Jump to content
SAU Community

Recommended Posts

hi i drive this

skyline-1.jpg

so i got my car tuned last week and have been having nothing but problems

and the dyno is whacked looking

dyno2.jpg

current mods are: safc neo, custom t3 (stock compressor housing bored out with a bigger wheel, t3 exhuast housing), sard fpr, greddy fmic, 3inch straight pipe

can anyone tell me why there is a huge "dip" in the powerband?

Edited by sd9k
Link to comment
https://www.sau.com.au/forums/topic/236635-rb25-engine-troubles/
Share on other sites

need ecu

meh alot of money went out this past month so it will have to wait

which baffles me is that my car has run perfectly fine in the past with about the same amount of hp

any other ideas?

AFM maxing out by the looks of it and hitting airflow cut. How you managed even that power on the stock AFM is interesting....

Also, you aren't running the standard injectors and fuel pump are you?

Edited by PM-R33

ya stock injectors and fuel pump

prolly back the hp down to around 230-250 or so

i've ran that power before with nps

but i think it's just way too lean

takin git back to the dyno friday

so hopefully everything will be sorted by then

or it rather be

ha

Yep AFRs are horrible, knock sensor is probably going nutso

huh?

AFR's look fine to me, sitting on 12:8 - 13:1 quite consitently. Dosn't seem anything wrong there

Gets a slight leanout as the RPM goes up, but that looks to be totally controlled by the tune as its not sharp, its slight, even and linear.

270rwhp is 200rwkw, which is what is probably the limit of the stock turbo.

And as your the aftermarket turbo, its likely reaching the AFM limit as stated. Every car is different with the AFM. Some are fine, some dont like it. Just how each seem to be really.

I'd be looking to

1. Change the fuel pump (do it regardless)

2. Upgrading the AFM

In the short term to get it driving nice, smooth and so on. Retune required there.

3. As i'd roughly say the turbo should make 340rwhp or so (hard to tell but thats what id be expecting), injectors might not be a bad investment at some point depending on how 1 & 2 go.

Cheers

remember ppl US power is about 20 to 40 % more then Aussie power. We work on true HP figures not the fairy HP that gets quoted on the other side of the globe.

that AFR is too lean. i would not let any car off the dyno with a AFR like that unless the owner knows it needs to be fixed. IMHO

remember ppl US power is about 20 to 40 % more then Aussie power. We work on true HP figures not the fairy HP that gets quoted on the other side of the globe.

Couldn't disagree with this more - so bored of hearing Aussies say that. If any dynos could be said to read "untrue", its Aussie dynos. Low reading doesn't mean more true.

that AFR is too lean. i would not let any car off the dyno with a AFR like that unless the owner knows it needs to be fixed. IMHO

Very much agreeing with that - not sure why sd9k is asking for advice and then basically ignoring it. Sd9k - you are LUCKY that you haven't blown your engine up running that kind of setup, the ECU is obviously trying to save it and with no help from the S-AFC.

A Neo by no stretch of the imagination gives you a decent proper tune, and you shouldn't be running a bigger turbo like that with stock AFM/injectors/pump. I am pretty damn sure anything else you try at this stage will not work, a proper ECU and associated fuelling changes are the first things you should be considering. Really - you should have done that before changing the turbo if limited funds are an issue.

remember ppl US power is about 20 to 40 % more then Aussie power. We work on true HP figures not the fairy HP that gets quoted on the other side of the globe.

that AFR is too lean. i would not let any car off the dyno with a AFR like that unless the owner knows it needs to be fixed. IMHO

Haven't people been tuning around that a lot lately?

More higher end tuners etc.

I cant remember exactly ;)

Okay so your saying aussie dyno's read low compared to the ones used in the US ? that would explain a few things.

and yes that car needs some serious attention. if you drive it hard like that it will blow in a matter of time. Take the advice given by these guys, computer, injectors and fuel pump is a MUST for this car or you will destroy the engine, have to buy a replacement and then still be where you started from.

Okay so your saying aussie dyno's read low compared to the ones used in the US ? that would explain a few things.

Dyno Dynamics are pretty much the lowest reading dynos used anywhere. Again, that doesn't mean they are more or less accurate - they just put smaller numbers out.

