Welcome to the North American Subaru Impreza Owners Club Friday December 26, 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 > Normally Aspirated Powertrain

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 11-09-2009, 08:39 PM   #1
Ferraz
Scooby Specialist
 
Member#: 173553
Join Date: Mar 2008
Chapter/Region: International
Location: Sao Paulo
Vehicle:
1996 Civic VTi
Dark blue

Default NA power

Just out of curiosity, I would like to know what power level a NA subaru can reach??

Regards
* Registered users of the site do not see these ads.
Ferraz is offline   Reply With Quote
Old 11-09-2009, 09:00 PM   #2
07ImprezaMB
Scooby Specialist
 
Member#: 153861
Join Date: Jul 2007
Chapter/Region: MAIC
Location: Frostburg Maryland
Vehicle:
2008 WRX hatch
WR Blue

Default

it all depends on what kind of money you want to spend. With bolt ons (full exhaust, intake, lw crank pulley, and a tune you can make around 160. thats what i have done right now and i dyno'd at 162 whp and 157 wtq.

Now there are some options for us n/a guys that will allow much more power without boost. such as cams, port n polished intake manifold, throttle body spacers, rallitek has completely built cylinder heads available for the n/a's now to include port n polished heads, high lift race cams, and dual spring titanium retainer valvetrain, and now the accessport is available too. with these engine upgrades id say the n/a's could easily make it to the mid 200hp range with no boost.

Like i said its all about the money you're willing to fork out.
07ImprezaMB is offline   Reply With Quote
Old 11-09-2009, 09:12 PM   #3
subieracer07
Scooby Newbie
 
Member#: 155084
Join Date: Jul 2007
Chapter/Region: NWIC
Location: puyallup
Vehicle:
91 leggy wagon
silver

Default

^^^ with that said you better have a big fork and alot of lettuce to pull out lol
subieracer07 is offline   Reply With Quote
Old 11-09-2009, 09:18 PM   #4
GrundleJuice
NASIOC Supporter
 
Member#: 165749
Join Date: Dec 2007
Chapter/Region: South East
Location: stupid Florida
Vehicle:
2007 No YELLING
on the bus!

Default

there have been big budget 2.5L n/a EJ's that made 300+hp... but I don't know if that was whp or bhp. don't know if that was on pump gas or something else, either.
GrundleJuice is offline   Reply With Quote
Old 11-09-2009, 10:03 PM   #5
chazly413
Scooby Specialist
 
Member#: 151079
Join Date: Jun 2007
Chapter/Region: MAIC
Location: College Park, MD
Vehicle:
2005 2.5RS RBP
motec system exhaust-RIP

Default

It also helps to know the stock power for a car and compare that to its new power. It's one thing if a 2.5i stock dynos 130 whp and then gets 160 whp from bolt ons. Don't think they're always stock dyno'ing 105ish to the wheels.
chazly413 is offline   Reply With Quote
Old 11-09-2009, 10:10 PM   #6
Ferraz
Scooby Specialist
 
Member#: 173553
Join Date: Mar 2008
Chapter/Region: International
Location: Sao Paulo
Vehicle:
1996 Civic VTi
Dark blue

Default

Quote:
Originally Posted by 07ImprezaMB View Post
it all depends on what kind of money you want to spend. With bolt ons (full exhaust, intake, lw crank pulley, and a tune you can make around 160. thats what i have done right now and i dyno'd at 162 whp and 157 wtq.

with these engine upgrades id say the n/a's could easily make it to the mid 200hp range with no boost.
162whp is close to WRX power!! A 160+whp NA engine must fell very good!! A 200+whp NA will put a stupid smile on your face and leave it there!

Quote:
Originally Posted by RaceFaceXC View Post
there have been big budget 2.5L n/a EJ's that made 300+hp... but I don't know if that was whp or bhp. don't know if that was on pump gas or something else, either.
300chp is a LOT of power!

It is good to know you guys are getting more power options every day... I'm was always a fan of NA engines! The best engines in the word are NA (IMHO)... GT3, Carrera GT, C63 AMG... I really hope to see some really fast NA Subarus!

Thanks guys!
Ferraz is offline   Reply With Quote
Old 11-09-2009, 10:26 PM   #7
J-Chow
Scooby Specialist
 
Member#: 104722
Join Date: Jan 2006
Chapter/Region: VIC
Location: Richmond, aka Hongerland
Vehicle:
2006 2.5i - SOLD
Gray

Default

Keep it NA, go H6 engine :P
Slap in that tribeca or Outback Engine.
J-Chow is offline   Reply With Quote
Old 11-09-2009, 11:09 PM   #8
07ImprezaMB
Scooby Specialist
 
Member#: 153861
Join Date: Jul 2007
Chapter/Region: MAIC
Location: Frostburg Maryland
Vehicle:
2008 WRX hatch
WR Blue

Default

[quote=Ferraz;28776562]162whp is close to WRX power!! A 160+whp NA engine must fell very good!! A 200+whp NA will put a stupid smile on your face and leave it there!


