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Old 10-20-2000, 02:45 PM   #1
Trey
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Thumbs up COBB Heads and bigger NA-spec cam - installed

Hello gang,

I just got done test driving our shop car with our Stage 1 heads and a new NA spec cam. We'll be dyno testing this car early next week with even more goodies on it, but from our spirited little drive a few minutes ago, I'm pretty impressed by this little NA EJ25.

Here's my quick driving impressions:
Torque doesn't seem to fall off at all to redline. My first few hot laps of the famous Circuite de Rockwall , I was constantly hitting the rev limiter. In stock form, I'd only hit it if I was trying to avoid shifting during cornering as power dropped off well before redline. Now, the rev limit can definitely be considered the "fun" limiter. I'm not going to fall into the trap of making any outrageous HP claims but considering how the torque peak can be felt at a much higher RPM, I'm guessing we'll see some positive HP numbers next week. I'm also glad to report that the heads and bigger NA cam seem to get along fairly well with stock ECU. The car idles pretty well considering the cam profile (though much rougher than our Street cam), and doesn't hesitate or act strange under WOT. The car does run a bit leaner but after a few WOT runs, it started to richen back up. Oh, and the sound...I know it holds no performance value but it's incredible. Under throttle the car just sounds...angry. I like it.

Here's a breakdown on what the car had when I drove it last:
COBB Tuning Stage 1 Cyl Heads w/ 10.5:1 CR
COBB Tuning NA-Spec Cams (224 @ 0.050" duration)
Stock header to Stromung Cat-back system
Old Prototype Intake system (new one is still away getting powdercoated)
Stock ECU, intake manifold, throttle body

Next week we'll be testing it on the dyno with the Haltech E6K (bye-bye 6250 rev limiter!), throttle body, ExtrudeHoned intake manifold, headers, and a few other surprises we'll share at SEMA. We'll have the car out for the West Coast Subaru meet so you'll have to come by and visit when it's there.

Regards,
Trey
CobbTuning.com
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Old 10-20-2000, 02:49 PM   #2
JC
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Sounds good. I'm still waiting on a real burnout vid from the RWD Impreza though.
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Old 10-20-2000, 02:55 PM   #3
Marco
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Talking

Congratulations, Trey!!!
The car must be running owesome. I can't wait to see the numbers from the dyno test.

I'm very happy with the car now that it has the cams, but I guess I need to think about updating it.
It seems, for what I gathered from your post, that the new cams are better suited for an aftermarket ECU (no stinking 6250 redline), right?

Keep us posted!

Cheers,
Marco (praying to the stock market gods)
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Old 10-20-2000, 02:57 PM   #4
stimpy
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COOOOL!
I was wondering when we were going to get some numbers on those heads. You are just trying to get me to stay NA aren't you Trey??

What kind of gas mileage are you getting with that more aggressive cams and heads?

Jon
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Old 10-20-2000, 03:04 PM   #5
Matt
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Must.........resist.........need........suspension ......before......power.......


ARGH

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Old 10-20-2000, 03:09 PM   #6
8Complex

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Hey, quit working on the NA crap and get going on an SC system.
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Old 10-20-2000, 04:01 PM   #7
Trey
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The more agressive 224 degree cams work well, but you can definitely tell there's a shift in the torque peak. It's still very linear power, but I can "feel" the torque curve has shifted up due to the new profile. While they work with the stock computer in terms of idle and drivability, you'll end up getting completely frustrated with the stock rev limiter so I think I'll recommend these only for guys running aftermarket ECUs.

As for the heads, well they just help all around, but you will see the biggest gains at higher RPMs when air flow becomes more critical.

I haven't done any gas mileage or emissions testing. Due to the idle quality, I doubt these would be emissions legal cams unless you did something with the ECU mapping. Heads, on the other hand, shouldn't have a problem.

I'd love to dyno the setup as it stands, but we don't have time before SEMA.

After SEMA, we're taking the car to the track, posting some times and pulling the NA motor to start working on the forced induction toys.

Non-stop fun,
Trey
CobbTuning.com

P.S. My car is AWD again so all my feedback is based on that, not RWD. It will be RWD for SEMA though...to do some REAL burnouts.
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Old 10-20-2000, 04:41 PM   #8
ColinL
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Man, not I'm going to have to do another cam job.
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Old 10-20-2000, 05:42 PM   #9
imprezive
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how about some turbo cams "mild" and "spicy"
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Old 10-20-2000, 06:15 PM   #10
donjuan
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Could I have some cams with that please.

Mild, Hot, or Fire??
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Old 10-20-2000, 06:25 PM   #11
Penphoe
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Trey -- is your RS still in RWD mode? If so, do you have any idea how the car will feel/be with your mods in AWD mode?

