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Discussion Starter · #1 ·
Can the cams on the WRX somehow be optimized for torque? Are they already at the best they can be? How would I upgrade them?
Thanks.
 

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JimmyNY said:
Can the cams on the WRX somehow be optimized for torque? Are they already at the best they can be? How would I upgrade them?
Thanks.
One company I forgot the name make a cam kit for the rex, but it
cost 1000 bucks :eek:
 

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JimmyNY said:
Can the cams on the WRX somehow be optimized for torque? Are they already at the best they can be? How would I upgrade them?
Thanks.

Jimmy,

The cams can not be adjusted to any performance benefit in the WRX or atleast the little tiny amount of performance achieved wouldn't be worth the time, trouble, and expense.

-Jim
 

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Discussion Starter · #4 ·
OK guys, thanks for the info.
 

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Re: Re: Tuning your cams...

PlatinumWRX said:



Jimmy,

The cams can not be adjusted to any performance benefit in the WRX or atleast the little tiny amount of performance achieved wouldn't be worth the time, trouble, and expense.

-Jim
I'm sorry but how the hell did you come to that conclusion/assumption? I hadn't noticed that you tried various regrinds or have adv cam gears dyno tuned. you can't just post what you think would happen.:eek:

There are several companies working on adj cam gears right now which usually make GOOD power on turbo cars, just like new cams do. I think the real answer, is no one has done any extensive test (or released it) yet, so we don't know.

-C
 

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I think next areas of mod after stage 4 might be

1. FMIC.

2. Water spray on TMIC / FMIC.

2. Equal length headers.

3. Extrude hone the intake system.

4. Adj cam kit.

I am just waiting for a WRX with all the stage 4 and above mods and
see what we are looking at. Could it make 500-600 hp :eek:
 

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Back in the day when I used to race 2.3L ford engines in a "stock" category, one of the tricks we used was to file the camshaft keyway slot such to retard the cam timing a little, which helps with top end power a little, especially when you're prohibited from running aftermarket camshafts. That was an easy trick for that engine since its SOHC and the sprocket is right on top where its easy to get to. I'd be interested to see if any ajustable cam sprockets come out for the WRX, although I can imagine tuning them would be an absolute nightmare to get right considering that there are 4 of them(I think...my wrx isnt in the garage right now or I'd go look), and one thing you definitely wouldn't want is different cam timing on each cylinder bank. Personally, I don't think the gains would be worth the effort.
 

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Re: Re: Re: Tuning your cams...

TypeC said:

I'm sorry but how the hell did you come to that conclusion/assumption? I hadn't noticed that you tried various regrinds or have adv cam gears dyno tuned. you can't just post what you think would happen.:eek:

There are several companies working on adj cam gears right now which usually make GOOD power on turbo cars, just like new cams do. I think the real answer, is no one has done any extensive test (or released it) yet, so we don't know.

-C
Yes, I agree, by adjusting the cam timing, you can optimize for more horsepower, more torque, or a compromise between both.

Why do you think companies make VVT-i, VANOS, VVT, etc?
 

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I think cam timing can be beneficial as evidenced by the cam gears on the exhaust side of Supra TT's and Hondas but on a 4 cam motor like the EJ20, it is pretty tricky to tune since you have to tune each intake or exhaust camshaft exactly equal on both sides. I don't think the trouble of tuning it on the dyno and installing them is worth it though since there are so many ways to extract the max power out of the car without this modification. No matter what the block is only good to just over 400 HP so unless you're building a 600 HP monster (in which case you're probably using larger cams), I say drop this discussion and put it in the "interesting as a topic but not real world applicable" pile.
 

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God said:
I think cam timing can be beneficial as evidenced by the cam gears on the exhaust side of Supra TT's and Hondas but on a 4 cam motor like the EJ20, it is pretty tricky to tune since you have to tune each intake or exhaust camshaft exactly equal on both sides. I don't think the trouble of tuning it on the dyno and installing them is worth it though since there are so many ways to extract the max power out of the car without this modification. No matter what the block is only good to just over 400 HP so unless you're building a 600 HP monster (in which case you're probably using larger cams), I say drop this discussion and put it in the "interesting as a topic but not real world applicable" pile.
I wouldn't say that at all. I wouldn't try to tune it myself, although I'd do what you said and tune the intake cams the same and the same with the exhaust cams (so there is only two degrees not four). As you know from Hondas, just a little tweaking (retard exhaust, etc) can make very GOOD gains across the board. Since companies are already making them, it's already going to be "real world applicable." Instead of getting a bigger turbo for instance, you could squeeze another 20whp out of the stocker and finally run 12's.

I can't wait to see the gains.
 

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On another note,
Dan how are the roads there (wrt snow)? I'm eager to see what you run. I'm assuming phil with his race prog was making ~300whp so, you should see similar times to his, maybe better.
 

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You see gentlemen, when I need somebody who we all know knows what he is talking about, I call God, since I already know that I know what I am talking about. ;)

For future reference, if I write something that sounds like an interpretation of a fact or set of facts, or even a fact then IT IS. JimmyNY asked a few simple yes or no questions and I answered them to the best of my (considerable) knowledge.

