Jump to content
SAU Community

Recommended Posts

New battery sourced, thank @BK and @Dose Pipe Sutututu

On special at Autobarn too so win win...

The guy at Autobarn saw that I was replacing my Optima with this and said I was nuts going from an Optima to a Supercharge, haha

thumbnail_IMG_6028.jpg

thumbnail_IMG_6027.jpg

  • Like 1
  • 3 weeks later...

Ended up making 430rwkws on E85 at just 20 psi.

Having alternator issues (not the limiting factor I was expecting)..

Tuner says it's still got more in it with a new alternator so looking into the LS1 conversion...

...Not heaps though as the small rear wheel is just beginning to restrict things and potentially my small pod filter too....

8 hours ago, mr_rbman said:

Ended up making 430rwkws on E85 at just 20 psi.

Having alternator issues (not the limiting factor I was expecting)..

Tuner says it's still got more in it with a new alternator so looking into the LS1 conversion...

...Not heaps though as the small rear wheel is just beginning to restrict things and potentially my small pod filter too....

Alternator limiting how ? I smell bullshit...

Coils and fuel pumps are your most power hungry things and I'd expect dramas very early in the tuning process if this was the case from a alternator causing a low voltage condition.

On 2/2/2023 at 10:24 PM, BK said:

Alternator limiting how ? I smell bullshit...

Coils and fuel pumps are your most power hungry things and I'd expect dramas very early in the tuning process if this was the case from a alternator causing a low voltage condition.

mmmm, interesting...

This side of things (electrical) goes over my head so I just took him at his word...

I'll have a chat to him next week to get a clearer understanding...

if the alternator can’t keep up and the voltage drops then it slows the fuel pumps slow down and can’t supply their full potential along with a list of many other things it does to the tune 

Or he's getting misfires with more boost because the voltages are subpar and his coils aren't producing the required spark.

I've experienced this, hence I have a relatively new 90AMP Circuit Sports alternator in my car.

 

3 hours ago, r32-25t said:

if the alternator can’t keep up and the voltage drops then it slows the fuel pumps slow down and can’t supply their full potential along with a list of many other things it does to the tune 

Like I said, the low voltage condition from an alternator will mainly affect fuel pump and coil operation but it has to be pretty severe to do that, injectors draw stuff all by comparison. Coils would start misfiring and you would start to have low fuel pressure lean outs, but the fact it supported enough for well over 400kw with stable AFR and no jittery power curve from misfies uptop doesn't really point to coils misfiring or low fuel pressure from the alternator limiting things at all. My point is you will see something more sinister happening well before you get to tune the thing properly.

4 hours ago, mr_rbman said:

mmmm, interesting...

This side of things (electrical) goes over my head so I just took him at his word...

I'll have a chat to him next week to get a clearer understanding...

Now don't get me wrong, having a more capable alternator with more headroom is always a good thing. I myself went from the stock 90A to an ARD 140A as I could see I was  getting only 12v at battery with all 3 fuel pumps running at idle under test conditions and would cause dramas. The ARD jumped it back to about 14.3v at full load at around 70A. End of the day a better alternator is never a bad thing, just usually not a likely thing if everything else checks out.

1 hour ago, Dose Pipe Sutututu said:

Or he's getting misfires with more boost because the voltages are subpar and his coils aren't producing the required spark.

I've experienced this, hence I have a relatively new 90AMP Circuit Sports alternator in my car.

 

If this is the case you don't need to be at full load to see if something doesn't look right as your voltages even at idle will be a bit suspect.

1 hour ago, BK said:

this is the case you don't need to be at full load to see if something doesn't look right as your voltages even at idle will be a bit suspect.

Yes that is also true however it's not the first thing you look at when you're tuning.

Generally you'll interrogate voltages when things don't go as expected or planned, e.g. a misfire or sensors doing cooked shit lol

 

22 minutes ago, Dose Pipe Sutututu said:

Yes that is also true however it's not the first thing you look at when you're tuning.

Generally you'll interrogate voltages when things don't go as expected or planned, e.g. a misfire or sensors doing cooked shit lol

I get where you're coming from, but establishing the very important basics with things like what baseline voltages are at battery and fuel pump terminals, fuel pressure, base timing, spark plug type and gap and so on should be a given as a precheck before going anywhere near a dyno.

Going on a dyno to tune without doing any of this with something like say less than 13.0v at pump terminals or god forbid actually at the battery is just asking for tuners to crack the shits, as that will immediately flag potential problems elsewhere. i also accept unforseen things happen that can't be picked up until actually exposed on the dyno too, which is why the are such a great tool.

I notice a lot of places are asking for dyno prechecks to avoid exactly this sort of thing.

On 2/5/2023 at 5:30 PM, mr_rbman said:

so what should i do (from home) to eliminate other issues or potentially confirm that the alternator isn't up to the task?

Measure voltage at the battery, and voltage at the pump .

You can get multimeter that log over bluetooth pretty cheap from jaycar. Then you can see what us happening under load. 

 

I cant recall what ecu you are running, but it should be able to log its own voltage if it is any good.

1 hour ago, Ben C34 said:

Measure voltage at the battery, and voltage at the pump .

You can get multimeter that log over bluetooth pretty cheap from jaycar. Then you can see what us happening under load. 

 

I cant recall what ecu you are running, but it should be able to log its own voltage if it is any good.

cheers.

Link G4X so yes you're right, i'll plug the laptop in and have a squiz (not used to a car with logging capabilities 🙃

1 hour ago, mr_rbman said:

cheers.

Link G4X so yes you're right, i'll plug the laptop in and have a squiz (not used to a car with logging capabilities 🙃

Start a log, wind out second gear, stop log.

Then look at voltage vs. RPM and see what it's doing.

(This is my experience, may not apply to others) Voltage might be perfect at idle, but over a certain RPM it will fall flat on its face and do nothing then back to 13V+ towards redline. Hard to catch without proper logging.

  • Thanks 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
    • Also playing with fire if they start to flow more air down low than what the stock twins can. It's not even up top you need to worry, it can be at 3000rpm and part throttle and it's getting way more flow than it should.
    • Any G40/1000 or G40/1250 results out there?  
    • You still want a proper tune on the stock ECU though. Stock tune + stock ECU with GT-SS/-9s is probably playing with fire if you're running more than stock airflow/power.
×
×
  • Create New...