Jump to content
SAU Community

Recommended Posts

Morning all,

2 weeks ago i had my gearbox / clutch replaced and had the guys re-tune the car too as it had been over 3 years since my last tune, with another tuner.

The new dyno sheet showed the car at 193rwkw, which concerned me as my last dyno tune back in 2007 had me around the 220rwkw mark.

When i questioned the new tuner, he put the difference down to the fact others "tweak" their dyno settings to give off false readings. i had heard of people doing this in the past but surely 30 rwkw is quite a large "tweak" in settings. Isnt it?

I gave my new tuner the benefit of the doubt. However, the car feels much slower as turbo response times are now very laggy. At times it feels as if i am driving a NA car as i cant feel the punch of the turbo i once used to feel. The boost just doesnt put me back in my seat like it used to.

The tuner did carry on that the new tune is a "safe tune" but in all honestly the car felt quicker before i even had the Power FC installed.

Now on top of the above, the fuel economy has become very poor. Coming from a minimum of 350km a tank prior to this new tune, my first tank out of the workshop came to 190kms. Keep in mind the driving has been kept rather sensible as i am still wearing in my new clutch.

Am i right in assuming the tune is attributing to the poor fuel economy i am experiencing? Makes me wonder why this is happening as the car is noticably slower too.

Do you guys have any suggestions before i go back to these guys and complain? These guys are very well known in the industry and have a good name so i find it tough to go back to them and complain about their work results.

Current mods are :

3.5" turbo back exhaust

FMIC

K&N Air Filter

Apexi boost controller (high setting at 12 psi)

Walbro Fuel Pump

Power FC

Spitfire Coil Pack

Appreciate any advice guys, as i am at rock bottom at the moment as i have just spent over $3k to have my car eating more fuel and driving much slower.

Thanks

Con

Link to comment
https://www.sau.com.au/forums/topic/337864-new-tune-resulting-in-30-rwkw-less/
Share on other sites

It can only be the tune or the car.....either way the dyno is there to tell you. The fuel consumption is not normal so just mention that and take it back to have it checked. The tuner can't fix it if he's not aware of the problem. You may kill two birds with one stone

Do you have a copy of the "old" tune? Then re-install those maps. Or the previous tuner should have a copy.

The economy - check "closed loop" has been turned on.

Driving / performance - maybe it's simply psychological, the number is lower so you expect the performance to be down as well.

thanks for the responses guys.

How do i check if "closed loop" is switched on? is this checked on the PFC hand controller?

AFRS?

BTW i spoke with my tuner breifly this morning and his advice was to continue driving the car for another week and monitor the fuel consumption as it could be a fluke. (sounds to me he couldnt care less TBH)

Edited by CK34GT

193rwkw is bang on for std turbo. mine made 192rwkw with a good tune

your economy should be 350kms to a tank and some dynos will give higher readings

ie moving the air temp sensor is enough to inflate your reading from 190rwkw+ to 210rwkw+ so take it with a grain of salt

and for what its worth your better of making less power and having a quicker car vs havingt more power on an inflated sheet

to check if 02 feedback is on

read the powerfc faq in my signature and use the online emulator also in my signature

if your economy is 190kms to tank its likely 02 feedback is off (turn it on)

Peak power sounds right but if the economy is that bad it is possible it is a sloppy tune hence the lack of response, feeling down in average power. Could take it back or take it elsewhere, bit of a gamble really as we have no idea who the tuners are.

if 02 feedback is working and turned on, you dont need to tune every cell to get good fuel economy

it certainly helps, but its not the be-all and end all if working 02 feedback is ON

if 02 feedback is working and turned on, you dont need to tune every cell to get good fuel economy

it certainly helps, but its not the be-all and end all if working 02 feedback is ON

how lean does the O2 feedback tune it anyway?

193rwkw is bang on for std turbo. mine made 192rwkw with a good tune

your economy should be 350kms to a tank and some dynos will give higher readings

ie moving the air temp sensor is enough to inflate your reading from 190rwkw+ to 210rwkw+ so take it with a grain of salt

and for what its worth your better of making less power and having a quicker car vs havingt more power on an inflated sheet

to check if 02 feedback is on

read the powerfc faq in my signature and use the online emulator also in my signature

if your economy is 190kms to tank its likely 02 feedback is off (turn it on)

From what i can see, i must check the 02H setter and make sure it is switched on right?

and can i change this from my PFC hand controller if it is turned off?

Cheers

193rwkw is bang on for std turbo. mine made 192rwkw with a good tune

your economy should be 350kms to a tank and some dynos will give higher readings

ie moving the air temp sensor is enough to inflate your reading from 190rwkw+ to 210rwkw+ so take it with a grain of salt

That is one area that I agree with. The car shouldnt be returning such a poor fuel economy. I had my gtst with a hi-flow and very similar mods making 230rwkw and I was always getting close to 500km/tank.

Something is not right, I have not the experience or knowledge to say what that is, and I would be getting the tune looked at. Maybe one of the experienced tuners on here could have a look at your tune file if you upload it?

ok just ran down to check the settings on th PFC....

Sensor Check Screen:

I found that only IGN and ECC was on (filled black circle)

Everything else was off (empty circle)

Function Select Screen (as below)

Boost Control, air flow warning, injector warning - OFF

Knock Warning & O2H F/B Control - ON

I dont get it, if O2H in the sensor check was off, why is the O2H F/B Control showing on in Function Select Screen.

How do i actually switch the O2H sensor on in the Sensor check screen - this should likely fix the fuel consumption problem right?

Edited by CK34GT
or most likely the tuner didn't give a rats arse about rows 3-15

This makes sense as only IGN and ECC (line 1 & 2 i see) is turned on and all remaining lines off.

Any thoughts on what this could mean?

What is the importance of lines 3-16 ??

Edited by CK34GT
02 feedback aims for stoich 14.7 by default

you can change it with datalogit

no, you can change which cells are trimmed under constant throttle, not how much they're trimmed by.

OP, he means rows 3-15 in the fuel map, nothing to do with the sensor screen. whilst on that screen tho, what does the o2 voltage show at idle?

for it to be using that much extra fuel just from the tune he'd have to go through every cell and richen them all up and take out loads of timing under light load, which would just be silly but you never know...

Unless the tuner is really SHIT i doubt they would go through and change everything to make it really rich...could be wrong.

Coincidence, but failed Fuel Pressure Reg?

Depending on how they can sometimes fail it could make the thing rich under low load and lean on power...or rich everywhere = sluggish.

Take it back and get them to SHOW YOU while cruising on the dyno that the AFR meter shows either 14.7 or 1.00....shouldnt be anything other than that....

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 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.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...