Welcome to the North American Subaru Impreza Owners Club Tuesday November 19, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC General > Proven Power Bragging

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 06-08-2006, 04:23 AM   #1
ka mano
Scooby Specialist
 
Member#: 78022
Join Date: Dec 2004
Chapter/Region: NWIC
Location: Seattle, Washington 05 WRB GGA
Vehicle:
PdxT built 2.5L 6sp
30R.82, 274/276, H2O+meth

Default GT35R .63 or GT30R .82? A data-driven debate on spool-up, top-end, & risk of surge

Iíve searched this to find important observations, interesting conclusions, and some data. Since this question pops up here and there I thought compiling some search results in one place could be useful and provide us a place to present and discuss performance data comparing the GT35R .63 with the GT30R .82.

If thereís a Holy Grail for us Knights of the Subyru, itís the wide power band... building power ASAP and staying there to redline, but not driving the compressor so hard the engine chokes & spews a packed-air punch back at it.

Some swear by the smaller housing / bigger wheel combo... good spool, more power potential. What backpressure?

Others want even faster spool and settle for the whp they get with the 30... steering clear of any urge to surge and the on/off boost leap they associate with the 35.

But just how quick is quicker, how big is bigger, and how risky is that risk?

This thread is not meant for cheering our favorite snail and simply repeating that x is better than y because tuner A said a and B said b (saw a lot of that, of course, and left most of that out in my post that follows). Letís present data Ė- track times, dyno pulls, ECU logs, pressure measurements, etc. -- and discuss them.

Weíre assuming a 2.5L block built to handle either turbo, factoring in differences in heads, and trying not to get side-tracked with comparisons to the GT35R .82... not what this thread is about.
* Registered users of the site do not see these ads.

Last edited by ka mano; 06-08-2006 at 08:11 AM.
ka mano is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 06-08-2006, 04:26 AM   #2
WRXRallyBlue
Scooby Specialist
 
Member#: 48831
Join Date: Nov 2003
Chapter/Region: SWIC
Location: Reno
Vehicle:
2002 Protuned Wagon
Bugeyes Forever

Default

subscribe
WRXRallyBlue is offline   Reply With Quote
Old 06-08-2006, 04:30 AM   #3
ka mano
Scooby Specialist
 
Member#: 78022
Join Date: Dec 2004
Chapter/Region: NWIC
Location: Seattle, Washington 05 WRB GGA
Vehicle:
PdxT built 2.5L 6sp
30R.82, 274/276, H2O+meth

Default

Here are some relevant posts I found:

Quote:
Originally Posted by metoo
...are you saying that a
Quote:
Originally Posted by metoo
GT35R with the .63 will spool slower than a GT30 with the .82?
Quote:
Originally Posted by Gruppe-S
On a 2.5 definitely. ...
Quote:
Originally Posted by Gruppe-S
Gary
Quote:
Originally Posted by CBRD
... the 3076R... will spool comparably if not slightly quicker than the .63 35R, but will operate more effectively at boost pressures less than 24psi or so.. the GT35R's seem to like to be in the 24/25psi range to even "wake up"...
Quote:
Originally Posted by CBRD
The GT35R does spool nicely.......
Quote:
Originally Posted by CBRD
.63 is a good choice, but will ultimately limit max race gas hp ...

the difference between a 3076R (.82) and 35R (.63) wont be extremely significant on pump gas, only on race. ...
Quote:
Originally Posted by PERRINJeff
... First off, i haven't seen much if any testing on the .63 AR with the 35R. I drove my 06 STI with this installed for about 3 weeks and it wasn't bad. But it was worse than the .82 30R. Spool up was in the neighborhood of 4300 vs. 4000 for the .82 30R. ...
Quote:
Originally Posted by SloRice
...Here are some numbers from the weekend.
Quote:
Originally Posted by SloRice
...
- Perrin GT35R .63 - 384whp/365wtq on 94octane, 437whp/397wtq on Cam2 112, stock engine, ~24psi ...
Quote:
Originally Posted by 2004WRBSTi
Well I am not disappointed at all no matter how you look at it, the spool is great it pulls sooo hard...The [GT35R] .63 is by no means maxed out yet at all, I put down 437WHP on CAM2 on Buschurs heartbreaker, Tim Bailey (PDX Tuning) Ö said there was no hint of knock AT ALL on pump or on CAM2, but I will say my EGT's on pump were a little high due to the smaller housing and the backpressure from the .63. ...
Quote:
Originally Posted by AZScoobie
...I have tried all the AR's. The thing that needs to be watched is the Gas flow the turbine supports. Its very important that you get this right on EJ motors. Do the math at 1.0, 1.5 and 2.0 times the manifold pressure. The answer will be right there in front of you.
Quote:
Originally Posted by AZScoobie
Beware of surge issues with the 35R and the .63. That turbine is pretty big and it offers alot of trq on that shaft.

