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Professional Amateur Wanderer
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Discussion Starter #1 (Edited)
This is a continuation and distillation of this thread: http://www.thenewx.org/forum/56-rugged-rocks-off-road/185649-ruggedrocks-com-180amp-alternator-installed-10.html


Update, 4/3/18: awaiting replacement sense wires to test.

Here is our data @SteeevO

We are trying to collect as much data to send to Rugged Rocks and DC Power to alleviate a voltage fluctuation we are seeing at idle.

Known members with Rugged Rocks/DC Power Alternator installed + output:
No code has to be inserted here.

The Problem:
- On cold start, we are seeing initial voltage around 15.2v.
- At engine idle, there is a wide fluctuation in voltage. With the most extreme case being 11.7-14.9v. Mostly 13.7-14.3v at idle (LNXPenguin's rig) 13.67-14.85 (KingTruc's Rig).
- On my vehicle, at night, idling with just stock headlights on, you see noticeable dimming and brightening at stop light. Voltmeter shows fluctuating voltages.
- Video from @kingtruc showing example of fluctuations

What we know:
- Crankshaft pulley diameter: 5.879"
- Alternator pulley diameter: 2.0625"
- Pulley ratio: 2.8504
- Engine Idle: 580-675 RPM (observed on OBDCII) LNXPenguin's rig

Observations:
- Alternator output seems to stabilize reliably above 750 RPM (at engine), 2,137.5 RPM (at alternator pulley) based on KingTruc's rig w/ 180A alternator
- Alternator may stabilize as low as 2000 RPM at alternator pulley, 700 RPM (at engine) based on LNXPenguin's rig w/ 270A alternator
- Based on observations, a 1 25/32" diameter alternator pulley, creates a 3.30:1 ratio, this should get 650 RPM at engine to 2145 RPM at alternator, theoretically fixing the problem.

Suggested corrective actions applied:
- Got rid of cheesy stock battery clamps and charging cables.
- Upgraded alternator output cable to 1/0 with 5/16" lug at alternator B+ output, to 300A ANL fuse holder, to 5/16" lug to fastening bolt of marine style terminal.
- Upgraded battery ground cable from 4AWG to 1/0 with 5/16" lug at engine block. Cable was fed through the stock hall current sensor, and terminated 3/8" lug to military style terminal on negative post.

Batteries:
- Odyssey Extreme Series 34R-PC1500 KingTruc
- Odyssey Extreme Series 34R-PC1500 LNXPenguin

User Notes:
@kingtruc
No code has to be inserted here.
@LNXPenguin:
No code has to be inserted here.

Final Notes:
The smaller diameter of the RR pulley introduces a bit more belt slack and nearly maxes out the tensioner's ability to pull in the slack, after much deliberation, I think the unanimous decision is to use this belt 5070862 for the GT-R!

**Apologies to the mods for all the edits. Just didn't want to lose any of the information. I combed 23 pages to distill it into a more digestable format. **

Please, for the love of God, people chime in and help us solve this problem. Remember, "Only you can prevent forest fires." That's not the one.

"TheNewX-er's unite and solve problems!"
^
|___________ This is what I was looking for.

"With your donation of just your $0.02 cents a day, you can help your fellow X owners solve the seemingly unsolvable"

--LNXPenguin
Queue sad music like those *other* commercials
https://youtu.be/1SiylvmFI_8
 

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Professional Amateur Wanderer
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471 Posts
Discussion Starter #3 (Edited)
More research found this:

Looking at the replacement harmonic balancer, looks like the overall diameter is larger than stock.
https://www.rockauto.com/en/moreinfo.php?pk=6757372&cc=3294358

6.536" / 2.0625" = 3.168:1

650RPM (at engine) * 3.168 = 2059 RPM at alternator

Xterra is with the dealership now, but I will take this measurement when I get the rig back.
 

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Premium Member
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22,508 Posts
List of users considering upgrade to RR alternator after problems are solved:
@IssacHunter 180A
@Surf and Snow
@Polar Bear
@Jordan
@Scott Farris
@Stevejensen
Maybe getting a list of potential buyers will help get the issue resolved, I'll try my best to keep this up to date.
Confirmed interest and closely monitoring this R&D. Thank you all for being so diligent and thorough through this R&D to help work out these kinks. I, and likely many other beneficiaries in the future, truly appreciate your hard work and willingness to share/document/and solve this issue.

Beers on me if/when we meet/(again)!

:eek:ccasion5:
 

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Senior Member / (Q4WC) Club Moderator
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411 Posts
My $0.02c
It sounds like the idle speed is too low to get smooth current.
What pulley options are there? Even the best engines out there still fluctuate around 50 or 60 rpm at idle. This obviously multiplies at the alternator.
I took a look at their specs and the smooth operating RPM was from around 2500 - 8000. Even though the unit will start giving you power from 1230RPM, looking at the curve, higher RPM would help.

