power for pound......one for the nc30/35 racers

[Cammo]

My bike basically has a full exhaust system, hrc nc30 carbs, nc35 hrc cdi, quitening gears removed.

Running the open carb setup and modifying the carbs to hrc spec is easy and cheap (non genuine parts) for good gains.
Get as much air into it (for a bigger bang) for the price you can afford, and jet accordingly. When you push the peak power up further, it's nice to have the increased rev limit of the hrc cdi.

I hear what you're saying about ram air being surrounded in secrecy, it's an edge for some racers who have outlaid big money on setup. I would like this, but aren't willing to outlay that sort of money when I'm happy with the hrc setup. I would rather spend the money on a fibreglass tank or similar...

Other than engine mods, gear it lower to make the most of the torque, and lose all of the weight that you can. If you read through Rally's weight list, there are lots of small items on there that you can remove without spending a cent (e.g. engine cover noise baffles).


I wholeheartedly agree that suspension and tyres are the biggest gains, along with probably all classes of the Cali Superbike school for myself...

[chrisxr]

dead simple



stock motor
twin exhaust
ram air
set up carbs
modified ignition
Output for this
vfr 400 61 to 64 hp 26 - 27 ft torque
rvf 400 63 to 67 hp 26 - 27 ft tourque
cost for above £600
figure varying on mechanical condition of motor


same as above with motor with raised compression "ports modified" secondry gears removed and rotor removed + 2 hp on vfr + up to 4hp on rvf
£350 on the above
engine become noisy oil will apear on over run and power will not be as linear

as above but serious motor work gears cut thinner head re shaped parts made to reduce friction clutch modified cams dialled in stronger valves to cope high reving cdi unit plus many many other little tricks on stock pistons
cost £1300 + above

vfr 67 - 69 bhp 27-28ft tourque
rvf 68 - 72 bhp 27 -28ft
engines life expectancy becomes under 100 hours use before power drop off




or simply big bore piston kit on stock motor
70 bhp 31 - 32 lb ft vfr
70 - 72 bhp 31 - 32 ibft rvf

£800 all in built fitted

or as above with tuning
figures of 72 to 76 vfr
and 73 to 78 on rvf

they are what you should be looking at paying for your power and that is what you can expect


also for race use use race fuel and + 2hp providing a advancabloe ignition is used

they are on genuine figures i have seen on a dyno that shows stock bikes with a half system on and set up well at best 58hp and well set up rvfs with twin stacks and hrc boxs 61hp

so if you got a stock bike with a system on doing 65bhp you have either got very lucky or a been to a very optimistic dyno.

[Cammo]

Good prices.

I would be tempted to take a big bore engine off ya Chris, but shipping would kill the price.

[chrisxr]

ram air aint no secret i will ram air your bike inc second hand pump my own ram air ducts and all dyno time inc jets for £150 or just ask me what to do.

its not exactly a arm and a leg..

[royster81]

Personnally I would say a decent race exhaust system & Ramair with jetting to suit, is the combination of upgrades that would give the best return. A word of caution, once you've got that far a couple of things worth considering is fitting a fuel pump & modifying the fuel tap to stop possible fuel starvation problems.

i was under the impression the pump and tap mod had to be done for the ram air to work,i agree with what your saying but ,everything i hear points towards this being the best thing to do

I'm a little further on from that point myself with maxton suspension, EBC cast disc's & some gas flowing done to the engine, and I would say that all upgrades have been worth having. Like you, I've only really been interested in doing things that give a siginificant change .

the suspension on the bike suits me,i haven't found a problem with it,nor did the racer who took it for a session at the track i trackday at but i can see it happening as i know how much it changes a bike and the confidence it gives,discs...o.e. ones for ok for what i'll be done i think but the gas flowing i have no knowledge of,more advice needed on this i think

At this moment in time my engine is getting refreshed by chrisxr, once the bikes back together he's going to fit one of his programmable cdi's, as again this sound's like it could give a good return for the money, along with some dyno time to set-up.
I let you know how it goes!!!

yes mate i'll try and keep this post going so maybe others can benefit from it,the cdi's chris does sound outstanding and i'd be interested to hear what he thinks would be a good start for me and what path i should wonder down,after all ,he's the man in the know....

