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I had a look through into your dyno reading which appears its missing a big chunk of power band down low, the black line represent the missing figures. You've mentioned the tuner experienced some ECU faults, not sure if that is why he made it retarded. Would be a good idea to find out the cause. I've posted the ecu file for it, he can use for reference. It would be totally different to drive once every thing runs properly, also was the VCT enabled in your car?

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Slowskyline would you have a reading from your current tune? or have a look at the tune on my test car. I'm pretty sure its about the same.

What do you mean by reading?

I have had a read of the 1st 100 pages of this thread plus the last 10 or so, but I can't say as yet I've seen one boost plot with the SS or G2/G3 turbo where the boost is solid from spool up to redline.

I can understand where stock housing highflows are used there might be a restriction, but is there a complete aftermarket turbo in the HG range that can hold anywhere between 15-20 pound with an EBC from spool to redline? I saw some people were recommending a super stiff wastegate but honestly I'd prefer the minimum to be lower and then increase it with the EBC to have the choice, and still have it hold whichever figure is input, rather than have to tune it with a decrease across the rev range like the dyno plots I've been seeing. I've had my fair share of stock turbo's and garrett's in the past and havent had to factor in declining boost before.

Is this unrealistic for this type of turbo?

I had a look through into your dyno reading which appears its missing a big chunk of power band down low, the black line represent the missing figures. You've mentioned the tuner experienced some ECU faults, not sure if that is why he made it retarded. Would be a good idea to find out the cause. I've posted the ecu file for it, he can use for reference. It would be totally different to drive once every thing runs properly, also was the VCT enabled in your car?

Yes, I should just clarify for anyone reading that my results are in doubt, it certainly seems that there is more potential within this turbo and my setup.

As far as I know, VCT is on. But I'm confused about whether it has been set up properly, or if it is actually turning on at all. In my NIStune file, the VCT recovery RPM is set to 5500 and the cut RPM is set to 5600rpm. As well as the fact that in the gauge display, the light next to the VCT solenoid does not come on at all. So it seems to me that it is not set up properly, which may be as a result of the ECU problems.

I wish my tuner had been more clear about what sort of problems the ECU caused him, so I could figure out how to sort it. I would like to drop in and speak to him about it, but he is always very busy. The NIStune guys are not sure how to fix it because they have never seen a similar problem with the codes I am getting. At this stage I just don't know.

I have had a read of the 1st 100 pages of this thread plus the last 10 or so, but I can't say as yet I've seen one boost plot with the SS or G2/G3 turbo where the boost is solid from spool up to redline.

I can understand where stock housing highflows are used there might be a restriction, but is there a complete aftermarket turbo in the HG range that can hold anywhere between 15-20 pound with an EBC from spool to redline? I saw some people were recommending a super stiff wastegate but honestly I'd prefer the minimum to be lower and then increase it with the EBC to have the choice, and still have it hold whichever figure is input, rather than have to tune it with a decrease across the rev range like the dyno plots I've been seeing. I've had my fair share of stock turbo's and garrett's in the past and havent had to factor in declining boost before.

Is this unrealistic for this type of turbo?

Look at my lines...

My boost controller is a Greddy profec B spec 2. It runs 0% gain, which is the setting used to control boost falloff at higher rpm. If I knew what I was doing, I am fairly sure I can get an almost dead straight boost line on both settings.

post-68383-0-47536200-1323745737_thumb.jpg

post-68383-0-94019000-1323745771_thumb.jpg

I have had a read of the 1st 100 pages of this thread plus the last 10 or so, but I can't say as yet I've seen one boost plot with the SS or G2/G3 turbo where the boost is solid from spool up to redline.

I can understand where stock housing highflows are used there might be a restriction, but is there a complete aftermarket turbo in the HG range that can hold anywhere between 15-20 pound with an EBC from spool to redline? I saw some people were recommending a super stiff wastegate but honestly I'd prefer the minimum to be lower and then increase it with the EBC to have the choice, and still have it hold whichever figure is input, rather than have to tune it with a decrease across the rev range like the dyno plots I've been seeing. I've had my fair share of stock turbo's and garrett's in the past and havent had to factor in declining boost before.

Is this unrealistic for this type of turbo?

You want an external gate.

Look at my lines...

My boost controller is a Greddy profec B spec 2. It runs 0% gain, which is the setting used to control boost falloff at higher rpm. If I knew what I was doing, I am fairly sure I can get an almost dead straight boost line on both settings.

On your dyno dynamics sheet the two higher boost settings are fairly consistent. Have other people managed this? What turbo is it?

Also, do you know why the lowest setting creeps super slowly from 5 to 10 psi?

On your mainline sheet it's the other way around, the lower setting is more consistent and the higher one bleeds back 5 psi. Is this that the turbine housing is too small to hold 20 psi or what?

You want an external gate.

I agree that external gate is more consistent, however I've had aftermarket internal gate turbo's that hold a set figure between 12 and 20 without problems. That's why I'm asking now, if this is just inherent in the design of these ones (like their wastegate design or turbine bore or something) and something that should be expected?

How can a boost creep or bleed be tuned around if the behaviour is slightly different in each gear? Wouldn't that be an opening for detonation if it was tuned for fourth and the bleed/creep characteristics were different in 2nd for example?

