Quick Shifter question.

[toybm]

I`m thinking of getting a quick shifter for my track bike for 2011. I know there are a lot of options out there, from a couple of hundred to almost a thousand dollars. My main concern, other than the price, is the type of interrupt - fuel or ignition. How much does it matter and which is better?
Thanks.

[caboose483]

What if any fuel management system are you using?

[toybm]

What if any fuel management system are you using?

Sorry, the bike is a 02 F4i and I`m running a PC3 (not PC3 USB) so I can`t plug a DJ Shifter switch into it. I was looking at a stand alone unit but wanted to get the highs and the lows of fuel cut vs ignition cut.

[caboose483]

Sorry, the bike is a 02 F4i and I`m running a PC3 (not PC3 USB) so I can`t plug a DJ Shifter switch into it. I was looking at a stand alone unit but wanted to get the highs and the lows of fuel cut vs ignition cut.

Ok.

My knowledge only pertains to how the DJ and Bazzaz units work so I don't really have any information for you.

FWIW, the DJ website says theirs work by cutting the fuel and/or spark. So i don't even know for sure how mine works.

[Brian P]

If you have just a PC3usb with the quick shifter switch plugged into it, it's cutting fuel only (because it does not have access to ignition).

If you have a PC on a bike that has two injectors per cylinder, and it's wired only to the lower injectors, then you also need the separate module which results in it working by cutting ignition.

If you have a PC with the "hub" and ignition unit on a bike with only one injector per cylinder then I don't know, it could be fuel or ignition or both.

[omnivore]

Price out a PC, ignition module, and quick shifter.

Same price as the Bazzazz system, but Bazzaz has all the same features, PLUS traction control.

I know where my money would go, if I were racing a fuel injected bike.

[Brian P]

Only trouble with that, is Bazzaz is not available for the original poster's bike.

[toybm]

Thanks for the input guys.

One option I have right now is to get a PC3 USB and plug a Dynojet shift switch to it and I'm good to go, without the need for any other boxes or patches. If I do this the PC3 (non USB) that's on the bike now will be useless to me. And if I change bikes I will be looking for another setup again.

I could also go with a PC stand alone shifter module for about 300+, but for the same cost the PC3 USB does fuel and quick shift duties, so I can't justify the stand alone PC quick shifter.

I have found another manufacturer that offers stand alone units, one that cuts fuel and one that cuts ignition for half the price of the PC unit. It is also compatible with the PC shifter switch that I already have.

My main question applies to the method of interrupt, not really the virtues of any particular brand or model, but which method of interrupt is better, Fuel or Ignition cut???

And yes, I tend to be cheap most of the time.

[Brian P]

If there is a choice in the matter, I'd cut fuel rather than spark. It'll avoid having a nasty backfire on every gear change.

[quikcolin]

There is a ton to read here... this might of already been mentioned.. but Bazzaz has a standalone quick shifter option (as does... or did anyways PC).

My money would go toward Bazzaz personally...

[D23]

If there is a choice in the matter, I'd cut fuel rather than spark. It'll avoid having a nasty backfire on every gear change.

And I would rather cut ignition than fuel.

In road car tuning, especially high boost turbo cars a lot of the time we set up rev limiters as ignition cut (if the factory default is to cut fuel) and run fuel cut defenders for overboost issues...

The reasoning behind this isn't exactly the same as what we are talking about here but a lot of tuners would rather cut 1or2 in 4 ignition cycles than lean the fuel supply out even for fractions of a second.

To answer the question it doesn't matter that much and would be up to the individual and what was available for their application. I don't think anyone has grenaded an engine due to a shifter fuel cut alone.

Don't sweat it either way.

[FriendlyFoe]

how much is all that going to cost you? A newer track bike would probably cut more off your lap times lol

[Brian P]

High-boost turbo engine bouncing off the rev limiter frequently is, of course, a different ball game from what we are talking about here. With a quick shifter the engine will see a couple of missed firings (only air going through the engine) and then maybe one or two lean firings (which won't hurt anything on a normally-aspirated engine) and then back to normal for at least a couple seconds (hundreds of engine revs).

[D23]

Yea I know...

Was just saying if it was up to me to choose I would cut ignition. Out of practice it would be my choice but you are right.

The only way to know if one is better is to try both on the same bike obviously but sparing that, I was just saying either way is safe given how little the interrupt actually is on.