Looking at the closed loop, pros and cons.

[Fleecer]

I ran a few years with various tunes and a manually adjustable fuel pressure regulator. Depending on temp, tune, conditions, and length wot, I would datalog and adjust accordingly. The manual fpr would add fuel evenly all across the board, whereas the loop tune is able to add fuel where needed.

I think the closed loop is better/safer for the machine as it provides the correct afr at all times in all rpm ranges. Hence, much less labor intensive, and more dummy proof to the end user who isn't an experienced tuner. It is bulletproof, set it and forget it once hooked up and requires no maintenance.

In my opinion, the loop tune made my sled harder on fuel, as the fuel mixture was always perfect and/or on the safe/rich side. If there was a gain in performance, I did not notice it in seat of the pants testing, and/or with my butt dyno.

In my opinion, I could set things closer to the edge when adjusting the fpr manually, so for me, the loop wasn't worth it. Just my 5 cents.

 

[Phatboyc]

It may not, but the ECU already will - Yamaha added in a specific tune for 87 octane for times when you may not have access to 91 octane (lower left text box in the image below).

View attachment 163148

I though that image was an early '17 draft and it was clear that the knock sensor isn't used in stock form. It has to be activated which Hurricane and TD did lost of testing early on to get right.

 

[jonlafon1]

Adjustable fuel pressure regulator. I understand what the purpose is and why.. But can someone explain install and proper use/ is this something you adjust a lot? You get bad fuel/low octane im guessing that's when this gets used or adjusted more?

 

[Kuzzy]

Adjustable fuel pressure regulator. I understand what the purpose is and why.. But can someone explain install and proper use/ is this something you adjust a lot? You get bad fuel/low octane im guessing that's when this gets used or adjusted more?

Interesting question. It will further the value of this thread.

The threads true intention is to gather information for others besides myself about the closed loop as well as performance alternatives. So many things that I didn't fully understand have really came out this last couple months in this forum

 

[DMCTurbo]

Closed loop will keep AF correct up until injectors max out. Once injectors max out you need more fuel pressure. This is where the requirement for an adjustable fuel pressure regulator comes into play

 

[DMCTurbo]

I ran a few years with various tunes and a manually adjustable fuel pressure regulator. Depending on temp, tune, conditions, and length wot, I would datalog and adjust accordingly. The manual for would add fuel evenly all across the board, whereas the loop tune is able to add fuel where needed.

I think the closed loop is better/safer for the machine as it provides the correct afr at all times in all rpm ranges. Hence, much less labor intensive, and more dummy proof to the end user who isn't an experienced tuner. It is bulletproof, set it and forget it once hooked up and requires no maintenance.

In my opinion, the loop tune made my sled harder on fuel, as the fuel mixture was always perfect and/or on the safe/rich side. If there was a gain in performance, I did not notice it in seat of the pants testing, and/or with my butt dyno.

In my opinion, I could set things closer to the edge when adjusting the fpr manually, so for me, the loop wasn't worth it. Just my 5 cents.

You have the ability to adjust the AFR values with the closed loop if you so desire. I'm not sure if it's only available if you purchased the advance tuning option or if it comes included when you purchase the closed loop.

 

[justinator]

You need the advanced tuning option to adjust target afrs with closed loop,which comes at an additional cost.

 

[1nc 2000]

Just unplug the 02 sensor and the tune reverts to the preset parameters.
This is one way to tell if it runs cleaner and or makes more power.

 

[Fleecer]

Adjustable fuel pressure regulator. I understand what the purpose is and why.. But can someone explain install and proper use/ is this something you adjust a lot? You get bad fuel/low octane im guessing that's when this gets used or adjusted more?

As far as install, TD has a video on how to install his. Most people set it and forget it at 46-47 lbs, but you can adjust it to get your target AFR Ratio, if your tuner makes it available on the dash as an option.

 

[NYTurbo]

Be very careful playing with adjustable FPR, very common for the gauge to read incorrectly, so say you want to set it back to 45 psi and gauge is reading 55 but in reality it's only 48 . You turn it down 45 but in fact your now at 38.

 

[Turboflash]

Are they consistent if they are set exact same way evert time? Ie key on engine not running? Or are they still inconsistent?

 

[NYTurbo]

Are they consistent if they are set exact same way evert time? Ie key on engine not running? Or are they still inconsistent?

I don't trust the gauges. Seen some read 60 pounds when in reality when checked with high end fuel pressure gauge were still sitting at 43 lbs. Their good day one but just be cautious if you see a funky pressure reading. The gauges do take a beating especially when mounted to the belt guard as most people mount them .

 

[KnappAttack]

I take the fluid right out out of the fluid filled gauges and leave the vent plug out of it to fix the radical readings on them.

If not vented to the atmosphere they read very inaccurately. Put a hair drier to the gauge to heat it up and see what happens if you don’t vent it. Pull the vent plug & fluid and you won’t see these swings in pressure. Gauge works on pressure differential, you can’t put it in a heated environment, install fluid and cap it from the atmosphere and expect it to work.

First thing I Doo is pull the rubber plug and dump out all the oil, then leave the plug out. Works good and consistent EVERYTIME. No more issues. It’s a trick I learned long ago when messing with fuel pressure on my old turbo 1200.

 

[Sweforce]

If the tune senses knock it pulls timing.