  • 2 weeks later...
Couldn't disagree with this more - so bored of hearing Aussies say that. If any dynos could be said to read "untrue", its Aussie dynos. Low reading doesn't mean more true.

Very much agreeing with that - not sure why sd9k is asking for advice and then basically ignoring it. Sd9k - you are LUCKY that you haven't blown your engine up running that kind of setup, the ECU is obviously trying to save it and with no help from the S-AFC.

A Neo by no stretch of the imagination gives you a decent proper tune, and you shouldn't be running a bigger turbo like that with stock AFM/injectors/pump. I am pretty damn sure anything else you try at this stage will not work, a proper ECU and associated fuelling changes are the first things you should be considering. Really - you should have done that before changing the turbo if limited funds are an issue.

i'm not ignoring advice at all man

i just don't come on here that much

but as far as the car is concerned right now

the guy who was supposed to retune the car never returned my calls

so i said f**k it and returned the boost back down to stock

and all of the corrections on the safc back down to 0 and the car runs fine like it did

and as far as the turbo on the car, it came like that when i bought it so i didn't really have a choice in the matter

but thankfully i'm coming into some moeny here next week like 1k bucks

so i'm pretty hyped

going to buy 550cc injectors, GTR fuel pump, and a z32 maf

is an ecu reflash a good idea or should i just wait to get a PFC

i've heard nothing but good things about PFC so i'm assuming that's the standard esp for RB's

but i'm open to other options as well

thank you all for the support and advice :cool:

Cheers.

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

    • Very nice - I also have a 92 GTST and hardly see any others around these days
    • When I need something else to edit, I use Movavi. A friend who does video editing on a daily basis recommended me) it's an easy video cutter to use for beginners
    • I need to edit some videos for work but I'm not good at all this. Which video editor can you recommend?
    • I think you're really missing the point. The spec is just the minimum spec that the fuel has to meet. The additive packages can, and do, go above that minimum if the fuel brand feels they need/want to. And so you get BP Ultimate or Shell Ultra (or whatever they call it) making promises to clean your engine better than the standard stuff....simply because they do actually put better additive packages in there. They do not waste special sauce on the plebian fuel if they can avoid it. I didn't say "energy density". I just said "density". That's right, the specific gravity (if you want to use a really shit old imperial description for mass per unit volume). The density being higher indicates a number of things, from reduces oxygen content, to increased numbers of double bonds or cyclic components. That then just happens to flow on to the calorific value on a volume basis being correspondingly higher. The calorific value on a mass basis barely changes, because almost all hydrocarbon materials have a very similar CV per kg. But whatever - the end result is that you do get a bit more energy per litre, which helps to offset some of the sting of the massive price bump over 91. I can go you one better than "I used to work at a fuel station". I had uni lecturers who worked at the Pt Stanvac refinery (at the time they were lecturing, as industry specialist lecturers) who were quite candid about the business. And granted, that was 30+ years ago, and you might note that I have stated above that I think the industry has since collected together near the bottom (quite like ISPs, when you think about it). Oh, did I mention that I am quite literally a combustion engineer? I'm designing (well, actually, trying to avoid designing and trying to make the junior engineer do it) a heavy fuel oil firing system for a cement plant in fricking Iraq, this week. Last week it was natural gas fired this-that. The week before it was LPG fired anode furnaces for a copper smelter (well, the burners for them, not the actual furnaces, which are just big dumb steel). I'm kinda all over fuels.
    • Well my freshly rebuilt RB25DET Neo went bang 1000kms in, completely fried big end bearing in cylinder 1 so bad my engine seized. No knocking or oil pressure issue prior to this happening, all happened within less than a second. Had Nitto oil pump, 8L baffled sump, head drain, oil restrictors, the lot put in to prevent me spinning a bearing like i did to need the rebuild. Mechanic that looked after the works has no idea what caused it. Reckoned it may have been bearing clearance wrong in cylinder 1 we have no idea. Machinist who did the work reckoned it was something on the mechanic. Anyway thats between them, i had no part in it, just paid the money Curiosity question, does the oil system on RB’s go sump > oil pump > filter > around engine? If so, if you had a leak on an oil filter relocation plate, say sump > oil pump > filter > LEAK > around engine would this cause a low oil pressure reading if the sensors was before the filter?   TIA
×
×
  • Create New...