Welcome to the North American Subaru Impreza Owners Club Sunday April 20, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Subaru Conversions

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.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 04-09-2013, 01:53 PM   #1
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default GM 3.9 Pushrod V6 with VVT into 05 Subaru Legacy GT -- Then Compound Charged

This thread will attempt to document my swap. Going to put a 3.9 GM V6 with VVT into a 2005 Subaru Legacy GT. Mated to the AWD manual transmission, then compound turbocharged. I plan to keep the stock computer for running the gauges, and megasquirt to run the engine.
This swap is similar to the 3.8 GM 90 degree V6 in legacy thread, however mine will be manual and not automatic. I will also attempt to Compound Turbocharge this setup, using my new found engine bay room to put both turbos on the passenger side of the motor. I am thinking something like a GT35R as the small turbo (possibly even a HE351V variable geometry turbo) and a HX55 as the large one in the stock location.




The first step will be to get an adapter plate made to bolt to the engine, which will allow the AWD manual transmission to mate up to it. Then comes a custom flywheel and pressure plate. Even before this, I still need to find an STI 6 speed and R180 to swap in first, before i go about this.

Could anyone help me out by measuring on the subaru motor, on the back of the motor (clutch side). I need to know the offset of the crank face to the edge of the motor, where it would normally bolt to the transmission.
Basically run a straight edge across the back face of the block, then measure how far the crank face is offset from here... This measurement is needed to determine what thickness of adapter plate i will need, as well as getting a feel of how much the flywheel may need to be stepped off from the crank. I know that the crank offset from the back of the block on the GM V6 is much smaller than that of the subaru.
* Registered users of the site do not see these ads.
farmerz24 is offline   Reply With Quote
Old 04-10-2013, 11:39 AM   #2
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Quote:
Originally Posted by farmerz24 View Post
This swap is similar to the 3.8 GM 90 degree V6 in legacy thread...
Where is that thread?
Patrick Olsen is offline   Reply With Quote
Old 04-10-2013, 01:01 PM   #3
Umadbroej26
Scooby Newbie
 
Member#: 352405
Join Date: Apr 2013
Location: Oddville kentucky
Vehicle:
1996 Mutt
Exotic sea

Default

I will measure when I get off work and let u know
Umadbroej26 is offline   Reply With Quote
Old 04-10-2013, 01:38 PM   #4
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

Patrick --> its on legacygt.com with thread title "My subaru will beat with a buick heart"

Umadbroej26 --> I could also use the measurement when the flywheel is on the engine, from the flywheel face to the edge of the block (please indicate if this is the 5 or 6 speed flywheel). Thanks alot!
farmerz24 is offline   Reply With Quote
Old 04-14-2013, 09:59 PM   #5
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

Took Some measurements today off a 3500 which is very close in dimention to the 3900. The gm v6 is about 19-20 inches long. The subaru motor is about 15 1/4. The engine is only 16 inches wide at its widest point (the edge of the heads).

THe subaru motor is about 28-30 inches wide. There is about 34 inches between the frame rails. That leaves about 9 inches on each side of the motor. However, the engine is about 16 inches tall from crank center to top of motor. The subaru motor is only 1 foot tall.

For the flywheel face to block face offset, the measurement i got was the flywheel face sticks out past the block face by 21mm. If anyone knows the subaru measurement that would be greatly appreciated. Thanks.


farmerz24 is offline   Reply With Quote
Old 04-16-2013, 10:25 AM   #6
AStihi
Scooby Newbie
 
Member#: 257896
Join Date: Sep 2010
Chapter/Region: MWSOC
Location: Shelby Twp. MI
Vehicle:
2013 BRZ, '02 WRX

Default

The one question that keeps running through my mind is... why? Sounds like it'd be quite fun in the end, but why that particular engine??
AStihi is offline   Reply With Quote
Old 04-16-2013, 01:53 PM   #7
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

This engine makes 240ft/lb of tq @ 2800 rpm... N/A. I think my current 2.5 needs 20 psi off of a 68hta to do that. Parts are cheap. It can use common LS V8 pistons and rods..
It's different and hasnt been done. A V8 is too big to keep AWD. What engine would you use? The H6 im sure is a candidate, but i want low end OHV TQ. There will be so much room beside the motor for activities!!! (Turbo setup)

A compound turbo setup using a HE351Ve (VGT) as the small turbo and a HX55 or something as the large turbo should give insane power figures. 1000 streetable WHP?
What engine would you use?