The flat-four is a whole different animal than an I4, I6, or V6.
Add to this the fact that Subaru does an EXCELLENT job setting up the cam timing from the factory and you arrive at the "conclusion" NOT "assumption," Type C, that cam timing is not worth the time, trouble, and expense involved.

As an aside,
I don't consider grinding cams a method for "optimizing" the WRX cams. I consider this a half-assed method of making new cams for car that often results in wear issues because of steep lobes and jerk control issues that can lead to horrible valvetrain vibration and possibly failure.

I'm curious, tan. How exactly can you optimize the WRX cams to behave like the computer-controlled variable valve timing? Obviously the STi CVVT which boost torque across the powerband and raises (along with other contributing components) the rev limit of the EJ20 to 8,000rpm.

In the future, don't assume that Honda (or Toyota, or Mitsubishi, etc.) tuning methods are automatically applicable to Subaru engines. The only tuning methods directly applicable work have to come from the air-cooled VW, Flat-Ferrari, or Porsche camp.

Have a nice day, and thanks for assuming that I go off half-cocked and post "assumptions" to my favorite bulletin board when I am a well respected moderator and a mechanical engineer.

-Jim
 

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Congrats on the puppy! What breed? Thanks for your prompt attention in this matter.

Type C,

I don't understand how you can consider adjusting the valve timing for what will be WAY less than 20HP, when you can spend half the time and trouble installing breathing and/or fuel mods on your EJ20. Listen to the experts, they know the EJ20, really THEY DO!

-Jim

God said:
Weather here is nice. I've just been working so many hours I have no time to do anything at all. On top of that I got a puppy so spare time goes to him. It'll be summer sometime before I can get to the track.
 

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to Jim (from -hh for Tan)

You see gentlemen, when I need somebody who we all know knows what he is talking about, I call God, since I already know that I know what I am talking about.
Nice to see some Engineering Humility. I've called God many times (the real one), and he has told me that when it comes to Mr. Murphy when he pisses on my parade, I'm on my own to solve it :)


For future reference...
...a good moderator will read for complete context, and will figure out that the attributions got screwed up before slamming the wrong guy.

BTW, this is Tan's current project boss, borrowing his account. (BSME DU '83, if anyone cares).


JimmyNY asked a few simple yes or no questions...
Agreed. Here, the question was on changing the existing timing. The basic answer is that there's better bangs-for-the-buck.

The flat-four is a whole different animal than an I4, I6, or V6.
Compared to...? Looks like its merely 2/3rds of the engine in my '85 911 :), and not substantially any different from the boxer 4 that was under the hood of my 1971 Subaru (Model "FF-1G").


Add to this the fact that Subaru does an EXCELLENT job setting up the cam timing from the factory...
I agree, and this is really the crux of the question here. Generally speaking, the "low hanging fruit" (here, the easy horsepower and torque gains to be had) have already been exploited by most manufacturers for most contemporary vehicles. For a fixed cam system, you should be able to tweak it for more HP, but you'll lose torque, or some other desirable characteristic (such as life). Its a multivariate trade-off and the manufactuer has chosen what he thinks is the best overall compromise. Again generally speaking, its not a good idea for most people to question their choice.

However - (although partly because of this) - for most driving enthusiasts, the biggest bang for the buck isn't any hardware for the car, but a good professional driver training class or three.


Afterall, there are few things more embarassing than going to an Auto-X and seeing some guy in a lousy stock Neon beat your 911's lap times. Makes you wake up to learn how to drive, instead of just trying to buy better hardware.



-hh
 

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PlatinumWRX said:
Congrats on the puppy! What breed? Thanks for your prompt attention in this matter.
No problem Jim. German Shepherd. Only kind of dog I buy ever.
As for the cam timing issue, no one here is saying that playing with cam timing won't help, but with the time and money involved you can do many other mods which will benefit you much more. As for regrinnding cams, this obviously is a horrible idea. The valvetrain will suffer greatly until eventually a failure will occur somewhere. The good tuners will grind new camshafts out of fresh blanks (like Jun). I do not believe Jun has cam gears on their 600 HP GC8 WRX but it does it have their cams (which are already optimized when they are cut).
 

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Engineering for the consumer market
You have to realize in engineering for the consumer industry, engineers have to bite the bullet when it comes to performance. The cams in any car is a performance compromise. They have to compromise performance to reliability, fuel economy, emissions, and most importantly, george washingtons.

When the consumer engine gets modified for racing, they don't need to heavily compromise performance. They make new cams that produces (for example, WRC) the optimum balance between horsepower & torque, as well as the power curve. Maybe for endurance races, they need to be somewhat concerned about fuel economy.
Engine layout
True, HOnda four cylinders are inline, making it easier to change the cam timing by a few degrees, were depending on SOHC or DOHC, you need one or two adjustable cam gears.

Flat fours, can be interpreted as 180 degree V-block. In the V-blocks, you have to have more (or the same amount, depending on the engine) cam gears which drive the cams and valvetrain. It works the same way as most V6's, as they are a pain to do on both banks, as God said. The Subie flat-4, is an internal combustion engine, that runs the Otto cycle. Not a different animal than other Otto cycle engines. It's a different means of packaging with its associated benefits.

