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Old 01-26-2008, 09:40 PM   #1
KevinG
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Default 99rs build

sorry for this type of post but when searching most the threads that pop up say to search...

i am looking to build a NA dirt monster... base platform is the 99rs...

i know the suspension that i am looking at getting and the breaks too...

i am getting stuck with the engine build part, i have not built a NA car before... only a skyline and a wrx (current)...

where can i find internals for a kickass 2.5L (or even a stroker kit) ???

a strong/beefy full exhaust that can take a beating???

companies/shops/vendors that specialize in the RS (so far i know of only wrx/sti)???
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Old 01-26-2008, 11:03 PM   #2
ballitch
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The EJ25 already has the 79mm stroke crank, I think it's the longest stroke of all the suby motors, but I could be wrong.

Are there any rules governing mods to your engine in the class you will be racing in? Or are you doing this just for some weekend rallys?



~Josh~
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Old 01-27-2008, 12:07 AM   #3
KevinG
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just weekend warrior stuff... for now
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Old 01-27-2008, 12:09 AM   #4
Fred
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If you're just rallyxing, a 2.5RS with stock power, good tires and good suspension will kick anything else in the nuts. So don't bother.

If reeeeeeeeeeeeeeeeeeeeeeeeeeally long straights are involved, or you just want to blow some money, WRX swap and good LSD X 3 (since more than stock power will be worthless without them).
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Old 01-27-2008, 01:25 AM   #5
ballitch
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In that case, I would maybe get some form of intake (read the ebay ones are not that bad and can be modded to fit), maybe a borla knockoff header and a better axle-back and mid pipe section. But traction and suspension are going to make you faster than power.

Cracking the tranny to throw in a better center diff is probably out of the question, so I guess you could find a decent rear lsd. Maybe hit up J-hot imports on ebay about their rear lsd conversion stuff.

~Josh~
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Old 01-27-2008, 09:00 AM   #6
Subie Gal
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if you want the best of the best, go here

http://www.techworkseng.com/index.html
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Old 01-27-2008, 10:36 AM   #7
Matt Monson
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Kevin,
Did your searches bring up the "na power paper"? I don't knoe why that thing isn't sticked. It should be. It contains detailed information of all of your options.

Also, I STRONGLY suggest AGAINST putting an intake on your '99 unless you've got an AFC to add fule up top. For whatever reason, the 99rs doesn't add enough fuel for the extra airflow an intake provides. The means that above 5500rpm your car will detonate. Because in a rally-x you will spend most of your time between 5000 and 6200 rpm this is a bad combination for the health of your engine.

Lastly, you aren't that far from Rallitek and Primitive Racing. I would pay both those shops a visit. Primitve in particular can provide you with skidplates and a diff protector, both items many of us consider essential for a dirtmobile...
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Old 01-27-2008, 08:54 PM   #8
KevinG
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i got the subaru rear diff guard installed and the rally armor skid plat is on order... i will stop by primitive soon...
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Old 02-01-2008, 08:31 AM   #9
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decided to go with the 2.2 heads... hopefully it is a good decsion... should he get it PnP with some cams or just stick with the stock 2.2L head's design?
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Old 02-01-2008, 09:20 AM   #10
Matt Monson
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That's a ludicrous idea. That's like putting in a lower flowing fuel pump. It's going backwards. Keep reading...
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Old 02-01-2008, 09:30 AM   #11
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swap in a 00 motor and 00 rs ecu....plug and play, flashable ecu, and bye bye crap 99 maf....then throw in a delta cam, other head goodies and have fun revving like a stock wrx.
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Old 02-01-2008, 04:55 PM   #12
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Quote:
Originally Posted by Matt Monson View Post
That's a ludicrous idea. That's like putting in a lower flowing fuel pump. It's going backwards. Keep reading...
i ,kevin (not my roommate) just read all the post. so i understand that using a lower flowing fuel doesnt make sense... but i didnt see the post you are referring to that says the 2.2L heads are a bad idea on the 2.5L sb... can you please explain...
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Old 02-01-2008, 05:20 PM   #13
Matt Monson
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It's the same logic. The Ej22 heads flow about 20-25% less flow than the Ej25 heads. When I first started talking to people about the high compression Frankenstein you saw a handful of guys make the same mistake that you are making. The additional compression you gain by putting ej22 heads onto and ej25 block is not a gain that is large enough to offset the loss of flow you have by removing the ej25 heads. The high compression frankestein is only a good idea for someone who had an ej18 or an ej22 in their car from the factory. Otherwise, if you had an Ej25 to start with, build that engine...
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Old 02-01-2008, 05:35 PM   #14
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Quote:
Originally Posted by Matt Monson View Post
It's the same logic. The Ej22 heads flow about 20-25% less flow than the Ej25 heads. When I first started talking to people about the high compression Frankenstein you saw a handful of guys make the same mistake that you are making. The additional compression you gain by putting ej22 heads onto and ej25 block is not a gain that is large enough to offset the loss of flow you have by removing the ej25 heads. The high compression frankestein is only a good idea for someone who had an ej18 or an ej22 in their car from the factory. Otherwise, if you had an Ej25 to start with, build that engine...
what if you did a 2.2 heads WITH cams?
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Old 02-01-2008, 05:50 PM   #15
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I looked into this type of build for my older impreza once. IIRC it is the size of the valves and ports that is where the 2.2 heads lose flow, not in the cams. If you are gonna bother with pulling the heads off and all that detail you could also look into getting a thinner Cometic copper head gasket, milling down the stock heads, getting a P&P job, and then possibly swapping better cams all into the 2.5 heads.

One of my buddies has a 99rs that he has built N/A and uses it for the local rallycrosses and he has all the head work done with lower compression gaskets and it hauls serious @ss!!
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Old 02-01-2008, 09:44 PM   #16
Matt Monson
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Quote:
Originally Posted by KevinG View Post
what if you did a 2.2 heads WITH cams?
Why would you spend $175 on cams, and another $200-300 on head gaskets, intake manifold gaskets, exhaust manifold gaskets, idler pullies, timing belt tensioner and timing belt when you could just spend $175 on cams and get more power? And this assumes you get the ej22 heads for FREE. Hell, if you are stupid enough to do this, I'll give you a set of them for free and I'll even pick up the freight. Really. I will. There's no logic in where you are going with this thing.

I am going to walk away now. I ran an RS with bolt ons and cams and got 138whp with it. I also built a high compression Frankenstein, put it into a '95l that weighed about 200lbs less than my RS and guess what? My RS walked all over it. We never got that second car on the dyno but I would hazard to guess from how it drove that it wasn't more than 125whp. That's all I've got. I won't waste any more breath on this topic. You've been offered sound advice and what you choose to do with it is not relevant to me...
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Old 02-02-2008, 12:48 PM   #17
KevinG
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cool... josh just canceled the order on the heads... he did find a used cobb intake for the rs...

we were just confused cuz the power paper never really talked about the 2.2 heads any more after post #2.... i understand flow more means more power but i thought that higher compression off set that... oh well... time to start looking into delta cams.
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Old 02-03-2008, 01:26 AM   #18
Matt Monson
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Cool. Keep asking questions. You caught me on an off moment last night and I was pissed at someone else. Sorry. I am still here but if you can't tell, I don't like repeating myself. I'll try to be more patient. We were all noobs once...
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