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Old 01-28-2013, 08:40 PM   #1
Scargod
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Default GT4294R a crazy choice for my track motor?

Since I can't get my hands on a Borg Warner EFR 8374 I have been using BW's Matchbot turbo calculator to look at other choices. While I know it will be a little laggy on the low end I am road racing and it seems like it will do well above 3 grand. I just don't find anything about anyone running one and wonder if it will fit in the engine bay!
My '08 STi build:
I'm using a reversed N/A impreza intake and I am running a Turbo XS FMIC.
I will port the heads and run bigger valves and Kelford 272 cams. ID 2000 injectors.
I am using Full Race 1.5 headers and will modify the up-pipe for twin-scroll and wastegates.
Going to run CP stock compression fully coated pistons. Wosser H beam rods (weighing 399 grams each). Balanced crank.
I am considering running it to 8K max RPM.
Matchbot calculations say it will make 350 HP and 457 FPT at 4K/538 FPT max@5K/653 HP at 8K!
Am I crazy?
UPDATE NOTE:I found and purchased the Borg Warner EFR 8374 with .92 A/R turbine side!
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Last edited by Scargod; 01-30-2013 at 06:31 PM. Reason: added update
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Old 01-28-2013, 08:59 PM   #2
25rsti
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Yes...jk idk it will be laggy but who knows.
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Old 01-28-2013, 09:10 PM   #3
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Borg S400SX3 FMW for the win. Cheaper than garrett and better performing.
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Old 01-28-2013, 10:03 PM   #4
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653hp on a 42R??? i dont think match bot has that one right gtx4204R flows like 115lbs of air, gt4202 is at about 97lbs and a gt4294r is at 85lbs... or was that for the 8374? (cause that's a 79lb turbo)

If you're going garrett do a GTX as they just look so much better than the GT's

Matt
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Old 01-28-2013, 10:18 PM   #5
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Quote:
Originally Posted by Scargod View Post
Since I can't get my hands on a Borg Warner EFR 8374 I have been using BW's Matchbot turbo calculator to look at other choices. While I know it will be a little laggy on the low end I am road racing and it seems like it will do well above 3 grand. I just don't find anything about anyone running one and wonder if it will fit in the engine bay!
My '08 STi build:
I'm using a reversed N/A impreza intake and I am running a Turbo XS FMIC.
I will port the heads and run bigger valves and Kelford 272 cams. ID 2000 injectors.
I am using Full Race 1.5 headers and will modify the up-pipe for twin-scroll and wastegates.
Going to run CP stock compression fully coated pistons. Wosser H beam rods (weighing 399 grams each). Balanced crank.
I am considering running it to 8K max RPM.
Matchbot calculations say it will make 350 HP and 457 FPT at 4K/538 FPT max@5K/653 HP at 8K!
Am I crazy?
so much bigger then you need and not close in size to the 8374. If you did get the turbo you would def need to rev the motor out to 9k to make a some what usable power band
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Old 01-28-2013, 10:32 PM   #6
WhatTurboLag?
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A 42 is way too big for a road race car.


Gtx35 would be a lot better.
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Old 01-28-2013, 11:18 PM   #7
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ls7 swap!!
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Old 01-28-2013, 11:30 PM   #8
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Quote:
Originally Posted by WhatTurboLag? View Post

Gtx35 would be a lot better.
+1

PTE 6266 or BW 8875 would work
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Old 01-28-2013, 11:33 PM   #9
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I wonder what these opinions are based on? A prettier turbo is not one of my considerations.
According to Matchbot, I see a 67 lbs/min airflow @8K.
It looks like all hell will break loose between 4K and 4.5K RPM and torque will never fall below 396FP till 8K. A 3,500 RPM range seems pretty good.
I did a spreadsheet and looked at many turbos by plugging in the numbers into Matchbot.
3582, 3776, 4088 and others. To me none looked better except on the low end.
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Old 01-29-2013, 12:35 AM   #10
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how about a FP 3794r? Flows 90 lbs/min and spools by 6 k!

Btw: the Turbo XS FMIC core is only good for about 600whp!
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Old 01-29-2013, 01:13 AM   #11
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Quote:
Originally Posted by Scargod View Post
I wonder what these opinions are based on? .
Results with those turbos
Not using a program that guesses what you'll make
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Old 01-29-2013, 08:23 AM   #12
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Quote:
Originally Posted by Paul View Post
Results with those turbos
Not using a program that guesses what you'll make
I am not going to question your experience.
Everyone: #1 priority is I want a twin scroll turbine. I won't consider anything else. Twin scrolls make bigger turbos work better at low RPMs. 10-15% better according to BW.
What I seem to be wanting to know is if I can believe the Matchbot numbers. Sure, there are some variables, but why would Borg Warner put out Matchbot and video tutorials on how to use it and it not be grounded in physics and based on solid engineering and dyno data? Why would those results be guesses? Also, I'm not a wet behind the ears kid. I am old and I have an engineering background. I believe in numbers over butt dynos. I just don't have a lot of experience with turbos.

