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Stock twins replacement/upgrade - Hybrid GT28R's

855K views 4K replies 407 participants last post by  Strokercharged95GT 
#1 · (Edited)
So I've been keeping watch over the past two years (as many others have..and for longer) for hybrid turbos which retain the sequential operating system and offer significant hp gains.

Well Stu Hagen, King of the Sequential twins (not necessarily "stock" sequential twins in this case), has come up with this exact option. Below please find a link to the initial discussion from the dyno section. #49 on pg. 2 is where it gets interesting.

One beta tester already has these on. I'll let him come on board with the specifics but basically he is finishing up the plumbing and then he'll be putting them on the dyno. and doing a "how to". I will be doing the same as soon as I get my pair.

He also has a manifold which will allow these turbos to really breathe. Inner diameter of the turbo inlet is the same as the ID of the piping. 600+ on race gas should be possible with this setup.

Hopefully the guys on the "other" forum will chime in here and help this get rolling also as I've cross-linked the threads :) . Big thanks to Stu and all the others involved in this project. They add so much to the Supra community.

http://supraforums.com/forum/showthread.php?t=427097

http://www."theotherforum".com/vb/showthread.php?t=3834
 
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#47 ·
Hey Stu,

I would also be very interested in either of these setups, since I love the sequential setup, and would prolly never go single.
3 questions though:
- If the GT28R one makes it over beta, will they be available with lines and other misc stuff that fits?
- Will the #1 boost controller also work reliably with the unmodified stock turbo setup?
- Did I understand that right that the hybrids youre using right now are a direct bolt on upgrade that dont need any modifying at all? You do need some sort of piggyback or similar, right?
 
#48 · (Edited)
Wow--things are progressing here.

1) My current set up, which are Aarons hybrids, are a direct bolt up using the oem band clamps. What this means that you dont need to take off much to install these. I think it I took like 4 hours to install them. Biggest pita is the underside oil line and the banjo fitting on the block. Hard to do as a "blind" feel install. Aarons are honed machined compressor housings with a T3 wheel. Thats all. Supporting an additional 50 whp +/-. Also less money.

2) The BNR upgrade uses GT28R "cartridge" Which means larger turbine and larger shaft. This requires an almost complete tear down to install, Since these are entirely new cartidges, the band clamp housing is machined off and totally removed. The new install uses bolts to attach to the exhaust housing (look closer at the pics and you will see) One side note that I was in error about. These GT28R's are NOT ball bearing as I thought. After discussing this more with BNR, he reminded me that he could not install the BB ones because he would bore right thru the housings. Not enough meat for those. The initial set was made well over a year ago, maybe 2, and "hammerhead" was the guy who bought it. It has taken him all this time to get around to installing them and coming up with his own style manifold and oil/water lines.

The 24 sets that I am doing now will most likely have all the water/oil lines premade. I am waiting for Bobby ("hammerhead") to finish everything up here in a week or so to iron out certain fitment issues. We are discussing the manifold issue as well. Maybe have these made. But cart before the horse here. He will be providing dynos, etc. very soon. These should make more power than the ones I am running now. Or at least the same, but capable to boost an additional 4 psi safely due to 33% larger shaft. (Turbo balanced to 180K or 24psi)

I do not intend to be the overall "provider" for these. That has yet to be determined. I am only facilitating there progress and beta testing. Since I know quite a bit about the system and have provided BNR with all the cores that he needed for this initial batch. I am also doing the "correct" style of hose and fittings for the water and oil lines. i want these to be a pefect fit. We will most likely stay with the banjo style fittings as opposed to the AN style. (Not like what you see above by "turbosupra"). AN fittings sometimes have issues when removed and re applied whereas banjo's do not.

I think the "ultimate" final package would be the oil/water lines and the manifold as a kit. But others may want just the turbos.

3) The new electronic boost controller that I am almost finished with is designed to plug directly into the EBV VSV up top. This will have the ability to control the amount of pre-transition boost from stock (10psi) up to 18psi. No more hose rerouting, just plug and play. I just need to set up the map sensor and adjust the circuitry to be accurate to boost levels (calibrated) Once overall boost is increased over stock, it is a good idea to raise the pre-transition boost a little to match full transition boost. Similar to stock from 10-11 psi, this can be like 15-18psi.

Stu
 
#52 · (Edited)
Wow--things are progressing here.

