how to get to 80bhp?

[darenor57]

hi hav just started racing a zxr 400 done a season last year but its standerd and wanted to no wat it would take and how much it would b to get it around 80bhp im in ireland and would like to no if ya could give me any info tanks for any replys

[extonyg]

you will struggle to make 80bhp out of a 400, it will take major head/engine work to get that sort of power which means lots and lots of £££££££.good way to get more power is strip all excess weight off the bike.
if your bike is totally standard you can start with all the basics like ram air setup, dyno jet needles, full exhaust system etc.
then you can go more into ported/polished head work, adjustable cams, base gasket removed etc etc.
depends how much money you want to spend.
have a look in the racing section or use the search box (top right) and that should give you some ideas on what you can do and prices etc.

[darenor57]

oh right so wat would a good 400 b puttin out bhp wise mid 70s if i had ram air setup, dyno jet needles, full exhaust system,ported/polished head work, adjustable cams and base gasket removed wat would i be lookin at?

[mick41zxr]

Done properly, low 70's. As you get past that it is the law of diminishing returns. Put some money aside in your budget to really get the handling sorted.
Regards,
MB

[Ballsout Racing]

Dynotechs full tune will give 80bhp on a Dynojet, 73/4 on a Dynopro Dyno.

Basically:
Ram Air
Full System, MHP
Head work, Set Squish, CR etc, fully ported head.
SP cams.
Dynotech use Stainless valves.
+0.5 or +1mm pistons (depending on rules)
And an ignition system for revs to 15,000+ depending on pistons, engine life etc.

[rmkd177]

Can we just clear a few small points...dynojet needles DONT work with ram air systems...and 'polishing' a head (ports) is 'old hat'...the desired finish is not shiny...
To add to Grev's list i would include flatslides which gives 2bhp over cv's...and although not prefered by some...we wouldnt be without them...for many reasons.
We are showing a touch over 80bhp with stock pistons (1989 H2 pistons to be exact)...and it doesnt cost £££££££ we actually run a stock exhaust cam and stock pistons...just a question of getting the right tolerances to cope with the 15,000++rpm that no doubt Grev will agree are invaluble.
One of my engines is used on the Irish roads by Andy Farrell and runs to 16,000rpm...stock pistons and 80bhp...
And if you doubt my figures ask Ryan Farquar...the only F400 to inflict a defeat on the invincible Ryan and his 'supertwin'...by 15seconds at that.

[darenor57]

Can we just clear a few small points...dynojet needles DONT work with ram air systems...and 'polishing' a head (ports) is 'old hat'...the desired finish is not shiny...
To add to Grev's list i would include flatslides which gives 2bhp over cv's...and although not prefered by some...we wouldnt be without them...for many reasons.
We are showing a touch over 80bhp with stock pistons (1989 H2 pistons to be exact)...and it doesnt cost £££££££ we actually run a stock exhaust cam and stock pistons...just a question of getting the right tolerances to cope with the 15,000++rpm that no doubt Grev will agree are invaluble.
One of my engines is used on the Irish roads by Andy Farrell and runs to 16,000rpm...stock pistons and 80bhp...
And if you doubt my figures ask Ryan Farquar...the only F400 to inflict a defeat on the invincible Ryan and his 'supertwin'...by 15seconds at that.

any idea how much tat would cost i no andy well live about 10mins away from him

[mark400]

The race manual (available on this site) also reccommends polishing and lightening the con rods - You could also trim the gennie bit off the crank,put a bung in to guarantee oil flow to the big end bearing while having it lightened and balanced...

Dynotech have told us to always use fuel of at least "V Power" quality - Which is 99RON.

My brother has just had his engine whispered on at Dynotech, and they achieved 72bhp with the following spec :

Standard cams
Full scorpion race system
Standard ignition (Coils and blue CDI)
No advance
BB Airbox & plate - Jetted accordingly by Dynotech

To go the extra bhp, as Mick41 says - Is the law of diminishing returns ! For example, a friend of ours does drag racing with a Hayabusa. To reduce internal frictional waste, he now uses Titanium shims, and is about to go to Titanium valves (as he "has a mate"), but to commission these commercially would probably cost £50 - £100 per valve !

What is equally important is weight,and you can shave weight in lots of places (See my thread) as more power doesn't also mean later braking, but saving weight will allow you accelerate quicker & corner faster & brake later.

Apart from Dynotech -

Roger Middleton is a black belt at ZXR's , so if you live nearby - What are you waiting for

I saw Mike Saunders on the beautiful RMKD no177 ZXR400 at Cadwell in 2007, as he went past me on the bottom straight doing about 160mph !
RMKD race successes are well documented - Look at Rogers blog for more info on the Olivers Mount race with Ryan Farhquar being beaten by Rogers bike

http://rmkd-racing.blogspot.com/

[Robbie]

dynojet needles DONT work with ram air systems

Hi Roger what needles do you recomend using instead of the dynojets on cv's with ram air?
cheers.

[Ballsout Racing]

Yep, agree with everything Roger says. Every tuner will do something slightly different, but the end result seems to always be very similar.

Out of interest, Bemsee do a random dyno run on all of the top bikes straight after a race, and all of the top spec bikes, no matter who's tuned them come within 1 or 2 bhp of each other and all have an almost identical power curve. If any bike shows significantly more than that then they know there's cheating going on.