Welcome to the North American Subaru Impreza Owners Club Thursday August 28, 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 03-10-2003, 05:13 PM   #26
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

Well, will the Club Spec cams be as fast as the Street Cams before I get headwork? Also will I keep low end torque and pass emissions?
* Registered users of the site do not see these ads.
joefocker20 is offline   Reply With Quote
Old 03-10-2003, 05:16 PM   #27
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

The club spec cams are relatively flat before 3k, they make more peak hp but they don't have a large flat powerband like the street cams. Due to the amount of overlap the club spec cams will most certainly fail emissions. Also, the club spec makes the car drive very much like a WRX, gutless at low revs and scary at high revs... if that's your cup of tea go for it. Just don't plan on going FI later on.
BOY is offline   Reply With Quote
Old 03-10-2003, 05:21 PM   #28
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

So the Street Cams with headwork, bored TB, and Link or an ECU reflash would probably be better? I want my car to be fast off the line and street legal. I test drove a WRX the other day when it was snowing, and without being able to hit decent boost, it was amazingly slow, it didnt have the power to turn a sharp corner at a light and come out of it in 2nd gear..
joefocker20 is offline   Reply With Quote
Old 03-10-2003, 05:26 PM   #29
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

As an auto/rally crosser I love the low end of the street cams. They don't have the same top end, that's for sure but down low coming out of a corner is what I'm all about. Honestly the street and club cams end up being almost identical in 0-100 mhp runs but they get there differently. The street cams pull down low and after each shift, the club cams are sluggish then have a surge of power up top. Very similar to when I ran against stock WRXs, we'd jockey position in each gear and I'd usually beat them to 100 mph, but after that the RS is useless (gearing, aero, we're screwed). Also, I knew that I'd probably put some time of mechanical boost on the car at some point and the club spec cams just don't take to positive manifold pressures very well.


Edit: BTW, my car has the N/A record for Texas hp/tq... I hope someone can beat it since I was planning on being N/A a little longer... anyone, dyno day coming up... please beat my old numbers.
BOY is offline   Reply With Quote
Old 03-10-2003, 06:29 PM   #30
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

Whats the elevation there?
joefocker20 is offline   Reply With Quote
Old 03-10-2003, 06:30 PM   #31
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

And also, how are the street cams from 3000-6500 rpms?
joefocker20 is offline   Reply With Quote
Old 03-10-2003, 11:37 PM   #32
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

Has anyone driven comparable cars with both Cobb and JA Cams? Which ones are better? Will JA Cams pass US Emisions?
joefocker20 is offline   Reply With Quote
Old 03-11-2003, 12:21 AM   #33
dcoty
Scooby Specialist
 
Member#: 3149
Join Date: Dec 2000
Location: montreal quebec
Vehicle:
01 V7 GC/R32 sky

Default

Joefocker- I had the street cams on stock heads before the racer cams, and the streets give power right around 3,500 (a little below actually 3,300 or so). As for above stock redline, they will make more than stock for sure, but I wouldnt see it making much power over 6,500-6,700rpm. Its just a guess though. But they have great pull to redline for sure. The racers are good to 8,500, but the idle does get lumpy.
With the racers and ported heads you slam into the rev limiter very quick, they make tons of power up there, you will need a raised redline to get all the benefits. I havent diriven my car above the stock redline with those cams before, it spun a rod bearing during the last part of tuning at 7,200 rpm (due to previous nitrous damage) but the guy tuning it said it make very impressive power in the 7,000 range, they diddnt start to die out.
Good luck, sorry I dont have experience in other brands of cams...
Dan
dcoty is offline   Reply With Quote
Old 03-11-2003, 12:38 AM   #34
joefocker20
Scooby Specialist
 
Member#: 13745
Join Date: Dec 2001
Chapter/Region: RMIC
Location: Colorado Springs, CO
Vehicle:
2004 STI
Silver

Default

Dan, did you lose any low end torque with the racer cams? I'm debating which one to get, and if they'll pass emissions. As I posted before, I'm getting a Exedy Flywheel, Cobb Clutch, Cams, and having a TB bored later this month or early April. I'll probably get heads in the summer.
joefocker20 is offline   Reply With Quote
Old 03-11-2003, 08:52 AM   #35
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

I've yet to hear of the club spec cams passing emissions. With engine management maybe but I'd doubt it. Dan (dcoty) is right on about the pull the club spec give, the cars I've driven with them had the stock redline and this is what I remember... slow, come'on, where's the cam, oh here it comes, holy crap, damn there's the redline, I want more revs!!

