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[SirDragsAlot]

just wondering, is it safe to assume that every fuel injected computer system has a built in rev limiter?  in theory we should be able to hold the gas to the floor and the rev limiter should stop us from blowing the engine up, right?  for example i have been told that the yamaha motor that ford used in the sho taurus can rev to 10000 rpm with mods, is this a myth?

[lilpooh21186]

gm v6's never make it to the rev limiter.

any motor can rev to any rpm, can the motor actually make it there though?

TRUTH

[BoostForLife]

If a car doesn't have a tach, it probably wasn't meant to be revved up high.
I would assume that every car that was manufactured would have some sort of fuel cut-off for warranty purposes, otherwise morons would be blowing their shit up very frequently because they can't drive or shift.

I would think that as long as the hardware is strong enough to support the revs (bolts, valvetrain, and balancing), good AFR's, timing, and abequate oil pressure you can rev up much higher than stock.

[Kenny Rogers]

Why does it matter anyway?  It's useless to rev a car higher than the fuel cutoff for most cars with bolt-ons.  The Yamaha engine in the SHO is not the same Yamaha engine in the R6, lol.  They can't all be revved to hell and back while still making power.


Edit:  The original SHO V6 could spin pretty high, making 10,000 RPM possible I suppose... but pointless.  Either way, to answer your original question, even that motor was electronically limited.

[92CXyD]

New SHO w/ paddleshift, 360bhp, AWD coming out 2010: http://www.bringbackthesho.com/phpnuke/pressrelease.html

[Towdogg]

I towed a mint 93 sho the other day,  the drivebelt came off...

Cleanest taurus I have ever seen..  It was blue with grey leather..

[Kain]

heat and flow rates negate the need to rev higher. if its not designed to rev higher, then it shouldnt.
Rotating mass also plays a very large roll.

[patsmx5]

heat and flow rates negate the need to rev higher. if its not designed to rev higher, then it shouldnt.
Rotating mass also plays a very large roll.

Huge roll at that. Loads from reciprocating stuff skyrocket with RPMs

[Kenny Rogers]

heat and flow rates negate the need to rev higher. if its not designed to rev higher, then it shouldnt.
Rotating mass also plays a very large roll.

Huge roll at that. Loads from reciprocating stuff skyrocket with RPMs

Which is why it's always better (from a stress standpoint) to up the boost, not the RPMS 

[onlyflash944]

i always float the valves in my sohc

[Kain]

heat and flow rates negate the need to rev higher. if its not designed to rev higher, then it shouldnt.
Rotating mass also plays a very large roll.

Huge roll at that. Loads from reciprocating stuff skyrocket with RPMs

Which is why it's always better (from a stress standpoint) to up the boost, not the RPMS 

but arent you producing more heat and power as well and also increasing the stress?

[patsmx5]

heat and flow rates negate the need to rev higher. if its not designed to rev higher, then it shouldnt.
Rotating mass also plays a very large roll.

Huge roll at that. Loads from reciprocating stuff skyrocket with RPMs

Which is why it's always better (from a stress standpoint) to up the boost, not the RPMS 

Yeah, that's usually the case. For the most part anyways. I've run the numbers before, considering the smallest cross sectional area of a BP 1.8 connecting rod, the mass of the piston and rod, and and dada and you have to make about 350whp to put the same amount of compressive load on the rod as it sees when spinning 7k RPMs, the stock redline. But rods often fail below that power, not from exceeding the working stress, but from buckling.

[lilpooh21186]

i spun my b16 stock head to 9k  with no problems. But i wasnt using it as my rev limit to say i would still shift at 82-84 ish but that extra 800 rpm would stop me from shifting into 5th in the quarter.  when spinning tire it would bounce of the 9k but with the light load id say its not a big problem

[ratcityrex]

Which is why it's always better (from a stress standpoint) to up the boost, not the RPMS 

True that!!!!! Its not as hard on the motor, In most cases.

i always float the valves in my sohc

sohc what? I use to take my a6 to 8K all the time :yes: I even miss shifted once or twice and took that shit to the moon. Never missed a beat. I ran it from 7500 in 3rd gear and went to take it into 4th, and with my sloppy linkage and me wide open throttle shifting I slamed it into 2nd. So you do the math and tell me how high I reved it.

[onlyflash944]

sohc what? I use to take my a6 to 8K all the time :yes: I even miss shifted once or twice and took that shit to the moon. Never missed a beat. I ran it from 7500 in 3rd gear and went to take it into 4th, and with my sloppy linkage and me wide open throttle shifting I slamed it into 2nd. So you do the math and tell me how high I reved it.

i'm guessing you've never driven a big block anything

[ratcityrex]

You mean like the 1964 bb 390ci ford truck I have?

[onlyflash944]

it was a joke, clearly not a good one

[98vtec]

rev limiters will not keep you safe from mechanical over rev.

[Joseph Davis]

Subaru Justy had no revlimiter.

[Joseph Davis]

If by lucked out you meant drove it off a cliff, sure.

[onlyflash944]

If by lucked out you meant drove it off a cliff, sure.

9.8 m/s/s is darn fast accleration

[souron]

Subaru Justy had no revlimiter.

thats because justys are awesome, and with the auto they are ALWAYS in the powerband!!! just ask highroller about our hill climb adventures 

[Zeniceguycrx]

my old dbl barrel carb accord would rev to 9,000rpm
I painted the valve cover red and put type r stickers on, when people said it wasnt a real type R I would sit them in it and rev it to 9000.  People would beleave me after that

[Joseph Davis]

Subaru Justy had no revlimiter.

thats because justys are awesome, and with the auto they are ALWAYS in the powerband!!! just ask highroller about our hill climb adventures 

I doubt any Justy CVT lasted much longer than warranty.  So, Chad had one when he was 19 and picked you up from elementary school in it?

[patsmx5]

New SHO w/ paddleshift, 360bhp, AWD coming out 2010: http://www.bringbackthesho.com/phpnuke/pressrelease.html

I would so drive one the new taurus.

[92CXyD]

Repacked 500 with a ecoboost motor not sure I would.

[patsmx5]

Repacked 500 with a ecoboost motor not sure I would.

500's are nice. Ecoboost motor looks badass to me.

[crttaz]

Ecoboost motor in a Mustang

[Joseph Davis]

Subaru Justy had no revlimiter.

thats because justys are awesome, and with the auto they are ALWAYS in the powerband!!! just ask highroller about our hill climb adventures 

I doubt any Justy CVT lasted much longer than warranty.  So, Chad had one when he was 19 and picked you up from elementary school in it?

drain the fluid out of a cvt justy and you can drive for a few hours before you have any issues appear

Right.  That's why you only see manual trans models driving around anymore.

[BoostedSchemes]

butler was a booming town



No.