Jump to content
SAU Community

Recommended Posts

  • Replies 46
  • Created
  • Last Reply

Top Posters In This Topic

there are 4 runs each differnt colour of pattern of line. The upward hill lines are the max power. The bottomw jagged lines are a/f ratios.

an ideal afr on a turbo car is 12:1

meaning 12 paers air to one part fuel.

on a na car its about 14.8:1 me thinks

Question: Why the hell on your dyno graph do u run real lean when it gets to red line around 6500-7000rpm???? Dangerous?

Enrico: Not sure why the graph runs lean at the end... The car was only run to 6500-6700 before the dyno operator backed off... Looking at the graph here, the lean AFR's aren't under power, so I assumed this was just the AFR's going into decelleration mode?

Even so, nothing goes over 12.5 which isn't "too" bad.

To be honest, I don't think the dyno operator really knew what he was doing. I certainly wont be going back to that establishment...

As for 2nd gear? Mines auto... Trying to keep the auto in 3rd or 4th when flooring it from low revs is impossible. Kickdown takes over and your in 2nd gear again :D

Noones ever successfully explained to me why dyno runs need to be done in a certain gear anyway... If it's to do with the ratios, how can we compare between say, a bombadore and an r33 on the dyno... Even if they both run in 4th (1:1), the diff ratios are different anyway...

Thoughts?

Looks like he did a 2nd gear run too. the fuel leaning out is taking foot off pedal.

strutto, if that was fully stock (which it appears) that dyno shows a nice healthy engine - ripe for the modding:)

hippy, it appears to me that street tuning is something that takes a bit of experience. Not too many tuners around these days that do it anymore, infact I dare you to tell me the name of one in Adelaide:) The road side of things is good for off boost and driveability, but you need to get the car on a dyno for a final trim and to make sure everything is ok.

Also, just do be careful you dont go crazy and pull too much fuel, just because you dont have a huge amount of mods, doenst mean you cant smash ring lands if you pull too much fuel.

Well the reason people say to do the run in 1:1 gear is that power is a function of torque and rpm.

Imangine if you use a lower gear, the mechanical advantage will be higher, therefore the torque will be higher, giving a higher power figure.

That is until you get to peak power, which will read the same, as the wheel speed is alot slower for the same rpm (as in a higher gear) but as the torque is higher due to mechanical advantage, the difference is cancelled out.

My understanding anyways, and I do have the 3rd gear and 4th gear dynos with the same power to prove the theory:)

Hmm, well if you have got a 3" from front pipe back, you 'should' be getting more than 5-6psi. Stock boost is 5psi to 5000rpm then 7 psi to redline, you should have a couple of extra pounds with cat back..

dynos not bad though, I didnt read the previous posts and didnt realise it was an auto till after I posted:)

This was done on 5-6psi...  (No factory bleed, DIY bleed closed).
Hmm, well if you have got a 3" from front pipe back, you 'should' be getting more than 5-6psi.  Stock boost is 5psi to 5000rpm then 7 psi to redline, you should have a couple of extra pounds with cat back.

Yea, I have disabled the factory bleed and use my own incabin bleed. This was closed during the dyno runs. Factory wastegate opens at 5psi I believe. The extra 1psi or so up high is due to the less restrictive exhaust I reckon...

interestingly enough, my safc was used to richen the mixtures up top....

It did 5 runs on the dyno in 4th gear and by richening the mixtures (+9%)from about 5k onward (75%throttle) I was able to gain a healthy 17rwkw and totally eliminate pinging. The car has a much fatter power curve and feels 100% better on the road. Plus I have the peace of mind that it isn't pinging and is safe to run at 12psi.. I'd go dyno tuning over road tuning unless you really know what you're doing.

hippy u r gonna fark your engine up man.

it only takes about 30mins for someone that knows what they are doing to tun your car on the dyno!!

also fyi i could get my gfriends old 1.3 litre mazda 323 to wheel spin in 1st gear, so spinning the 33 in first is no biggie! :P

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

    • I know why it happened and I’m embarrassed to say but I was testing the polarity of one of the led bulb to see which side was positive with a 12v battery and that’s when it decided to fry hoping I didn’t damage anything else
    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • 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.
×
×
  • Create New...