1) My current set up, which are Aarons hybrids, are a direct bolt up using the oem band clamps. What this means that you dont need to take off much to install these. I think it I took like 4 hours to install them. Biggest pita is the underside oil line and the banjo fitting on the block. Hard to do as a "blind" feel install. Aarons are honed machined compressor housings with a T3 wheel. Thats all. Supporting an additional 50 whp +/-. Also less money.
Stu can the same effect be had by actually buying the turbos direct from garrett and modifying the stock manifold to suit, welding in new flanges and porting etc or is it a better idea to use the cartridge in the original stock turbos?? On the back of this, will the same work for J-spec turbos as I guess your probably using US/UK turbos?

Are there any other things in the sequential system when doing this upgrade that need looking at? ie actuators, vsv's etc? And have you found fitting parts an issue once the new turbos are in?

how do the vsv's cope with the change over from turbo to turbo

2) The initial set was made well over a year ago, maybe 2, and "hammerhead" was the guy who bought it. It has taken him all this time to get around to installing them and coming up with his own style manifold and oil/water lines.
By own style manifold, do you mean just porting and welding in the new flange to hold the housings? How does the new setup effect flow etc, do you feel the stock manifold is up to the job of the increased flow/pressure produced

The 24 sets that I am doing now will most likely have all the water/oil lines premade. We are discussing the manifold issue as well. Maybe have these made.
would you consider the lines and manifold being made a tough job Stu....this is something I have been trying to research for years and never been brave enough to try and get things underway?

very very interesting reading
 
#50 ·
Fantastic work Stu ! I am simply in awe of your dedication. A few questions though.

1) Have these required extra effort in terms of tuning or can the stock ECU actually adequately account for the change in airflow.

2) On a similar note, what type of output (boost/rwhp) is capable on pump(93) vs racegas?

I’m otherwise assuming that these are within the bounds of the stock fuel system (i.e. ~525 rwhp or so). This looks on paper like a killer street setup. The big low-end torque of the great Toyota sequential design coupled with possibly 125-130mph trap speeds.
 
#51 ·
1) Should be PNP. Although, based on the past 4 years of people in UK and Australia, with similar set-ups, there were issues with using the proper actuators.
There were issues whether to use modified OEM ones, or aftermarket ones designed to better fit the new turbos. We plan on the latter. That's why these are in "test". Only real way of determining is to see what happens once installed.
IMO, no issues. I would expect about a 100-150 rpm lag way down low. Even with the ones I have now, I see a "slight" difference. The little "dip" in the seq curve at transition becomes more pronounced tho.

2) From what I have heard so far, I would expect 450-460 on pump gas at 18psi. Although we are thinking that 20psi on pump still is doable. These are WAY more efficient, heat producing wise. But then again, it is hard to determine what the ECU will do at 20psi. As far as fuel, these for sure will approach the limits of a stock fuel system. Maybe a dual feed, and some minor stock tweaks may make things OK. But I will tell you, that these can be pushed, maybe with a shot, close to 700 whp. IMO, I wouldnt do it, but they are capable. Just like hitting 24psi on stockers, maybe not efficient 700, but non the less capable.

Stu
 
#54 ·
Wow what an amazing post,

Stu, I wish you the best of luck with your new hybrids, let me know how your testing ends up, I could be interested in buying a pair of these if you get all the bugs out. I Actually subscribed to those australian guys' post years ago, I would read the thread for hours, I thought what they were doing was absolutely amazing. Good luck with everything, ill be stopping back here daily.

-Brett
 
#57 ·
Aaron300
If I had more time, I would have swapped the manifold onto the stock shitters. On Pump they made 458/478. That was enough to put 3550 down the track in the 11.2/11.3's(6spd)

Stu
We need to talk about this Boost controller you are working on. I do not run my car seq for traction issues. The car flat out hooks way harder and better TTC. But I do miss the Seq. Im gonna need to pick your brain a bit on this. To make this a true bolt in job we may need the help of Cowboy Bebop to make a Billet Oil return flange with 5/8" Connections since the "BNR" Center section uses 5/8" returns and OEM is 7/8"

-or-

Maybe it would be easier to make 7/8" Drains for the "BNR" center section. I think 7/8" is way overkill though.

Ill have to attach some other pics I have of the oiling setup. Pics are at work.

Its late, im tired, All of the above... May make no sense...
 
#61 ·
Stu,

Like everyone else, I have been following this project of yours for some time and am very happy to see you getting near the end of your quest. :)

I have the AEM on my car, so would this be a benefit or detraction for this setup? I would think it would be fine, but I haven't seen it addressed specifcallly.

Thanks. :)
 
#62 ·
Actually, just in the last year or so we are seeing more AEM's now on twins. KBlake recently had good luck pooping up the HP just by the AEM. I also think that the AEM would be a benefit. You can control the VSV's with the AEM. This could be a + in this case. Surely not a detraction IMO.

