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So just out of curiosity, what kind of things can be done to an engine and keep it super sport legal? I know obviously the powercommander, exhaust, and stuff like that, but I was wondering if there are other things (more technical) that people are doing? I remember in a thread about MS93.1 vs C12...SG meantioned that he blew two SS motors because of the 93...figured he must have done something to the motor that raised the compression or something in order for that to happen?
I'm not super mechanically inclined, but i get by.... just wondering if there are some internal "tricks" or anything.
Note: this is just out of curiosity and maybe the making of a winter project, not something i'm looking to do before the last race haha
I am pretty sure things like a thinner head gasket are legal to bump the compression a little over stock. I am not sure on the machineing of the head and cylinder mating surfaces though.
Doesn't the CCS rule book clearly define what isn't legal leaving all other things open to interpretation? Kinda like NASCAR crew chiefs playing in the gray area?
Joel
head gaskets were the first thing that came to my mind, but thats why i was asking about legal mods....i'm not sure. i'll have to look.
Do you NEED a base gasket?
Looking at the rules... machining the gasket surface of the head IS allowed, so there's a start. Other than that, thinner gaskets, and then I think you're into big bucks, blueprinting.
Or you could race a twin produced before 1994 and go nuts.![]()
SS... its all laid out in the rule book... but generally a supersport engine build means, milling the head or case or BOTH to increase compression. A combo of some milling and a kit head gasket can get you to the compression your engine builder is looking for.
Also, a valve job to ensure the valves are sealing tight, and cam timing. Beyond that a general rebuild, new rings, bearings etc. depending on what condition your engine is in.
There are good reputable engine guys who are at LRRS events every weekend. They are Pat Doyle at New England Performance ( located in the Dunlop Garage vending parts during LRRS events, shop in Plaistow, NH) and Sean Sweeney from Sweeney Racing Engines (shop in Lynn, MA).
Both are good at what they do. Depends how handy you are .... some or all of the build can be done by the owner... but alot of it is expirence and assembly of all the pieces to make a good supersport motor.
Me? I pull 'em out, drop em off to get done and put em back in.
isnt going 1mm overbore legal?
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The rules specifically mention up to 1mm overbore, but the pistons must be the same compression ratio as stock.
Based on my read of the rules, I dunno as you're allowed to mill the cases, or either side of the cylinder, looks like you can ONLY mill the head to bump compression.
Compression Ratio HP Determination
That'll show you what compression changes due to HP, assuming you only change compression. (Gotta check to see if it properly addresses lower returns around the 12:1 mark...) I generally estimate 2% per 1 point of compression gained.
1mm overbore is allowed in CCS but is rarely done because the cases are chrome plated. So you would have to bore the cases, then send them out to get replated and that is big money to gain 1mm in size per piston. I havent heard of many CCS racers doing the overbore once the bikes went to plated cylinders.
I am guessing 10%-15% increase. A quality engine builder will have a setup to help the bike be better at certain tracks. For example, the cam timing will be set to make better mid range power than overall HP for a smaller track like NHIS.
In the past with New England Performace, we have change the cam timing in my GSXR600 for Daytona for the best top end HP, then after Daytona, re-did the cam timing to make the bike stronger for the LRRS season.
With the Spec Fuel, a strong stock motor and proper tuning is pretty much the setup at Loudon. When you get a season or two on a motor, then a rebuild/supersport build is the way to go.
In 05, I ran my ZX6R "636" all year with out touching it... completely stock engine, just mapping for the race fuel and go.
At the expert level, "most" guys have their bikes built, but as an Novice/Amatuer there is no real benefit of spending money on the engine when there is so much time to be found just in the riding.
See THIS is the conversation I was looking for, thanks Scott. This answered a lot of questions I had. I know I still have a lot of time to be found in my riding, but I have noticed that I'm getting out motored a lot in the expert class and I pretty much assumed that there must be a reason for it. I had heard people talk about having SS built motors, but had no idea what that meant.
My bike has like 13k miles on it, about 3k on the track and I've never touched it other than changing oil and stuff like that. This winter I want to have someone look at it and tune it up for me I think. I'll probably run this bike for another season then look into getting another one...not sure yet.
Whats the price range on having New England Performance go over the engine? either a tune or a SS build....
Ryan, does your bike have a Power Commander? If so have you had it mapped properly for the race fuel ?
If not, you should see a improvement right there... just bring your bike over to Rob @ Robs Dyno Service and he can map the bike this weekend for you.
If you do have it mapped, then I would suggest giving Pat @ NEP a call 603-642-6977 or stop over at the Dunlop Garage and ask for him.
I haven't put a powercommander in it yet, thats something I was planning to do this winter as well.
As far as the tuning goes...right now i'm more interested in having someone go through the engine and tune it up and make sure it isn't going to blow up on me anytime soon...not necessarily a SS build
as far as my original question, it was more curiosity and information to use down the road
lighten up some rotating mass. like a total loss system by removing the fly wheel or just lighten the flywheel. shave some weight, get you air and fuel on the same page and a valve job never hurts. and if youre doing a valve job then some adjustable cam sprockets are a good idea too.
When I start my KTM in the morning, rules are broken. Its inevitable...
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Running a worn out oil pump and 0 weight oil is a common trick. Less oil pressure equals less friction.
Ryan, getting outmotored can be a really deceptive thing. one or two MPH more mid corner speed and a killer drive can make a bike seem to have 15 HP more than the one next to it. The differences in technique are subtle at the top level, but the yeilds are significant.
paul....yea i know it, and the fact i'm still running a stock rear shock has a lot to do with my lack of drive also (always scared to lite up the rear). So maybe saying i was getting out motored was a bit extreme, but I knew there was a lot that could be done to the engine and still be legal.
thanks for the info, got a lot to think about for this winter (first thing is to buy a rear shock however haha)