All I can say is I've been very happy with the street cams, they had me running with and usually beating WRXs through 100mph... not bad I say. Plus now that I have a turbo, I'm glad the cams are in there and should make a good chunk of power on the dyno.
BOY is offline   Reply With Quote
Old 03-11-2003, 09:12 AM   #36
DDMan
Scooby Specialist
 
Member#: 11221
Join Date: Oct 2001
Location: Rocklin, California
Vehicle:
2002 2.5 RS
Black as Midnight!!!

Default

How difficult is it to install the cams? Is it a job that a decently mechanically inclined person could to? I'v done just about every mod on my car, and am prety confident, but I dont have the 2.5L Service manual to look at what's incoved. Im assuming you have to remove the engine. Are there any timing issues that you have to deal with?

Thanks,
Dan
DDMan is offline   Reply With Quote
Old 03-11-2003, 09:54 AM   #37
Opie
Floresbian
Moderator
 
Member#: 470
Join Date: Oct 1999
Chapter/Region: South East
Location: Riverview, Florida - U.S.A.
Vehicle:
2015 Forester 2.0XT
'14 XV Crosstrek, '99 SF

Question

What kind of WHP #'s does a pure stock RS put out? It would be nice to compare that to the gains BOY's dyno graph shows. And also to estimate crank power.

For example, if a stock RS put down 100 WHP and mods such as BOY's put down 146 WHP, those mods show about a 46% gain in power. And if the stock RS has 165 HP at the crank, then BOY's car should be putting out about 240 HP at the crank (165 + 46% = 240.9)

Not to shabby if my math is anywhere near correct....
Opie is online now   Reply With Quote
Old 03-11-2003, 10:09 AM   #38
DanzBorin
Subaru Bounty Hunter
Moderator
 
Member#: 7131
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Houston - Back in the Alief
Vehicle:
2008 STi DGM (3rd
STI) prev 05 STi (white)

Default

Quote:
Originally posted by Opie
What kind of WHP #'s does a pure stock RS put out? It would be nice to compare that to the gains BOY's dyno graph shows. And also to estimate crank power.

For example, if a stock RS put down 100 WHP and mods such as BOY's put down 146 WHP, those mods show about a 46% gain in power. And if the stock RS has 165 HP at the crank, then BOY's car should be putting out about 240 HP at the crank (165 + 46% = 240.9)

Not to shabby if my math is anywhere near correct....
On the dyno he used, a stock 99 RS puts down right at 120hp...

So, you are a bit optimistic... He was making a bit under 200hp is my estimation...
DanzBorin is offline   Reply With Quote
Old 03-11-2003, 10:10 AM   #39
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

Opie, the dyno run was made at Forced Induction Systems (FIS) in McKinney, TX. They took over most of Cobb's customer base when Cobb moved to Utah. The dyno is a Mustang unit just like Cobb's and setup to be as close as possible to Cobb's original TX dyno. That being said, Cobb baselined a 2000 RS at 122.5 hp and 133 lb-ft torque. The impressive difference between the 2 is the stock RS (and the bolt on power adders) have a torque band of ~1000 rpms and falls off very rapidly after that. My setup, as you can see has a little engine bog in the 3000-3500 range but is very flat overall. Check out Cobb's website http://www.cobbtuning.com/impreza/im...rformance.html for his stock -vs- "power packages" dyno comparisons. Its not just about peak numbers, its (to quote Shiv) the area under the curve

edit: Danzborin's right, we figured 180-185 hp and 190-200 lb-ft crank (using both the % loss calculation and the straight loss calc these numbers seem the most reasonable).
BOY is offline   Reply With Quote
Old 03-11-2003, 02:56 PM   #40
ERaab212
Scooby Specialist
 
Member#: 18466
Join Date: May 2002
Chapter/Region: Tri-State
Location: being pulled over......
Vehicle:
2003 GT35r Evo VIII
11.033@132

Question

So if i put just the club spec cams in my car with just intake and exhaust will i feel a noticable difference. I dont have to worry about emissions because of where i live. However will they make my motor be less reliable? is the idle ok? how streetable will it be?


ERIK
ERaab212 is offline   Reply With Quote
Old 03-11-2003, 09:51 PM   #41
dcoty
Scooby Specialist
 
Member#: 3149
Join Date: Dec 2000
Location: montreal quebec
Vehicle:
01 V7 GC/R32 sky

Default

I am not familiar as to how aggressive the club spec cams are ground, but lets say they are the equivalent of the cobb street cams:
There are no issues at all, i could start my car in -40C weather no problem. You do not have a rough idle at all and the power is definitly noticable. Streetable? Definitly, youll never know you have them until you hit the gas. Im pretty sure they are similar to these.

