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-   -   What would be needed to run at 8500 RPM? (https://www.ft86club.com/forums/showthread.php?t=108619)

200hp/tonne 07-20-2016 12:58 PM

What would be needed to run at 8500 RPM?
 
I read through the Element tuning thread but that engine was running a lot of boost at 9000 rpm.
Assuming the tune takes the raised rpm into account, is the stock engine assembly capable of handling an 8500 rpm redline? If not, what will be required to do this? What parts are susceptible to fail at this rpm?
Thanks in advance everyone

Amputechture 07-20-2016 01:04 PM

Valve springs and retainers

Lantana frs 07-20-2016 01:06 PM

Valvetrain would shit the bed first imo. Did element ever release hp/tq numbers from their na project?

ichitaka05 07-20-2016 01:21 PM

Like other have said, valves & retainer will go byebye, but also if you don't get proper bearings, your engine gonna be knocking really quick.

200hp/tonne 07-20-2016 02:55 PM

Quote:

Originally Posted by ichitaka05 (Post 2709119)
Like other have said, valves & retainer will go byebye, but also if you don't get proper rings, your engine gonna be knocking really quick.

Isn't the stock rev limit close to 8000? Just another 600 - 700 rpm would need new valvetrain?

How much can the stock valvetrain handle?

go_a_way1 07-20-2016 02:57 PM

Quote:

Originally Posted by 200hp/tonne (Post 2709210)
Isn't the stock rev limit close to 8000? Just another 600 - 700 rpm would need new valvetrain?

How much can the stock valvetrain handle?


Why would you even want to rev past the stock redline, power just dies after that point

wparsons 07-20-2016 02:59 PM

Stock redline is 7400, so you're adding 1100rpm to get to 8500.

As was already asked, why do you want to rev that high? The stock cams (and probably intake manifold) just won't make any power up that high.

ichitaka05 07-20-2016 03:20 PM

Quote:

Originally Posted by 200hp/tonne (Post 2709210)
Isn't the stock rev limit close to 8000? Just another 600 - 700 rpm would need new valvetrain?

How much can the stock valvetrain handle?

Quote:

Originally Posted by go_a_way1 (Post 2709211)
Why would you even want to rev past the stock redline, power just dies after that point

way1 is correct. SPECIALLY for NA boxer engine. Unless you got a snail under that hood, it's a waste to have an extra rpm. Boxer engine acts totally different than high revving NA inline engine... like F20C

scmil95eg 07-20-2016 03:23 PM

Quote:

Originally Posted by ichitaka05 (Post 2709119)
Like other have said, valves & retainer will go byebye, but also if you don't get proper rings, your engine gonna be knocking really quick.

Please explain, honestly trying to learn here.

For high rpm, you typically upgrade the valve SPRING and retainer to fit the new spring. The valve itself it typically OK, but it never hurts to upgrade and freshen up the seats while you're in there. Understood. Makes sense. Got it.

But in my ~17 years in the racing industry I've never heard or read anything about high rpm piston rings or their correlation to engine knock. Piston weights go down as desired rpm goes up, skirts shrink, maybe you only run 2 rings instead of 3, but as far as I know they all use the same rings, and the rings have 0 to do with knock... Can you reference or link anything I can learn from?

ichitaka05 07-20-2016 03:28 PM

Quote:

Originally Posted by scmil95eg (Post 2709239)
Please explain, honestly trying to learn here.

For high rpm, you typically upgrade the valve SPRING and retainer to fit the new spring. The valve itself it typically OK, but it never hurts to upgrade and freshen up the seats while you're in there. Understood. Makes sense. Got it.

But in my ~17 years in the racing industry I've never heard or read anything about high rpm piston rings or their correlation to engine knock. Piston weights go down as desired rpm goes up, skirts shrink, maybe you only run 2 rings instead of 3, but as far as I know they all use the same rings, and the rings have 0 to do with knock... Can you reference or link anything I can learn from?

Oh~ not piston rings. If I wrote piston rings, that's not what I meant for engine knock. What I meant is engine knock happens from crank bearing wearing down. Boxer engine is famous for wearing down crank bearing and how quickly engine knock happens.

Hopefully that clears up some confusion

DustinS 07-20-2016 03:41 PM

FWIW Element is running to 9k with a large turbo, upgraded valvetrain (Springs/Retainers), Larger Exhaust valve, and internal oiling mods/Accusump system to keep the oil pressure good.

Lot's of info here: Element Tuning FA20

Major issues are going to be valvetrain, oil pressure, and the fact a stock engine probably isn't going make power that far out

Matt@Cosworth 07-20-2016 04:09 PM

agreed

to make power up at that point you'll need to re-tune the engine so a shorter inlet manifold and shorter exhaust primaries and cam timing adjusted to suit
and then as others have said to make it mechanically live that those rpms will need a stronger valve spring at the very least and some re-working of the oil pump as the oil pressure is dropping off pretty quick by this point

there's a reason why FI is so popular on this engine

200hp/tonne 07-20-2016 04:12 PM

Quote:

Originally Posted by go_a_way1 (Post 2709211)
Why would you even want to rev past the stock redline, power just dies after that point

I have been looking inside the tune files, and what I have seen so far of most dyno plots is that when the power is "dying" up top it is the same rpm range as the soft rev limiter i.e. the ignition timing table has timing retard from 7000-7400 rpm. So even if the engine has medium good volumetric efficiency at 7000-8000 rpm it would be a good place to make decent power gains. The valves and ports are bigger than normal for the rev range from what i have read so far.

Another reason for me wanting a slightly higher rev limit is to avoid shifting to 3rd in some of the faster autocross courses, and to avoid shifting to 5th at turn 16 and the start/finish straight at PittRace.

Lantana frs 07-20-2016 04:19 PM

Change the cut out to 8600 and tie a mulch bag to the rear bumper.


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