www.zxrworld.co.uk

as title suggests im looking at pushing out around 64bhp out of my l model zxr as im entering bemsee f400 in the sub 64 class for next year, got the bike yesterday to get a bit of track time in this year and get used to riding a 400 instead of my R1. Will be refreshing the engine after a few track days this year, big ends, shells, rings, re-seat valves, stem seals etc. but what modifications are people running to be competitive? have a micron system sorted already, was thinking filter, advancer and re-jet? any help is much appreciated
cheers
alan

A ram air box seems to be very popular, apparently can add 10/12hp but I'm not sure I believe its quite that effective lol

Also running total loss seems to be popular too, I'm guessing for lowering the rotating mass of the crank so it revs up faster?

They are just two things that spring to mind (:

was looking into running total loss, how long does a battery last though? I think ramair would bump the bike over the allowed 64bhp along with the micron pipes i already have?

90 minutes racing I should think, maybe more if you bump it rather than using the starter, but also you could charge it between races obviously so shouldn't be too much of a problem,

I'm not familiar with the ruling, but if its based on a stationary dyno, then the ram air wouldn't have any effect until you got on the track but that's probably not allowed and cheating anyway,

Thought about SP cams? I've been trying to get hold of some for yonks for my road bike for when I deresrict it

guitarcarrot wrote:I'm not familiar with the ruling, but if its based on a stationary dyno, then the ram air wouldn't have any effect until you got on the track

Those big fans at the front of the dyno aren't there just to push air through the rad.

Shouldn't it make 64 Hp without much effort? My stock SP motor made more than that with just a Beet pipe. And there's no way your going to get 10 Hp increase with a ram air box.

CaNsA wrote:

guitarcarrot wrote:I'm not familiar with the ruling, but if its based on a stationary dyno, then the ram air wouldn't have any effect until you got on the track

Those big fans at the front of the dyno aren't there just to push air through the rad.

Actually thats exactly what they are for...hence why they are situated so low...ive never seen a mobile dyno yet that run simulated air speed.

Alanh... i wouldnt use the micron system they are about as poor as you could get along with scorpian. A beet /beet copy or MHP system would be a good asset.

CaNsA wrote:Those big fans at the front of the dyno aren't there just to push air through the rad.

AKA Not the only reason.

Whats up with the micron pipes + zorst?
Aslong as the baffles are removed then its all good right?

its my first season racing, chances are its gonna kiss the tarmac a few times , beet pipes are expensive and not something id necessarily be able to afford to replace straight away after an off whereas cams, airbox etc. could easily be put into another motor. micron, ramair, sp cams and jet work should see me pretty close shouldnt it? Also is removing the base gasket for more compression a viable option?
thanks for all the replies, definitely gives me a good idea of how much tuning it takes to hit 64bhp.

I would keep your money for entry fees and test days and a cheapo caravan.
Get your bike healthy and clean, and get that suspension spot on. Dont worry about cams, systems, blar blar..
Then next season look into getting on the 64 limit if you want to stay in the sub class.
If i was starting again, that what i would do.
Its an expensive addiction as it is without spending a fortune on stuff that wont help you in yr first year anyway.
If your on facebook, look up http://www.facebook.com/#!/groups/257254159742/
ask the questions there to the guys you will be racing with.
And, motoforum get some of the 400 guys looking in.

will be rebuilding/refreshing the engine anyway so may as well chuck some sp cams in if i can get them for reasonable money, losing the base gasket costs nothing and ramair kits arent silly money now, bike will need a re-jet either way so wont work out costing much more doing it that way. Got plenty time and a few spare £ to do it so may as well give me the best chance to do reasonably well possible. I will be spending a lot of time on sorting the suspension out though, got the brakes just about sorted now just need a master cylinder and radial conversion kit. May have a spare bike dirt cheap with a dead cylinder head so will probably refresh that engine and keep the one i have at the minute complete incase anything goes wrong (means i will have 3 sets of wheels, one with wets, one with sportmax qualifiers that will soon be replaced with racetecs/supercorsa's and a set with road tyres from spare bike. is this overkill or worth keeping all 3?)

If your on Facebook then search EDIASIA Formula 400 group, most Bemsee 400 racers are on there and both sub 64 and full power so plenty of advice

Mine has Kent cams, ram air, beet copy exhaust, and flat sides with a ported head and std pistons running total loss and is about mid 70's

Think an exhaust and rejetted ram air running total loss would possibly be around sub 64 without the cams etc but go join and find out more

A number of folk run the Micron full system in the full power class, but think there may be a mod in the balance tubes to get full potential, maybe there is a restriction or baffle to remove.

Be carefull about just losing the base gasket, I did this last year on an L transferring my race head after losing a rod and it was fine. I rebuilt the whole engine in a set of H cranckcases this winter and would have run into trouble, but Luckerly Dynopro in Basingstoke replaced my valve set and checked the squish and reckoned the pistons would have hit the valves if I'd just built it with no base gasket

I have a Brembo master cylinder and with stock calipers are great brakes, but some just use later ZXR or GSXR m/c with std or later calipers too

It's a great class and very friendly so I'm sure you'll find no end of help

Already joined the group on facebook, had a lot of help so far will stick a post up on there but looks like the setup you mentioned (micron,ramair and rejet) will probably be the route to go down. Got a set of cbr600rr3 calipers off a mate thats bike met a sticky end and bike came with braided lines so just need a gsxr m/c then theyre sorted. What rear shock you running? Seen a lot of bikes still running a stock one, is this good enough set up properly? also are progressive springs and correct weight oil enough for front forks?
cheers for all the help guys, have a much clearer idea of what im going to need

I would'nt waste money on the stock stuff. A good aftermarket shock set up for you, now thats a worthy investment.... maybee find a second hand ohlins/wp/topend nitron, then send it to maxton same with your forks. About 400 quid now for maxton to convert your forks and set up and refresh your rear shock.

Totally confused here

As has already been said, the bike is rated at 65hp at the crank totally stock out of the factory in Japan. You don't have to 'tune it' to put out 64hp, that's how it comes out of the box. This viewtopic.php?f=168&t=13065 is a stock bike at 62hp at the rear wheel.

Spend your money on getting the bike set up suspension-wise for your weight. People always search for more power when a propely set-up suspension is worth probably 10hp and costs a lot less than tuning to achieve.