I'm curious, tan. How exactly can you optimize the WRX cams to behave like the computer-controlled variable valve timing? Obviously the STi CVVT which boost torque across the powerband and raises (along with other contributing components) the rev limit of the EJ20 to 8,000rpm
Jim, you're putting words in my mouth here.

I'm referring to mechanisms such as VVT-i, Vanos, VVT (Mazda, but Toyota used VVT first), Variocam (Porsche), where there is are fixed cam profiles, but the phasing of the cams are varied produce a desired output.

Of course, using adjustable cam gears, does not allow for computer control, but the concept of change the phasing remains the same.

Add to this the fact that Subaru does an EXCELLENT job setting up the cam timing from the factory and you arrive at the "conclusion" NOT "assumption," Type C, that cam timing is not worth the time, trouble, and expense involved.
My turn to put words in your mouth here.

Going slightly off topic here, you can say the same thing in general in regards to the rest of the car.

For example:
Using the Link ECU
You've had some problems mapping the air-fuel curves, timing curves, etc, and you've reduced your performance. Can you make the conclusion, "NOT" assumption that using the Link ECU is not worth the time, trouble, and expense involved?

Based on your experience, you can say Yes. But what's stopping others who have had success.

The engineers at Subaru (see stuff on engineering for the consumer) did a good job of balancing power with reliability, economy, tailpipe emissions, and cost to the customer with their ECU. They also take into account another factor, which is hard to control is the fuel type and quality. It's hard to predict how good the fuel is in our next tank.

Boost
I don't really need to say anything on this, since it's obvious with government regulations.

Without getting too redundant here, using that quote, makes modding pointless. But we want our cars to perform they way we want it, not the target market, which it as designed for. That's why there are tuner companies, that learning from their mistakes and successes are able to offer products which tweak the compromises automotive engineers are forced to make.

------------------------------------------------
But to the original question, can the cams be optimized for better torque? The answer is yes. Getting cams which are optimized for a better torque curve is possible, good luck finding one, since most tuners like more horsepower better, so they will be optimized for horsepower, rather torque (kiss fuel economy and tailpipe emissions goodbye).

The method of going in and physically change the phasing through the use of cam gears -- it takes a lot of time and effort on the dyno to get what you want, if it even gets the results you're looking for, but doesn't necessarity account for other other factors such as engine speed, engine load, MAP/MAF sensor reading, etc., which computer controlled does. Someone is going to try that route sometime, and hopefully he/she may post it on a forum for us to gander.
 

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I don't understand how you can consider adjusting the valve timing for what will be WAY less than 20HP, when you can spend half the time and trouble installing breathing and/or fuel mods on your EJ20. Listen to the experts, they know the EJ20, really THEY DO!
I do and you, my conceded friend, are DEFINATELY NOT one of them. Please don't pretend to be. Up to this point I've kept my mouth shut, but quite frankly you don't know what you're talking about 80% of the time. The Nitrous thread, PT/FB, launch techniques (after you were running 2.0's mind you), now this. You really make yourself sound silly when you pull things out of the *air*.

You see gentlemen, when I need somebody who we all know knows what he is talking about, I call God, since I already know that I know what I am talking about.

For future reference, if I write something that sounds like an interpretation of a fact or set of facts, or even a fact then IT IS. JimmyNY asked a few simple yes or no questions and I answered them to the best of my (considerable) knowledge.
??? Your considerably knowledge? I also have an Engineering degree. Woohoo! Can I toot my own horn now? Also, Dan is a very good guy with lots of good info, but (as he has said himself), he is NOT a tuner, and IS also new to the WRX as are we all. He makes good parts, but isn't the de facto source of knowledge (And an important thing to note, he, unlike you, doesn't try to act as if he is). It's called humility.

"For future reference" why don't you NOT pass off your opinion as fact. Until you dyno a WRX having tuned the cam gears, your assuming results, are just that: assumptions. We all can dissagree, which is good. For all we know you might not be able to make 1hp. I can admit that.

No one here is making any personal attacks but you. Just stick to the facts. Wait, let me open a site and pretend that my word is god. And BTW, 20whp isn't unheard of when dyno tuning a car, especially a turbo car. But again, you really don't know what you're talking about.

-C

[btw, there are NO personal attacks, or flames in here, so there is no need to delete or lock as you often like to do when things don't go as you would like]
 

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i graduated with a business degree, and a concentration in Real Estate.

SO THERE!

:p

if anyone want's to know about mezz debt, intereast rate swaps, PPM financing or how to maximize IRR's by using value engineering, talk to me.

unfortunately, value enginnering has nothing to do with mechanics, and really doesn't apply much to cars. (carports? yes. cars? no.)

play nice kids. i usually don't, but you should. :)

dR
 

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dark_rex said:
i graduated with a business degree, and a concentration in Real Estate.

SO THERE!

:p

if anyone want's to know about mezz debt, intereast rate swaps, PPM financing or how to maximize IRR's by using value engineering, talk to me.

That's my point. I didn't notice Corky Bell registered on here :D
 
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