...Cya Clark
Quote:
Originally Posted by rotanner
Just ran the following:
Quote:
Originally Posted by rotanner
2005 STI, stock long block

60ft 1.752
1/8 7.741 @92.25
1/4 12.024 @116.86
Conservative shifting

Have Perrin 35R kit w/.63 A/R, PE 850, TXS FM, Walbr 255 Greeddt SP2, Element Tuning header, UTEC.

I think the 35R with the .63 AR is not a good street combo. ...
...After talking to a few people, including Phil at Element Tuning, they say that .63 creates too much back pressure with the 35R. ...
Quote:
Originally Posted by Element Tuning
...Running the 35R with a .63 exhaust housing is like running a 2" exhaust on your car. It's just not going to make reliable power on a 2.5 liter Subaru. This is a mismatched combination and you could get better performance with a bolt on turbocharger. Also with such poor spoolup (4500 rpm?) you want to be rewarded with massive power and the .63 wonít deliver it. The .63 is a better match for something like a 50 Trim. ...Phil
Quote:
Originally Posted by calib17a
... research compiled to find a garrett bb turbo for rotated mount that would meet the criterea alot of us want, a wide powerband, early and quick spool, power up top.
Quote:
Originally Posted by calib17a

Just found these 2 threads:

GT30R .63 housing vs. .82 housing logs
http://forums.nasioc.com/forums/showthread.php?t=804081&highlight=gt30r+.82

STI GT35R Dyno Sheet With UTEC Data Log (.63 a/r) although he's running a Crawford S3L Shortblock

http://forums.nasioc.com/forums/showthread.php?t=805778&highlight=gt35r+housing

I like the characteristics of gt30r with the .82 a/r and the gt35r with the .63 a/r housing.
Quote:
Originally Posted by Dizastical
I finally finished the final tune on my 2004 STI with the Ultimate Racing GT35R Turbo Kit. This GT35R has a .63 exhaust housing. Everyone talks about compressor surge on a 2.5 with the .63 housing using a GT35R. It may surge on paper but I have not had it surge once durring the 1000 miles of driving. I have finally had the time to fine tune the car to where it makes lots of power on pump gas. Here are the mods the car has .......
Quote:
Originally Posted by Dizastical

Crawford S3L Shortblock
Stock heads/Cams
...

For every day driving the car runs 93 octane gas and 24 psi of boost. I have not brought the car to the 1/4 mile track yet but I did bring it to the 1/8 mile before this final tune and the car ran 7.80 @ 95.8 MPH with a 1.81 60'. ...

Here is the link to the dyno sheet. Again this is in 4th gear 93 octane @ 24 psi. ...
http://www.f1dyno.com/pictures/F1Dyno_Runs/Scan0001resize

Here is the complete 5th gear log from 2000 rpm to 7000 rpm. 93 octane @ 24 psi . ...

Dave
Quote:
Originally Posted by Dizastical
the [GT35R] .63 has yet to surge after 1500 miles of hard driving. I run 23 psi on 93 octane for everyday driving. I see full boost in 4th gear at 4300. in 5th at 4100. Pulls very strong all the way to red line. ...Dave
Quote:
Originally Posted by 11SECWRX
Anyone running this set-up [GT35R .63]? I have seen one dyno and the car made almost 500whp and still spooled pretty quick.
Quote:
Originally Posted by F1DYNO
...Crawford S3L Short Block
Quote:
Originally Posted by F1DYNO
Ultimate Racing GT35R Rotated Turbo Kit With a .63 Exhaust Housing
...
TurboXS Blow Through MAF
Turboxs Dual Stage Boost Controller
Snow Performance Stage 2 Water Injection
...

