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It would be interesting to see a comparison between different FMIC to have a baseline

But why would you say with an electronic boost controller attached the drop would be worse?

Doesn't an EBC usually sample the manifold pressure and modulates the actuator/wastegate in order to maintain it's target boost?

That would compensate for boost drop down the line, not exacerbate it.

I made 375rwkw (400 in a manual due to trans slip) with the same cooler on the same dyno in the same model car.

That's not to say there's no pressure loss, but as mentioned, are all FMIC's like that?

But why would you say with an electronic boost controller attached the drop would be worse?

Doesn't an EBC usually sample the manifold pressure and modulates the actuator/wastegate in order to maintain it's target boost?

That would compensate for boost drop down the line, not exacerbate it.

That's actually somewhat of a myth. My Profec for example, is connected to the inlet manifold so it can show the actual boost being run (plus one or two other reasons, see below*). But it does not do closed loop control to achieve it. It's just like most other boost controllers. It just pulses the solenoid valve according to the settings for duty cycle and gain (however those terms are encoded in the setup menus!) on a fixed basis. The only way that you know you're getting the right boost is that it shows you on the screen. If you're not getting the right boost then you just turn up (or down) the setting until you do. Ie, the control action occurs during setup, by the user. Thereafter the boost controller is pretty much a fairly dumb instrument.

*The other thing that the manifold boost connection does on EBCs is alert the EBC to the fact that the turbo is now making boost (it watches for transition from vacuum to +ve pressure) so that it will start pulsing the solenoid. This is so that the solenoid does not pulse madly all the time, which would wear it out. The other reasons are around alarming and duty cycle cutting for overboost situations.

The concept of closed loop boost control might sound attractive, but there are many aspects of driving a turbo engine that make it questionable as a simple bolt on affair. For example....part throttle operation. Let's say you have enough load and throttle opening to be running half of your full boost. That means that you are controlling boost with your right foot. Might be difficult, but it is doable. If you were doing that, and the EBC was seeing half boost in the manifold, then it would be keeping the wastegate closed trying to ramp the boost up. The boost would indeed ramp up, in the pipework between the turbo and the throttle body, and you would have to progressively close the throttle to stop the manifold pressure from rising with it. This would make for VERY difficult control. You would be fighting the boost controller for control of the manifold pressure. If the EBC was just doing what it normally does (as if the throttle was fully open, as it was when you set it up) then the pressure in the pipework would not soar out of control and you would stand a much better chance of controlling the manifold pressure with your foot.

Hey Ryan.

Get the ss2 with type b rear internally gated. I made 297rwkw on pump fuel. My dyno results are on hyper gears webpage and loved it that much I recently brought another but this time external gate for my track car.

  • Like 1

One more result to add. This is from a high flowed R33 turbo running E85 on 18psi of boost. Tuned by Racepace Dyna on dynamic roller dyno. FInal result of 309.9rwkws.

309rwkw21uhfe85.jpg

Pressure drop is from the core or more it's ability to flow the required air flow and the runner entry has a lot to do with it, the more turbulence created by the air trying to get into the runners the worse the pressure drop, the more air you try and flow through a core the more pressure drop, you dont lose pressure in pipes or end tanks unless there is a restriction or the piping is to small

This won't change with the fitment of a EBC, the only difference is where the EBC is connected, if connected to the inlet manifold the EBC will make the turbo harder to counter react the pressure drop to maintain the set pressure in the manifold meaning the turbo could be pushing 20psi at turbo to make 15psi at the manifold ( figures are just for example )

This is why i giggle to myself when people say they make 400rwkw+ from a stock GTR cooler, sure you can but how hard are your turbos working to do it and how much would you pick up by using an appropriate cooler

One more result to add. This is from a high flowed R33 turbo running E85 on 18psi of boost. Tuned by Racepace Dyna on dynamic roller dyno. FInal result of 309.9rwkws.

309rwkw21uhfe85.jpg

Thats a nice result, what boost level was that at

This is why i giggle to myself when people say they make 400rwkw+ from a stock GTR cooler, sure you can but how hard are your turbos working to do it and how much would you pick up by using an appropriate cooler

Do you expect there is much more power to be had from a GT30? I would have thought 400kw was doing pretty well when the cooler is limited to 250kw apparently. I always laugh when people put a power cap on a certain parts, when it's the entire setup causing the limitation.

How much of the restriction is due to heat, and what's the point of measuring pressure both ends of the cooler if you don't have temp sensors also? We are essentially talking about making a car defectable here by cutting holes in battery trays and reo bars, so saying a 100mm cooler is mandatory to making what is fairly low power is a big call, especially when that cooler is proven to flow much more.