Yea i was really happy making that much power with only bolt ons. here is the dyno sheet to prove my numbers.



And yes my car is very peppy i love driving it, i cant wait until i get it built
07ImprezaMB is offline   Reply With Quote
Old 11-09-2009, 11:24 PM   #9
jeonster
Scooby Newbie
 
Member#: 198854
Join Date: Dec 2008
Chapter/Region: NESIC
Location: Hartford, CT
Vehicle:
2013 WRX
Silver

Default

thats nice! I just have suspension mods stock engine and I hate it when minivan moms pass me. It makes me feel powerless. lol
jeonster is offline   Reply With Quote
Old 11-10-2009, 12:11 AM   #10
dk2.5i
Scooby Newbie
 
Member#: 206144
Join Date: Mar 2009
Chapter/Region: BAIC
Location: North Bay
Vehicle:
2007 impreza 2.5i
grey

Default

Quote:
Originally Posted by 07ImprezaMB View Post
it all depends on what kind of money you want to spend. With bolt ons (full exhaust, intake, lw crank pulley, and a tune you can make around 160. thats what i have done right now and i dyno'd at 162 whp and 157 wtq.
not to tthread jack but what intake are you runing
dk2.5i is offline   Reply With Quote
Old 11-10-2009, 12:23 AM   #11
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

You will be bound to a torque limit by the displacement of the engine and the fuel type used.

You can not make more torque.

However, you can shift that torque around to different locations on the rpm band. Shift it low, you get broad daily functionality but relatively low hp numbers. Shift it high, you get a more sport geared power band and high hp numbers. Torque is the instantaneous force the engine applies to the road at any given moment. Horsepower is the application of this torque over time, the energy expenditure of the engine. HP = energy out.

The normal goal of na builds is to first optimize the system. You raise the torque to its limit. You also broaden the torque band over more of the power band to make the car more broadly usable. Beyond the slight gains from stock, you will never see any more raw torque gains from the car. The goal from then on is to keep shifting the torque band higher in the rpm range and bumping up HP. Depending on the dyno, you will typically see between 150-170 ft-lb. from the Subaru engine. In stock form or anywhere near stock form, this torque band is centered around 3500 rpm and rolls off in both directions. Some mods will shift it a little higher. Some mods will broaden the torque band. You will see most Subaru engines not make very high HP numbers simply because the torque band is geared low. You want to make big hp numbers, you have to gear the engine for high rpm operation. A lot of this comes from the designs of the intake manifold, heads, cams, and exhaust manifold. These parts will largely define how air flows through the engine and where peak efficiency will occur. Keep moving the torque band up and you will keep making more HP. I mean, if you can keep 150 wheel ft-lb at 8000 rpm, you'll make 230 wheel HP. If you can get it to 9000 rpm, you're at 260 whp. You get the idea. You are always bound by the size of the engine, but rpm can net you major HP output...if you are willing to build an engine for it.

The downside is that the efficiency range is really only good around 4000 rpm or so. If you have an engine that will actually wind out to 9000 rpm and have the efficiency range between 5000 and 9000 rpm, it'll run like crap below 5000 rpm. The car will idle poorly, have more cleaniless (poor burning, high smog), idle poorly (may need to idle up at 1500 rpm to keep it from dying). There is a certain something you give up when actually building a race engine.

The other way to make power is to change the fuel. Put more energy into the combustion chamber, and you will get more power out given the same displacement. It's why nitrous is used. It's why people step to E85 or race fuel. There are still limits to what the engine can support in terms of load and heat, so you can really only go so far safely. Maybe you'll opt to seriously build up the engine.

I'll leave on a final note. There is a way to make a car faster for free. Two words = weight reduction. Lower static mass and lower rotating mass. Make the output energy from the engine go further. Reduce waste. A 3300 lb. car with 300hp is the same as a 2200 lb. car with 200hp. Rotating mass is another big factor. For example, there's a lot of energy wasted spinning up the stock flywheel, and a light weight one uses significantly less energy to spin up. On smaller levels, this also includes pulleys, wheels/tires, driveshafts, etc. Many times you're removing both static and rotational mass. On a quarter mile drag race, a light weight flywheel will make it so the car will use about 2.5% less overall energy from start to finish. This is quite dramatic just putzing around town too. Reving up in 1st gear alone from idle to redline is a solid 7% reduction with a lightweight flywheel. Weight plays a major roll in the whole scheme of making a car fast.
Back Road Runner is offline   Reply With Quote
Old 11-10-2009, 12:33 AM   #12
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