[chrisxr]

can i just say that raised compression motors cause the power to flaten out at high rpm and other modifications such as ignitions that pull peek power up on stock compression motors wont always have the same affect at the top end of the rpms on high compression engines. Unsure why this happends but its been my observations maybe its cause the piston is already being forced back harder on the compressing stroke due to the greater compression and that coupled with extra advance causes it to try and push it self down on the up stroke.... dunno maybe some one has a theory on that

But.................................... that said how often are you reving your bike at 14500rpm? it dont really matter what happends there a good motor will see most gains from 9k to 13 k that is where you spend most of your time riding...(unless its a drasticly modified motor) dont always pay attention to the final figure its of very little use to you.......

[royster81]

dead simple
stock motor
twin exhaust
ram air
set up carbs
modified ignition
Output for this
vfr 400 61 to 64 hp 26 - 27 ft torque
rvf 400 63 to 67 hp 26 - 27 ft tourque
cost for above £600
figure varying on mechanical condition of motor:

and here lays the answer to my question,and it only took 2 pages,the above coupled with the right gearing,sticky tyres and suspension and i can see big smiles and worn out knee slides

same as above with motor with raised compression "ports modified" secondry gears removed and rotor removed + 2 hp on vfr + up to 4hp on rvf
£350 on the above
engine become noisy oil will apear on over run and power will not be as linear
as above but serious motor work gears cut thinner head re shaped parts made to reduce friction clutch modified cams dialled in stronger valves to cope high reving cdi unit plus many many other little tricks on stock pistons
cost £1300 + above
vfr 67 - 69 bhp 27-28ft tourque
rvf 68 - 72 bhp 27 -28ft
engines life expectancy becomes under 100 hours use before power drop off

i think this is where it gets a bit crazy for "just" a track bike,there's no championship points at a track day and £1650 for the above work would be great for a racer looking the very best for his bike and wanting something that can compete with the zxr/sv650/rs250 in the clases over here,but chris you've won me over with the first answer.....know where did i put the wifes cheque book.....

[fat eddy]

Hi royster,



With regards to the fuel tap mod and fuel pump upgrade this was somthing that was done to my bike at the same time as adding the ram air unit. I heard of people putting ram air on and not completing the fuel changes, supposedly not having problems, but I would recommend it, the thing is, it doesn't really cost that much for the s/h fuel pump and doesn't take that much effort to do.

When it comes to getting suspension & tyres right these will give you big performance returns, but for the moment if it's working, then fair enough. I found on mine that there was just too much movement, the back was bouncing round like a pogo stick, the front forks was also bottoming out on the brakes. Once this was sorted it gave the bike better composure which then gave me a better confidence to push harder.

As mentioned before I'm getting chrisxr to refresh the engine along with sorting out the setting up of the bike. If I didn't think he was capable I simply wouldn't be having the work done there. Obviously there's nothing wrong with RLR and I know that some people believe that he is the choice between winning and losing when it comes to racing Honda 400's. But I just can't see for all the extra money what your getting from him that you couldn't get from Dyno-pro. You should have a word with Chris, he definately seem's to know what he's talking about, especially when it comes to these V4's.

Good luck..

[chrisxr]

are you after some discount eddy?

cheers mate but i dont think i am anything like comparable to rlr .......

[Jon]

Chis
Do you a "distance kit" for Ramiar on RVFs (it is a VFR but has RVF carbies) that I could get off you?
Some bits from you, track down my own fuel pump (to save on freight) and some instructions on how to mod carbies?

regards
Jon