Surely I can't be the first person to ask why the boost figures at 4000rpm aren't the same as the boost figures at 7000rpm?

On your dyno dynamics sheet the two higher boost settings are fairly consistent. Have other people managed this? What turbo is it?

Also, do you know why the lowest setting creeps super slowly from 5 to 10 psi?

On your mainline sheet it's the other way around, the lower setting is more consistent and the higher one bleeds back 5 psi. Is this that the turbine housing is too small to hold 20 psi or what?

The lines are with the EBC fully setup for the tune to run that boost. The lowest setting is the boost controller switched off, you can see how horrible some actuators can be. The thing could not even hold any boost, it was just a test to see what the actuator can do. With steady control, you can almost perfectly control boost with a good EBC.

My turbo is the SS2 turbo. The other graph, which runs more boost, is with a stiffer actuator. With my boost controller at 100% for the dyno dynamics run, that was as much boost we could get out of the thing. Needed a tighter spring.

I agree that external gate is more consistent, however I've had aftermarket internal gate turbo's that hold a set figure between 12 and 20 without problems. That's why I'm asking now, if this is just inherent in the design of these ones (like their wastegate design or turbine bore or something) and something that should be expected?

How can a boost creep or bleed be tuned around if the behaviour is slightly different in each gear? Wouldn't that be an opening for detonation if it was tuned for fourth and the bleed/creep characteristics were different in 2nd for example?

Surely I can't be the first person to ask why the boost figures at 4000rpm aren't the same as the boost figures at 7000rpm?

External gates arent always consistant, just larger so they dont usually cause boost spiking.

The issue you will usually see with boost tapering off is the wastegate blowing open from the massive pressure in the manifold, sometimes up around 60psi or more. Most wastegates will leak at those pressures. Added to that is the engine is reving more, and swallowing more air, requiring the turbo to work harder to compress the air. Eventually it wont be able to flow any more and boost will start to drop. Remember that boost is only a measure of restriction.

It does make it hard to tune around but as long ars these problems are consistant the tune will be ok. If you are worried, ask them to back it off a bit. (even NA's knock up hills though). Or you can fill on ethanol and never worry about pinking again. :cheers:

External gates arent always consistant, just larger so they dont usually cause boost spiking.

The issue you will usually see with boost tapering off is the wastegate blowing open from the massive pressure in the manifold, sometimes up around 60psi or more. Most wastegates will leak at those pressures. Added to that is the engine is reving more, and swallowing more air, requiring the turbo to work harder to compress the air. Eventually it wont be able to flow any more and boost will start to drop. Remember that boost is only a measure of restriction.

A good external gate with a good boost controller will usually always be more consistent than an internal gate. When the wastegate is purely controlled by the actuator, the only thing you can do with a boost controller is bleed air off. But as you pointed out, it isn't just the boost pressure that opens the wastegate. With an external gate you can apply pressure to the top of the diaphragm to hold the gate shut and hence control boost much better.

That was my point when I said he wants an external gate. He said he would prefer to run a softer spring and then use an EBC to control the boost. With an actuator controlled wastegate, that's going to be very hard to achieve. But with an external gate you can use the EBC to hold the gate shut and achieve your target pressure.

Edited by Hanaldo

So do other internal gate turbos from other brands do not have this issue on stock manifold or do they?

I'm pretty sure I've looked at dyno results for other brands and haven't noticed this with internal gates.

I'm not knocking Hypergear, as I'm interested in getting one myself. I just want to know if anyone's tackled the problem or if everyone that has a HG turbo with internal gate just says "that's the way it is" and tunes around it?

Internal gate can control boost consistantly just depending on how much boost. Ie run 15~18psi no worries, boost hold straight, run 20~24psi, there will be a tappering off depending on the size of the turbo. That is due to the in-consistancy in exhaust manifold pressure. Can be fixed to certain extend with a high pressure actuator or run externally gated, also lowers EGT and makes abit more top end.

Stao dont you supply high pressure actuators for your turbos?

Yeah he does, does a pretty damn good job of holding high boost considering the very high exhaust pressure these turbos run.

We normally supply a high pressure actuator with the turbo depending on power goal and boost level that the owner targets. Exhaust manifold pressure depends on inlet manifold pressure, as well as the size of the turbo.

Based on the results you've currently got from your car and your customer's car's Stao, which turbo in your range is ideal for the 270 - 290kw range on no higher than 18-19psi? Do you have some of the results of them with regard to their boost curve etc? Do you have to run a very solid wastegate actuator to hold the boost steady?

I'm guessing the SS range is a little more aimed at response than these, however I saw you experimenting with FNT nozzles to get better results out of the smaller turbos, so I'm interested to hear if it's possible on a quicker responding turbo without needing to crack 20 psi+ as it's an unopened rb25.

I'm guessing an ATR43 G3 is closest to this sort of goal?

Are your SS turbo's more or less the highest-tech ones in your range?

The ART43G3 is a bigger turbo that the turbo's in the SS range. It is not the turbo you want if you are after response. The SS series pushes roughly the same amount of boost to make similar power, earlier.

Check page 73, Tao made 285rwkw with the SS2 turbo on 18.8psi.

It isn't the psi that kills motors, it is the torque and detonation, forget the psi limit. If you get a big enough turbo you could make 500kw on 15psi, doesn't mean that an unopened rb25 would be fine with it.

Edited by Rolls

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