Quote:
Originally Posted by Ferraz View Post
162whp is close to WRX power!! A 160+whp NA engine must fell very good!!
Not even close. The only reason why a na and torque car looks similar is because you are just looking at peak numbers. A TD04 falls flat on its face in higher rpms. This dramatically limits peak hp numbers. You see 160-170 whp on a WRX. You may see around this on some na engines. They don't make nearly the same torque. The na will put down 150-160 ft-lbs. The turbo will put down double that. It'll put down 280-320 ft-lb around 4k rpm. A na engine isn't even in the same city let alone the same ballpark. Now there is an upside. HP is the end all factor. It is what defines energy out, i.e. what makes our car go. Because the WRX does stick it so low in the rpm band, it gives up a lot of potential that it could have had if the turbo was larger and the peak range was placed higher. Also because how we drive and our gearing, we typically sit between 5k rpm to redline speeding up. This is above the efficiency range of the stock TD04, and the turbo car loses a good bit of their potential advantage. Hurray for us!? Nope, all the turbo owner needs to do is toss on a bigger turbo, and they instantly make 300-400hp, and we are now not even in the same state. Forced induction is a multiplier.

Big HP on na is a hobby. It's what you do when you aren't really trying to make big power. It's what you do as a hobby, just to see what you can make the little engine do. It's what you do when you have $10k you don't know what to do with and want to try something a little out of the ordinary.
Back Road Runner is offline   Reply With Quote
Old 11-10-2009, 12:36 AM   #13
jeonster
Scooby Newbie
 
Member#: 198854
Join Date: Dec 2008
Chapter/Region: NESIC
Location: Hartford, CT
Vehicle:
2013 WRX
Silver

Default

I like how Back Road Runner explains things. Please be my Biochemistry professor!
jeonster is offline   Reply With Quote
Old 11-10-2009, 12:52 AM   #14
chazly413
Scooby Specialist
 
Member#: 151079
Join Date: Jun 2007
Chapter/Region: MAIC
Location: College Park, MD
Vehicle:
2005 2.5RS RBP
motec system exhaust-RIP

Default

Quote:
Originally Posted by jeonster View Post
I like how Back Road Runner explains things. Please be my Biochemistry professor!
I feel the same way
chazly413 is offline   Reply With Quote
Old 11-10-2009, 02:39 AM   #15
Sir Punk
Scooby Specialist
 
Member#: 173492
Join Date: Mar 2008
Chapter/Region: MWSOC
Location: Minneapolis,MN
Vehicle:
99 RS
BRP

Default

what kind of MPG do people get from NA that have 160+ whp? say highway at 3k rpm
Sir Punk is offline   Reply With Quote
Old 11-10-2009, 03:18 AM   #16
Captain Pingus
Scooby Newbie
 
Member#: 227692
Join Date: Oct 2009
Default

Quote:
Originally Posted by Sir Punk View Post
what kind of MPG do people get from NA that have 160+ whp? say highway at 3k rpm


And What bolt ons do they have?
Captain Pingus is offline   Reply With Quote
Old 11-10-2009, 11:19 AM   #17
07ImprezaMB
Scooby Specialist
 
Member#: 153861
Join Date: Jul 2007
Chapter/Region: MAIC
Location: Frostburg Maryland
Vehicle:
2008 WRX hatch
WR Blue

Default

ok to answer all of your questions i am running the injen rd1222 cyborg intake. and on the highway in 5th gear at 3k ill average around 30-32 mpg in the mountains, and about 34 on flat roads. and making 160whp i have uel header, high flow cat pipe, cat back exhaust, lightweight crank pulley, intake, and opensource dyno tuned. And road runner has a very good point with the torque factor on our n/a's. a stock 06-07 wrx makes 169whp and 174wtq compaired to only my 157wtrq. And thats with modifications. Put the same mods on a wrx and u have another 40-50 hp. torque wise we have no competition against a forced induction car.
07ImprezaMB is offline   Reply With Quote
Old 11-10-2009, 11:48 AM   #18
Sir-Knight
Scooby Specialist
 
Member#: 73636
Join Date: Nov 2004
Chapter/Region: E. Canada
Location: the 'wa, ontario, canada
Vehicle:
2007 Impreza 2.5i SE
newport blue pearl

Default

that was an impressive piece of theory.. I feel wholly educated on the subject now :P
Sir-Knight is offline   Reply With Quote
Old 11-10-2009, 12:02 PM   #19
Ferraz
Scooby Specialist
 
Member#: 173553
Join Date: Mar 2008
Chapter/Region: International
Location: Sao Paulo
Vehicle:
1996 Civic VTi
Dark blue

Default

Thanks for the great info, Road Runner!! Yes, the WRX has a lot more torque down low, but it has no top end! And for some reason, I like cars that pull hard at high RPMs... That is what attracts me on the JDM ej207.

