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2000 Subaru Impreza W"RS"X BRP
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Discussion Starter · #1 ·
I have a Brand New set of EJ25 Heads fully assembled...I want to build it up to handle speeds above 10,000 RPM...I will see about having it completely disassembled and reassembled with the neccessary hardware...

I will appreciate any feedback on anything that will make this Head capable of the increased speeds...Please post referrals and product information...I'm looking for head shops and valvetrain parts information...There are a few shops over here in Florida but I don't really know what parts the Subie Aftermarket prefers to use...Ferrea Valves is down the street from me and they produce some expensive hardware...ARI in West Palm Beach has ads posted in Turbo and has certainly built their share of heads for Hondas and DSMs, Race Engineering in West Palm also seem to please the H-Boys...

Whats happening on the West Coast...Anyone have any experience with Benson Machine Shop? Cobb Tuning seems to have a Monopoly on the Subaru Aftermarket Heads...I thank them for all the info that they have provided to us, at no cost too...

I will post a few pics that may help others and anyone can take them and use them any way they want...

Thanks,
Zee
 

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Discussion Starter · #6 ·
Exhaust Ports

I want to make a custom turbo header with using the best possible collector design keeping the primaries and the exhaust ports the same size...

Zee:sunny:
 

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Discussion Starter · #10 ·
Another Pic of Intake Ports...

The ports look great..I really want to see Major HP gains from these heads...What options do I have with the cams? I will like a set of Fresh Cams but ReGrinds is fine for now...

Thanks Guys...I really hold your opinons and suggestions very high up...Without your help, I will still be lost and confused...

Zee:sunny: :)
 

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Discussion Starter · #12 ·
Pics and Cobb Tuning...

I don't know how to combine pictures in the same post...Cobb Tuning is great but their prices are outrageous...The only reason they charge so much is a lack of competition...

Zee:cool:
 

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You could contact Paeco. Here is their website, but it doesn't have a huge amount of info. Your best bet is to call them, get a catalog. Look inside and see what you want to do, then call back and talk to them about it.
 

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10K RPM......HMMMMMM Lots of considerations come to mind. Multiple valve springs, improved oiling(flow channels, oil pump and filter), polished intake ports, High temp valves and new guides, copper head gaskets, cams with higher lift shorter duration, forged low compression pistons(with clearance for the higher valve lift), forged rods, high performance main bearings, ballanced forged crankshaft, high performance flywheel and clutch setup, undersized pullies and high strength belts, adjustable cam pullies....And a new engine management system!
What level of boost are you targeting?
The exhaust system will require a complete remove and replace...
New brakes are a must!
New urathane engine and tranny mounts, front and rear tower braces, high performance strusts, and you may want to go to 17" rims with 'sticky' 240 Mph directional tires.
The tranny and rear gears are good to about 245 Hp.....beyond that...

Are you sure you want to do this?:checkit:
 

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Discussion Starter · #16 ·
In the Works...

Well, I don't want to spill the beans, so to speak, but I have the Vishnu Kit on order, I have an incomplete TEC 2 setup, I drive with the ACT Clutch and I love it...I need to research specific parts that will be used to build up these bad boys...I'll check with Paeco...Money is very much an issue but it can be done if you know the right people and negotiate like a Mutha...I have expressed interest in JE slugs recently and have received great info and prices from a few local speed shops...The most expensive part of the BottomEnd is the Rods...ARI quoted me $700+ for Crower Rods and 500+ for the JE Pistons...Balancing and Knife Edging the Crankshaft should be another $200+...Its not gonna be done anytime soon but it will be done...This year, my goal is to pay off all my debt...I will have my car running boost in a month or two, but really low boost, like 5lbs or less...I have been looking at tranny options and I know that Dogs are the way to go but the costs is too rich for my blood...No corners will be cut in the engine tuning dept...My car sits on nothing but 17"s at all times...:D and is wrapped in the finest rubber Japan has to offer...Proper Engine Bracing has already been considered...Stronger Suspension components have been purchased as well...What levels of HP do you think I will gain at say 9,000RPM and 5lbs of boost? I imagine that I will make tons of power just by running at those engine speeds...And I don't even want to mention the sounds it will make... :eek:

Zee:checkit:
 

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Well, beyond cams, valves, valve springs, and retainers, you may want to look into some porting for those pesky unequal (and one is kinked) exhaust ports.

The bottom end will be the trick, though. The rod length/stroke ratio is very important in making a high-revving motor and I think that our EJ25's just stroke far too far for normal internals. There is a possibility that you can reconstruct everything with necessary hardware and bearings to keep it together, but I wouldn't have an idea myself. I suggest talking to Cobb and seeing what they've done for high-revving 2.5's (most I've heard is like 7500rpm out of them).

Realistically you need to sit down and decide what type of power you want, as well. You can't very well have a lot of low end power and still have enough to get you going in the high end, and vice-versa. The drivetrain should be able to handle a decent amount of top end power without too much trouble, though, as long as the bottom end isn't too torquey and you don't beat the crap out of it while shifting.
 

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long stroke engines don't spin fast....you'll need to go witha shorter overall stroke in oder to spin 10k as well as a fully balanced and blueprinted bottom end with higer perf bearings...you will prolly end up destroking it to a 2.2 in order to make it spin that fast....and this is gonna cost you an ASTRONOMICAL amount....you'd be better off building it to make a ton of power by 7500 RPM....plus good luck getting a subaru to shit at 10k RPM.
 

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Discussion Starter · #19 ·
Well, you know what I mean...

10K RPM is not a "Real" number to me...I want the valvetrain to handle high RPM and Over doing it is a good idea...I really will make a Rev Limit at around 8,000RPM as I don't want to De-Stroke the motor...Lower Compression pistons and Forged Rods put together with strict tolerances will be all I need, I think...The CrankShaft is really small and well balanced when compared to the Honda B-Series engines and the Mitsubishi 4G63...I figure that I will build the Head to handle around 10,000RPM and build the bottom end to be boost friendly...When its all said and done I will attempt to run 1 bar and see what power I make with that and go from there...Keeping my Tranny in mind the entire way...The Lower Compression Pistons are there for more than just the added strength...They are there to shift the torque higher up in the powerband...That alone should keep the tranny from prying itself apart...Of course the RS Gearbox is extremely week, theres no getting around that...So, I have sourced a few Sti Boxes from the land down under and thank god for our strong US dollar...

Zee:cool:
 
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