Suzuki GSX-R Motorcycle Forums Gixxer.com banner

1 - 12 of 12 Posts

Registered
Joined
43 Posts
Discussion Starter #1
planing to send my oem cams to reprofile them 401'' in / 346''ex at 260in / 257ex duration. the engineer told me that it will be ready and i will just put them in. 馃
My question is if i need adjustable cam sprockets or the power curve will be ok ?馃
running already 13:8 pistons and ported head.
anyone got the answer??
 

Premium Member
Joined
4,596 Posts
what does the machine shop say? I'd sure wanna dial em myself, you'll have to ask the shop if the phase changed at all.. prolly gonna need the wheels..
 

Likes to race old junk.
Joined
2,222 Posts
Adjustable cam sprockets aren't very expensive...you're already going to be right there at that point, working on it.
Degree the cams and then you'll know what you actually have, and be able to adjust accordingly.

I'd also want to know the piston to valve clearance, if you're adding hotter cams to the high compression pistons...or just take the word of the machine shop?
 

Registered
Joined
43 Posts
Discussion Starter #5
i mean he is gonna build on the oem camshaft and then machine it down to the specs i mentioned earlier. so lets say the oem cams are like 105/99?? but those yoshi reprofile working in 105/110.. 馃
is it possible to make them work without touch the sprockets and without adj cam sprockets?? and what is going to be the result??
 

Registered
Joined
43 Posts
Discussion Starter #7
What you mean twisted?? Not much of change about the degrees?? Or waste of money doing it without adjustable cam sprockets??馃
 

Premium Member
Joined
4,596 Posts
has the lift and or duration changed or just the phasing? degree, if they say they are bolt up they prolly are bolt up, specially if you talked to yosh reps, your choice really, if you want to insure they are dead nut for your timing then why not? are you going to map the ignition timing as well? if so get the wheels, you can dial it in sweeter with wheels..

exactly what is your end goal?
 

Registered
Joined
43 Posts
Discussion Starter #9
Said he's gonna change both lift and duration. But staying on the oem cam sprockets.
My goal is to make a smooth power curve all the way up to 13.5rpm because now with my compression maximum power stays stable form 11.5rpm to the end 馃馃 so I need to get bigger cams. Reprofile as i mentioned or aftermarket with adjustable cam sprockets
 

Premium Member
Joined
4,596 Posts
someone told you more lift and duration equals a smoother power curve? hmm.... to smooth all that out you are definitely need a dial..

and to smooth it all out you will need ignition and fuel mapping, exhaust tuning, cam degreeing, air box flow, it's all synergistic..

not sure why folks don't understand Suzuki spends fortunes in tuning these bikes, all sorts of R&D time and money..

these are highly tuned sportbikes, highly tuned.. right down to the exhaust valves you name it.. you can design an engine to deliver peak HP at various stages in the RPM's, delivery curves so forth, where your bike delivers now is where it's designed and tuned, there is a lot involved from tuning the engine cases to cam profiles, crank profiles, mapping, bore x stroke, exhaust so on so forth..

you can ask any owner of 1ks which generation had the most low end mid grunt thus far and they'll go all the way back to the gen 3, 05/06 1k... ask any racer.. that motor delivered the smoothest most powerful low end mid grunt ever, and didn't lack up top.. very strange why Suzuki changed that dynamic on 07 and is yet to replace it? pressure form the DOT? fact is they use that motor in a restricted state on their non faired 1ks they began producing? so they know that engine had something.. in many people's minds it was the pinnacle of Suzuki's engineering to date, many here know this...

maybe their philosophy was an I4 engine cannot live on low end/mid superiority alone? you'll have Vtwin's that get larger intakes by rules because they complain they cannot compete with the inlines even tho they naturally have that low end grunt but through rulings have more top end HP, so Suzuki in order to keep up on the straights must deliver more on top, so they take it from the low end and leave it to gearing and rider skill to get off that apex as quick as a Vtwin, or so Suzuki plans.. or maybe its a rabbit hole they don't want to go down, constantly having to compete with changing rules that favor italian Vtwins made in nations who's owners of the series reside and were born?

these bikes are modeled off race bikes all the way as the rules say they must use stock production engines, all but modoGP and a few other off series..

seems today the focus is more on SBK since AMA is all but gone? or who knows what their chasing today? MGP? they sure aren't winning anything but in the motoAmerica series.. riders like Matt and Ben won on whatever they put under em, after that 15 year reign they sat back, left it alone.. oddly it all ended immediately after the end of the 05/06 gens? another oddity is Suzuki got their only SBK title in 2005? Corser.. then it seemed as if Suzuki just pulled away from racing development altogether, lest in the 1k series?

seems to me all you needed to smooth out what you already had was just a matter of fine tuning what was already there? degreeing cams, timing, fuel mapping, so forth, fine tune..

you're adding and moving things around here, depending how you degree in the cams and tune will decide where that power will hit hardest, in essence you're not just looking down into the rabbit hole any longer you've breached the precipice of said rabbit hole, you are now free falling.... :)

fortify that ATM.....

you might find that to take advantage of the added lift and duration, opening the valves further for a longer period of time you may need to port the head to handle added air/fuel or it might just stumble on itself? certainly want an exhaust that can handle the added output..

then mapping, may need larger injectors? more holes, more juice, certainly you'll want to up the A/F CFM's to take advantage of the added L&D? no? otherwise your simply sending the same amount of fuel through what's essentially more lift and duration? a tad more compression? or is L&D how they plan to smooth it out? time will tell...

keep us in the loop please, pics?
 

Registered
Joined
508 Posts
you can ask any owner of 1ks which generation had the most low end mid grunt thus far and they'll go all the way back to the gen 3, 05/06 1k... ask any racer.. that motor delivered the smoothest most powerful low end mid grunt ever, and did lack up top.. very strange why Suzuki changed that dynamic on 07 and is yet to replace it? pressure form the DOT? fact is they use that motor in a restricted state on their non faired 1ks they began producing? so they know that engine had something.. in many people's minds it was the pinnacle of Suzuki's engineering to date, many here know this...
Not only that, but it was the 'model or template' for the king of sportbikes, the BMW s1000rr!

Did you know this? Published many times in different articles.

Here's one:

576211
 

Premium Member
Joined
4,596 Posts
did not know that, I had a yellow black and it was a monster indeed, loved that bike sure like to have another.. the hemi gixxer for sure...
 
1 - 12 of 12 Posts
Top