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NiSmO [email protected]
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Discussion Starter #21
I've not seen any on kill yet, but these are done more with response/track in mind than drag racing so instead of the max power per mm of inducer the wheel design etc is more aimed at managing shaft speed versus flow etc to keep the turbine wheel intact and the turbo responsive. They DO flow a lot but the target will be response vs flow as opposed to flow vs mm, I'd imagine you'd realise that less mm for flow does not necessarily equate to better response.

If I were a betting man, I would treat a 74mm EFR like an entirely smaller turbo than a 72-76mm Precision - both in terms of flow and very much so in response. Fwiw Vibrant Performance recently set a new record for FWD Time Attack cars at Tsukuba with their Civic running an EFR9280 at "Over 1000hp" and shared a log showing them pulling out of a tight corner from mid-3000rpm range during the record setting lap. Not many turbos capable of a legit 1000+hp will do that on a 4pot without nitrous, and certainly not something you'd expect from a G42 or 72+mm Precision donk. Or really even one around 67-68mm.
which is why i'm deeply interested how these perform. I live in an area with a ton of tight roads and highway, but my main drive is tight until i reach the thru-way. I want something that is going to respond ideally in those situations.

Someone really needs to do an apples to apples comparison. With a manifold that can accomodate all these turbos. I'd pitch $$ towards that data.
6266, 6466, 6766, 6870/5, 7175
gtx3582, gtx3584RS, G42-1200
EFR8474, EFR9280


All on a stock motor Supra. With proper supporting mods and a nice standalone.

HELL I'll even volunteer my supra for it! For the good of the community.
 

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Someone really needs to do an apples to apples comparison. With a manifold that can accomodate all these turbos. I'd pitch $$ towards that data.
6266, 6466, 6766, 6870/5, 7175
gtx3582, gtx3584RS, G42-1200
EFR8474, EFR9280
That kind of thing sounds amazing, but implausible I suspect. Would need a bunch of crowd funding for fabrication, dyno, parts etc time as well as the logistics to make it happen. I also think one of the most interesting turbo developments at the moment is the new Xona Rotor UHF turbine range, all the early results seem REAL promising - probably the most blatently "different" designs I've seen in a long time and the results so far seem to imply that they've managed to increase flow significantly at no cost to spool.... which kinda seems to result in pretty crazy power versus response from what I've seen so far.

They seem to be offered on turbos ranging from ~65lb/min up to 115lb/min so very much in the area that everyone but the real crazy folks would be looking at.
 

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But if you are switching from a typical setup to an EFR setup, then you have to make some provisions for it, ie: delete the BOV and have the IC piping welded, and possibly have to do the same for the wastegate to the header if you pick one with an internal WG. Then you are pretty much locked into the EFR setup.

But as already mentioned, the internal WG EFR's are too small on the exhaust side.

Al
Block off plates exist for BOV and WG flanges. To your point, the internal housings are a tad tight do I stayed external for my setup.

Went from a Precision 6766 to a EFR 8374. I road course the car occasionally and the 6766 died a miserable death. Seems like this isn’t uncommon during road course use, which I get and harbor no ill will.

The data exists, but usual sentiments, 6766 hit hard once it was lit. 8374 is a tad more progressively. Been looking to maybe downsize further actually.
 

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First of all, depending on fuel quality, on 93 octane without methanol/water injection the car is at maybe 18psi max, and 14psi-16psi more practically. Your first objective is a turbo that is left of the choke line at peak engine speed over the boost range. Depending on the slope of the choke line, that can be tricky in the 93 octane 14-18psi range.

The second compressor objective is to be the right of the surge line as engine speed and air mass flow goes down. One of the nice factors on the new Garrett G25 series and the EFR 7163 is a nice bulge on surge line. But those are probably too small for your intentions.

Are you choosing a cast log manifold over a divided header because of cost? Full Race has an IWG header designed for the EFR or other IWG turbos. It isn't that much more expensive. https://www.full-race.com/store/borg-warner-efr/manifolds-efr-series/toyota-supra-2jzgte-t4-efr-iwg-twin-scroll-turbo-manifold-1/

The EFR has three factors that will make the installation simpler and neater. The IWG allows routing the wastegate into the downpipe with building an awkward merge with the dumptube. The IWG which can be enhanced with a TurboSmart actuator. Those can have upper and lower ports or just upper ports. It also has a recirculating BOV built into the compressor housing, and TurboSmart offers a version of their Kompact BOV to replace the BW plastic. It also has a 3-port boost solenoid with a mounting location on the compressor housing. The end, the only connectiors is a vaccum line to the BOV and a few wires to the boost solenoid and maybe a speed sensor.

The few Garretts with IWG don't have the built in BOV.

The big tradeoff is on the bottom end. What engine speeds do you normally run? My guess on the street you are more likely to be at 2500 rpm than 7000rpm. The 8474 extends both the surge line to the left and choke line to the right. So it is a bit better than the 8374. The 9280 will leave you wanting on the small end although it reduces backpressure on the high end. Better for drag racing.

If you want boost at 2000 rpm either a small turbo that is reaches its limit on the high end (e.g. 7163, G25-660) or go with a bit of a compromise, the 8474. Note there is a 960hp S2000 in a new HPA video that used a 6266 Precision and was limited by the turbo. Note that it ran 42psi using C90 Ignite fuel.
 

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NiSmO [email protected]
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Discussion Starter #25
Dave,

Yes, I want the perfectly sized turbo for my application.
Anything IWG will not reach my goal.
That fullrace manifold is very nice, but again it's 5 times the price of the cast manifold.
yes, the 8474 is looking like a great turbo choice, it looks amazing, but i'm not sure it'll get me the top end i'm looking for.

