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Hi Guys,

I have had my R34 GTT for about 8 months now, I have spent a fair bit to get it to this point but I am curious as to why my graph looks the way it does and isn't smooth like so many others I have seen.

I have the following mods on my car:

Hybrid FMIC

Bosh 044 in tank

Deatchworks 600cc injectors

Sard FPR

3" turbo back exhaust

Yellow Jacket Coil packs

Hypergear SS1PU (set to 17 PSI on the wastegate)

Z32 AFM

Power FC

Below I have supplied the dyno sheet and I have a few questions:

1.Why does it plateau in several spots?

2. What can be done to make it a smoother tune up top?

3.Should I be looking to move away from the Power FC at this point?

4. Who is known for there Power FC tuning skills in the brisbane area?

5.Is the A/F ratio where it should be?

post-53828-0-64105700-1327272782_thumb.jpg

Edited by RandomHero83

Your afrs might be considered a little lean to the tuning standards of many in Australia. You want to be in 11's to help cool the intake charge. As to your dyno graph, you don't specify if you are using a boost controller and by your comment, I assume you aren't. How does your boost curve look? I really, really doubt you are holding a steady boost line. What I can suggest is get your self a good ebc, set it to about 15psi, and give it some gain to help prevent boost falloff. I can't see your tune so I can't vouch for it (timing could be sloppy, afr looks steady though), but I do suggest you get an ebc then had to erd, I think they are up that way.

Also, the power FC is not your problem. Plain and simple, even though it lacks newer features(MAP sensor, flex fuel, 3d mapping(these aren't essential)), it still is a tried, tested and proven performer. It is not the issue. The issue is power is dropping and coming back on then dropping etc. My old skyline did the EXACT same thing. I had an EBC with a 2835 or something highflow. My EBC was not setup right and it hit the limiter, bled off air to drop boost, then ramped up again and repeated over and over. My boost settings were set lower than my actuator settings. This was corrected by adjusting the boost controller properly.

As much as Tao swears by those actuators, I will not trust them alone to do their work. Sure it will hit 14psi, but how long will it hold it? You should see my old dyno graph with his actuator on my SS2 turbo. Its a 10psi actuator yet it took all the way until redline to actually build up 10psi. Got a new actuator and boost controller and my 14psi low boost is almost flat line to red and high boost 20psi is just as good.

Edited by SargeRX8

Spoken to your tuner about it? if so what did they say?

No good coming on here and asking us what is the problem with the tune, all we are going to to is guess and suggest what is needed by looking at other peoples setups.

Another Tuner i will suggest is EFI Performance but they are the opposite side of town to RPM.

Get a torque/trac effort & boost read outs, then we can better see what it's doing.

Very hard to say with just a AFR graph

Your afrs might be considered a little lean to the tuning standards of many in Australia.

:huh:

I know 12.2 isn't lean but all the tuners who have ever done any work on my car like to tune into 11's, some even into high 10's when you are on full song.

If you for an aftermarket boost gauge, get your camera phone to record a video of the gauge while you ramp up full boost in 3rd gear/4th gear to red line. You are going to need some empty road coz you will go fast. After than watch the video and see what your boost is doing. If you see it flopping up and down from 14psi, then you have a problem you need to fix. If you manage to hold 14psi all the way to redline(that turbo is VERY capable), then the boost control is not your issue.

Edited by SargeRX8

Peak power is about right for that turbo (isn't it??), AFR's around 12 is reasonable, possibly could fatten it up around peak torque but it doesn't look like you have major issues.

How does it drive?

It drive's pretty good but feels like there is more power to be had and is falling short.

I have attached the boost graph with an overlay of the previous tune.

DynoBoost.jpg

I have an EBC but it is not in use atm the tuner did not want to use it (wanted to tune it on the wastegate) Should I reconnect it to stablise the boost drop.

The wastegate was set to 22psi when the turbo arrived but was wound down to 17 by my tuner (worried too much boost may kill the ring lands)

Edited by RandomHero83

^ What wolverine said.

If it's driving fine then a few bumps and dips in the curve don't mean much.

It could have spun the wheels coming on boost

It could have overshot target boost as it ramped up

It could have a bit of a misfire becasue the plugs are a bit old.

The boost drop may be related to the turbine housing size.

I think it is worthwhile trying different things to get it to hold flat, such as using the EBC but sometimes trying to eke out the last 5% costs more money than it is worth...having done it a number of times....lol

Personally I would have left the actuator alone and had the car tuned with it as supplied but that is water under the bridge now.

Cheers for the feedback guy's,

I think that the chance of doing damage to the engine may have been the big factor on being conservative with the actuator and the tune in general.

My tuner is a great guy but he will alway choose caution over what a customer would like to try and make the car do (I asked for 350-370HP) from everything I have researched it should be able to do it quite comfortably (engine is in good health and supporting mods are there) I just wanted some opinions on how the graph looked and if there was anything glaringly obvious that could need to be attended to.

