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Getting Gcg Highflow To Hold Boost For Longer, 18psi To 15psi Drop By Redline


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What fails and around what mark? Do all of their highflows use the standard bearing housing? You mentioned in that thread that the entire rear housing was glowing red hot, surely this would not be good for the life of the bearing? The car is a daily driven street car mainly, but it does see some track time so it has to be reliable.

Not all of them. I had sleeve bearings and Ball bearings with stock bearing housing. The problem is in the thrust washer, which is a flat piece of stainless steel. This moves under high back pressure causing the whole shaft moving towards comp side. I had 2x of them, all got broken wheels with massive back n forward play in exact same way. I think that design must've been changed now.

I've engineered my own collars, bearings and bearing housings to work with high back pressure and heat in high flows,its not just a 360 degrees thrust bearing. Honestly I'm not worried about the little sucker been hot, its engineered for this purpose.

Also the Gate controller's design has been changed long time ago. The current one is not a stopper at all, it can set to hold any sort of boost pressure you want it to, very easy to adjust, and very consistent, I've changed dyno ramp rate, threshed it day n night, went on few different dynos, it was very consistent, I don't believe you can hold 18psi any other methods.

I honestly think there is a lot of knowledge to be had in this thread:

http://www.skylinesaustralia.com/forums/35...-9b-t22706.html

This guy managed to make the same sort of power from nothing more than porting the rear housing and running a big compressor wheel.

Stao, I have seen your exhaust wheels, they are enormous. Have you thought about running a milder exhaust wheel and porting the exit more than a standard profile?

Maybe you can experiment with some of the theories found in that thread.

I will be working with a pair of Toyota CT12A soon, so I might give you a call about some bits we can try with them.

Rolls - do you run the boost line to the actuator from the intercooler piping or the plenum? If its off the cooler piping try running it off the plenum, worked for my car and works for every sr powered S13.

p.s its zebra...not Prue lol

Run it straight from the compressor housing to the controller as its a rb20 front housing with the nipple already there as they don't use a solenoid from factory.

Edited by Rolls
I honestly think there is a lot of knowledge to be had in this thread:

http://www.skylinesaustralia.com/forums/35...-9b-t22706.html

................

Yes I did read that through. Its a very interesting thread, reading it again after 7 years, its abit newish. He's using a bigger turbine housing (.81?), I don't think its a bolton housing for the RB25det tho. Also he's running the T04's 71mm comp wheel, I'm very concert about surge issue linked to Slide's high flows years back, The turbine wheel is too packed and heavy, But thats all there is available back in the days.

I did used mild wheels for high flowing, they comes to boost quick, but not making the sort of power I'm hopping for, and most people whom wants high flows are trying to squeeze the last KW out of it in comparing to some 300rwkws setups. This is the majority direction that high flowing is heading to. Of course small wheels are also used for people who's chasing max response and mild power.

Traditional wheels and setups are not made to do this. Stand up to the challenge, we had to make lots of custom parts so the turbo has the efficiency and last. None standard turbine wheels, gate controllers, high pressure actuators are all bits of the missing pieces archiving this goal. If I'm high flowing that guy's turbo today with his .81 turbine, I can easily max it over 300rwkws consistently.

Back to the boost holding problem. Rolls you mentioned about the twin entry actuators, I think if you can some how connect the bottom entry to exhaust manifold pressure without the heat and bleed that with a boost controller it should work, How ever it will act in the same principle as having a waste gate stopper, So consistency would be a concern.

Hes using the VG30 housing in that thread, its just an op6. You need to read the whole thread to see how the turbo developed, there are a lot of typos and misleading information. The final specs are also in a different thread that u need to find the link to in there.

The actual reason I pasted that link was to give thought to the possibility of porting the exhaust housing exit to held hold higher boost?

It would mean more lag yet ability to flow for longer.

However, EVERY high flow I have seen lately has an ENORMOUS rear wheel that is seemingly infinitely ported already so, this is probably a dream at best until you take the turbo off and take a look.

If you have a look at something like a HKS GTRS, the rear wheel is nowhere near the size of the wheels we see in high flows, yet still cuts the mustard as we all know.

I feel these high flows are sort of like commodores, every time they make a newer and better one its grown in cubes and they throw bigger band aids on it to compensate (brakes, tyres, etc).

I imagine when the limit is the housing size the bigger wheel compensates for this, where as with the GTRS you have a bigger housing so can get away with a smaller wheel. Not that I am anywhere an expert on this, but that would be my guess.

I imagine when the limit is the housing size the bigger wheel compensates for this, where as with the GTRS you have a bigger housing so can get away with a smaller wheel. Not that I am anywhere an expert on this, but that would be my guess.

Something along the lines of my thoughts. Actual engineering is bypassed by a big wheel that lets a lot of gas through it easily.

Seems like an awful lot of trial and error going on for a pretty heavy price.

Hes using the VG30 housing in that thread, its just an op6. You need to read the whole thread to see how the turbo developed, there are a lot of typos and misleading information. The final specs are also in a different thread that u need to find the link to in there.

......

I feel these high flows are sort of like commodores, every time they make a newer and better one its grown in cubes and they throw bigger band aids on it to compensate (brakes, tyres, etc).

The most I've yet managed to high flow a OP6 is 295rwkws @18psi flat on 98 fuel with wheel spin and that was pretty consistent. Bigger wheels can lower back pressure, flow more air, and work with a bigger comp wheel. Lot of turbo builders would back cut some of the TA and TB turbine wheels to archive similar and the down side is massive lag and missile switch sort of acceleration. Means poor driving ability.

So try to get the power and improve better driving ability is the most expansive part, involves making new wheels trail and error. So in another word building a new turbocharger to suit a certain purpose is cheaper in research.