I guess it's easier to blame parts than find the actual reason for the power limitation.

Do you expect there is much more power to be had from a GT30? I would have thought 400kw was doing pretty well when the cooler is limited to 250kw apparently. I always laugh when people put a power cap on a certain parts, when it's the entire setup causing the limitation.

How much of the restriction is due to heat, and what's the point of measuring pressure both ends of the cooler if you don't have temp sensors also? We are essentially talking about making a car defectable here by cutting holes in battery trays and reo bars, so saying a 100mm cooler is mandatory to making what is fairly low power is a big call, especially when that cooler is proven to flow much more.

I guess it's easier to blame parts than find the actual reason for the power limitation.

So is reading your problem or are you just not smart enough to comprehend what you have read

Where did i mention a GT30, where did i mention 250kw was the max a GTR cooler would flow or even fitting a GTR cooler to a GTS or that you had to have a 100mm cooler

That's alot of words you have put in my mouth or assumptions you have incorrectly made about my comment

My reference was directly to power lost to pressure drop and nothing else and none of what you said has anything to do with what i posted

Or are you saying if you make 400kw from a stock GTR cooler that you wont pick up any power by putting on an APPROPRIATELY sized cooler

I made 375rwkw (400 in a manual due to trans slip) with the same cooler on the same dyno in the same model car.

That's not to say there's no pressure loss, but as mentioned, are all FMIC's like that?

No, the Katashi 600x300x100mm cooler had identical readings before and after on my GTR.

When I'm trying to make it hold more boost the IT temp jumped significantly and the engine wanted to pin.

There are few criteria for this to work on your specific scenario. First your engine compression is about 8.3:1 while standard is 9:1, 2ndly you are running e85 fuel in combination of an external wastegate as well as a welly worked factory exhaust manifold. The spec of this engine as well as fuel used makes it less likely to knock due to rise of IT, if it does, the level of knock would not be as significant that required same or equal amount of timing deduction for avoidance.

However working with this specific cooler restrictions I still managed to pull off 300rwkws with it on pump fuel internally gated on SAT configurations. If a free flow cooler is installed, with the current EBC settings, it would be sitting some where around 24psi or higher.

So is reading your problem or are you just not smart enough to comprehend what you have read

I guess a discussion is too difficult for you without the personal insults? Have a snickers mate. :)

I was discussing what Hypergear posted specifically, relating to his GTT, and of course you would gain a little power with a larger heat sink on the front. If there was room, and if the customer was happy to run a monstrous cooler I would gladly fit one, and bugger the downsides. But to hack up another GTT engine bay just to run decent piping to it, generally isn't worth the risk.

On the road the cooler's job isn't difficult, it's not like loading the engine up on a dyno with a pissy fan. Most people can get away with smaller coolers and pay only a small power loss and in most cases there is simply no need for anything more than a decent 'legal' return flow, which I have proven many times. Perhaps instead of everyone bagging return flow's, work out which ones are crap and recommend the better kits? The current Blitz certainly isn't one of them, and for the price it was a bargain.

There is no 'power limit' on coolers, (or most other parts) only varying degrees of efficiency. That was the point I was trying to make.

  • Like 1

I guess a discussion is too difficult for you without the personal insults? Have a snickers mate. :)

I was discussing what Hypergear posted specifically, relating to his GTT, and of course you would gain a little power with a larger heat sink on the front. If there was room, and if the customer was happy to run a monstrous cooler I would gladly fit one, and bugger the downsides. But to hack up another GTT engine bay just to run decent piping to it, generally isn't worth the risk.

On the road the cooler's job isn't difficult, it's not like loading the engine up on a dyno with a pissy fan. Most people can get away with smaller coolers and pay only a small power loss and in most cases there is simply no need for anything more than a decent 'legal' return flow, which I have proven many times. Perhaps instead of everyone bagging return flow's, work out which ones are crap and recommend the better kits? The current Blitz certainly isn't one of them, and for the price it was a bargain.

There is no 'power limit' on coolers, (or most other parts) only varying degrees of efficiency. That was the point I was trying to make.

