori Man » Fri Oct 21, 2011 9:42 am

Very nice chart, that fuelling looks almost perfect !

Are you running standard headers ?

If your happy with the performance I would leave as is , you must be getting great MPG too :smt004

Got to get mine on a dyno soon :smt010

MM! :smt001
Nothing worse than having an H and not being able to scratch it !
Living life on the edge, SuPposedly

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Tirpitz
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Re: Tirpitz's 62bhp ZXR400L4

Post by Tirpitz » Fri Oct 21, 2011 10:12 am

Hi MM,

Yes, everything is stock apart from that can. Bought it a few weeks ago more for the sound than anything else and intended to have a dyno run anyway to try and get rid of the flat spots that come with the bike as stock. So I was really surprised after fitting it when it had cured the flat spots and seemed to have released a noticeable bit more power, without any carb work. But I wanted a dyno run anyway just to check the fuelling - as you know, you can get more power running it lean but then it eats a piston :smt009 As you can see, fuelling is fine.

Guy at the Dyno (Dynobike at Malton - got a good rep) said it was a bit lean on the pilot which was causing a bit of a flat spot at 4K but recommended it be left alone. He said if he richened it up it would likely spill over into the needle's range and make that rich, which would just cause a problem elsewhere. I don't notice the spot at 4k, it pulls away fine and who runs the engine down there? So, as the man said, it ain't broke so I'm leaving it alone. He reckoned about 58bhp at the rear wheel would be normal with the OEM can.

I get about 130 miles before reserve and that's with 'enthusiastic riding', so no complaints there. :smt001
ZXR400 L4, purple / black / pink
Hel braided hoses
Pirelli Diablos
Ohlins steering damper
A16 carbon fibre exhaust can
Nitron Sport shock

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Mori Man
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Re: Tirpitz's 62bhp ZXR400L4

Post by Mori Man » Fri Oct 21, 2011 10:58 am

Honestly, end cans do nothing for power except the very best that come with jet kits and even then it's 1~3PS .

What it has likely done is as you said got rid of flat spots you had so when your canning it ( looking at you power line) it pulls all the way to the top without fluttering - that's giving you the extra oomph feeling, still no bad thing :smt001

Yup, when there is so little wrong it pointless messing about as you just shift the problem further along.

A full system and cams could get you another 10 ponies though, FCRs in the mix will add a few but give a better punch midrange - you might fatten that up by 10 ponies, just imagine what your line would look like :smt003 :smt003 Still haven't cam'd mine yet and it is geared for top end so I see 130MPH on the clock in 4th @ redline - I usually go to rev limiter as the power hasn't dropped off but in 5th n 6th redline is fine.
Nothing worse than having an H and not being able to scratch it !
Living life on the edge, SuPposedly

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Tirpitz
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Re: Tirpitz's 62bhp ZXR400L4

Post by Tirpitz » Fri Oct 21, 2011 11:22 am

Yeah, you're probably right. With the OEM can it felt as if it had power bands. These might have felt powerful but I reckon all that was happening was that the bike was climbing out of flat spots - a false impression. Now it just pulls cleanly right through, there's no kick-in point anywhere. I bought the can mainly for the sound as it has a nice deep burble lower down the rev range. It's not plod attracting either (it's BS stamped too) and if anything it's quieter when the engine is being caned higher up - or maybe the deeper notes are not as audible to the rider. Sounded nice and sweet during the dyno run. Deffo a saving on weight though, the OEM is a brick in comparison.

Dunno if I'd go for the expense of serious tuning work and add-ons. I'm thinking of getting a gixxer 750L (keeping the ZXR tho) for some serious headbanging activity :smt003
ZXR400 L4, purple / black / pink
Hel braided hoses
Pirelli Diablos
Ohlins steering damper
A16 carbon fibre exhaust can
Nitron Sport shock

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Re: Tirpitz's 62bhp ZXR400L4

Post by Mori Man » Fri Oct 21, 2011 12:22 pm

Strangely enough when you restrict a can the fueling goes leaner - or so I am told.

" If you run a db killer and take it for track days, dyno the bike with it out "

But, I put an absolute wad of steel wool in my BEET can to shut it up - free flowing it makes 107db at 5K , I got that down to 86db at 5.5k for the test.