And of course customizing a turbo for performance to extreme requires alternations to its components, just like a bigger and powerful car would have better breaks, stronger gear boxes and etc.

To me boost control is different compartment to turbo building. Which is why most performance turbos are made to suit external gate. The key is Force = pressure x area. You need to work around that to control boost.

Yes I did read that through. Its a very interesting thread, reading it again after 7 years, its abit newish. He's using a bigger turbine housing (.81?), I don't think its a bolton housing for the RB25det tho. Also he's running the T04's 71mm comp wheel, I'm very concert about surge issue linked to Slide's high flows years back, The turbine wheel is too packed and heavy, But thats all there is available back in the days.

I did used mild wheels for high flowing, they comes to boost quick, but not making the sort of power I'm hopping for, and most people whom wants high flows are trying to squeeze the last KW out of it in comparing to some 300rwkws setups. This is the majority direction that high flowing is heading to. Of course small wheels are also used for people who's chasing max response and mild power.

Traditional wheels and setups are not made to do this. Stand up to the challenge, we had to make lots of custom parts so the turbo has the efficiency and last. None standard turbine wheels, gate controllers, high pressure actuators are all bits of the missing pieces archiving this goal. If I'm high flowing that guy's turbo today with his .81 turbine, I can easily max it over 300rwkws consistently.

Back to the boost holding problem. Rolls you mentioned about the twin entry actuators, I think if you can some how connect the bottom entry to exhaust manifold pressure without the heat and bleed that with a boost controller it should work, How ever it will act in the same principle as having a waste gate stopper, So consistency would be a concern.

That would be me....my old account that the Mods never fixed after it was corrupted. The good old days...have learn't much since. That turbo worked great --->for the cost. But pretty average overall. I was always fighting surge with the old school TO4B Vtrim compressor wheel. The turbo would never run more than 15psi boost and dropped off up top to around 11psi. The site crashed back in the day so the info is all jumbled up now. For the price forget about building your own these days go with the tried and tested as Hypergear sell.

In reference to your reply about the Gibson GTR actuator. They did run a line from the exhaust manifold..not sure if it was a pressure feed or Exhaust temp...however they may have run the Positive pressure to the gate from the manifold as you say.....as it obviously did work.

Matt

So guys I'm hearing conflicting info here, without taking the turbo off and modifying the waste-gate/boost control like hyper says is there anyway I will make it any different? and is there a chance that the gcg turbo won't like it and it will reduce the lifestyle? If I was to speak to them what would I want to ask to see if it has the standard style 360o thrust washer?

Mate call GCG - Get a heavy duty actuator

The actuator you have now simply will not be upto the task, and the EBC's sometimes just can't hold it.

We all know that, seen it plenty of times now across the forum where people upgrade the actuator and the problem goes away almost immediately.

There is no reason that I've seen yet to suggest a GCG hi-flow cant hold 18psi beyond 4000rpm.

Yes yours is the smaller version compared to the OP6 (and its only about a 25rwkw difference in most cases), but it should be holding a long longer and as i said earlier...

GCG are silly for not forcing people to BUY HDuty acutuators are part of the hi-flowing as plenty of people have had this issue and with hiflows in general.

The stock actuators dont like holding 18-20psi, and then add to the fact they are 10-15 years old.

No EBC is going to account for a failing actuator, and look @ 99% of the thread here about boost control/hiflows, I've yet to see anyone get all funky with actuator setups over and above a normal heavy duty one :laugh:

Yeah I'm sure they know all about it, might have a chat today I've just had less than welcoming service in the past, hopefully I get someone in a good mood today.

i duel port actuator should work but you need a boost controller that can control them. If you run the controller as if you were running an external gate i can't see why it wouldn't work. Basically you are giving the spring a helping hand in holding the gate close with boost pressure.

Something like one of these setups;

post-27020-1286238946_thumb.jpg

Edited by D_Stirls

Well if its a true ball bearing center section the bearings take care of the thrust loadings .

I didn't have time to read the thread but I have vague recollections of it .

Really today I wouldn't bother with 8/8 bladed T04B wheels because they were designed to work in diesel turbos with big heavy T04 turbines . There's too many better compressor wheels like some of the GT ones or even the later smaller 76mm E or similar ones . Not sure about 16/18/20G Mitsy wheels but they could be worth a look .

I reckon the TB31/TA34 turbines don't really fit in with power and response , too low in the blade height and a fair bit of cropping std - poor trapping efficiency IMO . One of the last Hi Flows I had made used a HT18S turbine and it probably would have been alright except for the -24 8/8 bladed T04B compressor . I had not learnt at that stage that larger than std compressors with a lower blade count is a good way to get the pumping capacity up and get the thing spooling ok as well . Sadly not too many turbos use 5/5 bladed compressor wheels and the only ones that spring to mind are the IHI ones from early Subaru turbos ie VF8s and VF12s . I'd say this is why OS mobs like Forced Performance in the US had to make their own up for Hi Flowed Evo TD05 based turbos , these days they make up their billet "HTA" compressors and from memory some of those have seven full height blade wheels .

I reckon if you could get them the turbines and compressors from Garrett's TR30R would be nice , hell even a smaller trim GT30 turbine could work .

What really kills is the lack on a bolt on twin scroll twin integral gate turbine housing . They would be the way to get around the "lag" and high pressure wastegating issues associated with hi flow turbochargers .

Until then I dunno , maybe some of the TD06 bits could work .

As for that RB20 expensive but if keen extrude honing could probably help an RB20 or 25 Hitachis T housing .

A .

discopotato03 you are like a walking encyclopaedia on turbos that just randomly drops pages all over the place. :P

haha i was thinking the same thing, he busts out an essay and is always full of info :)

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