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Discussion Starter #1
I'm making (and have made) several critical modifications to my MV Agusta F3 675 since coming on board with Design Corse in order to maximize its performance for racing. I figured I'd start a tread to go through each modification I'm making to the bike (within the rules of what is permitted in the middle weight class for racing out here in California).

The first change is the exhaust. While this is not what I recommend spending your money on first when it comes to mods, it just happens to be one of the most exciting and aesthetic changes to the bike, so I thought I'd start with it.

The stock exhaust, while not bad looking, is very heavy, and gets very hot with the back can sitting right under the bike. This is why the stock bodywork is metal - anything else would melt. Indeed, my racing bodywork did melt!

The HP Corse "racing only" can from Design Corse is less than half the weight of the stock one (just the slip on for now - I'll move to a full system when the rule change here happens - right now it's not allowed). While some might bemoan the change from the tripple pipe look, I was more interested in weight and heat reduction and a performance increase. I have not had a chance to get it onto a dyno to see if there has been a horsepower increase, BUT power delivery is certainly smoother - there is less of that jerk/delay that is often attributed to the ride-by-wire of the F3. It's very subtle of course.

The sound (while it has nothing to do with performance, to me the aesthetics of being on a bike like the F3 vs say a Ninja is part of why I race this) change is amazing. The attributes of the 3 cylinder engine have roared to life in a deep throaty rumble (as opposed to marbles in a can).

One interesting note is that the link that holds the exhaust to the frame as to be loosened to get the rear wheel off, but it's no big deal.

This is for racing only - it does not fit on the bike with stock bodywork, but they have other fantastic options to use on a street bike.

http://www.designcorse.com/shop/mv-agusta-parts/mv-agusta-f3-parts/mv-agusta-f3-exhaust-systems



 

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Discussion Starter #2
I've been messing with the gearing of the bike too. Where I'm racing it I find that I do a lot of short shifting down to 2nd coming out of corners and then a short shift into 4th before heaving breaking. I wanted a little more low end so I could sit in 3rd through the entire corner and also be in 4th longer on the straights. The track is a flowing corner speed track where 600 cc are generally faster than 1000cc bikes.

Std gearing is F16T and R43T. The first move was to change to a 520 chain, and I'm using the Tallon sprockets from designcorse.com

This last time out I went to a F15T and R41T. The change was dramatic and to say the least, awesome. More low end like a twin, but more manageable. I spent much less time shifting, and could carry almost as much drive out the corners in 3rd as I was before in 2nd. I'm going to change the back to a 40T to see how that feels my next time out.




 

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Looks great! Good luck!!
 

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Discussion Starter #6
Lol... just thought it was time for a new thread on specifically what I'm doing to the bike
 

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From 15/43 to 16/41 as a change of final gearing of about 1.7%
I seriously doubt a professional racer could tell much of a difference with that minute of a change, never mind a amateur novice racer. I think you got your ratios wrong, mate.
 

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Discussion Starter #8
From 15/43 to 16/41 as a change of final gearing of about 1.7%
I seriously doubt a professional racer could tell much of a difference with that minute of a change, never mind a amateur novice racer. I think you got your ratios wrong, mate.
16/43 to 15/41

and I'm going to change that to 15/40
 

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Dropping a tooth in the front alone would make a noticeable change in power delivery for same gears, but dropping 2in the rear as well nearly makes very little net change as crash2much has stated. It would probably add 300rpm or so to the gear which may be what you need to ride out 3rd through the turn.

Dropping to 15/40 will set you nearly near dead equal to 16/43. I think of it as 1000rpm a front tooth and roughly 300rpm per rear tooth. Ifnyoubwant more bottom you'll want 15/42. Just watch you don't sacrifice speed in the stretches. Guess that's the transition into custom gear boxes.

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It's not just gearing "ratios". A smaller rear sprocket increases chain-pull angle which helps pull the bike out of it's mid-corner sleep. There are also wheelbase and swingarm length changes with different sprockets too due to the chain length.
Look further than the end of your noses people! ;)


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It's not just gearing "ratios". A smaller rear sprocket increases chain-pull angle which helps pull the bike out of it's mid-corner sleep. There are also wheelbase and swingarm length changes with different sprockets too due to the chain length.
Look further than the end of your noses people! ;)


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Hi Rob, good to see you still pop in every now and again mate.
Truth in what you're saying, and adjusting that hub for longer or shorter wheelbase too, quite a bit happens on the back of the MV when you touch that swing-arm and sprocket set-up.
 

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Discussion Starter #14 (Edited)
Dropping a tooth in the front alone would make a noticeable change in power delivery for same gears, but dropping 2in the rear as well nearly makes very little net change as crash2much has stated. It would probably add 300rpm or so to the gear which may be what you need to ride out 3rd through the turn.

Dropping to 15/40 will set you nearly near dead equal to 16/43. I think of it as 1000rpm a front tooth and roughly 300rpm per rear tooth. Ifnyoubwant more bottom you'll want 15/42. Just watch you don't sacrifice speed in the stretches. Guess that's the transition into custom gear boxes.

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My bad - going to 15-42 from 15-41, and NOT to 15-40... that was me typing on rum n coke ;-)

I will of course loose top end speed, but on the tracks where I'm racing you never get there anyway. In fact I never even get into 5th let alone 6th ;-)

The reduction of rear sprocket size is of course also something to consider with regards mid corner torque/drive, though going up to a 42 will reduce that effect in return for more pure low end torque.

it's all playing with it to see what works well for where I'm racing the bike

Corran
 

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Discussion Starter #16 (Edited)
New Fork Internals

I forgot to post this modification that's done to the bike as well - putting in F.G internals into the stock fork. The rules do not allow for the whole fork to be changed, only internals, which is why I went in this direction.

http://www.designcorse.com/shop/mv-agusta-parts/mv-agusta-f3-parts/mv-agusta-f3-suspension/f-g-racing-fork-cartridges-detail

The reason I chose these was the range of adjustment is massive - 48 clicks on rebound and 42 on compression - as well as the cost to benefit ratio. I'd also heard good things about them from a few people in Europe, so I took the plunge.

Putting them in was an all morning affair, but it went well (and the kitchen survived). Now I'm dialing them in - they feel very different to the stock forks and are much more sensitive in getting them just right. Having less on hand information than with Ohlins, it's all been trial and error, but I'm starting to get them dialed in. It's hard to put my thumb exactly on what I like about them however... to articulate the improvement over the stock forks, but other than feeling quite different, I really like them - better overall front end feel.

Here are some photos of the process of installing them, and thanks once more to Design Corse for helping me out here!

PS - Duscati showed up on Ortega the other day with a trailer of bikes, and everyone was huddled around two bikes - the 1199 Superlegere... and my F3 ;-)










 

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Discussion Starter #17
So... my next thing was the tank... I have a tank protector on the tank, but... well... the fit isn't perfect... there is always a little movement. So I decided to just carbon cover the entire tank. I make paddleboards for a living so I have access to everything that's needed.

First I sanded the entire tank down to the bare material, filled in some of the useless recesses made for stock fairings, and then covered it in carbon with extra reinforcing in critical impact areas.

The final tank looks amazing.






 

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Discussion Starter #18
It's like Christmas when you get home and this is at the door!



With a full Termi exhaust, race filter... and more....
 
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