If they are the same grind as the cobb racer cams:
I have those and the idle is lumpy,not horrible, but you can feel it when sitting at a stoplight. People know you have aggressive cams. I had tuning issues with the unichip because I was running very very rich. With the cams in the car it was rough on startup in very cold weather only (I had misfires #2,3,4) but that was due to tuning and running very rich, otherise you shoudnt have problems. They are perfectly streetable, anyone could drive my car without "tips" from me as to things you should or have to do while driving etc. The car sounded different too, in a very good way!

It depends on how aggressive you want, i would suggest the cobb street cams, they are really great, racer cams are for a more extensively built engine since they make power up to 8,500 rpm which requires springs and retainers at the least (maybe valves too) as well as some form of engine management to tune and raise the redline

If you keep it simple (no other work like heads ported etc etc) you probably wont need tuning with the street cams at all and the reliability of the engine will be fine, you do need to do valve lash once after the cams are in the car for 1000-1500 klms though, not a big deal.

Dan

Last edited by dcoty; 03-11-2003 at 09:56 PM.
dcoty is offline   Reply With Quote
Old 03-12-2003, 09:50 AM   #42
BOY
NASIOC Supporter
 
Member#: 232
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Ft Wayne, IN
Vehicle:
99 RS-T RIP
02 Forster-S

Default

http://www.cobbtuning.com/impreza/en...html#streetcam
STREET PERFORMER CAMSHAFTS
The World’s best selling, most popular camshafts for the Subaru 2.5L. Designed specifically for street cars, naturally aspirated or running bolt-on turbo kits, our performance camshafts are a must have for any performance street engine. Working within the narrow parameters allowed to us by the stubborn factory ECU, we’ve designed a camshaft that helps the engine breathe better without causing problems with the idle quality or engine computer. To do this, we carefully studied the physical characteristics of the engine and valvetrain to determine where to focus our efforts. The end result is a unique camshaft profile that improves the entire powerband and reduces the engine’s tendency to run out of air at higher RPMs.
Dyno testing, comparing a stock 2.5L Impreza with and without camshafts has shown a +14 PEAK HP GAIN to the wheels and +13 ft-lbs PEAK TORQUE GAIN, with maximum gains of +19 HP at redline!! These gains were seen when comparing otherwise unmodified, stock cars. More gains are possible if your vehicle is modified with upgraded intake and exhaust systems.
SOHC Cam Specs
Duration @ 0.050" 211 degrees
Intake Lift 0.410"
Exhaust Lift 0.350"
DOHC Cam Specs
Duration @ 0.050" 208/218 degrees
Intake Lift 0.355"
Exhaust Lift 0.355"

http://www.cobbtuning.com/impreza/en...2.html#clubcam
CLUB RACER CAMSHAFTS
Commonly referred to as our “Spicy” cams, the Club Racer NA Cams are built specifically for Naturally Aspirated use and are designed to push the power even higher into the rev range. Torque peak moves up approximately 600 RPM and Horsepower peaks at the stock redline. Even though these cams are more aggressive than our normal offering, they are still well suited for a street driven car. You will not experience poor drivability due to the cams – however there is a slight chance of a check engine light on some cars due to the picky nature of stock ECU. This light does not negatively alter the driving characteristics and the only other noticeable difference will be a lumpier idle quality. Not recommended if you later intend on going to forced induction.
SOHC Cam Specs
Duration @ 0.050" 224 degrees
Intake Lift 0.410"
Exhaust Lift 0.350"
DOHC Cam Specs
Duration @ 0.050" 226/218 degrees
Intake Lift 0.360"
Exhaust Lift 0.360"

"Race Cam" specs not available on Cobb's website
BOY 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
STi Cobb Stage 1 heads/cams, $1350!!! burnin4 Engine/Power/Exhaust 3 02-16-2007 12:16 AM
FS: 2.5 RS head with Cobb street cam chucky Private 'For Sale' Classifieds 13 02-16-2004 09:43 PM
Any one with Cobb Heads and Cams in SoCal? Hill Racer Southern California Impreza Club Forum -- SCIC 1 07-14-2001 02:33 PM
COBB Heads and bigger NA-spec cam - installed Trey Normally Aspirated Powertrain 25 10-23-2000 05:09 PM
Any one with COBB heads & cams? MD20 Technical Forum Archive 2 08-12-2000 04:55 PM


All times are GMT -4. The time now is 09:07 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.