When I wipped out the plugs they were well sooty so suggest it's richer , damn I am talking bollox :smt005

Yup, dyno the bike with a db killer in then remove it will run lean hence dyno it out so it goes rich when placed back in

Which suggests the bikes are actually rich running as standard which confusses or maybe adds to my hot starting analysis :smt017

Soz, I am off back to me beer :smt005
Nothing worse than having an H and not being able to scratch it !
Living life on the edge, SuPposedly

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Tirpitz
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Re: Tirpitz's 62bhp ZXR400L4

Post by Tirpitz » Fri Oct 21, 2011 11:32 pm

Yes, the bloke did ask me before the run whether I normally ran the bike with baffle in or out, as it removes in seconds with one allen bolt. He wanted to dyno it as it normally runs. I did try running it with the baffle out when I bought it but it ran like toad, all noise and no go at all, felt really flat and gutless. So I put it back in and it ran great, so I've left it in.

I reckon they do run a bit richer on the standard can. I've noticed since removing it that it needs a bit more choke to idle from cold and is more likely to die coming up to junctions for the first half mile or so when setting off unless you keep the throttle blipped to prevent it. Am pretty sure it's leaner now.

Funny you should mention hot starting probs as I got talking to the bloke about this. He's tuned a few ZXRs for racers so has some knowledge of the bike. He said he's aware of it, and on other bikes, but he reckons it's nothing to do with rich running. He says it's because the carbs are placed in a position where they are affected by heat radiated off the engine when it is hot. This heats up the float bowls and causes evaporation from these and the inlet tracts, leaving the carbs dry. The motor then needs a good spin to fill them back up. He said the mistake some people make when the bike won't fire up is whacking the throttle open while they spin the motor which then floods the engine when the carbs do fill, so it then deffo won't start. He's solved the problem on ZXRs and other models by fitting a heat shield of silver between the carbs and the engine to keep them cool. He said something about taking the inlet rubbers off and cutting holes in the shield for the rubbers to fit through, then you put it all back on. Said that Demon Tweeks do a version but you could easily make your own. Worth a try.
ZXR400 L4, purple / black / pink
Hel braided hoses
Pirelli Diablos
Ohlins steering damper
A16 carbon fibre exhaust can
Nitron Sport shock

cargo
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Re: Tirpitz's 62bhp ZXR400L4

Post by cargo » Sat Oct 22, 2011 7:51 pm

Tirpitz wrote:Yes, the bloke did ask me before the run whether I normally ran the bike with baffle in or out, as it removes in seconds with one allen bolt. He wanted to dyno it as it normally runs. I did try running it with the baffle out when I bought it but it ran like toad, all noise and no go at all, felt really flat and gutless. So I put it back in and it ran great, so I've left it in.

I reckon they do run a bit richer on the standard can. I've noticed since removing it that it needs a bit more choke to idle from cold and is more likely to die coming up to junctions for the first half mile or so when setting off unless you keep the throttle blipped to prevent it. Am pretty sure it's leaner now.

Funny you should mention hot starting probs as I got talking to the bloke about this. He's tuned a few ZXRs for racers so has some knowledge of the bike. He said he's aware of it, and on other bikes, but he reckons it's nothing to do with rich running. He says it's because the carbs are placed in a position where they are affected by heat radiated off the engine when it is hot. This heats up the float bowls and causes evaporation from these and the inlet tracts, leaving the carbs dry. The motor then needs a good spin to fill them back up. He said the mistake some people make when the bike won't fire up is whacking the throttle open while they spin the motor which then floods the engine when the carbs do fill, so it then deffo won't start. He's solved the problem on ZXRs and other models by fitting a heat shield of silver between the carbs and the engine to keep them cool. He said something about taking the inlet rubbers off and cutting holes in the shield for the rubbers to fit through, then you put it all back on. Said that Demon Tweeks do a version but you could easily make your own. Worth a try.

I reckon your dyno man is right...................I had a serious hot starting problem at the Manx...............we did a test and came in after two laps and waited approx time it take to refill the tank............and it completely refused to start....................and I have no doubt it was a heat/carb/fuel vaporising problem.
I re fitted the hoover pipes to put cold air in the area around the top of the airbox and an extra hoover pipe to feed cold air to the rear of the engine under the airbox.
Also I covered the airbox in heat reflecting silver tape and put a heat shield between the airbox and engine......................I can be certain if all that helped but come the race it started after the pit stop mind you I had a fit young thing doing the pushing.

I still have another bike that absolutely refuses to start on the button hot or cold..............but give it a push and it fires easy

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