[fungames43232]

I am asking this question to see you guys have seen the same thing as I have. I am only referring to fuel and spark not mods. I am by far not a professional tuner nor is my buddy. He just happens to have a mobile dyno to play with. I have had the pleasure of playing with a V-Max (carbs) and ZX6 (EFI) and my results were very similar with both. With the V-Max, I ran the A/F from 8 all the through to 14 and only saw a max of about +- 2 hp difference. I changed from the resistor boots to non-resistor boots and there was absolutely no difference in HP. Remember this is all top end HP. BTW I can rip out carbs on a V-Max, change the jets and replace in under 20 mins now LOL. I saw the same results with the ZX6, the power between A/F was not much at all. That said, when the A/F was right, both bikes were much more crisp and my butt dyno said different than what the mobile dyno said. So my question is, I see alot of threads with a 10 hp gains just from a tune is this normal? That said, I have also personally seen false gains from an un-named bike/tuner shop. How did that happen? I took my bike there (before I met my budding on a vmax forum) and they did a base run. We met another guy that had his 2 sheets from them (claimed 11hp gain) at a spring dyno day. The dyno on my bike was within 1 hp between the 2 dynos. His dynoed out within 2 hp of his baseline. No where near an 11 hp gain.

 

[nickalltogether]

All dynos read differently. You are not going to dyno the same on two different dynos. You should be aiming for a 13:1 operating air/fuel ratio but that is hard to get with the ram-air these bikes have. Good luck.

 

[tittermary]

I am asking this question to see you guys have seen the same thing as I have. I am only referring to fuel and spark not mods. I am by far not a professional tuner nor is my buddy. He just happens to have a mobile dyno to play with. I have had the pleasure of playing with a V-Max (carbs) and ZX6 (EFI) and my results were very similar with both. With the V-Max, I ran the A/F from 8 all the through to 14 and only saw a max of about +- 2 hp difference. I changed from the resistor boots to non-resistor boots and there was absolutely no difference in HP. Remember this is all top end HP. BTW I can rip out carbs on a V-Max, change the jets and replace in under 20 mins now LOL. I saw the same results with the ZX6, the power between A/F was not much at all. That said, when the A/F was right, both bikes were much more crisp and my butt dyno said different than what the mobile dyno said. So my question is, I see alot of threads with a 10 hp gains just from a tune is this normal? That said, I have also personally seen false gains from an un-named bike/tuner shop. How did that happen? I took my bike there (before I met my budding on a vmax forum) and they did a base run. We met another guy that had his 2 sheets from them (claimed 11hp gain) at a spring dyno day. The dyno on my bike was within 1 hp between the 2 dynos. His dynoed out within 2 hp of his baseline. No where near an 11 hp gain.

Yep you got it, the air fuel myth. at best you might see 2-3 hp difference from afr changes. Its all about the rideablity.

 

[nickalltogether]

^Most power is made in timing for sure.

 

[tittermary]

All dynos read differently. You are not going to dyno the same on two different dynos. You should be aiming for a 13:1 operating air/fuel ratio but that is hard to get with the ram-air these bikes have. Good luck.

13.1 is just a number, this to is different from dyno to dyno or better yet o2 senser to o2 senser and like op observed difference from 13.1 to 12.5 might only be 2-3 hp.

tune for max power NOT afr, this is why the pcv with autotune still needs to be done on dyno or datalogged.

 

[tittermary]

^Most power is made in timing for sure.

we agree

 

[nickalltogether]

13.1 is just a number, this to is different from dyno to dyno or better yet o2 senser to o2 senser and like op observed difference from 13.1 to 12.5 might only be 2-3 hp.

tune for max power NOT afr, this is why the pcv with autotune still needs to be done on dyno or datalogged.

I can agree with the max power part too. Some motors do like the richer AFR's. I am lucky enough to work at a (car) shop with an AWD dyno... I get to watch cars get dyno'd all day

 

[fungames43232]

That's what I thought too. I just see soooo many posts about gaining 10hp with a tune and I took it to extremes and didn't see but a few HP on 2 totally different types of bikes.

 

[fungames43232]

And yes I know all dyno's read differently but if 2 bikes give about the same reading on 2 different dyno's my guess is the dyno's are close.

 

[garth285]

I;'ve tuned quite a few bikes and I found that 12.8-13.1 air fuel is great for max power.... I tune bikes with a wideband 02 sensor data logger so i see what the bike actually does under actual loads..... some dynos do not give a good enough load on the motor to accuratly tune the air fuel as well....

usually at idle you run 12.8-13.2:1
cruising at small TP's you can run as lean as 14.5:1+
and wide open i tune to 12.8-13.1:1

 

[nickalltogether]

Do the bikes need to idle richer than normal motors? I know typically with cars we tune to 14.7 at idle (or so). I suppose with the radical cams these things have a richer idle is required.

 

[Patrick]

Do the bikes need to idle richer than normal motors? I know typically with cars we tune to 14.7 at idle (or so). I suppose with the radical cams these things have a richer idle is required.

Beat me to it. After seeing Garth's post I was gonna say....stoichmetric is 14.7:1.

 

[garth285]

from what ive been told personally from people to people tuners to tuners they like to idle them a lil rich... honestly I'm sure a lean idle is perfectly fine.

***EDIT*** I idle my bike at 13.5:1 btw

 

[tittermary]

I;'ve tuned quite a few bikes and I found that 12.8-13.1 air fuel is great for max power.... I tune bikes with a wideband 02 sensor data logger so i see what the bike actually does under actual loads..... some dynos do not give a good enough load on the motor to accuratly tune the air fuel as well....

usually at idle you run 12.8-13.2:1
cruising at small TP's you can run as lean as 14.5:1+
and wide open i tune to 12.8-13.1:1

and I agree that these are good basic in the ball park guidelines, I also agree that a good tune can't really be made without some data logging runs, dyno is just a starting point.

I do think there are some dyno's out that there (won't get into this battle but I will say dyno jet is not one of them) that do an ok job if you can't data log.

I will add one more point, I believe that in top speed runs a leaner then max power say 14.2-14.3 at the higher rpms in top gear (last 3-500 rpms) can give you more top end on some bikes.

 

[tittermary]

from what ive been told personally from people to people tuners to tuners they like to idle them a lil rich... honestly I'm sure a lean idle is perfectly fine.

***EDIT*** I idle my bike at 13.5:1 btw

I run 13 or so fwiw, I also like my small tps numbers a little rich since on a road course it makes the small throttle openings and throttle tip in smoother. I
have been trying out a load based fuel setup past few weeks and with out starting world war three I gotta tell you its's pretty damn impressive I bring this up because its a little harder to tune for stuff like this (small tps) but I really like it so far, I used to be a die hard alpha-n guy but not so sure anymore.