How often to Dyno tune

[butthead]

When i bought the car , the bloke said that he had the car on a dyno for 4 hours.

I was wondering how often a car should be dynoed, it was last on a dyno on 24/10 2001. My car is running great but VERY VERY RICH, which is supposed to be a safety thing.

Should i get the car on a dyno to see how things are or is it a waste of money & time.

[TTT]

if it is running VERY VERY RICH, then that is sort of an over kill.

I think that a safe air:fuel setting is 11:1 or even 11.5:1

above that would be too lean for constant on boost type driving.

My R32 GTST was at about 12.3:1 on MAX load when on the dyno but it never had a problem cause it would only be on that for a few seconds at a time.

If your car is as rich as you make it out to be, it would be effecting performance, it would be fouling up your plugs and oxygen sensor and you would be getting SHIT fuel economy..

The way I see it, you have an R33 GTR.

It is worth what... over $40K??

spending $70 for a single power run on a dyno would show you HOW rich/lean your car is...

then I believe the most expensive I have seen is about $110 per hour for dyno tuning at like Croydon Racing Development (CRD) at Silverwater.

If you have a POWER FC or some sort of aftermarket programable ecu, then it wouldn't even be more than an hours worth of tuning..

I think for under $200 you could get your car tuned to perfection and still be safe.

As for how often you need to get your car dyno tuned, once it's set, you shouldn't have to retune unless you do another power mod.

say you went and got it tuned and then later found that you only had a cat back and got some dump/front pipes which resulted in some more boost and power, you would be wise to make sure that this hasn't put your A:F ratio out of whack...

NOTE: the above is my opinion.

Some people say that the optimal air:fuel ratio for a turbo car is 12:1....

But I personally would prefer to be a little on the saefr side of Optimal...

Hope that helps..

[Merli]

Pretty much spot on there GTST...

Don't expect to get your car tuned at CRD for any less than $800 though... That's their minimum cost... Jim is an excellent tuner, but quite expensive...

[TTT]

my friend had a power fc installed and tuned on an S15 in November for under $500..

I'm pretty sure it wasn't that expensive..

they are very busy though and need like at LEAST a weeks advance booking.

[xaero1]

The optimum ratio for air:fuel on any combustion engine is about 12:1 - if you are looking for power.

However, if you run an engine at 12:1 you are looking at over-heating problems, which is why most engines run slightly rich, because with less air in the mixture the engine will run cooler.

You probably already know this!

[butthead]

Thanks for the info GTST, its running too rich , i've alreadly replaced the 02 sensors 2 months ago & i'm not getting too much above 200km city driving. When i give it in 1st gear, off the mark a big black cloud of smoke comes out about 2-3 metres high (like a diesel truck)lol.

The car has a lot of mods ( standard internals i think), it was taken to the HKS workshop in Japan before it got imported to aust & it only produces 245awkw, but it does feel quick, people on this forum seem to be getting that on stock turbos & with less mods?

I've got to take it to eastern creek for some times in the near future.

[TTT]

200km to a tank??

Jebus man...

you weren't kidding about it being rich..

I would definitely spend a few hundred tuning it..

that's not right..

I'd also recommend a spark plug change after the mixtures are corrected..

I think that on your baseline run, the A:F ratio's will be off the chart.. as in below the 10:1 reading that most dyno's are calibrated to.. (I think)

[BHDave]

245kw at the wheels! I love rb26s.

If you're blowing that much smoke and getting such bad milage i reckon you need to have it looked at. Theres probably another 20kw hiding in there easy

If it is only blowing smoke when you put your foot down then it may just be the pump settings are out of whack and it needs a bit of road tuning to iron out drivability issues.

Still talk to a tuner, dyno time is a great way of seeing what your car is doing anyway so give it a go

[DaiOni]

"Don't expect to get your car tuned at CRD for any less than $800 though..."

My car (the magna, not the FD, obviously) was on the dyno for several hours (quite a few actually) and he charged me about $200... (actually, that covered install too...)

It was a sponsored car (unichip sponsored, among others) and I was giving him a good plug on my website though!

Nice guy - and a great tuner!

Definitely expensive - but you get what you pay for

[butthead]

It only blows smoke when i'm taking off & a few seconds after reving the engine (stationary). The dyno tuner said that he had noted it down when the car was last there.

He said that there was a air flow metre problem caused by a bad compressor surge. He said that some one had modified the turbo housing or the turbo wheel.

Where do i start to correct this problem. He said that he doesn't deal with those type of problems.