LaterZ!
Darren!!
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Old 10-20-2000, 06:53 PM   #12
Andre Vandenberg
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BUMM I'm gonna be at SEMA without my car..

Glad to see you have a REAL Suby again
and Trey, a "real" burnout is ALL 4 not just 2!
Andre
PS Where's my banners - Photo shoot is MONDAY! Still 0 Cobb stickers ;(

[This message has been edited by Andre Vandenberg (edited October 20, 2000).]
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Old 10-20-2000, 10:18 PM   #13
Sunrise City Rider
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Thumbs up

I am guessing that the cost of the latest cam profile will be the same as the original spec cam...?
Zee
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Old 10-21-2000, 07:46 AM   #14
Overtime
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Trey-

I can't wait to see the power gain for the heads/cams combined with all the "bolt-ons" (including the throttle body). That's going to be the magic number.

Do you expect any problems to arise from changing the compression ratio and adding a more aggressive cam? In terms of anything-gas mileage, reliability, etc. Idling has been touched on already, but I avoid idling anyway.
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Old 10-21-2000, 08:32 AM   #15
Trey
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Right now the car is still in AWD mode, so my feedback was based on that. I will be going back RWD next week to tune the car on the dyno before the trip out to Las Vegas.

As for the new cam spec, it'll be the same cost as the Street cam, and will not replace it. The street cam works great for what it's been designed for. This cam is a more agressive design intended for more competition type uses and needs a higher redline.

In regards to problems due to the higher compression, I don't forsee any other than the need for higher octane gas. Please keep in mind though that this cam profile was not designed like our original street cam where we were concerned with mileage, reliability, etc. It was designed more for out-right performance. It's still not nearly as radical as we could go, but we expect gas mileage and emissions to suffer. Reliability problems, I don't think so. We're not pushing the valvetrain any harder than we have before so it shouldn't be an issue.

Anyway, a few more days and we'll see what this puppy does on a dyno. Can't wait.

Regards,
Trey
CobbTuning.com
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Old 10-21-2000, 09:07 AM   #16
imprezive
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you avoid my question will there be a turbo cam in the future???
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Old 10-21-2000, 09:45 AM   #17
Trey
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Turbo cams - yes, already in the pipeline.

Thanks,
Trey
CobbTuning.com
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Old 10-21-2000, 10:00 AM   #18
imprezive
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Thumbs up

RIGHT ON!
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Old 10-21-2000, 11:37 AM   #19
Kevin Thomas
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Congrats on your N/A power gains Trey. It's about time someone has done this.

On another note: People were saying that you and RalliSpec had some sort of agreement that one was going to sell mild cams (you) while the other (RalliSpec) was going to sell more aggressive cams. I guess your second cam profile blows this out of the water. Just wanted to point that out unless I understood or read past posts about this wrong. Take care and again congrats.

*Makes me want to buy a 2.5RS and go N/A*

[This message has been edited by Kevin Thomas (edited October 23, 2000).]
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Old 10-21-2000, 03:26 PM   #20
Overtime
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Trey-

I am definitely anticipating the dyno results for the heads/cams combined with the standard bolt-ons and the obligatory comparison to the "stage one" turbo kit.

Keep those naturally aspirated products coming!
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Old 10-22-2000, 07:22 PM   #21
preza
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Sweeeet i cant wait to see the dyno results on this... do u know what day they will be posted ?
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Old 10-23-2000, 07:55 AM   #22
Rich L
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Exclamation

Once again... I say:

"Trey for President!!!"
you-da-man...
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Old 10-23-2000, 08:18 AM   #23
Trey
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Kevin - I have a great deal of respect for Rallispec, and we've agreed to install eachothers parts as we know they are of equal quality, but no agreement has been made regarding what parts we will/won't produce. We plan on meeting Rallispec (and others) at SEMA next week though, and perhaps we can discuss this issue then and determine if it'll be beneficial to our companies as well as the Subaru-aftermarket community. We'll see.

As for the dyno sheets, I expect to post them before the end of the week.

Thanks,
Trey
CobbTuning.com
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Old 10-23-2000, 09:13 AM   #24
WRC666
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Question

After last weekend on the track, I need more power. Handling is fine, a new suspension is already planned to make it even better.
But I need to get rid of that pesky Prelude in my mirrors...
Rpm's were between 4000 and 5500.
Power-Mods so far: UD pulley, intake, Borla catback, S-AFC
What would you suggest to add to this?
Cams? I still need to drive the RS daily.
Heads are kinda pricey, cams will be doable (+ labor).
Let me know.
Would even put some stickers on the car...
666
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Old 10-23-2000, 02:46 PM   #25
Rich L
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Trey,

Can your regular "street cam" be used with a future forced induction upgrade? (either turbo or s/c)
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