In my endless search for optimizing my F4i engine I tried the basics !

Experimenting with the original exhaust vs aftermarket,taping off an air duct...some work better than another.

After searching a little bit further ,I spoke with a customer who is specialized in tuning rally cars and he came up with the following possibilities

1)narrow down the exhaust tubes with 2mm and still working with the original collector and exhaust

I have found a local exhaust manufacturer who want's to experiment with it for a fairly honest price,except I have to pay for the dyno's : (

2)turning up the compression by 'sorry for my bad english' by making the cylinderhead more smooth(flattening?)

and 3) having a different cam shaft.So I picked up the phone and called HRC Europe,they're based in the area were i work.Everything they have is for hi end performance,nothing for the lower region ...

Does anyone has experience with these 3 tuning questions,it can save us all some $ and R&D

Thanks already

 

by part 2) do you mean porting and polishing? have to be extremely carful with that because it needs to be tested on a flowbench and you have to beware of the "boundary layer effect" polish it too smooth and it will actually hurt performance. that all sounds really extreme measures to get a smoother running bike. from what i've experienced so far these things pull like freakin zambonis on idle, even when poorly maintained. if i were you i would just adjust the valves and insert the proper shims, do a manual cct, and sync the throttle bodies and call it a day.

 

so would i tim.. its not gonna help you ride better if your f4i is already running like a proper f4i! let me try your bike when we meet ok?

 

sync the throttle bodies..maybe some new sparkplugs,air box mod...maybe a powdercommander set for low end? even thats over kill imo..leave all what you were talking about alone.

 

Thanks man ,looking forward to it ! Bike is ok ,but it always can be made better...

always want that extra little twist

Will start with the throttle bodies sync !

 

I think in #2 he is talking about shaving the head to gain more compression

 

Raise the compression and install a big bore piston kit, run the stock header, stock air filter, and as long of a can as you can get away with without scraping it.

 

power commander is a $300 paperweight/***** extension unless you have access to a dyno and the time to tweak the maps. Race teams can spend sleepless nights fine tuning the maps and only get.....5 more HP? One of my buddies picked up a tweaked map off ebay for his 929, it came from a small race team, they had about 100 hours into tuning the maps and it gave his 929 6hp.... not bad for $12 on ebay.... but thats a lucky find.

Slotted cam gears is a cheap way to get more HP but again, you need some baseline values (degrees) to start from. My buddy did a few 900RR's, he talked to some people on CBR forums and got some values that were working very well.

 

he doesnt want horsepower cockgobbler he wants torque.

 

LOL! ok, with those mods you gain both..... you want just torque...put a 65T on the back and work it like stripper pole. its a 600, how much more could you possibly milk out of it without installing a turbo!

 

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i think virtually anybody that rides a bike has seen that kick *** video

 

Block up one of the air scopes to the air box

 

you see the one with the turbo busa? it guns it at 40 and gets to 220 in like 19 sec

 

No CNC operators who already experiment with different camshafts...

 

I Say have it tuned ! you Can tune it for any Situation you need

 

I know ,but I try to benefit from other people experiences...
R&D cost money ! and the outcome is not always as predictable as it seems

 

Cams will give you more top end, but less down low. You would have to go custom and big $ to make a cam to give you low end power (but would loose top end). I'd say just get a solid tune done on the bike

 

tim i am telling you: this will give you more headaches, hard work and almost zero outcome. instead of going through all that trouble, money and very importantly: time and the risk that your bike will be running like doodoo you'd be better off putting in some hard extra seat time!

 

i dont want to rain on your parade but i feel that no matter what you do the amount of money you will put in will not be worth the gains.

decking the head and rasing the compression will require custom tuning and lots of dyno time.

if you want more torque change the gearing or switch to a v-twin