My Blouch 2.5 XTR with .82 hot side was an awesome upgrade to a motor with not much more than ported heads, matched passages and Full Race pipes. It made 400/400 on 100 octane at 24 PSI and I have all those dyno numbers. It also was set to 28 PSI for one track session and the change was amazingly faster. Problem is, I can't find a Blouch compressor map to verify those numbers in Matchbot. What compressor map would be comparable?

The other issue I have with opinions is some people are street racing/drag racing their street car. Does someone say the turbo I'm looking at is a bad choice because their experience is that a big turbo is bad because it's not streetable and not good for street racing? I trailer my car to the track and I get it dynotuned by EFI Logics. Why should I care about below 4 grand? Many turbos I looked at have good low-end torque but peak early and then drop off quite a bit as RPMs rise. These would feel great from light to light, but wouldn't serve me well at 5K when I need it to pull hard out of a corner and keep pulling.
Is there any compilation of turbos for 2.5L's that is not dated? I wonder what TT boys are running that are making 475-500 at the wheels?
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Old 01-29-2013, 09:43 AM   #13
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Here are some non-answer answers haha
1) gt4294R will fit - see below thread on gt4202r which was put into a suby
2) sadly on this site - there really aren't any dyno plot of the 4294 - the only indepth twinscroll builds for large turbos are Tino's 8374 EFR (which I know you can't get at the moment and hence your question) and an old gt4088r build - interestingly that Tino went from the 4088 to an 8374 - he seemed to make comparable power between the two turbos
- cliff notes
- "From the graph looks as if there is no additional benefit of spool over the GT40R. Top end looks to be very similar to the GT40R my tuner thinks that at the same boost level will make the same or more power than the GT40R.."
3) so anyway what I'm trying to say is this - the most comparable power/dyno curves to an 8374 seems to be a gt4088r - (real world data on a suby) so if you go with a 4294r you'll probably just have worse power curve and more topend.. maybe depending on fuel etc etc... anyway see the first thread that has the dyno plot overlay - and note - tino's setup is probably the best case scenario for spool and power since his is a custom lowmount etc etc... and it was the same motor/setup so the most accurate before and after

http://forums.nasioc.com/forums/show...4#post36285762

http://forums.nasioc.com/forums/show....php?t=1293167

http://forums.nasioc.com/forums/show...hlight=gt4088r

http://forums.nasioc.com/forums/show...gt4088r&page=9
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Old 01-29-2013, 10:02 AM   #14
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bw big s300 or small s400
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Old 01-29-2013, 11:27 AM   #15
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Quote:
Originally Posted by stretchedk7 View Post
bw big s300 or small s400
This. Or.

s362sx3 with the FMW.

Proven power. Better than GT35.

http://forums.nasioc.com/forums/show....php?t=2268889
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Old 01-29-2013, 11:33 AM   #16
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like he said ^
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Old 01-29-2013, 01:17 PM   #17
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I've found some mistakes when I went back and checked my inputs.*
Please be gentle with me guys! Please be considerate and understand that I don't know all the number lingo and acronyms; plus I can't find anything like "s362sx3".

Like stretchedk7 said, "bw big s300 or small s400". Not sure what you are suggesting. I've looked at the BW AirWerks S400SX and while it makes decent power it's not ball bearing, not water-cooled and performs worse (on paper), than others.

BTW, Garrett's "Boost Advisor" turbo selector picked the GT3076R at the low end, and GT4294R at the high end, as suitable for my 570 crank HP goal, while requiring 27PSI boost! *This is a lot different from what BW's matchbot is telling me. So I found some mistakes in my Matchbot work.
The 4294 is not looking so hot now... The GT4088R is looking like a good one.
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Old 01-29-2013, 01:22 PM   #18
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Matchbot is a great estimation tool, but it is only really as good as the knowledge of the system and user and it will let you give yourself better spool than you will see in real life. It takes a fairly small turbine housing to be able to spool near the surge threshold and you really don't want to be there anyway since surge sucks and the hotside will likely limit your top end.

It says I could hit 40 PSI on my S400SX FMW 1.25 AR by 4500 rpm. I would have to find one hell of a wide gear to generate enough load to make that happen even if it works on paper. Realistically, just have your spool follow along the left side of the efficiency peak, maybe 1-2% off and that will be your more likely spool candidate.

This picture will give you a good idea of what I mean, you just won't have enough load in 3rd or 4th gear to spool that close to the surge line without a tiny turbine housing.



