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Discussion Starter #1
how much can you raise the rpm limit on a wrx ive seen a guy pushing the ej20 stock internals to 8300rpm is this safe will it hold the bearings ???
 

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That's news to me... 7500 was supposedly the safe limit.. after which the engine started spitting shims and what not.. Perhaps this limit can be bumped up with the shimless designe implimented on the newer cars?
 

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I wonder why this is even an issue. Maybe I'm missing something, but redline is there for a reason. Plus, the power band dies in the 6k range, so why go to 8k RPMs?
 

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hes got a fp green so i think it doesnt die after 6k, and i noitced when i play gran turismo i can get better 1/4 times if i over rev on some gears...hey i guess this is like real life? but then againi have an auto i let it do all the work :p
 

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Damage to the engine aside,

I have to agree that raising the redline significantly would not really show much benefit on the stock heads. Sure, the Green will make power to redline, but you will quickly reach a point where the flow rate of the heads is a major limitation.

I know there are people running 8K on the V7 STi heads (w/built block) for good power, but those heads flow much better than the USDM WRX heads.
 

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Discussion Starter #7
im w a green and forged bottom end , also my car has the new desing of shimless buckets , thats why im asking i know this guy personally and he runs over 8000 rpm but w a 20g no problems for the moment and he is running like that for about a year or more and trust me he drives hard and he is not forged at the internals so my question relies on the bearings it self will it hold? has somebody done this i want to raise the power band to make it longer also my gears are longer than stock im basically set up for the highway not the track
 

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Discussion Starter #8
sarcasmo said:
Damage to the engine aside,

I have to agree that raising the redline significantly would not really show much benefit on the stock heads. Sure, the Green will make power to redline, but you will quickly reach a point where the flow rate of the heads is a major limitation.

I know there are people running 8K on the V7 STi heads (w/built block) for good power, but those heads flow much better than the USDM WRX heads.
how about if i port the stock usdm wrx heads???
 

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Sure, go ahead and do all of that, but you will blow your engine up. I give you anywhere from 5 months to a year and a half, but if you're willing to buy a new valvetrain and heads, why not just blow these up first? Might as well exploit the current setup then just replace it when it goes to hell, would be an interesting experiment in how much stress the stock longblock can take.
 

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Discussion Starter #10
??? on what are you based on ??? i do things right and thats why i ask im not posting this because my friend does it or stating that everybody will get away w that, i dont plan to run 8000rpm i was thinking on runing 7250 to 7500 rpm because my best power band its at 6500 rpm
 

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this whole post seems idiosyncratic to me. For one, the guys I've met who end up working an engine over to the point where they are altering redlines - this is imo one of the last things you'd ever do if you even get there - tend to know the ej20 / 257 to the hilt.

Basically, and this is speculative, but this is one of those posts where if you have to ask you shouldn't, stupid as that sounds. Anything is plausible, but I'm gonna speculate you aren't even remotely close to the situation where you should be considering this.

para
 

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Have you ever noticed that after around 6k you actually go slower when racing? A higher redline won't do crap, if you think about it technically, you'll just be able to stay in one gear longer and go slower.

Please, I am failing to see where a higher redline helps anything, please enlighten me.
 

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scubaroo said:
Have you ever noticed that after around 6k you actually go slower when racing? A higher redline won't do crap, if you think about it technically, you'll just be able to stay in one gear longer and go slower.

Please, I am failing to see where a higher redline helps anything, please enlighten me.
With a big turbo you can easily continue to make more power over redline. What he wants to know is how far is safe.
 

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Discussion Starter #15
finally the last two post are based on facts , and listen the stupid question is the one you dont ask if you do not know what we are trying to do here dont b other to post my two cents ill see what ill do and ill keep you guys posted thanks
 

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high rpm

I know of a couple people that have bumped the red line up in the 7500-8000 range even on the older shim style valve train.

The key is how long you stay at high rpm and how often.

If you plan on extended time at high rpm, ie lap after lap on a track at high rpm, I would limit the rpm to near stock - 7500 rpm range. If you will only briefly flash to high rpm then 8000 rpm is probably okay.

Keep in mind there are two issues. The valve springs may not survive extended periods of time at high rpm, but can live with brief periods of high rpm.

The engine rods are most stressed by high rpm. Tension loads on the rods go up at the square of the rpm, so the higher your rpm and the more time you spend there the sooner they will fail.



Larry
 

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Timdog1650 said:
Sure, go ahead and do all of that, but you will blow your engine up. I give you anywhere from 5 months to a year and a half, but if you're willing to buy a new valvetrain and heads, why not just blow these up first? Might as well exploit the current setup then just replace it when it goes to hell, would be an interesting experiment in how much stress the stock longblock can take.
he said he has a forged bottom end. that ain't stock.
 

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scubaroo said:
Have you ever noticed that after around 6k you actually go slower when racing? A higher redline won't do crap, if you think about it technically, you'll just be able to stay in one gear longer and go slower.

Please, I am failing to see where a higher redline helps anything, please enlighten me.
power comes from fuel and air. by spinning the engine at a higher rpm you can pump in more air. back that up with fuel and you will make more power. this is how motorcycle engines are closing in on 200hp/liter--by revving to 15k rpms or so.
 

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Discussion Starter #19
finally people are starting to reply w interesting points of views and understanding w i was thinking of doing thanks and keep posting
 

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scubaroo said:
Have you ever noticed that after around 6k you actually go slower when racing? A higher redline won't do crap, if you think about it technically, you'll just be able to stay in one gear longer and go slower.

Please, I am failing to see where a higher redline helps anything, please enlighten me.
With my turbo, the higher I rev, the more power I make.. This is with an 1820. With smaller turbos that cannot support the boost up there near redline, it makes no sense to increase the rev limit even further than it is right now.
 
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