a question on gsxr camshafts in bandit 1200

[2005B12S]

back on subject, as far as GSXr cams go, if you are looking for performance---- do it.

The GSXr cams really wake up the B12 powerplant and open the powerband above 8000rpm without sacraficing too much lower midrange.

[smooth operator]

I picked up my cams,the 89 750 cams,from Ron Ayers.
 It cost me $300 for the pair. Part #,(w shipping)
 12711-06B90  Intake cam GSXR750J
 12721-17C90  Exhaust
   I installed mine over the winter,so I didn't have back to back comparo rides. But it sure wakes up the top end where befor I was hitting a wall,  it now revs on.
    Dan

[Bob Holland]

After reading another post on here, I realized that if you are running GSXR cams, and the stock Bandit ignition, you wan't get the full benefit of the cams. The rev limiter on my stock ignition, was around 9,200, according to my digital shift light. The tach was around 600 rpms high. For the GSXR cams, you need to turn around 10,500, actual rpms. I have heard that there is a way to disable the stock rev limiter by cutting a wire that goes to the ignition, but I don't remember which one.

[okbandit]

I put the 89 gsxr 750 intake cam in my 2001.  I would have to agree with the top end hit.  I did not notice any change to the negative anywhere.  I understand that the exhaust cam will hurt your midrange so I passed for now.  I rode mine the day before and the day after for comparison.  It isn't a rocket ship, but you can feel it pull to redline now when it used to slack off around 9k.  Butt dyno says maybe 5hp on top, torque the same.  $150 well spent.

[smooth operator]

After reading another post on here, I realized that if you are running GSXR cams, and the stock Bandit ignition, you wan't get the full benefit of the cams. The rev limiter on my stock ignition, was around 9,200, according to my digital shift light. The tach was around 600 rpms high. For the GSXR cams, you need to turn around 10,500, actual rpms. I have heard that there is a way to disable the stock rev limiter by cutting a wire that goes to the ignition, but I don't remember which one.

  If anyone knows the method in doing this, I'd like to do it with mine. Fast Larry or Dale might know, I could try there if know one here knows the details.  Dan

[okbandit]

I have only hit mine once, in first gear.  I was used to the motor laying down and it didnt.  For the street, I like mine just the way it is.  It pulls till I shift anyway, with no lazy spots.  Have heard something about the gsf 600 blackbox setting the rev higher but I haven't heard of anyone trying it.  I would think the ignition maps would be different.

[okbandit]

By the way, mine pulls to 10,500rpm on the dyno with stock ignition.

[Bob Holland]

By the way, mine pulls to 10,500rpm on the dyno with stock ignition.

After thinking about, It may have been 10,200 that I was hitting the rev-limiter instead of 9,200, that was about 5 years ago and my brain is getting old.
I do know that my 98 would not go to 10.5, I would hit the limiter before the shift light came on, set for 10,250
At 10,500, my engine is still making 154 RWHP, so I could probably go to 11,000.

[reconstyle85]

Ok, so sorry for being a newb, I'm tyring to learn as much as I can here, but I want to make sure I am understanding the point of swapping to gsxr cams.... I'm understanding that the lift is higher on the gsxr cam, allowing the valve to stay open longer which means that more fuel and air get in, causing a bigger expulsion in the cylinder therefore creating more power?

Hopefully I'm not WAY off on that.

But also, if you are going to swap cams, whats the good and bad about doing just the intake, as opposed to doing the intake and exhaust?


Thanks for your help!

[Red01]

By doing just the intake you'll raise horsepower and not sacrifice as big of a hit to the lower & midrange zones. Doing both will give you the most peak power, but you'll loose some of the bottom end responsiveness.

[okbandit]

You are very close on the cam guess.  The lift is about the same in this case, but the duration, or length of time the valve stays open is longer on the gsxr cams.  If you are mechanically inclined and patient you can pull this off in a few hours.www.billsbikesnservice.com/cam.htm  This will give you a tutorial on what is involved workwise.

[reconstyle85]

I used the parts search on ron ayers to cross reference the cams, I used the p/n for a 1989 gsxr750 intake cam, and it also cam up with cams of 88-93 gsxf1100's. So my question is, ARE the really the same? and has anyone ever put the katana cams in their bandit? Would I be ok doing this?

[stinkypalm]

I am looking at going down the cam path but am leaning towards an 88 GSXR750 intake cam and a GSXR1100 exhaust to not loose much mid range. Right of idle losses I can live with.

I also want to do a bit of head work and HI-comp pistons. No one seems to have them is stock bore anymore as I
1. Don't want to recouat the bores and
2. Intend to race it next year and need stock capacity.

I beleive the ones Dale had were  (11-1) and supplied by JE and wonder if they still have the specs for them but I want 11.5.

I am aiming for better than 155 RWHP and over 100 ftlbs torque.

Lastly a set of of the FCR 39 carbs.

Hopefully this will then become scary enough.

 

[okbandit]

The bandit bores are not coated like the modern gsxr bores.  Just a bore and hone and off you go.  You can get the compression from milling the heads with the stock pistons if you can't find them, but I am sure someone still has them.  Have you contacted JE directly?

[Bob Holland]

2. Intend to race it next year and need stock capacity.

What kind of racing.
For dragracing, there is no real substitute for size, but if you need to keep the same bore, try APE : http://www.aperaceparts.com/
They should be able to get any size piston that you want.
You will still have to hone the cylinders, as new rings do not seat well in old cyl bores.