Speed Limiter

If anyone out there knows how to get rid of the speed limiter from an '04 R1 please advise. Mine hits 299 kmh on the track and some sort of (electronic) limiter cuts in and stops it going any quicker. I'm sure the same existed on my '03 but it only hit it occasionally. The '04 hits it all the time and is slowing it down.

Thanks:dunno

I imagine one way to cure that problem, would to get the race kit ECU, but that would be expensive.

Schnitz Racing a delimiter for the Hayabusa, which tricks the ECU into thinking the bike is 5th gear, but this is all the time and I have heard it may cause overfueling problems down low. Give the performance companies time and I'm sure they'll rise to the problem.

My curiousity, is if the ECU by chance, takes its info off of the digital read out on the instruement cluster, if you could maybe disconnect that side of it. As I have seen race bikes before with original instruements, but only the tacho working....food for thought.

Cheers Warp.

It may be something that applies only to your market.....

My all stock 2004 R1 goes to 14,500 (on the tach) in 6th on the dyno
(no limiter -189 mph)


Ivan

Thanks to everyone for their input. From what I have learned some markets do restrict their bikes to 299kmh/186mph. It is in the speedo as you can lean the bike over slightly and the revs increase (reduced tire diameter) but the speed won't.
I have ordered a Yellow Box speedo recalibrator for it. That way I can set, for example, the speedo to read 5% lower so I won't hit the limiter and the speed will be higher.
I only have an '03 wiring diagram and that suggests that the speed sensor sends it's signal to the ECU which then sends a signal to the speedo. I had considered disconnecting the feed wire to the speedo as I'm really not that worried about the speed reading... just making sure the bike goes as quick as it can as it's only used on the track.

If anyone has done this successfully please let me know.

People I have talked to about this so far don't know if it would affect anything else. I can't see why it should but who knows???

Ivan said he gets 14,500 in top... that's quick! I hit 299 on the speedo just over 13,000.

Without a speed sensor input to the ECM, there will be no extra fuel for ram-air compensation.....


Ivan

Hi Ivan

My thoughts were that the speed sensor sent a signal to the ECU, which was used for the fuel injection and ignition, and the signal was then sent on to the speedo and, at 299 kmh (in my case) the signal is returned to the ECU saying that's the limit - no faster so cut whatever it cuts out.

It sound slike you know better and if I disconnect the speedo I risk significantly affecting fueling etc. Correct?

If this is the case then the Yellow Box really is the only soultion so I can recalibrate the speedo back a few % so I don't hit the limiter. That won't have any significant affect on the ECU's function.

My only other option is a race ECU and wiring loom at some astronomical price.

If you know this is the case then this makes my choice simple... no choice but to install a Yellow Box. Please advise... and thanks!

Murray

Before you spend any money... see what rpm it will pull on a dyno in 6th gear.

If it is the same as the rest of the gears, then you don't have a limiter either, and your bike is just running out of hp.

Ivan

Ivan, you say that the speed input is needed to adjust the fuel mixture for the ram air effect at higher speeds. Are you sure about this? Surely this effect is purely accountd for by the inlet pressure sensor to add fuel at higher pressures? (ie if what you suggested is correct then having a 30 mph tail wind will give a Rich mixture!)
As you do alot of research into this EFI subject could you do a post on the '04 R1 ECU, what standard maps it has and how these maps are triggered to control the FI and Ignition timing. ie how many basic maps are there and how they are trigger and what additional inputs then do to these maps. Thanks, im sure there are lots of riders out there who would be enlightened by this!

Ivan, you say that the speed input is needed to adjust the fuel mixture for the ram air effect at higher speeds.

Are you sure about this?

Surely this effect is purely accountd for by the inlet pressure sensor to add fuel at higher pressures?


(1) Yes, thats the way all motorcycle ram-air is compensated for.
Besides, the service manual says this.

(2) I am absolutley positive.

(3) The IAP sensor (MAP sensor) has it's effect only at throttle openings less than 10%.
It is impossible for ram air to be compensated for by this sensor.

Whoever told you this does not know how these systems work.

If you need an education on motorcycle EFI, read some of the Suzuki service manuals and Kawasaki service manuals
(ZX-12 & Hayabusa) they have a great detail of info.

Ivan