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Old 07-29-2008, 08:24 PM   #1
nexgen
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Default i want to hit 8k rpm on my02 wrx

pk im fairly new to building subies but i've been working on motors for a while. i recently purchased a jdm sti gauge cluster for my car and then i started thinking why not rev to 8k insted of 7. on my last car an acura i fully rebuilt the motor and head. i put ti valve springs and retainers, ti valves, different cams, cam seals, 3 way valve job, a new ecu and i was reving to 9500 on a daily basis. my question is how high can i rev on stock head internals, and would i be able to get away with just valvesprings/ retainers?
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Old 07-29-2008, 08:46 PM   #2
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You might safely rev to 8000rpm on a stock 2.0 but why? You're not making any power up there, just increasing wear on your motor, and likelihood of doing bottom end damage.

If you are dead set on upping your rev limiter, the COBB stage 2 map will let you rev to 7250.
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Old 07-29-2008, 08:52 PM   #3
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If you want to rev to 8000rpm do a JDM STi V8 engine swap.
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Old 07-29-2008, 08:57 PM   #4
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Quote:
Originally Posted by sanjay View Post
If you want to rev to 8000rpm do a JDM STi V8 engine swap.
i would but i dont have the money and i also like working on my car this will give me time to build my motor in stages and spread the money out over time as apposed to just dumping a large sum at once. im still thinking about it though because it would definatly be the easiest way to go. anyone know the best place to buy a v8 motor from amd around how much i should expect to pay if i do?
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Old 07-29-2008, 08:53 PM   #5
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well eventually i am going to have a big turbo and a built bottom end as well. that'll move my power band up higher so i'll be able to use the extra thousand rpms
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Old 07-29-2008, 09:05 PM   #6
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www.romraider.com

turn the rev limiter up yourself, its not that hard.... stock 2.0 will spin about 8200 before it comes apart at the seams, but as was stated earlier, the cams and the turbo make ZERO power up there, so its 100% pointless

the oil supply and bearings are also not properly set up to handle that kind of sustained RPM, so the engine's bearing life will be short at those rpms if you dont replace anything to handle it

Last edited by Turbo_Mike; 07-29-2008 at 09:08 PM. Reason: I like editing
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Old 07-30-2008, 01:07 AM   #7
FuJi K
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I will evenually make my EJ22T rev to 8000rpms mainly for gearing when at the road course where I need to hold the gear for some turns.

You need supporting mods for that. Cams w/ more duration, better valve springs, better flowing heads, better oil pump, revised crank w/ more oiling holes.
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Old 07-30-2008, 10:28 AM   #8
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im not going to raise the rev limiter until my motor is ready to handle it i just want to know where to start with my head.
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Old 07-30-2008, 11:06 AM   #9
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As mentioned only run the rpms that high if you are going to make power there. Once you have the turbocharger that will do that there is nothing you need to do to the OEM valve train to handle it when adjusted properly.

Now if your shims are too loose or due to wear there is excessive clearance you can spit a shim and do some damage. I honestly don't know how this happens but it can even at rpms well under 8k rpm (we just build a motor for a customer that had this happen to his OEM engine around 80k miles. The best but costly option is to switch to the shimless buckets used in the newer WRX and STi models.

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Old 07-30-2008, 11:40 AM   #10
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Even with a bigger turbo, in order to make decent power above 6500 rpm, you're going to want some head porting and cams. Cams will probably require springs and retainers.
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Old 07-30-2008, 12:01 PM   #11
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If running big boost with a stock valvetrain, you might find the intake valves stay open because the airflow under pressure is greater than the springs can handle. Something to watch for when you add more boost but the power doesn't increase like it should.

Jay
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Old 07-30-2008, 12:29 PM   #12
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Stock heads, valves, and cams:





It's all about the turbocharger until you start hitting 500+ whp and then cams would be next. This is also running stock valves, porting, springs, but 272 cams with 10.3 mm lift (max for stock springs).



These are all 2.5 examples but the 2.0 actually revs out easier than the 2.5 because of the slower piston speeds and decreased displacement. These are actual results and not theory. Stock Subaru valve trains and porting are excellent until 500+ whp which then you should do cams (may require springs), and then big valves, and then porting if your budget allows.

I regularly ran my EJ205 to 8300 rpm with a GT30R back in 2002 with the stock valve train.

Now with all that said you'll break a rod before you need cams, valve springs, and porting 400 ft/lbs of torque on the EJ205 rods is the bleeding limit in my opinion and I have broken those rods before.

Pick a turbocharger and rev it only as high as it will make power as mentioned by many and if it's anything less than a GT30R, GT52, or larger you won't need 8k rpm.

Thanks,
Phil
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Old 07-30-2008, 02:36 PM   #13
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What will a 3" 8cm FP green rev to before it stops making power?
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Old 07-30-2008, 03:38 PM   #14
Turbo_Mike
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Quote:
Originally Posted by Element Tuning View Post
Stock heads, valves, and cams:

I regularly ran my EJ205 to 8300 rpm with a GT30R back in 2002 with the stock valve train.



Now with all that said you'll break a rod before you need cams, valve springs, and porting 400 ft/lbs of torque on the EJ205 rods is the bleeding limit in my opinion and I have broken those rods before.



Pick a turbocharger and rev it only as high as it will make power as mentioned by many and if it's anything less than a GT30R, GT52, or larger you won't need 8k rpm.



Thanks,

Phil

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Awesome post phil... good to have a few other people in the thread that have been there, done that, and got the T-shirt :-)
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Old 07-30-2008, 07:52 PM   #15
FuJi K
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I am tempted to run mine to 8000rpms with my hybrid buld right now.

'03 WRX heads STOCK, STOCK EJ22T shortblock w/ OEM EJ22T oil pump and NEW rod/main bearings. Heads are ported along with TGV deletes. I have it set at 7500rpms. Sounds AWESOME up there. I want a little more. hehehehe

Safe for 8000rpms??? Running EVO3-16G-8cm @22psi peak.
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Old 08-02-2008, 11:09 PM   #16
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As said before, just because you can run 8000rpm does not mean that you're going any faster. Its fun but you need ideally worked heads/cams/valvetrain as well as a revised (probably custom made) intake manifold with short runners to hold power up top.

But lemme leave it at this, I've got a ver8 that can do 8500rpm and its seen that twice since I put the motor in 16K miles ago. Its just pointless to rev it that high on anything less than a 30R or 35R.

I just rode along with a ver8 equipped car with a Dom3 (essentially a stock-location 30R) and that car pulled hard up to 8K but even still would not have made anymore power beyond that. I think his setup hit 355whp and that tapered down to 320whp or so at 8K and looking to taper much more beyond that. If anything, my VF37 has less of a taper, I've got 250whp from 4500rpm all the way to 8500rpm with a peak of 270whp around 5700.
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Old 08-04-2008, 10:28 AM   #17
ride5000
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i've had my redline set at 8200 for the last 5 years, basically since open loop fueling came out for the utec. i don't spin up there more than once or twice a year though, and always in a lower gear.

as far as whether you should rev that high or not, the thing is sometimes upshifting is just not an option, and it's nice to be able to venture up there if necessary and not have the ecu get in the way.
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