ZXR400 brilliant but needs more power

[Random]

What ways can you get more power from a zxr400?

Theres the Exhaust system you can a race system but can you bore the exhaust outlets and polish them smooth ?


Air intake K and N filters and other types of performance filters can be used you can even get a full ram air system but does
this even make a difference when you only have the standard carburettors, does the zxr750 carb fit the 400 that way wont it have a wider diameter to let the air through faster ?

How do flat side carbs work ?

We can also bore out the inlet manifold get more air and fuel to the valves faster but wont the valves only let a certain amount into the engine ?

[zimm]

short answer,

you can do all kinds of things to get more power.. it'll cost a lot, and wont get you "much" more power.. maybe an extra 15-20bhp, IF you spend 2-grand or so. enough to make the difference between being competitive and not if racing.. not enough of a difference to suddenly be able to keep up with R6's etc if you just ride on the road.


middle length answer,

race pipe
KnN filter
dynojet kit

then set up on a dyno, should see you at a true ish 65bhp with smooth delivery and crisp throttle response.. cost .. £150 + the pipe (£400-£1000)

after that you are looking at porting/skimming the head, SP or Kent race cams, stainless valves, 3 angle valve seats, flatslide carbs, ram-air.. cost ?

depends if you are paying someone .. or doing it yourself.. but the cams are ~£300 IIRC second hand flatslide carbs another £300-£400, ram-air £200 + buggering about to make it work .. and engine tuners charge a fortune, so call it another £1500+

highest BHP claim ive hard that i have any reason to believe is Roger's race bike at 83Bhp... and thats the result of 8 years of development and many many ££££

then there's the big-bore option of taking the engine out to 440cc should punt you into the mid 80's at the back wheel on a tuned engine, mid 70's if its stock..

but if we are talking about making the engine bigger ........ my personal choice looks like this,



ZX6r engine
full TTS tune (head, barrels, crank, rods, kent cams etc .. foo blah)
Yoshi pipe

115bhp

now it pisses on r6's lol

well it did before it blew up.

[deviant]

*cough* fireblade engine *cough*

[zimm]

*cough* fireblade engine *cough*

yeh, but .. its... a .. honda ...

[jake]

i tend to "cough", choke, then be violantly sick when i say honda...uhhhh ...oh nooo

[RedexRobB]

*cough* fireblade engine *cough*

yeh, but .. its... a .. honda ...

And it will snap your frame in half!

[zimm]

also, my 4/6 is insurable as a 1995 zx6r .. which is a lower risk then the zxr400 ! lol ..

carole nash see it as a zx6r with aftermarket bodywork and suspension .. which doesnt increase the premium .. lol

[zimm]

i tend to "cough", choke, then be violantly sick when i say honda...uhhhh ...oh nooo

im glad its not just me

[jake]

Hey Zimm, what happens when u change the frame of a model tho, numbers and registering and toad? I only ask, cos my bro smashed his r1 up into a car..down as his fault and not fully comp unfortunatly. So he has an r1 minus front wheel,plastics,forks and frame to do something with or break.

if i could get an r1 frame cheap then super, but they seem to go for around 800 ish...to much.. I told him to put it in a mini, have you seen them? v.cool

[jake]

check it out.
http://www.youtube.com/watch?v=TAC-hSCnJ8s


Random, i think the cheapest way about it is cut the baffle out of the standard pipes, fit a better can. make sure ya standard filter is in good shape, and get ya carb jets sorted,and you should feel an improvement.

[RedexRobB]

this one is quite interesting too!

http://www.youtube.com/watch?v=xLVQtK04lig

[zimm]

no idea about the frame reg etc .. my bike is registered with DVLA as a zxr400, just told them the new engine number when i applied for the v5, ah and the CC

its just the insurance company see it backwards..

R1 mini .. yeh .. V cool .. although if i was building one id use a hayabusa lump for the extra torque*.. also R1's/fireblades suffer from surging and need the sumps baffling or dry-sumps sorting out.. where as i "think" busa lumps are ok on this front.

any frame + v5 is going to be well pricey as dodgy geezers with nicked bikes want them.. best bet (although more hassle) is to get a shitter of an R1 with a blown engine etc .. build a good bike and sell whats left over.

*EDIT : actually, i'd be tempted to put a 600/750 lump at either end and link all the controls.. 220+bhp, 4wd and more revs !

[RedexRobB]

Only thing is its illegal to run a car with two engine in the uk, unless of course you switch one off for road use and then goto two on a track day etc..

[zimm]

where did you hear that ?

Z-cars do a twin-engined 4wd tiger cat, and built a twin hayabusa powered 4WD ultima couple of years back .. british leyland even developed the "twini-mini" using two front subframes and locked out steering in the back .. and that was back in the 60's .. 2 cooper-S lumps, 2 gearboxes ..

[superman]

OI nothing wrong with hondas........