De-tune race bike

[Ben.]

Class limit is 130bhp and I've got 145bhp from the motor.
Spoke to my local tuner and he said he can over fuel it to get to the power limit but it will make it jerky and horrible to ride.
Any other suggestions from the BCF lot? how can i de-tune the motor but still get a nice ride without flat spots etc.
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Road bike - sv650

[lihp]

Do you have different camshafts available to you?

[Barry_M2]

I'll be in rookie 1000's this year too Ben
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[robocog]

adjust the throttle stop whilst on the dyno?

If thats too temporary (could be adjusted on track and then reset) or cannot be lockwired/sealed- so you don't get accused of rule breaking...washers in the inlet ? (though a nice set of alloy gas flowed restrictors would possibly be better)

Can the timing be adjusted by an ECU or rev limited perhaps?..you dont have a lot of HP to loose ...just dyno it on a hot day with an un oiled chain I bet you wouldn't be far off

Regards
Rob
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[Wafer_Thin_Ham]

Why not just return bits to stock until you're inside the power limit, then fuel it properly.
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[G]

[MaybeGuy]

surely if he just overfuels it at the peak RPM it'll make it just fine to ride? What bike? FI? If it's carbs, ignore.
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[DrDonnyBrago]

How modified is it at the moment? Any stock parts you can switch back to?

[Mikey3]

[MarJay]

Rev limit seems like a good bet to me. Wonder if that can be set in the ECU?
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[Welshd1k]

restrict the airflow ? like a normal 'restrictor'?
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[Kickstart]

Hi

How standard is the bike?

From the figures you have given you need to lose 10% which is a fair amount from a bodge on fueling, or anything like that. You could possible knock a bit off by retarding the ignition a touch. Open the valve clearances up to the wide end of the range.

Not sure on the R1 system, but can the EXUP valve be mal adjusted to stop it opening fully.

All the best

Keith
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[G]

If it was FI, I'd definitely be looking to just limit the power at the top end, so you you've got more time at 130hp.
Unfortunately you don't have the flexibility you might have.

It may be worth working out a plan of action, then getting it set up on the dyno used in the series, presuming there is one present - that way you don't have to worry about other's over-reading etc.

[Ben.]

[Ben.]

[Ben.]

[Ben.]

[Kickstart]

Hi

Anything done to excess will cause issues.

However you could probably get back more than the cost of a stock engine by selling the tuned one (assuming it was done by someone competent).

Small bit of ignition retard might lose you 5% or so without any major issues. Stick on a stock exhaust to finish the job, and tweak the timing if the exhaust goes too far. Plus point is that you will probably gain a bit more mid range to help you recover when you make a mistake.

All the best

Keith
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[garth]

Or just change the head, no biggy.
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