Still hoping someone could get me the crank to block face offset of the 2.5 engine and 6 speed flywheel. Thanks again!
farmerz24 is offline   Reply With Quote
Old 04-16-2013, 03:40 PM   #8
treystoys
Scooby Specialist
 
Member#: 97436
Join Date: Oct 2005
Chapter/Region: South East
Location: Metairie, Louisiana
Vehicle:
03 WRX stage 2.2
white/w/ce28n's

Default

Quote:
Originally Posted by farmerz24 View Post
This engine makes 240ft/lb of tq @ 2800 rpm... N/A. I think my current 2.5 needs 20 psi off of a 68hta to do that. Parts are cheap. It can use common LS V8 pistons and rods..
It's different and hasnt been done. A V8 is too big to keep AWD. What engine would you use? The H6 im sure is a candidate, but i want low end OHV TQ. There will be so much room beside the motor for activities!!! (Turbo setup)

A compound turbo setup using a HE351Ve (VGT) as the small turbo and a HX55 or something as the large turbo should give insane power figures. 1000 streetable WHP?
What engine would you use?

Still hoping someone could get me the crank to block face offset of the 2.5 engine and 6 speed flywheel. Thanks again!
I think it's a cool idea and hope you pull it off. It's also cool it uses LS parts, how's the crank in the v6 and is there existing aftermarket support for it? Good luck man!

Trey
treystoys is offline   Reply With Quote
Old 04-16-2013, 04:03 PM   #9
BeBop86
Scooby Guru
 
Member#: 147776
Join Date: May 2007
Chapter/Region: NWIC
Location: Bellingham, WA
Vehicle:
'02 Impreza WRX
'85 Toyota Corolla

Default

Interesting... I'm excited to see odd and unique swaps.

Last edited by BeBop86; 04-16-2013 at 04:18 PM.
BeBop86 is offline   Reply With Quote
Old 04-16-2013, 11:53 PM   #10
BruceD_500
Scooby Newbie
 
Member#: 233041
Join Date: Dec 2009
Chapter/Region: E. Canada
Location: Windsor Onatrio
Default

I'll be watching... I love my Subaru but I'm sick and tired of head gasket replacements.
BruceD_500 is offline   Reply With Quote
Old 04-17-2013, 12:09 AM   #11
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

There's interest here. Someone get me that measurement so parts can be made!

60degreev6.com specializes in parts for this motor. The rod journals are actually a hair bigger than the standard 2.25 or whatever it is in the Ls motor. I know one guy did an offset ground crank and overbore to achieve 4.2 liters of displacement. The crank is a 2 bolt main but is also cross bolted Into the oil pan on each main cap to add strength.
farmerz24 is offline   Reply With Quote
Old 04-17-2013, 12:54 AM   #12
Imprezzedwitsubies
Scooby Newbie
 
Member#: 216116
Join Date: Jul 2009
Chapter/Region: South East
Location: Tampa, FL
Vehicle:
09 Impreza 2.5I
14' Triumph America

Default

Ahh thats the old Malibu SS motor. Those suckers were fast but they came only in a 4spd auto. Interesting swap for sure.
Imprezzedwitsubies is offline   Reply With Quote
Old 04-17-2013, 12:17 PM   #13
BeBop86
Scooby Guru
 
Member#: 147776
Join Date: May 2007
Chapter/Region: NWIC
Location: Bellingham, WA
Vehicle:
'02 Impreza WRX
'85 Toyota Corolla

Default

Will this setup be heavier than the Subaru motor?
BeBop86 is offline   Reply With Quote
Old 04-30-2013, 01:42 PM   #14
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

No one can help me out with the measurement????
farmerz24 is offline   Reply With Quote
Old 04-30-2013, 02:00 PM   #15
cowboy_Rob
Scooby Specialist
 
Member#: 194062
Join Date: Nov 2008
Chapter/Region: MAIC
Location: Camp Hill PA
Vehicle:
2003 Impreza WRX
PSM

Default

If you still need it I can get it for you but it will be a few weeks at least till mine is going back together
cowboy_Rob is offline   Reply With Quote
Old 05-05-2013, 03:25 AM   #16
Dirtracr95
Scooby Newbie
 
Member#: 346599
Join Date: Feb 2013
Chapter/Region: MWSOC
Location: Des Plaines, IL
Vehicle:
2003 WRX
WRB

Default

Interesting choice I'm partial to the ln3 and l27 and series 1 l67's very good rod stroke ratio of 1.88 can stroke it without worrying about side loading the pistons. Plus stock bottom ends hold 800+ HP
Dirtracr95 is offline   Reply With Quote
Old 09-10-2013, 04:52 PM   #17
BeBop86
Scooby Guru
 
