Not Happy, Something Is Wrong...

[Hanaldo]

Hey guys,

Just got home from a dyno day at Autoworx with my club West Coast Cruisers, really not happy with my car...

Long story short, it was converted to GTT using parts from a donor car about 2 months ago. At the time, KYP (the garage that did the conversion) had the car dynoed at Autoworx to make sure the AFR's were ok, car made 220rwhp @10psi with FMIC, EBC, stock exhaust except for the crappy mild steel 2.5" cat-back it had from when it was NA, stock non-turbo fuel pump, Apexi pod filter, and Splitfire coilpacks. They also replaced all the serviceable items, so new o2 sensor, new water pump, new timing belt, new gaskets, etc.

Soon after getting it back from KYP I got a custom 3" straight-cut stainless steel cat-back exhaust (made by Kermit), 5" high-flow cat, and 3" bellmouth Tomei dump/front pipe. Then I installed a 550hp Walbro fuel pump, and made up a heatshield for my pod filter. 2 weeks ago I got a NIStune ecu installed and tuned by Andrew at Hyperdrive, one of SAUWA's sponsors and a very reputable tuner in WA... He set high boost on the EBC to 13.5psi, and the car made 243.0rwhp. Doesn't seem too flash, but Hyperdrives dyno is known to read about 20-30hp below, so Andrew told me my car was realistically making about 265-270rwhp.

Since then the car has seemed to drive really well, it feels fast and it was a lot smoother than before it was tuned. But my fuel economy became shocking. I was getting about 280kms to a tank of fuel, driving on low boost and hardly ever hitting boost (I'm pretty relaxed, I drive it like it is a normal car). It is no better on high boost, and no better if I put my foot down all the time. Before the car was tuned I was getting about 360kms to a tank.

Now today, I ran my car at Autoworx again and the result was 233.5rwhp. 10 less than I got at Hyperdrive which is meant to read low, and only 13 more than when it ran at Autoworx a couple of months earlier, despite all my modifications since then. The worst part is my fuel consumption. I filled my car up in the morning before heading to Autoworx, and when I got home my fuel gauge was sitting on the half way mark and I've only done 85kms...

So I don't understand what the problem is... Bad tune is the only thing I can come up with. I have asked Andrew about it, but he said the only thing he can do is put it back on the dyno but I don't really want to pay for more dyno time and then find he still can't tell me what the problem is...

Any suggestions? I will upload the two dyno charts for comparison in a sec... I tried to be as detailed as I could, but feel free to ask me anthing if I missed something, I'm all ears.

Thanks guys,

Martin.

[MrStabby]

First thing i'd do is check that closed loop control is working correctly via CONSULT (use the nistune cable and software if you have it) The o2 sensor readout should flick back and forth during light load as the ECU changes to the fuel delivery hunting for stoichiometric. Generally the tuner mostly tunes the full load cells (which dont use closed loop). If you're babying it around the econ shouldnt change much at all AFAIK.

If closed loop is not working it could be o2 sensor, or the tuner forgot to turn it back on (IIRC there's a number of different ways to toggle closed loop with nistune)

[The Dan]

Put it back on his dyno or pay to put it on someone elses dyno. I don't see that you have too many options. And if it's a simple fix or something wrong in the tune, I doubt you'd be paying for it.

[Hanaldo]

Already checked for fuel leaks, there are none. I will plug my laptop in and see if the closed loop is working, thanks mate.

[GTScotT]

Personally, I would have the current tune backed up then cut my losses and have it re-tuned elsewhere.

I doubt it can be much more than that when you gained so little HP from all those mods, combined with poor economy it seems like it should be tune related. If there was a separate issue it would throw the tune out when fixed anyway.

[Hanaldo]

Ok thanks mate, I have been racking my brains trying to think of what else it could be other than a dodgy tune as Hyperdrive are supposed to be NIStune specialists I'll get on the phone to Andrew tomorrow then.

[StealthX]

Strange dude...

My tune at the moment was done by Andrew. It's got its flaws its not perfect, he only spent a few runs tuning my car originally, but I trust Andrew, never had a problem with his tune/work in over 30,000kms.