QSV is possible on the FSR, it'll just require some ingenuity.

looking into the xona rotor now.. I know the porsche guys run those.
 

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Dave,

Yes, I want the perfectly sized turbo for my application.
Anything IWG will not reach my goal.
That fullrace manifold is very nice, but again it's 5 times the price of the cast manifold.
yes, the 8474 is looking like a great turbo choice, it looks amazing, but i'm not sure it'll get me the top end i'm looking for.

QSV is possible on the FSR, it'll just require some ingenuity.

looking into the xona rotor now.. I know the porsche guys run those.
You are building an otherwise stock, unopened engine to run on 93 (more or less) octane to be driven on the street (were the rev range will be stretched to avoid shifts). What was your expected powerband? What is expected your peak engine speed and power expectation? What time of intake and exhaust were planned? Will the wastegate go through the mufflers or open dump tubes? What noise level do you expect?

Every race engine that is allowed to has headers. The design of the merge collector, the size and length of the tubes are all tuned for rev range and power levels. After all, the engine is an air pump. However, since you aren't in competition it is unlikely you will see a practical difference.

If you stay at the stock redline with the log manifold, a G25-660 or EFR 7163 may be all you need and provide significant boost levels at low engine speeds. I don't think you will find anyone here with the combination though.
 

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I picked up a G25-660 with the 0.92 V-band housing for my 1jz setup. Tubular manifold, fairly built engine, and at high altitude, so my results will likely be of little use to most folks on here, as I went this direction for autocross and street use.

Hoping to have things together sometime in early June, if everything works out nicely. Objective results will likely not be available until at least SIV, but I'll have subjective results soon enough. If anyone is interested just point me to this thread in a couple months and I'll post whatever impressions I have then. :)
 

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I picked up a G25-660 with the 0.92 V-band housing for my 1jz setup. Tubular manifold, fairly built engine, and at high altitude, so my results will likely be of little use to most folks on here, as I went this direction for autocross and street use.

Hoping to have things together sometime in early June, if everything works out nicely. Objective results will likely not be available until at least SIV, but I'll have subjective results soon enough. If anyone is interested just point me to this thread in a couple months and I'll post whatever impressions I have then. :)
For a 2.5L under 7000rpm on 93 octane, based on my analysis, that should work well. For the 3L there doesn't seem to be any boost that is left of the choke line at 7000rpm. They should work nearly as well at low engine speeds as the GT28 used in the Hybrid. The G25-550 and the GT2860 (same compressor as GT28, but has published compressor map) have about the same surge line. Both are 60mm compressor wheels. The G25-550 has a slightly bigger turbine (54mm). The G25-660 is 67mm/54mm. The G25-660's published map is better than the EFR 7163, assuming the published maps are accurate. And inertia should be lower, the smaller turbine making up for the lighter turbine material, and with a smaller compressor wheel.

I'd be interested to hear the results.
 

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NiSmO [email protected]
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Discussion Starter #30
those turbos won't come close to my goals.
 

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For a 2.5L under 7000rpm on 93 octane, based on my analysis, that should work well. For the 3L there doesn't seem to be any boost that is left of the choke line at 7000rpm. They should work nearly as well at low engine speeds as the GT28 used in the Hybrid. The G25-550 and the GT2860 (same compressor as GT28, but has published compressor map) have about the same surge line. Both are 60mm compressor wheels. The G25-550 has a slightly bigger turbine (54mm). The G25-660 is 67mm/54mm. The G25-660's published map is better than the EFR 7163, assuming the published maps are accurate. And inertia should be lower, the smaller turbine making up for the lighter turbine material, and with a smaller compressor wheel.

I'd be interested to hear the results.
David, I'll update you when I have some impressions of performance. For autocross, especially at 6500+ altitude, big turbos are literally useless. Ever spool at the absolute worst possible time? It's fun! Meanwhile you, as a driver, are just as fast or faster, in a bone stock Miata. That's kinda a kick in the knackers haha.

I understand it's not for everybody, and it definitely won't be putting 600+ to the wheels, but I think the G25-660 will be perfect for my application. The power of my setup is already about as much as any sane person would be able to use on an autocross course, so I'm chasing after throttle response. I'll rev it as far as it makes reasonable power, so we'll see if it's hiding any secrets past 8k. I doubt that it does, but this is what science is for, right?
 

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G25 thoughts...

I'd be interested to hear the results.
David, said I'd update you, and here I am. Got the turbo sorted out and finished installation last week. The G25-660 0.92 housing is about a perfect street turbo for anyone with a 1j that doesn't "need" 1000hp. It provides all the power you need to have a LOT of fun, and enough to get you in a lot of trouble, too. Throttle response is fantastic, coming from a Comp CT4-6265 0.70 dbb. Even at 6500', it is seeing positive pressure below 3k on a 1j with a head tuned for mid to high range power, and a tubular manifold.

However, that's only part of the story. The spool up characteristics, the time it takes between putting your foot down, and the car actually going somewhere, is significantly better than it was before. Truly, this is like driving stock twins (for response) with a healthy amount of extra power and torque. I can't wait to drive this thing at low altitude, I suspect it'll be a riot.

As for competition, it uh... it's good. So far I have only done a first gear autocross course (we really only get to play on small lots here, but better than nothing!) and I can drive the car almost entirely with my right foot. ;) That's good throttle response if you ask me, from a turbo engine.
 
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