I'm really thinking into gettting some sort of scatter shield. This thread reminds me of Honda.net " you have to take it to 10k rpms"

 

One time I missed going into 4th and hit second (past redline) with the buzzer, so I quickly shift into N. I don't know what rpm that is, but I'm guessing somewhere around 9K on a S4.

 

I have my fuel cut set at 8250 on my LT-8. There's just no power up there. Specificially on the chassis dyno recently i COULD NOT build any power past 8k so we set the cut at 8250 just for reasons unknown. Stock S4 internals are not made to spin that high, they'll only take it for so long before SOMETHING breaks. 89-91 internals can natually rev higher than S4's. The rotors are lighter, well balances and the compression ratio is substantially different. But i still wouldnt twist an S5 past 9k...

I managed to pull 181 WHP from a stock port S4 engine, ported/honed S5 intake manifold, Racing beat header & silencer and borla catback. No accessory belts, just alternator. Like stated we managed to pull 181 on a slightly lean run, put it back to 12.9 and ran her again and managed to pull a steady 177-178 rwhp at 7900-8000 rpms.

STOCK PORT

Good luck guys, don't blow your engines. and as always keep it safe guys.

-Markus

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Yeah i would trust the internals at a higher rpm than i would the clutch and whatnot from turning into shrapnal in my legs AHHH, but i've taken my NA s4 to 9 a few times on accident when my 3rd gear was screwed up, no problems from doing it just lots of smoke from oil

 

8k is good

 

sorry for asking it again, Aaron Cake

 

we had about 11,700 with a bridge port 13B with S5 internals before we had problems.

-Trent

 

It's funny how you said "problems" very calmly. Would you like to tell us what happend?

Worst thing i've seen is an old Rx-3 road race car that was use to spinning 9-10k on race days spin a bearing and literatly split the engine apart. The aftermath was quite a sight and not for the faint of heart.

-Markus

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Damn!!! I Dont think stock S4 stuff can be worth a **** after 8500. I'm not sure but I dont think they are balenced or blueprinted well enough to handle that.

 

if you go more than a few hundred beyond stock redline you are going to be asking for problems, its only a matter of time. like arron said the only real benefit to shifting past redline is to place the engine right back i the power band on an upshift, and the way the fc's are geared this would only be of benefit on the 1-2 shift. however since the engine and the internals are undergoing such drastic angular acceleration while in first gear, reving higher will waste a fair amount of power in this sittuation, so there is realy very little if anything to be gained by shifting eyond redline. i personaly shift at 8200 on the 1-2 and the 8k for everything else in my s5.

 

my 12a saw at least 12K+ rpm once.

 

Werd, my car doesnt pull past redline..

 

Ive hit 7800 (theres a soft fuel cut rev limiter here) in my s4. I think the fuel cut for s5's is 8900 or so, though ive never driven one.

 

i usaully shift at anywhere between 4000- 6000. rotories r meant to be redlined, just wont be right to do otherwise!!

 

When everything is working right, my power seems to drop off around 8600. But I'm slightly modified . . .

 

Ummm 7k is the start of redline on S4's.

I remember 2 times where I was doing some stunts and spun the tires enough that I bounced off of 8k before in my 88 GTU.

I'm giving a guess at 8.5-9k rpm since the tach stops at 8k.

It makes a different sound when it gets that high


I usually only go to 7.5k since it's useless to go higher on a stock port.

I have heard reasons not to rev that high because the oil system can't lube enough. I guess that's why they do the extra window bearing oil thing.

Also something about Eshaft flex.

Anyways S5 would be better at higher RPMS due to their rotors weight reduction.

I think Racing beat sells lightened rotors for high RPM use.

The clutch fragmenting thing does scare me though.

 

I cannot see a stock-port motor pulling more then 9000RPMS because the motor simply cannot digest and process the air at a quick enough rate ...Unless you drop it from 4th to 2nd while already at redline...

As far clutch/flywheel shattering - is this a common problem among FCs? You guys are scaring me a bit...

David

 

it's not a problem w/ FC's.

It's a problem with taking something not balanced enough to that RPM. Most clutches are not balanced to go that high.

Ever seen that video of the guy putting a CD on a dremel?

CD's don't like 15k RPM. They tend to blow apart.

 

you shouldnt rev pass 7.5 on stock...
1.) it puts ALOT of stress on the stationary gears
2.) stock injectors on FC's loose fuel at higher rpms with 460cc or 550cc and thats hard on the seals
( if you put hardened stationary gears and bigger injectors/porting...you could daily drive that thing to 9k