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Old 02-26-03, 10:00 PM
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redline question

i have an 87 gxl se and it redlines at 7k is it safe to take it to 8k once in awhile and does it make a difference in power just wondering.

thanks red

k-n drop in intake
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Old 02-26-03, 10:03 PM
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Here we go again....

NO! What power your N/A motor makes has long since started to decline. It started to decline at about 6200. At 8000 you are:

A: Making less power
B: Making less torque
C: Making rotary engine builders rich.

Jarrett

*edit* The previous statement assumes that you have no agressive porting, electronic turbos (those you can rev to 11,000), or any other racing mods...NO, exhaust and a K&N filter dont count.

Old 02-26-03, 10:06 PM
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tanks buddy
Old 02-26-03, 10:08 PM
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honestly......most rotary engines drop off their power band after 8-9000 rpm and begin to lose efficiency....but rotaries can spin freely to 10000 depending on the condition of your engine and etc......our engines are made to rev high....
Old 02-26-03, 10:12 PM
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If you check out the dyno in this link you can see it would be benificial to go past 7k because the total power under the curve would be greater.
https://www.rx7club.com/forum/showth...threadid=95492

However, I can attest that you don't want to believe the hype about reving the crap out of your motor. Unfortunatly by doing just that, last fall I qualifyed for J-Rat's condition C. (although technically I bought a J-Spec)
Old 02-26-03, 10:14 PM
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Originally posted by Bebesito21
honestly......most rotary engines drop off their power band after 8-9000 rpm and begin to lose efficiency....but rotaries can spin freely to 10000 depending on the condition of your engine and etc......our engines are made to rev high....
We got into this little discussion a couple of weeks ago. Here are the salient points.

Stock N/As make power over 8 grand, sure. But the toruque and power curve have LONG since taken that downward slide. Shifting at 8000 as opposed to say 7000 makes you SLOWER not FASTER. I could go into the restrictions in air velocity, heat transefer, etc...But why?

There is a redline, its on your dash and its there for a reason... After a certain RPM limit, the motor starts doing things you dont want to think about. Just because its a rotary DOES NOT mean it can rev to 10,000, and its NOT MEANT to rev that high.

Ask the motor builders on this site, they will tell you the same thing.

But hey, dont take my word on it... Kevin and the others need the money, I dont make a living off of rebuilding rotaries.

Jarrett
Old 02-26-03, 10:15 PM
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Originally posted by Snrub
If you check out the dyno in this link you can see it would be benificial to go past 7k because the total power under the curve would be greater.
https://www.rx7club.com/forum/showth...threadid=95492

However, I can attest that you don't want to believe the hype about reving the crap out of your motor. Unfortunatly by doing just that, last fall I qualifyed for J-Rat's condition C. (although technically I bought a J-Spec)
Okay keep in mind that he has an N/A not a TII
Old 02-26-03, 10:16 PM
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plus if you rev too high and are dropping the clutch at 8000 all the time you could break an engine mount among other things......

even if you are just reving high through acceleration, you can actually crack housings due to the movement of the engine in the engine bay......alot of those high reving rx7s have extra dowell pins and other stiffening enhancements that allow them to rev that high....
Old 02-26-03, 10:17 PM
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then what was j rat talking abou loss of power at 6200 and other people saying more power at 8-9k.
very confused please help
Old 02-26-03, 10:17 PM
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Originally posted by Bebesito21
honestly......most rotary engines drop off their power band after 8-9000 rpm and begin to lose efficiency....but rotaries can spin freely to 10000 depending on the condition of your engine and etc......our engines are made to rev high....
depending on the condition...hey...mine has good compression...can I rev to 10k? j/k....I think (hope) I know what your getting at....a motor built with the proper internals...s5 rotors...clearenced rotors..everything balanced, ports...fuel and MANY other things.....can see 10k or higher and make power and be reliable..

about 9k power band drop offs....depending on whether its a s4 s5...even a s5 probably will stop making power before its 8k redline stock...reving to 7k and making power to 7k and making power to 7k is alot different.
Old 02-26-03, 10:20 PM
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damn site hiccup..

Last edited by J-Rat; 02-26-03 at 10:22 PM.
Old 02-26-03, 10:21 PM
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Originally posted by red1rx7
then what was j rat talking abou loss of power at 6200 and other people saying more power at 8-9k.
very confused please help
Okay, we are talking about a STOCK N/A!!!!! Not a balanced, ported, fire-breathing monster. and NOT A TII!!

Okay, I will concede peak power at MAYBE 6500. But 8000? Not in this life time.

Yet again, I say this...Go ahead, rev to 8000 all day! Its gonna bite you in the end.

