Ryan00TJ

You've been busy. The final pic makes it all worth it! Looks great. Are you still planning on a custom Whipple tune since you can supply him all info he needs? Raylar and bobl said they make best power at 13-1 af/r. No way would I ever want to run that lean on my setup. What afr do you plan to shoot for? Once again, congrats.

Keith Atlanta

Thats really lean.

Ray never told me anything above 12.2 and Dustin told me 12.4. You might be able to pull off 13 at cruise but not when the engine is really working. Might want get Bobl involved but I am pretty sure his tests showed no considereable gain from 12.2 to over 13 so it wasnt really worth it.

Ryan00TJ

I fully agree. I was referencing 13-1 from older posts by Raylar and bobl's 496 dyno writeup where that is stated. I like the low 12 numbers you quoted much better for anything other than idle ratio.

donzi matt

Well the boat is in the water. For reference I am tuning with a Snap-On fuel pressure gauge that is verified accurate. I am using an Innovate LC1 wideband with a brand spanking new Bosch LSU 4.2 sensor.

Left with the wideband hooked to bank 1 of the port motor and fuel pressure gauge hooked to the same motor after verifying both motors at the specified 51 PSI key on engine off. Getting up on plane saw AFR's get into the low 14's so I cut power and grabbed my 10mm and allen wrench set to make a fuel pressure adjustment. Wouldn't you know the 3mm allen wrench was not in the holder. FFFAAAHHHKKKK!!!! Chugged home slowly and went back to the shop to get my allen wrench. Upped base pressure to 54 psi and headed back out. AFR's came down to mid to upper 13's in lower cruise speed down to 13.5 at around 4000. Fuel pressure is holding steady so it is not a delivery issue in my opinion. Upped base pressure to 59 psi on both motors. Cruise is down to mid 13's and high 12's over 4000. Boat has gained 3mph but is only turning 4700 RPM. Hooked up my scan tool and checked WOT with KOEO and only found 78% TPS on both motors. I need to re-engineer my throttle bracket as the throttle cable clevis is hitting the oil fill pipe in the intake and preventing WOT.

In other news, oil temps don't get a bit over 190 degrees now, so the coolers are working well

At the end of today I have a boat that at 3/4 throttle is 3 mph faster than previous WOT speed for conditions and fuel. My AFR's are still leaner than I would like at cruise and WOT but my idle is now at 12.0. Had I not checked AFR's and just left it at the specified 51 psi these things would have shattered a piston for sure. Those O2 bungs paid for themselves first trip out. I think I may have been ok if I had just done the 525 kit, but add in the new exhaust and it is just moving that much more air. Both motors are at the same AFR with the same fuel pressure so to me that does not indicate an injector issue. Time to call Whipple and get to work on some custom tuning for these things. I don't want to keep adding fuel pressure because my idle AFR keeps getting richer and at some point the pump is going to hit a pressure ceiling. I need injector pulse width modified to do this right and I would like to get my idle AFR back up. Hopefully I can get somebody to talk to me at Whipple that will actually discuss tuning and not just regurgitate the same sh!t they have on their website. This is going to be a bit of a process for sure.

Mr Maine

That's awesome. Sounds like you are getting it dialed in. Do you think it will foul plugs idling at 12:1? I know you want to get away from the higher fuel pressure, but just curious.

Seems like the o2 sensor did ok, I know they don't like moister. Is your gauge permanent or temporary? I just bought an innovation unit and put bungs in the risers but haven't used it yet

Keith Atlanta

I have an Innovation too. They see to be way more accurate if you keep it clean. Idle in the no wake at like 1500 or 2000 rpm for a second or two and get on plane as fast as possible. Then do your readings. As soon as the engine is done with testing, turn it off and swap it to the other engine - just wear gloves.

I dont know about others but my data was more consistant if I didnt idle around with the bung in or in and turned on.

Dont forget, I am in salt water too, so the calcification & salt build up could do different things.

donzi matt

My gauge is just temporary. I have owned this wideband for years. I added wire to the display so I can leave the controller in the engine bay but run the display up and tuck it into the passenger bolster. I alligator clip the power and ground to the battery. Crude, but it works. Once I get the tune dialed in I will pull the wideband once I am done.

Mr Maine

That's what I plan on doing. My o2 sensor is a Bosch 4.9, I don't really know the difference as these are new to me

donzi matt

The 4.9's are supposed to be very fast reacting. I couldn't tell you on longevity how they are though. Typically, the Bosch sensors in my experience are fragile, at least when it comes to things like race gas. On the other hand, the NTK wideband sensors are damn near bulletproof. I have one in a turbo 4 cylinder that swills 116 octane on a regular basis and they just last forever with no loss of speed or accuracy. I am very curious how they would do in a marine environment.

This is the one I have that runs the NTK sensor, it used to be the NGK AFX but now it is marketed by Ballenger Motorsports.
http://www.bmotorsports.com/shop/ind...gg3skiidieo0e0

underpsi68

I run the AFX wb in my car. It has been bullet proof. It has seen 8 years of methanol and now e85 with the original sensor still going strong.