I would suggest getting a 60-70 lb/min turbo with enough hotside to not inhibit your top end and have a wider power band with better response and recovery if you want that much airflow.
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Old 01-29-2013, 01:39 PM   #19
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OP: Have you tried searching in the power proven forum? If you do that you'll see tons of dynos in the 500-600 range and after studying them for awhile you can make a educated decision and what turbo you want to go with. Id look at plots with these turbos
TS GTX30
TS GT35r
TS PTE 6262
TS BW 300
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Old 01-29-2013, 03:19 PM   #20
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Treadstone performance is saying they got a shipment of efr's on their Facebook page. Not sure which ones though. Maybe give em a shout? Or see what full race has in stock. Shruuuug

-Matt.
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Old 01-29-2013, 07:17 PM   #21
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What kind of racing are you looking to do?
How much racing experience do you have?
How well prepped is your car?

These should be the first questions before anyone starts commenting on a road course turbo suggestion.

Just an FYI, low boost on a well prepped EJ25 with a GTX3582R can snap 285's free on command...on a well sorted GD chassis with a full aero package. Ask me how I know

-Micah
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Old 01-29-2013, 07:30 PM   #22
faeflora
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Quote:
Originally Posted by Scargod View Post
I've found some mistakes when I went back and checked my inputs.*
Please be gentle with me guys! Please be considerate and understand that I don't know all the number lingo and acronyms; plus I can't find anything like "s362sx3".

Like stretchedk7 said, "bw big s300 or small s400". Not sure what you are suggesting. I've looked at the BW AirWerks S400SX and while it makes decent power it's not ball bearing, not water-cooled and performs worse (on paper), than others.

BTW, Garrett's "Boost Advisor" turbo selector picked the GT3076R at the low end, and GT4294R at the high end, as suitable for my 570 crank HP goal, while requiring 27PSI boost! *This is a lot different from what BW's matchbot is telling me. So I found some mistakes in my Matchbot work.
The 4294 is not looking so hot now... The GT4088R is looking like a good one.
Look at the link I posted. I'm recommending a s300sx3- the 62mm FMW version. Also known as a s362sx3.

Yes, it's not ball bearing and not water cooled but it whups the ass of a GT35. And is much cheaper.

Matchbot is nice but you have lots of proven configurations at your disposal in the proven power forum. Stop ****ing around with simulators and look at real data and real, working results.
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Old 01-29-2013, 07:32 PM   #23
faeflora
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Quote:
Originally Posted by 3MI Racing View Post
What kind of racing are you looking to do?
How much racing experience do you have?
How well prepped is your car?

These should be the first questions before anyone starts commenting on a road course turbo suggestion.

Just an FYI, low boost on a well prepped EJ25 with a GTX3582R can snap 285's free on command...on a well sorted GD chassis with a full aero package. Ask me how I know

-Micah
And yeah, this too. OP, it sounds like you are a noob trying to buy your way into racing. If that's the case why not let one of the shops that competes build your car? Including the parts list.
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Old 01-29-2013, 07:36 PM   #24
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Exactly why I said the gtx35 or something around there. You are road racing, you want a wide powerband. A 42 would be way too narrow and really ****ty for that. Even for a street car it's not that great.
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Old 01-29-2013, 07:42 PM   #25
Scargod
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Quote:
Originally Posted by 3MI Racing View Post
What kind of racing are you looking to do?
How much racing experience do you have?
How well prepped is your car?

These should be the first questions before anyone starts commenting on a road course turbo suggestion.

Just an FYI, low boost on a well prepped EJ25 with a GTX3582R can snap 285's free on command...on a well sorted GD chassis with a full aero package. Ask me how I know

-Micah
Whazza 285? Must mean tires... what does an aero package have to do with burnin' rubber?
I'm a f'n old Tanzio Nuvolari, but Texan instead of Italian. I had several racing licenses in my 20's and (now), have two years of track time in NE with my STis. My car is well-prepped. I have turned fairly competitive times at Watkins Glen and Lime Rock, just doin' track time. I tried to do a TT with NASA at Summit Point when I broke pistons on my stock bottom end.
I built a new motor, which I mentioned and have been running without issue. Now, with new confidence, I am building an "Alpha" motor for the car.
I expect 450-475 WHP with this new build. The car is setup to handle it.
I did fine at NHMS when I ran 28 PSI accidentally! Boy was I passing Bimmers! I'm just out to play and have fun passing GT3's.

Just ordered the BW EFR 8374 with .92 A/R. Also ordered the high boost WG cannister. Thanks to Matty_STi for the heads-up and thanks to everyone for their input!
You can see what I have done at http://2008subarutrack.shutterfly.com/
faeflora: You've got a great imagination.

Last edited by Scargod; 01-29-2013 at 07:46 PM. Reason: addition
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