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Old 02-06-2005, 03:08 PM   #51
White 2.5rs
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yeah that is nuts
did u only use the ferra parts?
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Old 02-07-2005, 01:26 PM   #52
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7500 is not a problem for the bottom end. Pointless unless you have heads and cams or a turbo setup to make power up there. Mine and mikes rev to 7500. I know of three going to 8000 on a daily basis.

Side note.. I ran a JDM Ej207 to 9000 for a while and then the limiter was reduced to 8650 for over a year. It hit that rpm everyday. Finally I had oil pressure issues and the bearings where trashed.

Clark
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Old 02-08-2005, 11:07 AM   #53
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Quote:
Originally Posted by Kingpin
7500 is not a problem for the bottom end. Pointless unless you have heads and cams or a turbo setup to make power up there. Mine and mikes rev to 7500. I know of three going to 8000 on a daily basis.

Side note.. I ran a JDM Ej207 to 9000 for a while and then the limiter was reduced to 8650 for over a year. It hit that rpm everyday. Finally I had oil pressure issues and the bearings where trashed.

Clark
Can you give more detail on your setup. I know you've gone through a few setups. Maybe give average hp near 7k and beyond, average boost you have run up top. Time you have been reving this high and most importantly use(s) of the car/higher limit.

Thanks
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Old 05-24-2005, 11:15 AM   #54
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Bumping this up as more are spinning it past 7k and more engine builders are recommending its OK.


Try and post as much detail in your setup and use as possible.
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Old 05-24-2005, 02:31 PM   #55
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how much do you guys think my swap engine(still being built) can rev up to? i'm going with the USDM 2.5L, crower stage 2 cams,USDM wrx heads & titanium valve springs. i was thinking about having the rev limiter up to 8K, for 1st gear pulls only. i can also settle for 7500. i'll be using my car for street only.


*also i'll be running a vf34, sti pink injectors and 255 walbro pump. would the 34 be able to produce power after 7K?

Last edited by swift2fly; 05-24-2005 at 02:48 PM.
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Old 05-24-2005, 03:00 PM   #56
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swift2fly: your question was the exact modivation for starting this thread. I hope many more will post and update on their raised rev limits.

On a 2.5 the vf34 will likely run out of steam past 7k, the cams may help though. Seems more are reving the 2.5 bottom end to 7.5 with out issues; 8k is still kind of rare.
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Old 05-24-2005, 03:59 PM   #57
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i'll stick to the 7.5K idea then. i just want the rev to be higher for 1st gear...maybe 3rd gear also. as you guys know, 1st gear goes by so quick. on the 2.0block with the vf34, 1st was sooo much fun but too short.
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Old 05-24-2005, 04:15 PM   #58
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Default Sti Rev

Who: DSport Magazine Project STi

Limit: 7600 RPM

Time with limit: ?

Use: Street, Track, Drag... Everything

Setup: EJ257- Atomic Speedware pistons, Scat rods, Cosworth balanced, XS-Engineering Built, XS-Flash Tuning.

Power Band: 365+ WHP

Boost: 1.4-Bar (~ 21 psi)

*POSSIBLY going to add Cosworth CNC heads soon*
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Old 05-24-2005, 04:57 PM   #59
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Quote:
Originally Posted by swift2fly
i'll stick to the 7.5K idea then. i just want the rev to be higher for 1st gear...maybe 3rd gear also. as you guys know, 1st gear goes by so quick. on the 2.0block with the vf34, 1st was sooo much fun but too short.
Once its built and you've been running it for a while get back and update the thread with info / final details.


DSport: Thanks, happy reving.
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Old 05-24-2005, 07:44 PM   #60
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Quote:
Originally Posted by javid
swift2fly: your question was the exact modivation for starting this thread. I hope many more will post and update on their raised rev limits.

On a 2.5 the vf34 will likely run out of steam past 7k, the cams may help though. Seems more are reving the 2.5 bottom end to 7.5 with out issues; 8k is still kind of rare.
The cams will more then likely kill the turbo even earlyer in the power band due to the huge incresse inflow they offer.

8k on a built, with nice forged parts, ej257 bottom end is not a problem. Even just forged pistons make a difference. Most forged are lighter then the stock units.
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Old 08-22-2005, 08:08 AM   #61
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Bump cause more folks are revin their Ej257 past 7k.

