Terminal Velocity 3

[Roost]

I've just installed a new Akrapovic slip on exhaust and have about 5,000 miles. For all those miles the header pipes have been a perfect golden brown, running about 184 degrees stock. With the new slip on the pipe(s) turned bright purple in about 50 miles. This I know is a flow/back pressure problem. Or an issue with the fuel management system. I've just ordered (not installed yet) a Terry Components Terminal Velocity 3 fuel management system (closed loop). FYI I did remove the db pipes and the header temps were the same with or without! Has anybody run/heard of the same issue? I don't care about the color of the pipes as much as being worried about the exhaust valves!

 

[Phil_RC_1]

I would say that you are running leaner with the slip-on. An engine will run a little hotter as you get leaner. Typically though, a slip-on alone will not make that much difference. Anyway, I guess it is an issue with the A/F ratio which your TV-3 should compensate for.

I'll be watching for your reports of this closed loop system you have. Sounds very interesting.

FWIW: I believe our stock fuel management (07 and newer!) is only closed loop during lower rpms and lower throttle positions, above that it just runs the pre-loaded map (open loop). I "know" the FZ1 (06 and newer!) system is only part time closed loop, and I don't see Yamaha putting a more advanced system in the FZ6 then the FZ1.

 

[Roost]

Yes, at each start up the close loop will run. These are not the newer fly by wire systems. There is a self check at each start up.

 

[GTPAddict]

Curious, this is on a 2007+, right? IIRC, the previous years do not have oxygen sensors for feedback monitoring and therefore can't run in "closed loop".

 

[ChevyFazer]

If you unhook your battery for a min or so it will wipe the ecu's memory clear and allow it to "relearn" the fuel mapping with your new exhaust and will in turn add a little extra fuel.

 

[Roost]

So, in your thoughts should I hold off on the TV-3 vs. trying to disconnect the battery and "re-setting" the ecu? And for clarification the head pipes aren't all purple, but on there way more so on the center cylinders!

Thanks for the help thus far!!

 

[FinalImpact]

Where'd you get the 184 number from? That's more of head/coolant temp than a header temp weather C or F. In this case the cooling system may very well maintain the temp but the AFR can still be off. Does it backfire out the exhaust on decel? You might opt for the air block off plates atop the head too.

but ya, it sounds to have crossed over the line and went to a leaner state than it was. Disconnect the battery as mentioned by Chev.