i just was looking at a s5 and was woundering why they redline 1000 rpm more than the s4?

cos s5 has lighter rotors than s4

only s5 n/a has the 8k rpm redline

My S5 rev limits at 8500 - 8800 - who knows how accurate the stock tach is though - LOL

that is so true, on the dyno my tach read like 4k the dyno computer said 3600 ish

ok so whats going to blow up if i hold my s4 to 8,000. and what ever that is can i just get one off of a s5?

wtf.... whats your concern with this high revving nonsense, you dont even make power up there have you felt hot bad the power drops at high levels??? its worse than 1500 rpms lol

I quite regularly run rev limiter at events - been doing so for 12 years on this engine. If it was a no no Mazda would have made it lower.

I will run ANY car that has a limiter, on it, with no fears.

Dont rev a Celica with a 2zz-ge engine up to rev limit too many times. You will loose a valve or two.

Also the S5's only redlined at 8,000 RPM's if it's a manual transmission. So someone told me. Don't know how accurate that is though. But I've seen it. I was in a 91 GXL Automatic and it redlined at 7,000 when my 90 redlines at 8,000. *Shrugs* So I suppose it's true.

[quote name='CrassFC3S' date='Jul 13 2005, 11:32 PM']wtf.... whats your concern with this high revving nonsense, you dont even make power up there have you felt hot bad the power drops at high levels??? its worse than 1500 rpms lol


[/quote]



i just want to know what blows up, because mine pulls really good to 7500.

I don't believe you'll blow anything. You'll more then likely just fry something inside your engine because you're exceeding it's operational range. If you're going to do that I recommend not doing it very often and keeping an eye on your temp gauge. But that may not be the case. You could blow something.

few reasons the S5 non-turbo had a 1000 rpm higher redline:



- the intake manifold allowed for a slightly higher powerband



- more importantly, if you were to shift at 7000 on an S5 NA, when you drop into the next gear you aren't in the best place relative to the powerband. even though power drops off around 7500, it's still worth more to shift from 8000.

if you are slow on the shift from 7000 rpm, you will drop BELOW the VDI valve activation rpm. that's why you shift at 8k for maximum use of the powerband



- there were a few internal design changes that were seemingly due to the higher rev limit, but really not too much different from the S4



i have a rebuilt S4 core in my S5 NA, and i take it to 8000 rpm all the time...



- Aaron

s5 also has hardened stationary gears.



Anyone have any experience in the differences between a hardened and unhardened stationary gear when it comes to higher rpms? I just wondered if it made a big difference or not.



-Dan

[quote name='annuerysm' date='Jul 14 2005, 01:54 PM']s5 also has hardened stationary gears.



Anyone have any experience in the differences between a hardened and unhardened stationary gear when it comes to higher rpms? I just wondered if it made a big difference or not.



-Dan


[/quote]



i don't think the difference is "hardened" and "unhardened", it's just that they wen through a different treating process.



i would expect this would only make a difference in LONG term reliability or under high-stress applications. but the reliability issue was foremost to them doing that, which is really only beneficial after 10 years or so...

so would a s4 be pretty close to being as reliable at 7500 as a s5?

Only non-turbos...

All FC turbos have a 7kRPM redline.





-Ted

http://fc3spro.com/

rev limiter is set around 8k though, ive hit 83xx before! at least thats what my safc read....

ok i was wondering i got a 87 n/a rx7 and when i push it goes all the way to 8,000 can 87 motors go that high

If yours went that high, then yeah, I guess they can go that high. https://www.nopistons.com/forums/pub...IR#>/dunno.gif

stop revving so damned high theres no point jesus... you dont need to rev to 8500rpms to get the civic to race you... s5 n/a's were the only ones that had a 8k redline... you can rev your motor as high as you want but just know its gonna eventually fry something

lol ok becasue i was shifting at 7,000 7,500 befor but one time i kind of push it alittle more and it went to 8 so i was like screw it il just go to 8 now lol

you dont need to

High revs will yield power so long as the engine is breathing ok, another reason to rev higher than the powerband is so that you land closer to it when you change gear.



But Crass is right, if you're not racing all you're doing is shortening your engines life.

exactly, most people asking about this kind of stuff are not doing anything more than street racing

My "built" engine is supposdly safe to 10k, but I dont have a scatter sheild for the clutch, my stock ecu cant handle it....... However I do take mine up to 8k alot, of coure it has porting, the mani's are port matched, and everything flows very nice. My power does not drop off though.

the s5 n/a rx7's had lighter rotors the vdi, a generally better flowing manifold design(all mentioned above) and ALSO a better balanced flywheel made to handle the higher rpm's.

some one pin this in the reg. section, not the faq.