I'll admit to a knowledge gap when it comes to these things and believing what one person tells you without looking into it and trying to learn about it is just plain out negligent.

Edited by RandomHero83

It drive's pretty good but feels like there is more power to be had and is falling short.

I have attached the boost graph with an overlay of the previous tune.

DynoBoost.jpg

I have an EBC but it is not in use atm the tuner did not want to use it (wanted to tune it on the wastegate) Should I reconnect it to stablise the boost drop.

The wastegate was set to 22psi when the turbo arrived but was wound down to 17 by my tuner (worried too much boost may kill the ring lands)

By my viewing it's making 15psi at 4000rpm and turning over at 6500rpm :glare:

I would be more worried about the small power band than the wavy graph

Edited by SimonR32

How long was spent on the tune? It may just need a bit more time spent on it.

As for the boost, maybe try putting your EBC Back in to use as it should bring the boost on a touch quicker and if its a good one it should hold boost nicely.

The AFR looks O.K, theres one spot where it leans a little bit (looks like when the boost is ramping up) and you can see the power level goes a touch funny here, but its nothing major by the looks of it.

I run my AFR's around 12:1 up the top end with no problems, its really car/setup specific though

What's your knock like?

How long was spent on the tune? It may just need a bit more time spent on it.

As for the boost, maybe try putting your EBC Back in to use as it should bring the boost on a touch quicker and if its a good one it should hold boost nicely.

The AFR looks O.K, theres one spot where it leans a little bit (looks like when the boost is ramping up) and you can see the power level goes a touch funny here, but its nothing major by the looks of it.

I run my AFR's around 12:1 up the top end with no problems, its really car/setup specific though

What's your knock like?

As far as I know 10 hours or so was spent on the tune, I will try putting the boost controller back on when the weather is better and the ground is dry (no traction is no good for testing)

I am thinking that (based on what I have read and that there is a bit of room for wiggle in the A/F ratio's)

I should be able to setup the EBC again and then bring the boost up to a 16 PSI stable with a slightly quicker spool speed.

I am not sure what the current knock is I have the hand controller so i'll have a look at it.

What constitutes bad knock?

The question is do I have enough room in my A/F Ratio's to put the boos up to 16 psi constant or should I go back to the tuner and get him to adjust it? ( would rather it not cost me more on a retune)

Edited by RandomHero83

It really depends what cells it hits when you get it to hold constant boost and whether he touched some other cells in anticipation of a higher boost being reached

I don't know the tuner so can't say for sure. Id take it back just in case it does lean out. shouldn't have to spend to much time on it anyway

The power to boost level seems to be correct, the rear housing on that is pretty big for what it is.

I don't like people unloading those actuators tensions. Pop it off and make sure its correctly loaded. that flat shape down low indicates its loosely shut. Or send the high pressure actuator back swapping for a 14psi one, correctly load it then use the EBC. EBC helps holding the boost curve consistent up top.

12afr is tinny bit lean for my like, Trent normally run them at 11.5, won't matter much. You can goto see DVZ, he tuned one last year that the curve matched pretty close to mine.

The power to boost level seems to be correct, the rear housing on that is pretty big for what it is.

I don't like people unloading those actuators tensions. Pop it off and make sure its correctly loaded. that flat shape down low indicates its loosely shut. Or send the high pressure actuator back swapping for a 14psi one, correctly load it then use the EBC. EBC helps holding the boost curve consistent up top.

12afr is tinny bit lean for my like, Trent normally run them at 11.5, won't matter much. You can goto see DVZ, he tuned one last year that the curve matched pretty close to mine.

So tentioning up the actuaitor should make the boost climb steeper?

what psi should it be set to?

Is DVZ located in the brisbane area?

So tentioning up the actuaitor should make the boost climb steeper?

what psi should it be set to?

Is DVZ located in the brisbane area?

I tried setting my actuator for my HKS Turbo up by using a regulator, a digital pressure gauge and some air at home. It doesnt really work though. I found the best way to just tighten the actuator about 1 full turn at a time then adjust half turns, I think Stao's actuators are adjustable in the same way anyway. Lengthen the rod = Increase tension/wastegate opening pressure

I know a while ago someone on here had trouble cause there actuator wasn't pretensioned tight enough and was extremely lazy and slugish (from memory anyway)

So tentioning up the actuaitor should make the boost climb steeper?

what psi should it be set to?

Is DVZ located in the brisbane area?

DVS meaning me. Nope im on the central coast NSW.

Come for a roadtrip :)

I'll try upping the tension when this rain pisses off (that's if there are roads to drive on after)

I have some holiday time coming up DVS so maybe a trip to the dark side is an option, how much would a look over an tune adjust cost ( ball park figure)

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