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Old 01-09-2002, 10:19 PM   #1
Jayson_K
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Default camshaft question

Doing some searches i see only good things said about mild camshaft upgrades (ie. Cobb). My question is what's the downside??

Why doesn't subaru build their camshafts like this to begin with if it only increases performance? I mean there must be some reason no? fuel economy?

thanks
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Old 01-09-2002, 11:55 PM   #2
stimpy
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As far as I can tell, there is no downside to them. Fuel economy doesn't take a hit. Low end power/torque doesn't take a hit. Nothing but positive results. There might be a touch of extra wear on the valvetrain due to the slightly higher lift and extra duration, but Cobb as test and matched these cams for longetivity and best gains without recourse. I've had mine for 1 year now and don't have any problems I am aware of.

-Jon
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Old 01-10-2002, 12:14 AM   #3
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downside is if you have a DOHC, you pay mucho $$$. i could've bought a used turbo kit, paid a bit more for engine managment, and bam, major hp...not this "i think i feel a difference w/ my butt dyno"
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Old 01-10-2002, 12:16 AM   #4
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Reasons why they arent the stock cams
1)Idle is just enough different (only real noticable on cold starts here in Chicago) that it wouldnt be accceptable idle quality for OE. (dont get me wrong, they idle great)
2) engineering tolerances. These cams push the envelope of the drivetrain. OE has to be "safer" (once again, nothing to worry about, just different needs)
3) Emissions... the biggest reason. They had the ej25 over here, and changing cmas would require recertification by the feds.

But really, there are no downsides to the cams as far as Im concerned.
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Old 01-10-2002, 02:16 AM   #5
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Quote:
Originally posted by Midwayman
Reasons why they arent the stock cams
1)Idle is just enough different (only real noticable on cold starts here in Chicago) that it wouldnt be accceptable idle quality for OE. (dont get me wrong, they idle great)
2) engineering tolerances. These cams push the envelope of the drivetrain. OE has to be "safer" (once again, nothing to worry about, just different needs)
3) Emissions... the biggest reason. They had the ej25 over here, and changing cmas would require recertification by the feds.

But really, there are no downsides to the cams as far as Im concerned.
i like em...hehe...but yes the idle qaulity is the big part. High lift short duration makes for kind of a shaky idle but it's Nothing to be worried about. Brian when do you want to redo your valves??

jeremy
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Old 01-10-2002, 09:49 AM   #6
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to me the only downside is cost. proven gain, but if you're not installing them yourself it's pretty expensive for what you get.

even if you install them yourself, it's a fair bit of work and not something for the neophyte. especially if you strip those torx plus bolts in the camshaft cap and have to yank the cylinder heads.
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Old 01-10-2002, 11:00 AM   #7
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I didn't notice any idle quality differences initially. Now that the cam has worn some and I have STi engine mounts I can feel the subtle difference. It's just enough to wonder if there is a vacuum leak or something in the engine, but not bad. I had my service department confirm that nothing was wrong by checking all the parameters on the OBD-II system. They wrote off the slightly different idle to my fuel modifications (converted to parallel).

-Jon
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Old 01-11-2002, 05:07 PM   #8
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OK thanks! Next question - just installing new cams with no other modifications.

yea or nay?

I intend on a cat-back exhaust sometime, but would like to start with the cams...
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Old 01-11-2002, 05:21 PM   #9
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The usually order is intake, exhaust, pulleys lightened flywheel and clutch, then cams. Or course that is not set in stone or anything but since the cams are used to enhance the other breathing mods you already have. I donít think your gains will be satisfactory with nothing else done
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Old 01-11-2002, 05:47 PM   #10
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I agree. Since you have an 02 RS...

1) intake-- ganz flow.

2) exhaust-- whatever floats your boat. doesn't need to be $$$

3) headers-- i'd go for borla personally, but then again I don't have any right now.

4) cams-- yep, you should do these last. weeeeellll... maybe before the headers. but you should have intake and exhaust.
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Old 01-11-2002, 07:15 PM   #11
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You dont need the headers (or anything really) to realize gains form the cams, but like Colin said you should have an intake and exhaust before hand. (PRM intakes, $50, local exhaust custom job 2.25" catback.... 250-300 probably)

Cams alone are worth 14hp.
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Old 01-12-2002, 12:35 AM   #12
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I don't think Subaru is looking for any more NA horsepower. Imagine if they had these cams and a better flowing exhaust etc etc etc. How likely would you be to buy a WRX if it had only 27 more hp than an RS. With 165 ponies the RS fits very well into it's market segment. Imagine with 200hp what the insurance rates would be as well... The issue here is not that they "can't" but rather that they don't need to.

-Michael
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Old 01-14-2002, 12:39 PM   #13
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I have a little bit of experience on the effectiveness of the cams in various states of engine tune.

When I installed the cams initially, I had an iSR intake and a 2.25" catback. The difference was incredible. At that point, I never regretted the purchase and felt it was a very worthwhile mod.
I added a larger tube-style intake and found even more gains up top. The low-end suffered a little, but the top-end was just wonderful. Somewhere along the road I got real close to having my car turbocharged and so I removed the catback and sold it in preparation of the turbo-back. The car's power was down a substantial amount with the stock exhaust, but I can still feel the difference in power delivery.

Installing on a stock car (when compared to the basic bolt-ons with cams) feels like the car is just choked off and can't breathe well. However, it alters the powerband in such a way that you can feel their presence at everything past about 3k rpms.

-Jon
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Old 01-14-2002, 11:47 PM   #14
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which kind of cams do you guys have??
-Jim
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Old 01-15-2002, 06:37 AM   #15
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The only ones around I belive.. Cobb cams
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Old 01-15-2002, 08:46 AM   #16
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A local rally prep tuner is focusing on Subaru, started last year (thanks to our Pres. Toronto Subaru Club)

www.japaneseauto.com

He has developed cams, and will be re-programming OEM ND ECU's to convert the stock ECU into fully programmable standalone ECU. Cheaper than a unichip for the WRX and RS's.

Target price for the Cams are $750.00 Canadian and target price for the Stanalone conversion is about $900.00 Canadian. Oh yeah, he also sells tons of SYMS / Maxim Works stuff.

BTW. Yoshio is the one who converted the first WRX conversion from a stock RS, commissioned by Subaru of Canada.

Not bad eh.... Proud to be a canuck.

Muhahaha...
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Old 01-15-2002, 09:48 AM   #17
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I was under the impression that the Subaru ECU utilized read-only EPROMS. But, I would be glad to be proven wrong. Please keep us updated on that.

FWIW, I am using the Cobb Mild Street Cams.

-Jon
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Old 01-16-2002, 08:57 AM   #18
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Hi Stimpy,

The answer to your question is "Yes" on the Eproms for some of the older ECU's, but from what I understand, the Nippon Denso ECU's in the later WRX's, 2.5 RS's, and Legacy's can be re-programmed and re-mapped accordingly.

The software and interface for the ECU's cost approximately $20K. The good news is that he has made the investment and will start remapping the ECU's in the late February and March time frame.

Proud to be a canuck...

Headers + Exhaust + Pulley + CAI + Sway Bar + ALK + CAMS + ECU

Need more NA power....

How do you like your street cams?
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Old 01-16-2002, 11:27 AM   #19
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I absolutely love the cams. Even with my car back to near stock, I can feel them working.

-Jon
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