Wisemen and knowledgable tumers , 14000 rpm cfm? [Merged 7-7] STUPID high

[98eclipseRS]

alright I would rather not start this thread with a rant but here goes FILL OUT YOUR GODAMNED VEHICLE PROFILE SO WE AT LEAST KNOW WHAT YOU DRIVE!!!!!!!

with that out of the way, from your handle I take it you drive a 95 RS which would mean you have a 420a not a 4g63 which I am not even goign to try and give info on because I don't know enought about the engine to do that. If you do have a 4g however its not the bottom end that can't support 9k its the top end. On the stock turbo/ head anything above 7k is worthless hell really anythign above 6,5k is wasteful as well. if you wanted your car to make it to 9k safely and to make power up there, you would need for one a large turbo and a built valvetrain i.e. uprgraded springs, retainers, and valves. As well as a chipped ecu or soem sort of way of raising the rev limiter.

 

[95Eclipsers]

sorry about that i have a 95 tsi fwd also, im more or less interested in it, and yes it would be good for braging rights, and i always love drivin my buddys type r' into 9k

 

[David15151]

only engine which I have had first hand experience with high revs is a 13b Rotary engine. The powerband on a Rotary engine is pretty damn fun. Seems like they don't start getting real power till about 4-5k and its all uphill from there.

 

[MarkyGsX]

If you were to look at a dyno of a rotary engine...that's exactly what you would see....an uphill climb after 4k......rotary's were meant for high rev's....the stock rx-8 also revs to 9k.....

 

[David15151]

the muzzle flash was an awesome bonus when reving high on those suckers..
I never did research as to the cause of flames coming out of the exhaust after a high RPM shift..

my old RX7 beats my current car hands down in top end.. but launching... hah good luck!

 

[firstgen]

half the time you see honda guys that "can rev their motors to 11k or so on" they stop producing power at around 8.5-9 etc. just b/c you can rev that high doesnt mean your doing any good, why would you want to stop making power btw i own a honda so i know

 

[vteg]

The only hondas that make power at 11k are the race engines. I have see one dyno done on a NA b18c that made almost 300hp. The peak was at 10.5k. The driver shifted in the 11-11.5k range. This was one of Erick's racing's old engines. This car was running vtec killer cams, which make the car absolutely unstreetable.

The biggest vtec "street cams" stop making power around 9k.


I would like to know what needs to be modified in the head to get 8.5k assuming a built block with balanced moving assembly. I know the 4g63 uses hydraulic lifters. This is what holds back many heads. I have seen 4g63 dynos with the redline in the 8-8.5k region. Do these guys switch to solid lifters, or is there some other option.

 

[98eclipseRS]

I have seen 4g63 dynos with the redline in the 8-8.5k region. Do these guys switch to solid lifters, or is there some other option.

upgraded springs and retainers and you are good to go.

 

[JoeWagon]

ok i see all the honda guys around here tackin 9k safely why cant our 4g63 motors do it if there bullet proof, if they can how, im guessin building the head?

It's probably because they have as small as 1.5 liter engines. It's a common concept, that the less displacement per cylinder is likely to rev higher. V8 vs. most 4 bangers perhaps? Consider a viper with .8L per cylinder (8L/10cyl) that redlines at ~6000rpm and a Ferrari 360 with .45L per cylinder (3.6L/8cyl) that redlines at ~8500rpm.

In any case, don't worry about revving higher until you can make some power up there. Cars that DO shift at ~9k, *cough*shep*cough* certainly have more money invested in their car than most of us can ever hope.

Bottom line? "Tacking" higher doesn't mean faster. Don't doubt that our motors will hold up to high RPM, but there is no reason to, so we don't. Search for instances of mis-shifting to over 9,999rpm on the S-AFC or built motors that do 8.5-9k every pass.

 

[Tallen]

I know of many people revving to 8500 with a stock head...you'd probably want a newly rebuilt head if you do that though!
Springs and retainers is what you'd really want in that situation.

 

[RayRay32]

the stock motor is only good to about 300hp with the open deck sure guys do more but it is a gamble then.

What about 307 whp out of a stock LS. Its all in tuning, ask the guys at endyne about how they get over 400 whp out of twin cam vtec motor (www.theoldone.com). You dont need to resleeve the block.

You guys are thinking of small or stock turbos. What aboout those guys running huge snails who don't even get boost until 5k? I'm sure they appreciate being able to rev higher than 7500 rpm. I've read that the stock DSM valvetrain is good to about 8k. Revving that high on a 14b in a stock 1g will get you nowhere, but for the guy running the 272's, ported head, and 60-1 will appreciate winding the motor out. Then all he has to wory about is getting a tranny that will shift at 9k.

This makes me think outside of the box.
Why dont we take a ride with Brett Rau.

 

[JoeWagon]

Why dont we take a ride with Brett Rau.

Brent.