Post up suckas...
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Old 08-22-2005, 09:01 AM   #62
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I have a set of Cossie heads waiting to build a motor for my LGT... Those are good to north of 10K....

I'll have to get that **** started today since I have all the junk ready to go for it. The rods I got are supposedly good north of 9K and the Cossie pistons are sweet.
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Old 08-22-2005, 11:02 AM   #63
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Quote:
Originally Posted by XT6Wagon
I have a set of Cossie heads waiting to build a motor for my LGT... Those are good to north of 10K....

I'll have to get that **** started today since I have all the junk ready to go for it. The rods I got are supposedly good north of 9K and the Cossie pistons are sweet.

Be sure and enlighten us how you got by with that oiling system at >9000 rpms.....or didn't get by.

I'm aware you probably know this, but just because the cams / valvetrain / bottom end are good to 10k rpms, doesn't mean the engine will live there.

Good luck with your project!

S.
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Old 08-22-2005, 12:33 PM   #64
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You spot a potential problem (oiling) but offer no solution...

What would be needed to spin happily at 9k? Squirters? Higher presure pump?
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Old 08-22-2005, 02:56 PM   #65
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Quote:
Originally Posted by javid
You spot a potential problem (oiling) but offer no solution...

What would be needed to spin happily at 9k? Squirters? Higher presure pump?

I have no solution, nor do I intend to push my engine beyond 7600 rpms.

People have made 550-600 awhp with these engines at 7000-7200 rpms; Unless you are attempting to make more than that, it is a useless endeavor.


...and to answer your question: more oil volume, better designed rod bearings.


S.
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Old 08-22-2005, 03:01 PM   #66
White 2.5rs
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and better clearances on the bearings to journals
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Old 08-22-2005, 04:28 PM   #67
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Quote:
Originally Posted by White 2.5rs
and better clearances on the bearings to journals

...yes, and that
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Old 08-22-2005, 05:13 PM   #68
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I'm looking at trying an 8000 redline on my STI, but I want some power up there, and reliability.

From my reading, the crank, rods and pistons are OK to 8000 without much issue. The rod journal bearings are a weakness in the EJ engines period. Balancing of the engine can help to decrease the wear on these bearings. I think most of the rod bearings fail due to detonation less than excessive RPM. Detonation will slam the rod into the bearing; impurities in the oil, or just fatigue, will lead to spinning of the bearing.

Head work, cams, and springs are about getting some power out of the engine at high RPM (head porting and cams) and improving the longevity (valvesprings). I think upgrading the v-springs alone would give you more piece of mind about trips into the 7K's, but making any power up there, will require more air flow capacity.

Anything you can do to reduce the reciprocating mass of the crank will help out with longevity too, but stock parts are good for probably 500 whp.

No one knows too much about how well the EJ257 will hold up at high RPM, but presumably Subaru lowered the limit for some reason. Piston mass may be the primary reason, or it may be something else (friction, heat disappation, etc).
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Old 08-22-2005, 05:56 PM   #69
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Who: PDXTuning WRX
Limit: 8200 RPM
Time with limit: 2 years
Use: Street, Track, Drag... Everything
Setup: EJ257- CP Pistons, JDM Spec C Heads and Cams, PDXTuning (of course) Flash+UTEC, GT35R/.82AR
Power Band: 450+ WHP
Boost: 1.8 Bar (~ 26 psi)

As Clark said, the Spec C heads and Cams are a great combo. My EJ257 is a VERY early version, which I got before the car actually sold in the US.



Cheers,

Jeff
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Old 09-01-2005, 09:38 AM   #70
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The latest from our built STi

Peak Power: 420 whp at 6000-6700 rpm
Rev Limiter - 8000rpm (usually don't go past 7500rpm)
Motor - Axis Stage III shortblock, ported/polished heads, stiffer valve spring, stock cams

At this point i think I've got a bad rod bearing. Can hear it above 3500rpms...it's a nice clanking noise...teardown to come. Oil pressure issues for some reason, but Ill find out why.

