GSXR750 or 1k maximum speed inhibited??

Hey guys. My GSXR750 will post an indicated 186mph no matter what the conditions. I do understand the "actual" speed is in the low/mid 170mph range with all sorts of indication error from the factory and my choice of gearing.

Anyhow, my question resides in wondering if this bike is indeed inhibited from the factory. The bike does have a TRE, wich i have heard will bypass the factory limiter on the 1300 and 1k, but still lies dead at 186mph.

The reason i wonder this is regardless of the wind in my face, to my rear, hot day, cold day.....the bike will post a indicated 186mph on the speed and just sit there with the rpm about 200 from redline.

I would believe it had to do with the motors ability to pull and aerodynamics etc.......but if that was the case i would expect it to not be so consistant. Going downhill with a tailwind i would expect....maybe 188mph or such for example.

So....those of you that have SB 750 motors and run at Daytona and the other big tracks, will your bike post speeds beyond the factory max with just motor work and a PC? Or do you need to use a different ECU or such.

I was wondering if a same model 1k ecu could be retrofit to function on the bike being those are said to have a solid 10mph over the 750.

Thanks for any input.

 

Europe

I think 186 mph is 300 kph. I don't know if it's true. But I've heard that the reason that none of the speedos read past 186 (300) is because at one point in Europe there was fear of legislation that would restrict bikes from exceeding 300 kph. So regardless of the true speed, they didn't want any of the bikes to be able to indicate more than that.

 

I understand all of that.

What im asking is......when people have their suberbike motors rebuilt........will they go over that max speed? If so what is done......just motor work or does it have to be computer work also.

 

gsxr750

I am sure the TRE should have taken care of your speed limiter
The alternative is to soldier a Diode between 5th an 6th gears in your gear position sensor on side of motor and fill with syllicon, I will let you know if you want what ohlms just cannot remember now, this confuses the ECU to think it is in 5th and lets it rev on!
I have an K4 810cc Yoshi cams Head other block and crank work with Yoshi ECU it makes 152HP on Dynojet250 I use here as my messuring tool for mods.

 

I would of thought the TRE would of elliminated any speed inhibitor also. The bike does think its in 5th gear, i made the TRE myself.

It just really makes me wonder why the bike will run up to the indicated 186 no matter what the condition.......and no more as if the ECU has something to do with it.

My bike makes 120 hp........lets say i put in a bigger piston kit, head work all that mojo.......say 150hp with race gas now.......would it still only run up to 186?

I know there were bikes in the superstock class at Daytona that were going faster than the claimed max speeds by the bike companies. Computer manipulation? Motor work???

 

gsxr750

Must B ECU related! I never ran my std one, as long as you are no bank robber I could send you my one to try?
Does the motor feel to be running sweet @ that 186?

 

if you really need to know...

install an independant 'bicycle computer' to get accurate speed and do your runs.

 

io- do you have some sort of aftermarket ECU? Yea the bike is still running strong at that speed a few 100 rpm from red.


A bicycle computer will do me no good. I really care less of the speedo being wrong, i could care less of what it reads........mearly that the hightest it will read is 186.

Unless the bike will truely go faster but the digits don't show it.

 

Don't forget that your speedo reads off the sprocket so you could have Salt Flat gearing and be doing mach 1 and it would still read 186 mph at that RPM. Conversely you could have a stunter, stump puller, 130 tooth rear gear that tops out at 10 mph and when at redline your speedo will read 186.

The sensor picks up output shaft rotations and calculates that into a MPH based upon gear position and stock gearing. If you were to (and I don't recommend this) put your bike on a rear stand and take off the rear wheel and the chain (leave the front sprocket as it has the pickup on it) and spin the engine up to readline in 6th gear you're speedo will read 186 mph even though the bike isn't moving..

Borrow a GPS (Like a Garmin III+) with a max speed indicator.

PS there's a reason most instructors and track days and race orgs say to tape over or disconnect your speedo.

 

speedo....what is that? and I have my tach that can only see revs between 3.5-9K If I don't see the needle I'm not getting good performance out of my bike.

 

speed fallacy

The point I was trying to make is that I don't think you should assume that your speedo reading has much to do with your speed. Speedos are designed by marketting, styling, and legal departments, they're not an engineering tool. From what I understand, you won't read 188 mph if you dragged the bike behind an top fule dragster. The speedo is going to clip the signal to read 186 mph. The speedo reads the speed signal and displays it, it doesn't feedback to the ECU. So all the debate about what the bike will "run" up to with whatever gearing or mods shouldn't have anything to do with the bike's speed, but the speedo won't read past 186 mph.

 

Okay so let me get this straight.....you guys are saying the speedo can't physically read over 186mph.....??

I have stated that i do understand the speedo sensor runs off the drive sprocket, and also that with my gearing ratio im running that the speedo is "indicated" speed not actual by any means.

If i get this right......you guys are saying that on some days my bike may be going 177mph......other days 175mph......others 173mph.......but because of the speedo error that i have created......the digital gizmo is buzzing all the way up to 186mph.....and that is the highest it can go. So until my "actual" speed drops to something for instance....171 the "indicated" won't drop to 184mph etc.

 

as far as I know

I'm thinking that that's exactly how mine works, and I'm betting yours is the same.

 

ECU

Yes mate, I use a yoshi ECU

 

Okay, so with that Yoshi ECU...your bike will "indicate" higher than 186mph?

What benefit does the Yoshi ECU have? I run a Yoshi EMS on the bike already.

 

ecu

ECU Benifits- different tourqe map for diff gears, diff adv and retard on ign map- more RPM

Cannot awnser about speedo reading as I only use RPM

 

Those are all things the Yoshi EMS with the extra hub can also do.

 

Why do you use ems and not ECU as well

 

I would use a yoshi ems but i don't have one

 

Do or do not have

I am a bit confused now? do you or do you not have Yoshi EMS?