Member#: 147776
Join Date: May 2007
Chapter/Region: NWIC
Location: Bellingham, WA
Vehicle:
'02 Impreza WRX
'85 Toyota Corolla

Default

Updates?
BeBop86 is offline   Reply With Quote
Old 09-15-2013, 11:15 PM   #18
ProfessWRX
Scooby Specialist
 
Member#: 323379
Join Date: Jun 2012
Vehicle:
06 WRX

Default

Is there something I'm missing? Why NOT the gm3800? What don't I know about the 3900? I always assumed it was trash and I've not been around them enough to know how they take to boost. Whereas the 3800 will take gobs.

I saw your reasoning, but it still seems... off to me. Oh well. Have fun!
ProfessWRX is offline   Reply With Quote
Old 02-04-2014, 01:31 PM   #19
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

the 3900 makes as much tq N/A as the 3.8 does supercharged. plus it has aluminum heads, not iron. A guy threw one into his camaro with a gt40 and is running low 11's with less than 15 psi of boost in an IROC camaro.

so some updates.


aquired the 3900 motor:



test fit into bay:



first issue: boy is this ever sticking out of the hood.



corner view:




HMMM now what to do. Some oilpan and subframe clearancing as well as a 2 inch front subframe and transmission bracket drop get us here:

(before after sideview)




So thats quite a bit better, i realize a notch in the hood will be needed. but thats a small thing to give up to have 90% of peak torq by 1800 rpm.
peak tq is 240 or so ft/lb. N/A. And yes it will be going turbo once running. 400 wheel under 10psi..


Comments, advice, suggestions, flame???
I dont have the adapter plate yet, so the motor actually will go back another inch or so in that pic.. that will help slighly as the hood lines go down towards the ground as it gets closer to the front of the car.

Im going to try to notch the subframe to get it down another inch or so...
Anyone know if bump steer will be increased if the steering rack mounting location is lowered without lowering the front control arm mounting point as well?

Another thing i noticed is that the GM electronic TB looks very similar to the subaru one, probably made by the same manufacturer. They both have 6 pins on them, and the side motor housing looks similar. Wonder if the subaru ecu will be able to control this one like stock. If not i will mount the stock subaru TB on it for now...


Thanks, more updates to come.
farmerz24 is offline   Reply With Quote
Old 02-04-2014, 01:54 PM   #20
ProfessWRX
Scooby Specialist
 
Member#: 323379
Join Date: Jun 2012
Vehicle:
06 WRX

Default

Quote:
Originally Posted by farmerz24 View Post
the 3900 makes as much tq N/A as the 3.8 does supercharged. plus it has aluminum heads, not iron. A guy threw one into his camaro with a gt40 and is running low 11's with less than 15 psi of boost in an IROC camaro.
Sure, but the 3800 has run 8s completely stock.

Again though it's your build. Sounds fun regardless.
ProfessWRX is offline   Reply With Quote
Old 02-04-2014, 06:22 PM   #21
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Quote:
Originally Posted by farmerz24 View Post
Anyone know if bump steer will be increased if the steering rack mounting location is lowered without lowering the front control arm mounting point as well?
Yes. If the tie rods and the ball joint-to-control arm pivot aren't parallel, bumpsteer will be jacked up.
Patrick Olsen is offline   Reply With Quote
Old 02-05-2014, 12:04 AM   #22
Badler
Scooby Guru
 
Member#: 133597
Join Date: Nov 2006
Chapter/Region: SCIC
Location: Orange
Default

What tranny are you planning on using?
Badler is online now   Reply With Quote
Old 02-05-2014, 10:43 AM   #23
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

stock subaru 5 speed awd for now...
farmerz24 is offline   Reply With Quote
Old 02-05-2014, 11:55 AM   #24
05Scooby
Scooby Specialist
 
Member#: 153216
Join Date: Jul 2007
Chapter/Region: Tri-State
Location: Langhorne, PA
Vehicle:
2005 WRX stage 3
CGM

Default

didn't 3.8's and 3.9s have intake manifold issues?
05Scooby is offline   Reply With Quote
Old 02-05-2014, 01:07 PM   #25
farmerz24
Scooby Newbie
 
Member#: 272368
Join Date: Jan 2011
Default

your thinking of the older 3100 and 3400's.
farmerz24 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


All times are GMT -4. The time now is 09:22 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.