...For every day driving and track use I run 27 PSI. EVERY DAY! The car is rock solid on the street and track. Pulls extremely hard and does not ever skip a beat. The .63 housing spools very fast making full boost at 4100 rpm in 5th gear!

...The car is making a little over 500 HP at the wheels and about 485 TQ at the wheels . On pump gas and water injection. Here is the best pull of the day for me . I know the traps are high and the 60' is horrible! I am going to work on it. It is a beast out of the hole! Very tricky to get down the track also.

60'---1.931
330---5.113
1/8---7.666
mph---94.81
1000---9.860
1/4---11.666
mph---125.66

Dave
Quote:
Originally Posted by PERRINJeff
...I would much rather drive a 400WHP .63, than .82??? In fact one of the turbos we really try to push is the .63 GT35R. I would say that it spools the same as the .82 Gt30R and will make more power! Same reason the Green does as well as it does. Big compressor, tiny .45AR turbine, but big turbine hole. ...
ka mano is offline   Reply With Quote
Old 06-08-2006, 04:45 AM   #4
STimo
Scooby Specialist
 
Member#: 110273
Join Date: Mar 2006
Location: OC, California
Vehicle:
450 whp 30R STI
[email protected]

Default

Subscribed
STimo is offline   Reply With Quote
Old 06-08-2006, 04:50 AM   #5
homiusang
Scooby Newbie
 
Member#: 88836
Join Date: Jun 2005
Chapter/Region: BAIC
Location: Bay Area, CA
Vehicle:
06 Evo IX
GG

Default

This is an excellent post. Tons of great info here. Keep it up!
homiusang is offline   Reply With Quote
Old 06-08-2006, 04:57 AM   #6
STimo
Scooby Specialist
 
Member#: 110273
Join Date: Mar 2006
Location: OC, California
Vehicle:
450 whp 30R STI
[email protected]

Default

And just to add i have a GT30R .82 and i see full boost at ~4k (22psi) on stock motor, maybe a tad bit earlier than 4k. On ~93oct i made 392whp @ 22psi on a very conservative tune since it is my DD.
STimo is offline   Reply With Quote
Old 06-08-2006, 08:25 AM   #7
ShaggyGT
*** Banned ***
 
Member#: 19221
Join Date: May 2002
Chapter/Region: South East
Location: Jacksonville, FL
Vehicle:
2005 Legacy GT (STi)
UR35R/Rotated Intake Mani

Default

From what we have seen at the shop, the GT35R w/ .63A/R housing is more of a restriction than anything else. With your build do not waste your time with the .63 housing. If you want good spool with great power then go with the GT30R w/ .82A/R housing.

We have an STi the shop built that has a complete Ferrea(Sp?) Valvetrain and DPR Stage 3 cams, sleeved block w/ forged pistons, UR35R w/ .63A/R, FMIC, Water Injection, ect.. On the dyno the power drops off up top even with the headwork and better cams. Once we change the housing out to atleast a .82A/R then I suspect the drop off will no longer be an issue.

-Matt
ShaggyGT is offline   Reply With Quote
Old 06-08-2006, 09:04 AM   #8
silentbob343
Scooby Specialist
 
Member#: 57307
Join Date: Mar 2004
Default

Quote:
Originally Posted by ShaggyGT
From what we have seen at the shop, the GT35R w/ .63A/R housing is more of a restriction than anything else. With your build do not waste your time with the .63 housing. If you want good spool with great power then go with the GT30R w/ .82A/R housing.

We have an STi the shop built that has a complete Ferrea(Sp?) Valvetrain and DPR Stage 3 cams, sleeved block w/ forged pistons, UR35R w/ .63A/R, FMIC, Water Injection, ect.. On the dyno the power drops off up top even with the headwork and better cams. Once we change the housing out to atleast a .82A/R then I suspect the drop off will no longer be an issue.

-Matt
Please post some comparison data of that, I think it would be very interesting to look at. If its not too much trouble.
silentbob343 is offline   Reply With Quote
Old 06-08-2006, 09:26 AM   #9
ShaggyGT
*** Banned ***
 
Member#: 19221
Join Date: May 2002
Chapter/Region: South East
Location: Jacksonville, FL
Vehicle:
2005 Legacy GT (STi)
UR35R/Rotated Intake Mani

Default

I definitely will once he gets the car back in to swap the housings. The dyno results will be from two days but I dont think the results will be too off.