 

[rdeterman]

"si's in there stock form rev over 9k w/out problems" dude i dont thing that is not safe at all. i herd that even the type r's sometimes get valve float because the rev limit is to high. and they are "ment" to rev around 9k. i can n drop my auto car and still drive away fine... but it is very bad for my trans. but like everybody is saying.... we dont need high rpm's. we have high psi's. but i guess if you have a n/t, you would have high mpg? just kidding... its all fam.

there stock rev limiter is 8700-8800rpms honda wouldnt allow those cars to rev that high if it wasnt safe.. even though im not a big honda fan they make excellent quality motors..

 

[RayRay32]

Brent.

you got me man

I even have a shirt signed by him

 

[VtecRex]

My ole B16a CRX wouldn't cut out till 9,500 RPM's on my Mugen program. That is with a stock head and stock block. I used to take it that high till I saw that the peak power was a 7,600. As stated before it is the head that would really limit the revving...


anything is possible.

It's probably because they have as small as 1.5 liter engines. It's a common concept, that the less displacement per cylinder is likely to rev higher. V8 vs. most 4 bangers perhaps? Consider a viper with .8L per cylinder (8L/10cyl) that redlines at ~6000rpm and a Ferrari 360 with .45L per cylinder (3.6L/8cyl) that redlines at ~8500rpm.

what about the Honda V10 Indy car that can rev past 15k? Anything is possible with the right amount of funding.

 

[JoeWagon]

what about the Honda V10 Indy car that can rev past 15k? Anything is possible with the right amount of funding.

You didn't understand what I was saying. It's not about the cylinders, it's about displacement per cylinder. F1 cars have 3 liter V10's. .3L/cyl. That's a higher revving motor than Ferrari's .45L/cyl.

so, "What about it?" Well, it follows exactly what I was saying.

 

[vteg]

Thanks for that post RayRay. I have not been to Endyns site in over a year. He always has some cool toys in production.

The last time I was on his site he was working on a vtec block with some insane redline and compression that he said made 345whp and then blew.

 

[btracer]

haha well if you want braggin rights for highest redline... then try and beat the triple rotor motor... redline never mattered to me, it was what kinda power you could make. all the ricers at school brag bout their rpm or how high they got their speedo... :thumbdown

 

[MrDee]

I seriously dont know why one would want to rev their motors that high.After a certain RPMs the acceleration is barely noticeble.....gettin into next gear is much smarter.

I wouldn`t mind 9K on 5th Gear though

I wonder how fast i`d be going

 

[JrCRXHF]

My ole B16a CRX wouldn't cut out till 9,500 RPM's on my Mugen program. That is with a stock head and stock block. I used to take it that high till I saw that the peak power was a 7,600. As stated before it is the head that would really limit the revving...


anything is possible.

QUOTE]

i don't know what b16 you had or what else was in your setup but with a bone stock b16 and bolton's with hondata ecu i was maken power about 8500 and it was still going up. on turbo i stoped at 8,000 and hit max tq at 7,000 because the open deck was maxed out so u tell me where the power band is.

 

[VtecRex]

hondata ecu

Not a stock fuel curve with that thing. But a stock B16 stat it:


170hp @ 7800 | 116 lb-ft @ 7300 with the SirII I only have a SirI

 

[leakyfaucet]

I wouldn`t mind 9K on 5th Gear though

I wonder how fast i`d be going

Twice as fast as you'd being going at 4.5K RPM in 5th gear.

 

[pinknuggit]

It's probably because they have as small as 1.5 liter engines. It's a common concept, that the less displacement per cylinder is likely to rev higher. V8 vs. most 4 bangers perhaps? Consider a viper with .8L per cylinder (8L/10cyl) that redlines at ~6000rpm and a Ferrari 360 with .45L per cylinder (3.6L/8cyl) that redlines at ~8500rpm.

That is incorrect. redline has nothing to do with displacement. The reason the ferarri engines rev so high is becaue they have a ridiculously short stroke.
It's all about stroke and rod/stroke ratio, and piston velocity.
That's why, (example), when you take a 350 SBC and stroke it out to a 383, you drop rev capability.
It's all childsplay, though, until you take things into consideration like built bigblocks. People balance their bigblocks using good internals and they are plenty capable of turning over 7k rpms. A 572 turning 7k is enough to pwn some faces.
Of course V engines have alot more rotational vibrations than an inline engine, which is naturally going to have more overall balance.

 

[krazywhitboy]

i used to tach at 9k all the time when i had my rsx type-s, in fact, when i first got it, i mis-shifted from redline in third to second. the tach went all the way around past the end of the tach (past 10k).

 

[leet]

You didn't understand what I was saying. It's not about the cylinders, it's about displacement per cylinder. F1 cars have 3 liter V10's. .3L/cyl. That's a higher revving motor than Ferrari's .45L/cyl.

so, "What about it?" Well, it follows exactly what I was saying.

FYI, Formula 1 powerplants are seeing 19K RPMs these days.

Unless you're BMW.