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Old 11-11-2009, 06:43 PM   #51
BAN SUVS
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Quote:
Originally Posted by Button View Post
chazly413,



Why not maximize the horsepower you have & put the car on a diet? It might be cheaper & you can obtain the same goal(s) thru weight reduction.

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~Button
Horsepower and weight reduction are so utterly independent that managing progress on one should never discourage progress on the other!
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Old 11-11-2009, 06:54 PM   #52
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Originally Posted by chazly413 View Post
Can you suggest things to take off my car or change to reduce weight?
Lighter wheels, aluminum hood, coilovers, hollow sway bars, lightweight battery and nice aftermarket bucket seats for starters. Stick to stock brakes too. After that, it gets tricky, especially if you want to be in any sort of competition class for autocross or rallycross or whatever. Or if you happen to like having a relatively quiet interior during daily driving.
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Old 11-11-2009, 07:36 PM   #53
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I already plan to do lighter wheels, aluminum hood further down the road, I'm gonna do springs and struts over coilovers, but I'm not really all gungho about going crazy weight reduction.
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Old 11-11-2009, 07:41 PM   #54
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Originally Posted by jedz123 View Post
But High Compression pistons would help a bunch! I was surprised to see that the pistons had a semi deep bowl, I've torn down Ej18s and EJ22s and the pistons did not look like this.

There's a reason for that. The Ej25D was sort of an "afterthought" engine. What they did was take the heads off of the Ej20G WRX engine and move them over to this new engine they were putting together for the US market. Because of that, they left the combustion chamber size the same, which meant when they went to a larger bore (and larger volume) piston they had to drop some CC's off of their previous designs to get the compression ratio low enough. Basically, they rushed that engine to market initially and did what was cheap and easy to put it where they needed it to be.

Over time it evolved and they reduced the deck height on the phase II engines and went to pretty much flat top pistons with valve cut outs in them.
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Old 11-11-2009, 08:00 PM   #55
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Hmm. Matt, have you tried using EJ20G heads for a high compression motor?
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Old 11-11-2009, 09:43 PM   #56
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Originally Posted by BAN SUVS View Post
Hmm. Matt, have you tried using EJ20G heads for a high compression motor?
Nope. I prefer the SOHC Ej25 heads. I think it's a superior design.

However Subaru makes one that they call the Ej20D with high compression and a 7200rpm redline. It's a 2.0l sold in Japan and the world market.
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Old 11-11-2009, 10:06 PM   #57
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Originally Posted by chazly413 View Post
Can you suggest things to take off my car or change to reduce weight?
I think more inportant than how much to reduce is where to do it... One way, is to reduce rotational weight. flywheel; pulley; axels; driveshaft... From the body I think the best place to start is the front of the car: hood; fenders; bumper beam etc.

In a perfec world, it would be easy and to get a carbon roof and some light weight windows.
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Old 11-12-2009, 08:08 AM   #58
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Quote:
There's a reason for that. The Ej25D was sort of an "afterthought" engine. What they did was take the heads off of the Ej20G WRX engine and move them over to this new engine they were putting together for the US market. Because of that, they left the combustion chamber size the same, which meant when they went to a larger bore (and larger volume) piston they had to drop some CC's off of their previous designs to get the compression ratio low enough. Basically, they rushed that engine to market initially and did what was cheap and easy to put it where they needed it to be.

Over time it evolved and they reduced the deck height on the phase II engines and went to pretty much flat top pistons with valve cut outs in them.
Makes sense why my Head has N/A printed all over it... Another thing I noticed with my heads out of the car they do look almost identical to WRX heads of it's age... Thanks Matt for the Clarification! This is my first EJ25 so It's been fresh reading on all aspects of this motor...
Quote:
Originally Posted by chazly413 View Post
Can you suggest things to take off my car or change to reduce weight?
I know if you were to strip everything out of the car including spare, rear seats, carpet, speakers, Window motors, Hill Holder, A/C...the whole nine you can shed up to st least 150lbs... I've done it... and after the car felt faster... Great numbers that we used at the drag strip...
10lbs of rotating mass= 1 tenth of a second or =10hp in the 1/4mile
100lbs of sitting mas= 1 tenth of a second or= 10hp in the 1/4 mile
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Old 11-12-2009, 11:54 AM   #59
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Originally Posted by BAN SUVS View Post
Horsepower and weight reduction are so utterly independent that managing progress on one should never discourage progress on the other!
I respectfuly disagree. Try doing all the work yourself, and for each hp and lbs.ft you will sweat a pint and lose a lb of fat
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Old 11-12-2009, 01:19 PM   #60
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So not to steal the thread but since we are talking NA power and we have all the top NA guys in here now and a few that have experience with the PP6 and H6 swaps. My plan was for a ez30d and use 2 PP6's for a standalone EM. the EZ30d seems to be an easy swap, it's cheap and easier to come by but it's just the EM part i worry about. I have heard you can us 2 PP6's for a standalone but I don't know anyone that has done it, I may not be that smart. Matt do you guys sell and tune the ViPec? I've never heard of it and couldn't find a price for it or much info on it other that what's on their site. I had thought about the ez30r and hydra but the few that have tried haven't finished and I don't want a 2 year project. I've heard that AEM is making a EM for the ez30r but it's not out yet. What's your advice? I'm looking for a reliable 200 whp for track and street.
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Old 11-12-2009, 03:31 PM   #61
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I'd go an alternate route than the PP6. It's a rather good piece for a reasonably easy, OBD-II compliant and laptop jackable piggyback for common bolt-on, pre-RomRaider tuning, but I wouldn't use it as a standalone for anything.

