Hey,
I've seen that modded S4 n/as do not lose power approaching redline as they do when stock.
The question is, how high can I safely rev my engine before I hurt it or cut my leg?
Also dont they have a rev limiter at around ~7800rpms?

here's a dyno sheet of what looks like a S4 n/a, not sure whose it is... That's some very nice #s tho, I hope I can achieve as much

 

i think there ios a rev limiter.

 

I dont think there is. I've had mine bounce off 8k on missed shifts. As long as the motor is getting enough fuel (which normally isnt a problem for n/a's) and oil is being dispersed as needed by the injection system, u can redline it.

 

what justifies the redline on a rotory engine? I've seen 12A blocks and S4 blocks make power as high as 12,000 rpm before.

 

rev limiter at ~8k here. Shaft flex and seal float are the redline of the rotary, flex is especially nasty, spins bearings and creates rotor to housing contact.

If anyone figures out a cheap way to remove the factory rev limit, please tell me, ive got a built s5 block waiting for 9k runs...

 

there is a rev limit on the s4's.
Drago86 i am using a old school apexiRSM which should allow me to up the limiter

 

he wasn't talking about the redline....

A stock engine doesn't make much power that late, a bridge port or radical street port might give you really good gain up there.....

 

I thought the buzzer went off ~200rpm below redline but you could rev it as high as you wanted assuming your car could handle it (fuel etc...). Guess I was wrong.

 

yeah, i didnt think there was a rev limiter until one day i was getting on the highway and held the gas in a tad bit too long with out looking down. it was right before 8k that i hit it and it was followed by a very LOUD back fire.

 

buzzer 7k, redline 8k. why rev it past the buzzer though? that thing is so godamned annoying and prolly there for a good reason.

 

On my S4 NA, I get the warning buzzer (factory shift light?) at right around 6500 RPM, and fuel cut at 8000 RPM. I try not to take it all the way up to 8k very often, but if I'm driving hard I usually shift around 7k.

-=Russ=-

 

build up an s5 block... thats the best suggestion I have to offer. Stock redline at 8k. I think its limited at 8600.

 

Well he needs to be a little more specific in his descriptions then. He mentioned 7800rpm so I wasnt thinking a BP or PP motor.

 

bah I guess I'll shift at 7500 then =)

 

7500 is where I shift at, although I too have seen 8,000 and not seen ANY form of rev limiter. The car wanted to just keep reving as high as I would feed it. I am not sure what the limit on the S4 rotors and e-shaft assy is. I wanna say like 8200 but then again I know I have heard 8250 for an S5, but that may be just the rev limiter. I am gonna clearence my rotors and install hardened stationary gears and some oil mods and shoot for 9500 on the next rebuild.

 

ok, when i was drifting my buzzer goes i think at 6800 and i step on the gas and it quickly went to 8 and wa just there,i only did that ones, ok any ways rev limiter i thout it was like u know hondas or any other car that bounses off u guys get me? unless the only thing that stops the needle is that thing there u know the peace of metal that stops it, oh i have an n/a s4 no mods only suspension mods aight

 

you sound like a ********.

 

No personal attacks... aight?

 

The S5's BLOCK is not the reason it redlines @ 8K. The raised redline has much to do with the lighter flywheel, revised ECU and higher compression rotors.

 

rev limiter in and S4 is 7800.. if your engine is stock.. and no intake or exhaust mods there really is no point in going that high.. if you have a really open intake and exhaust you probably still don't need to go that high.. but by getting over 7K then that would just bring you back into the meatier part of the power band when you shift and the revs drop..

Frank

 

Hm... mine will "bounce" off the rev-limiter (at 8000 RPM or so) like a Honda or such.

One really important point for those looking to up their redline - you'll want to install a clutch scatter shield. Stock hardware is good up to 8000 or 8500 RPM, beyond that you will want to replace the flywheel/pressure plate/clutch with higher RPM rated components, and install a scatter shield. Unless you don't value your legs - a rotating assembly letting go at high RPMs has more in common with a grenade than anything else.

-=Russ=-

 

To give credit:

The car used to belong to John Wise. He recently sold it since he moved up to an RX-8. I'm unaware of who picked the car up...it had some high miles.

Now the kicker... THE ENGINE IN THAT CAR at the time of that dyno had S5 internals and S5 intake. So the reason the dyno shows 8000 RPM is because the engine was safely able to handle it.

 

A missed shift is totally different than running the engine in gear and under load... You can easily hit 8000 RPM+ by just revving the engine because of the inertia of the rotating assembly. However in gear and under load you will hit fuel cut in an S4 NA at 7800 RPM.

Oh and just because the FACTORY tach is buried at 8000 RPM, doesn't mean that it's 100% accurate. The factory gauges are not known to be very accurate.

 

only reason you'd wanna be able to spin your engine faster is if by the RPM your letting off your power is still climbing.. othewise get a honda.. then you can rev it to **** and not hav to worry about a shattering clutch taking out your legs since the flywheel faces the passengr!!

Frank

 

ive had mine up to 9 before. the closest it comes for my s5 is a really freaking annoying buzzed that happens after 8