Full Exhaust System Question

[The_HighwayMan]

I know there are several posts about exhausts and performance issue so I'll keep it simple. I'm looking at purchasing a full Yoshi system this winter for my '12 Hayabusa. The question is do I need an AutoTuner along with a Power Commander. I won't be installing it myself I'm just trying to find out what the consensus is. I ride with a guy that recently purchased a '14 Busa with a full Yoshi and his bike is back firing like crazy. I really don't understand what either do enough to make a decision on it myself.

[1busa]

You don't need an auto tuner. For the price of that auto tuner take it to an "Actual" tuner who can throw it on the dyno and do it the right way

[twotonevert]

Agreed, reflash the ecu and dont worry about an add on.

[OHHSHH]

The reason your buddy's bike is backfiring is because of the Pair valve. Do a quick search on the boards on what its function is and how to remove and or disable it. His backfiring will go away. Its a very simple mod to boot.

[The_HighwayMan]

Thanks for the replies. The only reason against a dyno tune is that I've been informed that the dyno tune is only good for that day on the dyno. So if conditions change then that tune is out the window. I'm parroting what a mechanic has told my buddy. I'm going to look into the Pair valve too.

[Lycan6]

There's nothing wrong with getting the PCV and auto tune especially if you live someplace where you have extremes in weather conditions during the seasons and you ride year round or if you move or add extras later. If you have someone to set your target afr for you then all you have to do is ride and and accept the changes it makes when you want to. There's no need for a new dyno. I would still have to ECM flashed to remove the factory restrictions but auto tune is fine.

[Don Hardcastle]

Thanks for the replies. The only reason against a dyno tune is that I've been informed that the dyno tune is only good for that day on the dyno. So if conditions change then that tune is out the window. I'm parroting what a mechanic has told my buddy. I'm going to look into the Pair valve too.

The dyno tune is "perfect" for that day provided your tuner knows what he is doing. The variances in temperature, humidity and altitude are typically insignificant and your ecu will deal with the changes.

[1busa]

^^^ Exactly


A bike properly dyno tuned correctly will run better than an Power commander "auto tune" any day of the week you still have to put in an initial map/ tune and the auto tune is supposed to make small adjustments along the way. It's not gonna radically adjust your afr to compensate riding in 100 degrees to 20 below in the drop of a hat. Not to mention those O2 sensors are fickle..... they don't last forever and burn out from time to time and that will throw your tune off as well.

[fallenarch]

This thread is going in a funny direction! First your mechanic who said a dyno tune is good only for the day the bike was dyno tuned should not be touching your bike! So when you have a bike dyno tuned, the map created is perfect for the elevation, humidity, temp, etc. of the place it was tuned. But the ECU can make small adjustments to the mapping given these conditions, so this is a non-issue unless you make radical changes to where you run the bike. The main thing would be altitude though, as it is unlikely that normal weather conditions will matter. It is true that a bike makes more horse power in cold weather due to denser intake air, your ECU can handle most temp extremes.

However that's where the Autotune steps in. If you take the bike to Pike's Peak for example, you can use the autotune to data log real engine performance and then adjust the mapping for those conditions. Basically if you add slip-ons the bike will probably adjust itself to run acceptably. If you change to a full exhaust and or change air filters to let more air in, you need a dyno tune. I have an autotune and have never used it as the dyno tune is so good. As for the backfire, you need to plug the PAIR valve host to the air box. The PAIR system is an emissions control device and can be simply plugged and ignored. Plugging the PAIR can be done after dyno tuning and will not effect the tune. Basically the PAIR system pumps air into the exhaust stream to promote the burning of un-burned fuel (the poping you are hearing). Since this happens in the exhaust pipe, it has no effect on the tune of the bike.

[1busa]

I agree with you fallen

A dyno tune is only good for that day!! the stuff that's said on this forum is hilarious sometimes......

[The_HighwayMan]

I appreciate all the response to my post. When the mechanic mentioned it I was leery so I brought it to the forum. I didn't want anyone's misinformation to end up hurting my engine. I didn't think that dyno tuning was as limited as he mentioned, and he's not touching my bike, lol. I'll get the dealership to put it on and dyno tune it. Thanks again for all the great info!

[dadofthree]

Lee's Performance in Charlotte, NC, Rodney Williford Racing Rougemont, NC IMO flash the ECU to remove all restrictions / detuning Suzuki placed on the Busa and have it dyno tuned. Some tuners can and will tune through the ECU, some prefer to add a piggy back controller for tuning for more precise tuning. Do your homework. Talk to tuners you're willing to drive to and seek their advice. They are the gurus of tuning. I'm not. Another thing to consider is ; does the controller have enough outputs to control your primaries and secondaries ?

Do your homework.