And again what does any of that have to do with what i said, your whole first post was nothing more then you putting words in my mouth and twisting what i said so you could take a shot at me, so much so i had people texting me about it, and what that last line in the first post wasn't a snicker at me

First of all i said a stock GTR cooler and didnt realise i had to spell out the fact i meant the stock GTR cooler was fitted to a GTR, not once did i mention hacking up a GTT to fit an illegal cooler or hacking the engine bay to fit the required pipe work

isn't that basically what i said, a GTR cooler has lost most of it's efficiency by 400rwkws and when was the last time you opened the bonnet of a 400rwkw GTT to find the engine bay that looked completely stock and then your worried about fitting a decant front mount, at over 400rwkws i would say a decant front mount would be the least of your legal issues and if you want to make 400rwkws or more what other option have you got for a GTT, does someone make a factory mount cooler that will efficiently flow the air required at that power level

So if there is no power limit on a cooler why bother upgrading, why not just run the stock one, which was exactly my point, while you can make 400rwkws from a stock GTR cooler fitted to a GTR how much extra would you make by bolting on a direct bolt on for a GTR to a GTR that is more efficient at that power level like a 79mm ARC item, or the 105mm ARC i have on my 34 to cover 500kw at all 4, i also said appropriately sized cooler not the biggest monster available, fitting a 150mm cooler to a 400rwkw GTR is inappropriately big and would hurt turbo response to a certain degree even though it will bolt in with only light "trimming" of the front bar without having to make custom pipes and hacking up the engine bay to fit them

So my first line was directed to the fact you tried to have a shot at me by arguing my point against me :/

What amuses me though is i have had people PM me about pipe work for their factory mount GTTs and it was you i recommended them contacting, but after this BS that is a mistake i wont make again

Ok children can we leave that now and get back to the issue at hand?

What brands of return flow front mounts being used appear to be good and which ones appear to be bad?

By the looks of things the Blitz one is not good?

Mine is a cooling pro one and made 320rwkw at 22psi but my tuner did say that was pretty much it's limit, however boost drop wasn't too bad (measured by map sensor) it did taper a little but it was still in the 20's from memory.

Are there any other experiences to note?

post-27668-0-52190600-1416644101_thumb.jpg

I've got this result from cooling pro return flow with the OP6 highflow on r33 rb25, on probably the 6th or the 7th run and results still remained consistent, and probably at the limit of the turbo too. I guess if you're trying to squeeze more out of it then you might benefit from a larger FMIC.

as a turbo developer I'm sure Stao needs more headroom to see the full potential of his turbos, but as an end user/ daily driver I wouldn't bother at the cost of drilling a hole in the engine bay when I'm already getting consistent results like this at this power level which is plenty for most people.

note I tried to keep the boost at 17psi, but it just kept climbing on the higher rpms regardless of boost controller setting, hence the boost curve. But that's another issue altogether

Does anybody know of any decent rb25 results with a vertical flow intercooler? Wondering if this would be a good option to keep all the pipework on the passenger side, but still make some serious power. Was looking at some Treadstone performance cores, the CV25 core is 150x635x90mm. Looking at another thread on a vertical flow install into r34 that might just fit with no reo cutting (I haven't measured though). With the Treadstone end tanks on top and bottom that would work out as an intercooler totalling 330mm high...

What would the disadvantages be? Maybe a bit less intercooling effect? Should pose little flow restriction though right..?

Does anybody know of any decent rb25 results with a vertical flow intercooler? Wondering if this would be a good option to keep all the pipework on the passenger side, but still make some serious power. Was looking at some Treadstone performance cores, the CV25 core is 150x635x90mm. Looking at another thread on a vertical flow install into r34 that might just fit with no reo cutting (I haven't measured though). With the Treadstone end tanks on top and bottom that would work out as an intercooler totalling 330mm high...

What would the disadvantages be? Maybe a bit less intercooling effect? Should pose little flow restriction though right..?

I'm running a Trust vertical flow intercooler in my R34 GTT with ATR43SS2 (mid 2013) from Stao, currently making 275rwkw at ~20psi on 98 with a manual box. Full specs and dyno sheet here: http://www.sau.com.au/forums/topic/55845-rb25-turbo-upgrade-all-dyno-results/?p=7370873

I haven't measured pressure drop across the core, it would be interesting to see.

Vertical flow cores should have lower pressure drop, because of larger number of core tubes and each tube is shorter length.

They should also, however, suffer from reduced heat transfer efficiency compared to a horizontal flow core of the same size. This is for the same reasons that the pressure drop is lower. More tubes = lower velocity, Lower velocity = lower convective heat transfer coefficient.

It might be possible to try to overcome those effects by trading off some of the pressure drop saving by packing in more internal finning in the tubes. Increase contact area and increase turbulence to compensate for reduced convective coefficient.

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