# 2015 sentra sv ft450 install



## jacksonkitchen37 (Nov 27, 2021)

hey yall!!!! Been a hot minute since I have been on. Having an issue here. Cant seem to find any specs or information at all on the crank trigger. Installing a fuel tech ft450. Got tired of looking for someone to tune after being boosted cause of ecu. So we move forward. Looking for information on crank trigger pattern as well as type of cam sync sensor (Hall/VR with pull-up, VR, VR differential, Random Hall, or ramdom VR). If there are any specs and or tech info it would be appreciated.


----------



## VStar650CL (Nov 12, 2020)

The crank and cam sensors will both be pulled-up Halls. The pullups will have been from the ECM, so if your new ECU doesn't have them internally, you'll need to add resistors externally (3.3K is usually a good value for Halls on any brand, but you can generally go as low as 1K if needed for stability). Pay attention to the voltage spec for your ECU. The OE sensors were probably 5V biased, and pulling up to 12V on an ECU spec'd for 5V can cause big problems.


----------



## jacksonkitchen37 (Nov 27, 2021)

Thank you for that info. Fueltech is pretty thorough with their harnesses. I'm checking now to see if they already have the resistors pre-installed. This is to terminate the frequency so it doesn't leach to other systems within the new harness????


----------



## VStar650CL (Nov 12, 2020)

No, the outputs on most Halls are N-transistors, which means they can only pull the circuit to ground and can't "push" any positive voltage. In engineering terms that's called "open collector" operation. The positive voltage has to come from elsewhere, in this case a pullup resistor inside the ECU. When metal is present the Hall pulls to ground, and since it can sink much more current than the pullup can source, it overpowers the resistor. That gives you a square wave that alternates between 0V when metal is present, or the pullup's supply voltage (5V or 12V) when no metal is present.


----------



## jacksonkitchen37 (Nov 27, 2021)

Well sir, I must say I am impressed with your knowledge!!!! Thank you for responding and divulging that info. I am still learning after 25yrs working building some type of powersport or a skit and get project. Shooting from the hip here, but is the crank trigger pattern 60-2, 90° index? Where does this I fo hide at? Lol


----------



## VStar650CL (Nov 12, 2020)

No, most Nissans use a 10-2 pattern repeating for the crank and infer TDC's from integration of the crank and cam. Don't know which MY Sentra you have, but I think the MR's and HR's all have the same pattern so this should help you out:








Good timing-CKP & CMP signal-Nissan-Juke 2010- | ROTKEE


Nissan, Juke 2010-, HR16DE 16V 1.6L, CKP & CMP signal, Good timing, idling




rotkee.com


----------



## jacksonkitchen37 (Nov 27, 2021)

Have one more question. This is the exact same crank ring installed factory on my car. My Sentra will be 2015 SV. I see my cam sensor rings have 7 teeth. If I am counting correctly I see 15 teeth in the picture repeating. Am I correct in this or I clearly still do not understand!! So to figure it out it is number of teeth divided by number of cylinders?


----------



## VStar650CL (Nov 12, 2020)

The cams turn once every 2 crank revolutions, so that wheel results in an index gap for each of the 4 cylinders. The number of teeth between the indexes varies with the engine design. Nissan is a bit weird that way. Most OEM's use a single index gap, the most common types are 60-2 (58 teeth with a 2-tooth gap) and 36-1 (35 teeth with a 1-tooth gap). The cam rings are a different story, there are tons of different arrangements specific to various engines.


----------



## jacksonkitchen37 (Nov 27, 2021)

Yeah, every thing I came across was single gap trigger wheels. This is the only one I seen and its identical to mine. This is what I get for boosting this car. noone else has one boosted with the mra8de and its what I had at the time. So here I am. I need to make a correction on the cam trigger teeth. Upon a thorough visual inspection there are 10 teeth. I will attemp to explain the pattern here, 1 gap 11 gap 1111 gap 111 going clockwise in rotation. Does this correlate with the firing order??? Its not this motors firing order but is clearly similar in the amount of teeth and their grouping. Thanks for the information my friend. I love this platform hence so much research and trial and error to further it. Appreciated


----------



## VStar650CL (Nov 12, 2020)

Yah, the numbers are definitely telling the ECM which cylinder is which. That's a bit Nissan-weird too, most cams vary the width of the pulse or gap to indicate position in the sequence. But like I said, there's no standardization at all with cam signals. Lots of bizarre stuff out here, and almost none of the patterns are documented by the manufacturers (including Nissan). If you look in the SM's, diagnosis is usually all scanner-based. If they give you any pattern information at all, it's usually very rudimentary.


----------



## jacksonkitchen37 (Nov 27, 2021)

agreed!!!!! yeah Nissan dont even list the type of sensors (hall/vr) in service manual or tech talk that I have found. I imagine their is a tech bullitn written up on it somewhere. head over to nissan and put my subscription to good use, Thanks again man. The input from other members is invaluable.


----------