Here's my most recent graph from his tune:

Even with weird AFRs like that its still safe and hasn't caused me any problems...

I'd encourage you to give it (tuning) a go yourself. (I'll lend ya my lambda sensor and AFR gauge if ya really want!) Depends on the Nistune software (how easy it is to use), but my EMS software wasn't hard at all.

Since then I've done a bit of my own tuning, tuned out a rough spot around 3k rpm and -10mmhg vacuum and i'm attempting to tune out another one at about 2k rpm and similar load.

The poor fuel economy could be caused by decelleration fuel cut or maybe your cruising AFRs are too rich. I've been working for the WA sporting car club today @ barbagallo today, and I've seen numerous cars with Hyperdrive stickers on them, so I doubt Andrew would've given your car back without it having a decent enough tune...

[paulr33]

put it on a dyno and check the basics. so many variables and so many things changed.

everyone is quick to blame the workshop so before you go doing any of that, get it all checked and check the basics on the dyno. check the tune, check the timing, check the fuel, check the fuel pump (walbro's can be ass sometimes) check the AFR's

excessive fuel usuage is usually

poor tune

poor closed loop

constant loading the car up / bring it on boost repeatedly

a good check is to give the car to your girlfriend or mum and let her drive it for a few days

i bet the economy doulbes or triples when they drive it (ie they baby it and dont bring it on boost constantly)

i know you said you dont do it, but its a simple mechnical check, if if they get same ass economy its not your driving

[R31Nismoid]

Everyones dyno "reads low", its the new black.

[wolverine]

a good check is to give the car to your girlfriend or mum and let her drive it for a few days

i bet the economy doulbes or triples when they drive it (ie they baby it and dont bring it on boost constantly)

That is a sure way to use more fuel with Ms Wolv behind the wheel. She is always ramping it onto boost.

Everyones dyno "reads low", its the new black.

The car needs to go back to the tuner, there is little else you can do.....

[DVS JEZ]

Everyones dyno "reads low", its the new black.

its just a number anyway, if you get a tune and the car feels better, more improved and good fuel ecomomy then its a good tune

[StealthX]

Everyones dyno "reads low", its the new black.

Yeah but that's easy to say when your car makes 450kw mate! haha

I'm the first person to add 30hp to my dyno graph above, cos it was on HD's dyno hahaha

My car might only make 223hp there, but im still convinced its a fast car. I've driven some pretty half decent cars around Barbagallo (mk1 esky with 350hp turbo cosworth, 300hp rb25 s13), and my car isn't that dissimilar in feel and accelleration... There's def something wrong with that dyno haha Maybe it needs a re-calibration?

'Street-tuning-yourself-and-using-your-butt-dyno' is the new black... lol That was me about 5 minutes ago

[NSNPWR]

How are you measuring how much fuel its using??? If youre only by the gauge, its highly likely the gauge is not accurate...fill it, drive it, note kms then refill it...divide kms travelled by litres used and report back.

[Hanaldo]

Gauge has been accurate up until now, last tank of petrol I got 280kms to a full tank. So that was about 18L per 100kms. This tank is going worse so far...

[JonnoHR31]

andrew seams to ignore light load tuning and only do full load tunes when hes busy. if he didnt spend much time on it then i dare say you have a rich light load map with no where near enough timing. i'm in perth and have nistune software if you want me to take a look at it for you?

[Hanaldo]

Would you mind mate? You want beer or something? I'm not sure how long he spent working on it, it was there all day but he had a couple of other cars to do and he had to install the board in my ecu so may not have spent that much time actually tuning it...

[snozzle]

whats the condition of the injectors and fuel pressure reg? afm? vacuum lines?

[Hanaldo]

whats the condition of the injectors and fuel pressure reg? afm? vacuum lines?

No idea on injectors, fuel pressure reg looks good, afm is brand new, vacuum lines are good.

[jarrod83]

probably way off the mark here, but i was trying to think of something to explain it using more fuel and making less power.

do the nistune ecu's still have the standard ecu's rich and retard if it knocks?

Jarrod

[JonnoHR31]

yes it has knock maps for both fuel and timing, something else to look at