-Matt
ShaggyGT is offline   Reply With Quote
Old 06-08-2006, 10:08 AM   #10
Division By Zero
Scooby Specialist
 
Member#: 7555
Join Date: Jun 2001
Chapter/Region: South East
Location: Charlotte NC
Default

Quote:
Originally Posted by ka mano
but not driving the compressor so hard the engine chokes & spews a packed-air punch back at it.
I don't think it's that black and white IMO. Besides displacement, you've got other considerations like how well the cyl head combo flows and other possibly less affecting parts like intake manifold etc.

I know on mine with GT32/35R setup (turbine wheel size is between the GT30 and 35R with a .78AR), it spools quickly and never experienced surging other than an occasional BOV related surge. I've seen 20psi before 4k rpms and no problems to report. That's on ported heads, intake and exhaust manifolds using WRX cams.

From what I've seen, seems like the .82 is the best all around option.
Division By Zero is offline   Reply With Quote
Old 06-08-2006, 09:22 PM   #11
ImprezaRSfan!
Scooby Specialist
 
Member#: 13520
Join Date: Dec 2001
Chapter/Region: MAIC
Location: Springfield, VA
Vehicle:
99rs ej207 spec-c
its for sale

Default

theres probably so many different variables and people with different blocks/heads which may make all the data people are posting hard to find a concensus.
ImprezaRSfan! is offline   Reply With Quote
Old 06-13-2006, 08:35 PM   #12
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Snoqualmie
Vehicle:
2006 STI / 2010 FXT
Aspen White / Silver

Default 30r .82 and 35r .82

30r is on a built motor - - - - - - - - line
35r is on a stock motor ------------ (solid line) Same guy tuned both cars
Same motors 2.5's
But look how the 30r Owns under the curve
Token-Negro is offline   Reply With Quote
Old 06-13-2006, 08:38 PM   #13
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Snoqualmie
Vehicle:
2006 STI / 2010 FXT
Aspen White / Silver

Default

We are talking about SPOOL HERE this is not a hp/lbft thing. But spool.
Token-Negro is offline   Reply With Quote
Old 06-13-2006, 08:41 PM   #14
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Snoqualmie
Vehicle:
2006 STI / 2010 FXT
Aspen White / Silver

Default

Sorry it is with a 35r but this is a good graph for the 30r .82
Token-Negro is offline   Reply With Quote
Old 06-13-2006, 09:32 PM   #15
MARKGSTI
Scooby Specialist
 
Member#: 70197
Join Date: Sep 2004
Default

..Stop being a PXXSY and get the 35r
MARKGSTI is offline   Reply With Quote
Old 06-13-2006, 10:17 PM   #16
keaniegenie
Scooby Specialist
 
Member#: 94494
Join Date: Aug 2005
Chapter/Region: NWIC
Location: Seattle
Vehicle:
2005 Element 92x
Black

Default

Quote:
Originally Posted by ka mano
Here are some relevant posts I found:

[/i]
That was one helluva post you did there!
keaniegenie is offline   Reply With Quote
Old 06-14-2006, 01:07 AM   #17
ka mano
Scooby Specialist
 
Member#: 78022
Join Date: Dec 2004
Chapter/Region: NWIC
Location: Seattle, Washington 05 WRB GGA
Vehicle:
PdxT built 2.5L 6sp
30R.82, 274/276, H2O+meth

Default

Thanks, kg.

These two comparisons posted above -- between the 30 and the 35 with the same exhaust a/r and between two of the three hotsides of the 35 -- are really interesting. I'm especially interested in seeing the power drop off you talked about, Matt, when you dyno'ed the 35R .63.

T-N, just wanting to double check that you got your legend right... the 30 outperformed the 35 at peak by ~83 ft lbs and 80 hp? Did the tuner push the 30 harder because of the internals?

It'd be great if someone could do a side-by-side of the 30R .82 and the 35R .63... more what this thread is about. 'In the interest of science,' I've thought about taking my 30R .82 off for an afternoon of tuning and testing with a 35R .63 if someone would give me a loaner. Could take allota coin though to make that happen.