Stu
 
#63 ·
I think I'll run 264 cams with the GT28R's. How about the rest of you? What rpm's will they "run out of wind" up top with Hammerhead's manifold I wonder? Waiting for dyno. results eagerly :)
 
#77 ·
This hybrid setup looks great! I am already set to receive a set of the "1st stage upgrade" type, but this might be my next move in the future.

Stu, what are the dimensions of the GT28R's from compressor inlet#1 to inlet#2? The same as factory (I hope..)? With the lengthened actuator rods it leads me to think the turbos are spaced further apart maybe?

Thanks again for all your hard work! I am sure the entire community thanks you as well!! This just might be the answer to bigger, upgraded turbos in Cali that still pass smog testing!!

Regards,
 
#78 ·
Stu,

you stated in a previous post that the GT28R's turbos with a shot of nitrous maybe able to break 700hp although it wouldnt last long. How about 600rwhp? What that be possible on alky/water injectior or race gas running 24psi? Would running 24psi everyday shorten the life of these turbos? What kind of cams would you recommend with these twins? At what rpm do you suspect the GT28R's to run out of breath? Lastly will any 3"dp fit these turbos and what kind of intake would fit these turbos? Sorry for all the questions but im trying to get as much info as possible.
 
#79 ·
Read this again and you get your answer first hybrid had oem shaft and made 630+ with a NOS sjoot the "new" upgraded T28R will have a30% bigger shaft and approx. provide 20% more power over the first hybrid so if you just make a assumption 530*1,20= 636 rwhp *1,20=700+ at the crank this is of course just an approx. and presume that the power rise linear which probably isnt completely true but at least give some kind of indication of what the turbos can produce power wise.

So in came Aaron, a member here, and a turbo engineer with GE. He and I collaborated and he came up with the first beta series T30 60mm turbos.
http://97supraturbo.com/New Turbo%...OEM-Hybrid.JPG
I supplied most all the materials Aaron had the hybrids made. These are currently on my car as we speak. They have made 501 whp in Vegas, and 534 whp here where I live. Both were just about at 20psi. (all this in my original thread from a year ago). We have about 20 sets out there still being tested. There has been a 630+whp on these with an undisclosed shot. His turbos have since bit the dust (he ran them at 28psi) So the limits to these are around 22-24 psi safely. The good news is there value, the downside is they still use the OEM shaft and turbine. I have literally beat the crap out of these and they are still doing very well. 3 HPDE and several drag runs with no issues. My minimum boost is 17.6 and maximum is 22 psi. These are true "drop-in" turbos. What I mean is removing the band clamps/oil and water lines, and your done.
Then came another turbo builder who had made a trial set of turbos with a true drop in GT28R set of cartridges. These require a lot more work to install since these no longer use the band clamp installation, and do not use OEM water and Oil lines. This individual knows turbos quite well. They use the same OEM compressor housing and all other stock piping, etc. The EBV and WG actuators are modified slightly because they no longer use the same "flappers". Other than that, completely stock looking.

The first beta tester for these goes by "hammerhead" here on the forums. He has made a custom manifold that would compliment these turbos. He also is doing a mock up set of oil and water lines. Hopefully he will be done soon and provide some dynos based on his level of mods. I should have mine installed by September. We are going to make several sets for testing. Right now, I have sent in 12 sets. Hopefully there will be more interest and we can some of these out there instead of myself and hammerhead. PM me for further details.

Here again are what the GT28R look like.http://97supraturbo.com/GT28R Turb...Conversion.pdf

These have been balanced to 24psi. They have a 33% larger shaft, and a larger Turbine. Estimate output is about 20% more than the ones I have now. This maybe a little lower with lesser mods than myself. Again, its all really unknown until more people start providing dynos, etc.
Keep in mind that these will probably be twice the cost as the ones I am currently running. So these, once marketed by someone, will be pushing the "single" cost factor. So they won't appeal to everyone. I should also mention that both these set-ups will run sequential. I cannot vouch for these new GT28R's as yet, as far as how well they perform sequential, but they are designed to run sequential. Although they could run TTC as well.

In conjunction to upgraded turbo's, I have also designed a small electronic #1 turbo boost controller that plumbs into the stock EBV VSV location. It basically will control the stock VSV to operate at different adjustable thresholds than how the OEM ECU controls it now. No extra hose routings required. It can adjust the boost levels from 10 -18 psi. Hopefully I will have these available at Speedforsale in a month or so. Just need testing
 
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