Anthony
www.mauromomtorsports.com
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Old 09-01-2005, 01:00 PM   #71
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"We use a forged crank and modify it for better oiling and finish with balancing & polishing it to within .25 grams at 10,000 RPMS."

"MAX 9000 RPM Rev Limit"

-Stage 5 Axis Racing Motor

"- Modified Axis Racing Forged Crankshaft
- Polished & Balanced to 10,000 RPMS"
"- 8000 Rev Limit Recommended"

-Stage 3 Axis Street Motor

"- Standard 2.5L STi Forged Crankshaft"
"- 7000 Rev Limit Recommended"

-Stage 2 Axis Street Motor

Does Ron know something about modifying the crankshaft that I don't that enables higher revs. I think he does. What's the diff?.......an extra oiling groove/hole per rod journal--like the STI spec crankshaft.

I'm not saying it's THE limit to spinning the STI motor to 8000 safely, but here is a guy who has built quite a few motors that advocates this modification, plus STI has also made this change to their "spec" cranks.
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Old 09-01-2005, 01:31 PM   #72
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Quote:
Originally Posted by bboy
Does Ron know something about modifying the crankshaft that I don't that enables higher revs. I think he does. What's the diff?.......an extra oiling groove/hole per rod journal--like the STI spec crankshaft.

I'm not saying it's THE limit to spinning the STI motor to 8000 safely, but here is a guy who has built quite a few motors that advocates this modification, plus STI has also made this change to their "spec" cranks.
What is this difference? Are the stock forged cranks not cross-drilled? I'd be really surprised if Axis didn't simply take a stock STi crank, machine it, then put their name on it.

And as far as Ron knowing anything that we don't....I would not count on that. My conversations with him were not indicative of an experienced engine builder. I could be wrong, though.

S.
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Old 09-01-2005, 02:08 PM   #73
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Well I'd like to know if this is truely an improvement. I'm haunting the realm of the unknown with this engine building stuff. The stakes are high--changing anything carries significant risks.

I can't find anything that says that the STI crank has more or less, or "cross-drilled" rod journals. I can find lots that says "cross-drill" is the opposite of good for high RPM. Here is what Ron wrote to me:

"Crank mods are $300 and include redrilling the crank for better oiling, full balance, and micro polish of the journals. You are exactly right about the bearings going dry at higher rpms, this is why the JDM cranks are drilled with 4 holes and not 2 per journal."

I don't have my rods off the crank yet so I don't know how the USDM STi crank is drilled, but I will soon.

As for Ron's credentials--he knows more than I do, which is not saying much.
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Old 09-01-2005, 02:18 PM   #74
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This from a British WRX forum:

"I use a standard crank, but redrill it for optimum
oiling, then balance and polish it. I continue to use
the factory bearings as they are not the problem. The
main reason for big end failures is the lack of oiling
at higher rpms. At some point over 7300rpms, the oil
can not "push" itself out of the oiling holes in the
crank and the rotaional force of higher rpms works
against the pump and does not let the oil sling itself
out onto the bearings. So, I drill a few more holes
in strategic locations and it has seemed to fix the
problem. You will also need an uprated oil pump which
I sell for $135. I have over 50 engines out there
with the new designed crank and not one failure.
The other main reason I suggest such a low rpm on
stock cranks is they are not balanced very well.

Any other questions let me know.

Ron"
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Old 09-01-2005, 02:35 PM   #75
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Quote:
Originally Posted by bboy
I can't find anything that says that the STI crank has more or less, or "cross-drilled" rod journals. I can find lots that says "cross-drill" is the opposite of good for high RPM.
The purpose is to provide oil to the opposite side of the bearing face, but I think it does nothing but produce aeration in the oiling system.


Quote:
Originally Posted by bboy
I don't have my rods off the crank yet so I don't know how the USDM STi crank is drilled, but I will soon.
IIRC the mains are cross-drilled, the rods are not. If I were doing the work on the crank I'd simply balance the crank....but I'm not in business, nor am I enamored with the idea of spinning the guts out of an engine with heads designed by Duntov, and the bottom end designed by PeeWee. RPM = $$$, period.

My .02

S.

Edit: I just checked a $$$$ crank I brought to work; it's not cross-drilled.

Last edited by n2xlr8n; 09-01-2005 at 03:12 PM.
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