GSXR1100 Cams in turbo bandit - anyone have dyno graphs?

[rerb]

Last dyno at 19 psi I made 238 hp and 165 ft-lbs. This is with .75 deg of timing pulled per psi and about 10.5-11 afr (playing it safe with watermeth). I peaked power at around 7k rpms and tq around 6k rpms, hp fell off by about 15 to the 10k rpm rev limit. Just curious what the shape of the graph would be with a set of 1100 cams as I have very long gearing and shortly past shifting into 3rd I'm out of peak power range when doing pulls. I'm happy with the peak power as it stock swingarm and I'd like to get some beefier rods in there before shooting for 300 (although I did boost creep to 270hp before the clutch started slipping on the dyno last season)

Side note, I got the rolling anti-lag to work. Nearly flipped myself right over letting go of the button in 2nd at 6500 rpms haha. builds 6-8 PSI depending on how long I sit on it, huge help with rolls. Only took about 20 minutes to wire up to the horn button. 

[Arttu]

I have never done back to back comparison where only the cams were changed. But I have tuned various oil cooled turbo build, with Bandit cams, GSX-R cams and aftermarket cams. By this far I haven't seen any clear connection between the cams and power curve shapes, or power numbers. Which is slightly odd since the cams should make difference and I have seen that also in real life with some other engines. I guess that other variables in these oil cooled builds just have been more significant.

A couple of examples:

Bone stock B12 engine, never opened as far as I know. Mitsu TD05 turbo, E85 fuel, 0.9bar boost.

 

GSX-R1100, 1216cc turbo pistons, ported head etc. Some other Mitsu TD05 variant, pump gasoline, approx 1.0 and 1.2 bar boost.

 

Funnily that stock B12 engine has been hard to beat in boost / power ratio I guess the main reason is higher compression ratio and better combustion chamber shape compared to other builds.

Any way, if you now get around 240hp at 19psi I think the cams aren't the first thing on the improvements list.

[rerb]

Wow, glad to know. Whats limiting me is probably the afr which is fairly rich, but my power tapers off far sooner than the other charts of stock cams show. Next season I'll spice up the tune a little and maybe turn down the meth and see what that nets me. I had some issues with the APE head nuts coming loosing causing the head gasket to shimmy around a little, I'll probably pop the head off and inspect too. I have busa pistons but also shaved the cylinder a mm for extra compression so it's still fairly high.

[Gixer1460]

Whilst running water / methanol can be adventageous, I'd be wary about its use 'carte blanche'. Its historic use was to suppress detonation through over boost or excessive CR - if you aren't ticking those boxes, save it for later IMO! A gasket shouldn't 'shimmy around' - the dowels should restrain it in position but loose head nuts is not good - never had or seen nuts loosen when correctly torqued / over torqued!

[rerb]

18 minutes ago, Gixer1460 said:

Whilst running water / methanol can be adventageous, I'd be wary about its use 'carte blanche'. Its historic use was to suppress detonation through over boost or excessive CR - if you aren't ticking those boxes, save it for later IMO! A gasket shouldn't 'shimmy around' - the dowels should restrain it in position but loose head nuts is not good - never had or seen nuts loosen when correctly torqued / over torqued!

Install error (i think?)- not sure how but last szn after taking off the head, i noticed 3 of the middle nuts were stripped off the studs. They were torqued to 50 ft lbs (and triple checked) when I put it together. They 100% were not stripped when I put it together (I even have an old video of checking torque right before throwing the valve cover on) I think I had the wrong length studs installed? I got a new set and made sure that they were in the correct orientation. rechecked torque at 55 ft lbs after letting it sit for a night. There were some scratches on the top of the jugs under the HG where the nuts were stripped, I assumed those were from the hg. I think I might have used those copper washers which I heard can lose tension overtime, who makes a good alternative?

 

Main reason for the meth is i was about 200 deg intake temps on boost which was a little hot for my liking. With meth I sit around 160

[TLRS]

Any overlap in valve timing? Afaik normal for n/a application but less suitable for boost, at least I think I read it somewhere?!

I also thought it was good to have cams that work early and spool turbo early. Then tune the rest of the graph with boost?

[TLRS]

Provided the charge can be kelpt cool enough obvs..

[Arttu]

11 hours ago, rerb said:

Wow, glad to know. Whats limiting me is probably the afr which is fairly rich, but my power tapers off far sooner than the other charts of stock cams show. Next season I'll spice up the tune a little and maybe turn down the meth and see what that nets me. I had some issues with the APE head nuts coming loosing causing the head gasket to shimmy around a little, I'll probably pop the head off and inspect too. I have busa pistons but also shaved the cylinder a mm for extra compression so it's still fairly high.

Under 11 AFR numbers start to be at the region where you may get rich misfires. And since misfires cause false lean reading on lambda you might be even richer in reality. So yes, tuning it a bit leaner would be also my first suggestion. Also too high water/methanol injection rate can cause misfires or just power drop in less severe case.

[Arttu]

9 hours ago, TLRS said:

Any overlap in valve timing? Afaik normal for n/a application but less suitable for boost, at least I think I read it somewhere?!

I also thought it was good to have cams that work early and spool turbo early. Then tune the rest of the graph with boost?

Pretty much all bike cams have some overlap. Effect of overlap on boosted engines depends a lot on setup. If the turbo is sized properly so that exhaust pressure doesn't get much higher the overlap works pretty much like on N/A engine. So some overlap is beneficial. Low / no overlap can be good if exhaust pressure is high like on many stock(ish) turbo cars.