I am not sure I want to know about a dual PP6 standalone setup; it's intriguing, yet frightening. Surely, it could be done, but how can one person hate himself so much?

If you're going to do a standalone, I'd suggest you at least take a look at the eManage Ultimate, which is what I was checking out when I was investigating my options.
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Old 11-12-2009, 04:57 PM   #62
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Haha, the pp6 is kind of a pain in the butt anyways but it's cheap and one of the only options for the 04 rs. I believe they actually sell a power adapter connects to the pp6 so it can control extra injectors but I have yet to see it and I wast sure how that comes into play in closed loop. It's probably worth the money and headache to invest in a serious EM for this.

If I could use a stock ECU that would be nice then all it is is wiring and my PP6 would still be usable. What are others using for their H6 swaps? stock ECU's or standalone? Does using a ECU out of an auto trans car like the outbacks and svx's make a difference? and does it make the wiring any more difficult?
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Old 01-12-2012, 03:19 PM   #63
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Back from the dead...

I'm not building an engine or anything, but I like to discuss ideas...

OK... Would it be possible to run something like the Tomei ITB manifold (or OBX copy) on N/A engine?

Would it fit?

Would you see any gains from it?

http://www.ebay.com/itm/OBX-ITB-Indi...ht_2939wt_1398

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Old 01-12-2012, 04:58 PM   #64
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It's an EJ-series engine: anything can be made to fit.

You'd see significant power loss.
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Old 01-13-2012, 07:09 AM   #65
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Quote:
Originally Posted by williaty View Post
It's an EJ-series engine: anything can be made to fit.

You'd see significant power loss.

Oh, and that would be swee... No, wait! That is bad!

Interesting.

Thanks
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Old 01-13-2012, 08:26 AM   #66
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You'd see significant power loss.
Why do you say that?
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Old 01-13-2012, 10:19 AM   #67
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anytime you increase airflow you increase potential power. you might lose power but if you tune it you will gain it right back.
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Old 01-13-2012, 04:07 PM   #68
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Why do you say that?
Effective runner length and width. That IM is designed to flow a crapton of air in a forced-induction application. With runners that fat and stubby 1) you'll never flow enough into an NA engine to get the port velocity up and 2) you won't turn it fast enough to take advantage of the resonant tuning. Since at least the 05-07 IM makes great use of both flow velocity and resonant tuning, moving away from that is going to be a bad choice 99% of the time. If you switched to that IM at the same time as putting a big honkin turbo on the motor then, yeah, that IM makes sense.

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anytime you increase airflow you increase potential power. you might lose power but if you tune it you will gain it right back.
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Old 01-13-2012, 05:48 PM   #69
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not sure if serious....
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Old 01-13-2012, 05:53 PM   #70
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not sure if serious....
Quite serious. Your comment unamused me.
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Old 01-13-2012, 06:37 PM   #71
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not sure if serious....
I thought ITBs were geared more toward throttle response, not so much increased power?
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Old 01-13-2012, 06:42 PM   #72
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I thought ITBs were geared more toward throttle response, not so much increased power?

they are. they generally lower low end and increase top end at the same time by lowering runner length. more air + more fuel almost always equals more power.
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Old 01-13-2012, 08:42 PM   #73
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they are. they generally lower low end and increase top end at the same time by lowering runner length. more air + more fuel almost always equals more power.
Wrong.


Stubby pipes are optimized towards high-RPM operation. Long pipes are optimized towards low RPM operation. Fat pipes are optimized towards high flow volumes (either from displacement*RPM or from turbo/blower). Skinny pipes are optimized towards low flow volumes (smaller engines, lower RPM). When you try operate a pipe in conditions for which it was not optimized, the result is a decrease in performance, not an increase.

Now, the EJ251/253 is a small, low-displacement engine that can't turn very fast. That means it needs skinny-ish, long-ish pipes. The ITB IM linked to above has short, fat pipes. The EJ251/253 won't be able to take advantage of the ITB IM shown above and in fact will make less power because the IM will be such a severe mis-match for the engine.
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Old 01-13-2012, 09:03 PM   #74
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Wrong.


Stubby pipes are optimized towards high-RPM operation. Long pipes are optimized towards low RPM operation. Fat pipes are optimized towards high flow volumes (either from displacement*RPM or from turbo/blower). Skinny pipes are optimized towards low flow volumes (smaller engines, lower RPM). When you try operate a pipe in conditions for which it was not optimized, the result is a decrease in performance, not an increase.

Now, the EJ251/253 is a small, low-displacement engine that can't turn very fast. That means it needs skinny-ish, long-ish pipes. The ITB IM linked to above has short, fat pipes. The EJ251/253 won't be able to take advantage of the ITB IM shown above and in fact will make less power because the IM will be such a severe mis-match for the engine.

you basically said the same thing i said just with longer words....so how am i wrong?
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Old 01-13-2012, 10:17 PM   #75
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You've been maintaining that the ITB IM shown earlier will produce more power on the EH251/253 "if you just tune it to get the power back". That's wrong. You keep going on about how the ITB IM referenced above will increase flow, and flow is power. That's wrong. Well, flow is power, but it'll decrease flow.
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