I had a interesting experience a few days ago... I have a friend who own a Civic SI. The car have some bolt on mods. CAI, exhaust, tune... His car was never able to keep up with my Stage 2 WRX in the city and winding roads. The other day we went for a trip... I decided to give him a hard time. So I went WOT every oportunity a got!! Nothing crazy, just a short pull to leave him behind. At some point the highway got empty. I was at around 5000 rpm, I flor it and WTF!? The civic is still there... I was geting away, but very slowly! Man, that Vtec has no torque, but it sure can breath up top! I think at redline our whp is almost the same! 1 because mine is falling; 2 because his is rocketing up!!!

Now, after that little experience, I belive it is time for Subaru to make better heads!! Maybe some AVCS + AVLS could help the NA cars a lot!!

Last edited by Ferraz; 10-04-2010 at 07:56 PM.
Ferraz is offline   Reply With Quote
Old 11-10-2009, 01:07 PM   #20
chazly413
Scooby Specialist
 
Member#: 151079
Join Date: Jun 2007
Chapter/Region: MAIC
Location: College Park, MD
Vehicle:
2005 2.5RS RBP
motec system exhaust-RIP

Default

^ Apparently it does have torque if it's keeping up with you haha
chazly413 is offline   Reply With Quote
Old 11-10-2009, 01:08 PM   #21
LetItSnow
Scooby Specialist
 
Member#: 38222
Join Date: Jun 2003
Chapter/Region: Tri-State
Location: Cicero, NY
Vehicle:
'10 &'12 Foresters
another Miata convert

Default

Quote:
Originally Posted by Ferraz View Post
Just out of curiosity, I would like to know what power level a NA subaru can reach??
256chp, bone stock?
LetItSnow is offline   Reply With Quote
Old 11-10-2009, 01:50 PM   #22
Ferraz
Scooby Specialist
 
Member#: 173553
Join Date: Mar 2008
Chapter/Region: International
Location: Sao Paulo
Vehicle:
1996 Civic VTi
Dark blue

Default

Quote:
Originally Posted by chazly413 View Post
^ Apparently it does have torque if it's keeping up with you haha
Only at high revs... Where the WRX is shoking

Quote:
Originally Posted by LetItSnow View Post
256chp, bone stock?
Yes, from a 6 cylinder
Ferraz is offline   Reply With Quote
Old 11-10-2009, 01:53 PM   #23
MattK
Scooby Newbie
 
Member#: 63113
Join Date: Jun 2004
Location: Ellicott City, Maryland
Vehicle:
2000 Impreza 2.5RS
Silverthorn

Default That's what you get for being nonspecific!

^^^
MattK is online now   Reply With Quote
Old 11-10-2009, 01:59 PM   #24
Ferraz
Scooby Specialist
 
Member#: 173553
Join Date: Mar 2008
Chapter/Region: International
Location: Sao Paulo
Vehicle:
1996 Civic VTi
Dark blue

Default

Quote:
Originally Posted by MattK View Post
^^^
True!! But it would be nice to see some H6 numbers too! If we can find any modded 6 cylindres around.

I would love to run a 3.0r Legacy on E100... Just to see what is what!
Ferraz is offline   Reply With Quote
Old 11-10-2009, 02:24 PM   #25
HamFist
Scooby Specialist
 
Member#: 2112
Join Date: Aug 2000
Chapter/Region: MWSOC
Vehicle:
2000 Impreza 2.5RS
BRP

Default

NA is definitely more about fun than peak power numbers. There's something about an n/a car that's fun to flog, especially with shorter gears. Short gears are what make n/a cars fun.

BRR is right about moving the power around. My last set of headers made great top end from 4500-6k. My newer headers have a meaty torque curve from idle-5500. However, it's nothing like a turbo.
HamFist 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
97 OBS Rallycross car - $1500 Budget for NA power - What to do? whitney32 Normally Aspirated Powertrain 166 08-22-2011 08:36 PM
NA power gc835 Built Motor Discussion 1 12-03-2006 12:58 PM
EJ25 NA power!!!! Eric@Bavaria Vancouver Impreza Club Forum -- VIC 29 09-19-2003 09:56 PM
What has more NA power? the 2.0 or the 2.5? STiWRXdotcom Normally Aspirated Powertrain 34 06-08-2002 01:17 PM
What else can I do for NA power??? CRAZY KEN Normally Aspirated Powertrain 2 06-12-2001 02:14 AM


All times are GMT -4. The time now is 02:43 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.