Short of that, it'd be interesting to see performance data of similarly equipped cars whose main difference is which of these two turbos each car has.

ka mano . . . -- The PXXSY with the 30R!
ka mano is offline   Reply With Quote
Old 06-14-2006, 01:26 AM   #18
Division By Zero
Scooby Specialist
 
Member#: 7555
Join Date: Jun 2001
Chapter/Region: South East
Location: Charlotte NC
Default

I'm really surpirsed PDX doesn't have this even already. Maybe not the same car but the same dyno. Although the only real way to test it would be the same car or a trend amongst many cars.
Division By Zero is offline   Reply With Quote
Old 06-14-2006, 01:36 AM   #19
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

Quote:
Originally Posted by ka mano
T-N, just wanting to double check that you got your legend right... the 30 outperformed the 35 at peak by ~83 ft lbs and 80 hp? Did the tuner push the 30 harder because of the internals?
I was going to ask the same thing - that's a big frigging difference, and it's not what I expected to see, or at least not that much.
flycaster is offline   Reply With Quote
Old 06-14-2006, 01:44 AM   #20
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

Quote:
Originally Posted by tmarcel
I'm really surpirsed PDX doesn't have this even already.
I bet they do but they may well be on different dynos. Their recent change makes "comparisons" a little more problematic in certain cases, which will resolve itself once they build up a bunch of charts on the new one. The horsepower numbers remain "fairly" comparable, but the torque curves look completely different, at least based on what I've seen.
flycaster is offline   Reply With Quote
Old 06-14-2006, 02:00 AM   #21
zilgiank
Scooby Newbie
 
Member#: 104279
Join Date: Jan 2006
Location: Sac/LA
Vehicle:
2005 Legacy GT
Atlantic Blue

Default

I bet that 35 isn't pushing as hard as it can...
zilgiank is offline   Reply With Quote
Old 06-14-2006, 02:03 AM   #22
Token-Negro
Scooby Specialist
 
Member#: 81659
Join Date: Feb 2005
Chapter/Region: NWIC
Location: Snoqualmie
Vehicle:
2006 STI / 2010 FXT
Aspen White / Silver

Default

Its not about the hp it was about the spool the 35 is a soft tune, due to the stock internals, but the spool was what we are after.
Token-Negro is offline   Reply With Quote
Old 06-14-2006, 02:09 AM   #23
sumfoo1
Scooby Specialist
 
Member#: 82146
Join Date: Mar 2005
Chapter/Region: South East
Location: Raleigh, NC (Brier Creek)
Vehicle:
2005 Legacy GT
OBP

Default

crap... double srry
sumfoo1 is offline   Reply With Quote
Old 06-14-2006, 02:10 AM   #24
sumfoo1
Scooby Specialist
 
Member#: 82146
Join Date: Mar 2005
Chapter/Region: South East
Location: Raleigh, NC (Brier Creek)
Vehicle:
2005 Legacy GT
OBP

Default

ohh crap i thought they were hp and tq side by side... not on top

it still seems like there isn't as much boost to the 35
sumfoo1 is offline   Reply With Quote
Old 06-14-2006, 02:15 AM   #25
WRXRallyBlue
Scooby Specialist
 
Member#: 48831
Join Date: Nov 2003
Chapter/Region: SWIC
Location: Reno
Vehicle:
2002 Protuned Wagon
Bugeyes Forever

Default

Quote:
Originally Posted by Token-Negro
but the spool was what we are after.
The title of this thread says "top end" also..
WRXRallyBlue is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FT perrin gt35r turbo! 4 gt30r .82 Bankaiup Engine/Power/Exhaust 1 11-05-2008 08:09 PM
WTT: gt35r .63 housing for .82/1.06 housing JT's06sti Engine/Power/Exhaust 4 03-21-2008 05:04 PM
V39 vs v30, spool up vs HP & torque manxaru Built Motor Discussion 4 02-20-2008 11:12 AM
GT30R .63 VS GT30r .82 Subiemaddness Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 7 02-04-2008 01:32 PM
Top End & TMIC: Possible? thebigshow Newbies & FAQs 13 03-29-2006 05:49 PM

All times are GMT -4. The time now is 10:38 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.