Unfortunately, from experience, high output alternators never do well. On larger vehicles, we tend to prefer fitting a second alternator which in our situation is not an option.
 

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Professional Amateur Wanderer
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471 Posts
Discussion Starter #9
We are being shipped new sense wires from DC Power. Fingers crossed this fixes the issue.

I want to know if my alternator and @kingtruc 's were from the same production run, and if the 270A @nworker will receive won't have this issue since its from a new run.
 

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NewX’er 4life
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2,441 Posts
We are being shipped new sense wires from DC Power. Fingers crossed this fixes the issue.

I want to know if my alternator and @kingtruc 's were from the same production run, and if the 270A @nworker will receive won't have this issue since its from a new run.
Wow dude, thanks for compiling this!

If this solves your issue, would this be something people who have a RR alternator waiting to be installed would also receive?
 

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541 Posts
We're working on the issue and I want this issue resolved regardless of how many additional alternators we will sell. DC power has done the math on the Alternator RPM as well and they are still a bit puzzled as to why you guys are seeing this issue. If the modified wiring harness fixes the issue then I don't see a problem with including that for future alternators.
 

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That video of the DVM swinging wildly absolutely BEGS for someone to put a scope on that alternator. Love to see what that waveform looks like. I am definitely not a power supply guy but the video makes me think the ripple coming out of the alternator is on the order of a volt or so. That's pretty darn large. On a power supply the output ripple from the diode rectifier is smoothed by a big capacitor, on our cars that capacitor is the battery. If there's resistance in the line connecting the battery to the alternator you will see larger than normal ripple. Maybe those new sense wires they're shipping you will help .....
 

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That video of the DVM swinging wildly absolutely BEGS for someone to put a scope on that alternator. Love to see what that waveform looks like. I am definitely not a power supply guy but the video makes me think the ripple coming out of the alternator is on the order of a volt or so. That's pretty darn large. On a power supply the output ripple from the diode rectifier is smoothed by a big capacitor, on our cars that capacitor is the battery. If there's resistance in the line connecting the battery to the alternator you will see larger than normal ripple. Maybe those new sense wires they're shipping you will help .....
That's what we're' thinking. The only reason it would really swing like that is if it's trying to compensate for something. The new harness will basically sense straight off of the output rather than through the OEM wiring harness. high resistance on the sense line can do strange things.
 

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Professional Amateur Wanderer
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471 Posts
Discussion Starter #14
Thanks Steve for keeping on top of all this. We are looking forward to testing the new cabling harnesses.
 

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Desert Explorer
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332 Posts
Just received the new cable from Rugged Rocks. Will try to install this weekend and update everyone.

Don't mind the background, I am advising friend on maintenance on his Civic.
I just got my alternator and this is the cable it arrived with:



Should I use or should I ask for one like yours @LNXPenguin ?
 

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Professional Amateur Wanderer
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471 Posts
Discussion Starter #18 (Edited)
@nworker, I know there are a lot of eyes on me right now to see how this all goes. I just got word back from RR, the blue wire with the ring goes straight to output of the alternator (B+). I will try to get this in place and report back as soon as I get a chance. My X is at the dealership for the gas tank not filling up right and the XM radio reception issues. There are several TSBs on both. They are also going to try and apply the TSB NTB13-021b which appears to have affected idle output on Xterras up to 2012. There were a number of assembly errors on my rig, so they are going to try the software update for safe measure and see if it fixes my idle dropping to 580 problem. Maybe this will create stable field. I wish others that have installed these alternators would chime in to let us know if they had NTB13-021b addressed. This does affect Frontiers to 2015 as well.
@PhullD, I am going to try to get this installed as soon as I get the rig back and will report. I am interested to see how the new firmware in NTB13-021b will affect voltage prior to changing the harness. If by some miracle it resolves, it might be I got an old ECM. My X was fraught with assembly errors that I had to take back to the dealership numerous times to address. There was the matter of the factory gas tank skid plate magically being deleted for my model year, but 2012 and 2014 had them. They also deleted the plastic engine cover, and a few other components along the way. This would also explain why the other X's listed did not have this issue if the proper firmware updates were in place. @kingtruc's rig falls in that TSB range officially, whereas mine should have been in the clear.
 

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Desert Explorer
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I installed the alternator and, after talking with Steven at RR, made my harness match the configuration sent to @LNXPenguin. Steven told me the blue, sense, wire monitors system voltage. After talking through the wiring we thought hooking the blue wire directly to the output post of the alternator is the same as running the sense wire to the positive terminal a few feet away.

I'll be doing a write up on the install. The biggest PIA was getting the bolts in holding the alternator to the engine. I found I had to loosen both bolts on the lower bracket to get the upper bolt to line up. After some cussin' and wigglin' it all went in as expected. Kind of like my first date...

My Bully Dog tuner shows 14.6 as does my Victron controller when I combine my house and car circuits. All looks good and I didn't let out any smoke although I did hit my socket drive on the negative terminal when I was removing the positive post. DOH!
 
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