Jarrettt
Old 02-26-03, 10:21 PM
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i didnt mean that it can rev to 10000 as you are driving around..... i mean that rotary engines by nature are rev happy......not that it is practical or possible for you to do that to your engine in your car....just that the rotary is capable of that

and as far as the power drop of.....my car pulls all the way to 8000.....i guess it just depends on the condition of your engine
Old 02-26-03, 10:22 PM
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i barely even take it to 7k only on occasion when i want to make the tires talk, bark whatever. im very caustious with the car- i did however get it for free and i dont want to **** anything up i ve had a starter go a an alternator and a battery go in one week. so im very careful
Old 02-26-03, 10:23 PM
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oh and any engine.....be it TII or NA will give out if you are constantly taking it to the redline.....the secret is to be able to rebuild your own engine....or you can just give your money away like J Rat says
Old 02-26-03, 10:26 PM
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i only took it to 8k maybe 3 times in 2 years
the motor has 153,ooo miles on it and runs real strong. And it pulls all the way to 7k/ as for rev happy im not maybe a few here and there cause i heard alot of people tell me i have to run the rotary hard and i was thinking wont that **** up my motor.
Old 02-26-03, 10:27 PM
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Originally posted by red1rx7
i barely even take it to 7k only on occasion when i want to make the tires talk, bark whatever. im very caustious with the car- i did however get it for free and i dont want to **** anything up i ve had a starter go a an alternator and a battery go in one week. so im very careful
Here is the deal bro...

Your FC, my FC, anyones FC will probably rev to 8000- 10,000k and still make some power. But the point is, the power band as long started to decrease. Why would you risk damage to your motor just to slow yourself down?

Your optimum shift point should put you square back into the sweet spot, or a little under (on a dyno graph).

So my question to everyone advocating overrevving thier motors is:

Is it really worth it?

My $.02 and I promise I will quit postwhoring your thread.

Jarrett
Old 02-26-03, 11:00 PM
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Originally posted by red1rx7
i only took it to 8k maybe 3 times in 2 years
the motor has 153,ooo miles on it and runs real strong. And it pulls all the way to 7k/ as for rev happy im not maybe a few here and there cause i heard alot of people tell me i have to run the rotary hard and i was thinking wont that **** up my motor.
ANY internal combustion engine creates friction, heat, bla bla, will wear man....but rotaries make all there power at higher rpms...especially the 6 ports...dont really make power until the 6 ports open...alot of the reason for not driving the car like a grandma every day is the oil injection..motor oil does not burn clean and leaves carbon deposits like **** stains in a toilet...my first motor popped b/c it never probably say 4k have its life...to apex seals carbon locked...driving it hard will help with this...not taking it to ******* 9k daily...sationary gears dont appreciate that to much...niether do apex seals etc...my motor sees 6k at least once a day...

the original question has been answered...your not going to be faster pulling to 8k....
Old 02-26-03, 11:17 PM
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I agree High reving is good once and a while ulness u have preppared the engine for it then i guess u can rev all u want but its not smart to hight rev it all day long. It s badd tor the engine and on ur wallet high reving uses more gas ( i pretty sure bout this) and gas prices are bad enought with out addin to problem .

so i say rev it once and a while, just enough so it sees 7-8k once and a while but not every time u drive

keep in mind that im still learning about rotaries so that just my thoughts i might be wrong then agin hell ive been right on occaision
Old 02-26-03, 11:57 PM
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I have seen what can happen when a flywheel
lets go at high rpm, and I for one really don't want to
be near one or in one when it does.
there is a reason why there is a redline and motor
damage is only one factor.
I know of one non rotary flywheel incident where the
flywheel came apart, up through the fire wall and
got the driver in the chest, sad to say he didn't survive.

matt
Old 02-27-03, 12:17 AM
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holy **** thats a scary thought
Old 02-27-03, 07:52 AM
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Thats why you get a scatter shield if your going to be reeving that high or at least a ballistics blanket.
Old 02-27-03, 11:02 AM
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Originally posted by hybridracer
Thats why you get a scatter shield if your going to be reeving that high or at least a ballistics blanket.
I agree 100%. but how many people on this thread
who are saying that they are running out to 7000 to
8000 rpm have a ballistics blanket ?
I would really like to see how well a ballistics blanket
would hold the heavy stock mazda flywheel that came
apart at 8000 tp 10000 rpm. i know its made to do the
job but its hard to imagine stopping a lump of
flywheel spinning that fast, with not much more than
a bath towel.

matt
Old 02-27-03, 02:49 PM
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there is truth in the fact that the power is on the decline but the real reason of shifting around say 8k is to be higher in the power band in the next gear...atleast when im at the track. -Gabe
Old 02-27-03, 03:12 PM
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the whole point of shifting at a higher rpm is to land you down back into the sweet spot in the next gear, it isnt slower, its faster. imagine having to shift at 6500, youd land at around 3900 rpms, seeing as how the rotary has no torque itd take forever to get into the powerband......


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