Jump to content
SAU Community

Recommended Posts

Hi Guys , just did a dyno run recently on my 34gtr.

PFC

Front pipe,

apexi pods

decat full exhaust

I made 338hp on 4 wheels with 37 KGm of torque.

I was just wondering, looking at the graph, does anyone experience a sudden leaning out of mixtures towards 7k rpm as shown in the graph? Could it be maxing out of afms or injectors? The engine hazard light did flash. I was thinking along the lines it could be detonating as well.

Btw, anyone noticed any difference when setting up the pfc using the normal air filter or selecting the power intake option?

Thanks

post-9392-1239444317_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/265095-dyno-run-test-results/
Share on other sites

the leaning out at 7k will be in the tune

there is no way std BNR34 with std turbochargers will max injectors

you can check easily by MONITOR, 1 CHANNEL, INJDUTY, NEXT, UP (and fang around)

when you press UP it will show the top score at any given time - ie: peak injector cycle

you should check the std airflow meters aren't maxing out (i suspect they arent)

again, MONITOR, 1 CHANNEL, AIRFLOW, NEXT, UP (and fang around)

check it doesnt peak near 5v

the engine check light flashes by default for 3 reasons

excessive knocking

injectors maxing

airflow meters maxing

the powerfc faq (in my sig) has all this information and much more

Thanks for the replies guys, most probably its the tune. Weird how the tuner didnt sort this out, I was even narrowing down to a clogged fuel filter.

I wonder if it only happens at that rpm range. If it does, I can live with not revving up to 7k rpms and might just going to get a retune in a couple of months time.

take it back and say fix it

no doubt youve paid a few hundred for the tune

its not like you said to him "give me a half assed tune that pings at 7 grand" so maybe take it up with him

be constructive, but i mean you paid good $ for it, so you should get a complete tune

too often we see a tuner, tunes the car on the dyno

the owner takes it home and it pings under certain load

i say the ownus is on the workshop to either advise the owner it will ping on the street

or an extra $150 for an on-road street tune to iron out the ping areas on the map

Paul,

actually, the tune was done on the road, only after, i decided to put it on the dyno to get some numbers that the pinging start showing on the graph and engine light started flashing according to another tuner, who just did a power run on it.

Looking at it, i might probably take it to somewhere else, that tuner is a bit stubborn and told me not to believe in myself but him. Have faith in the tuner. Well after the graph, i think i know the answer. LOL.

Thanks all for the replies, i will get the fuel filter replaced this weekend.

Cheers

Daz

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

    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
×
×
  • Create New...