Racing Techniques

[AreaT51R]

Originally Posted by ShortyDTP

But with rewving my engine higher , would i be wasting time , and get a higher time in the drag strip?

and thank you !!!!!!!!

If you have a sock motor and no EMS I would not reccomend going past redline. As for racing...the higher the available rpm levle the better. Look at it this way...F1 cars redline at about 13,000 rpm. Unless your motor has been balanced and blue-printed up to a higher rpm (example 10,000) you risk the chance of pushing the excintric shaft into the exhaust side of the housing due to the cintripatal (I don't know if that's spelled right) force and warping the internals...which means KABOOM!!! Some shops also reccomend using machined light weight rotars to reduce the force being pushed outward, you also need to have the intake and exhaust ports opened up enough to support more flow. By raising the rpm redline you may be able to eliminate a shift point. Right now you may need to shift into 4th gear (hypathetically speaking) before the finish line. By raising the redline point you would be able to take the car futhur before shifting and may only need to shift into third which would eliminate the time it takes to shift. Also, as the rpm level rises past the stock redline the power level rises drematically, of cours that is only if you have a turbo capable of flowing enough CFM to not choke out. So...If you could raise the RPM redline, your car would performe better in a racing situation than it would stock provided it has the right modifications to support it.

[AreaT51R]

Originally Posted by dayna240sx

Why are you guys making a big deal about 225K miles? Its not that uncommon.

Bull Shit it's not uncommon! Most RX-7's need a motor rebuild at around 80K miles. Your dad must have driven like a grandmother!

[AreaT51R]

Originally Posted by Jims5543

You dad gives you a car he bought new and obviously took very good care of foe almost 20 years and the first thing you want to do w/ it is beat the shit out of it at the 1/4 mile track.

225K miles in a rotary are not uncommon. My buddy has a '88 turbo that has 250k miles on it. His DD is a 87GXL w/ 160K miles on it. This misconception of our engine blowing comesfrom people:
A. not taking care of them
B. beating the shit out of then and not taking care of them
c. modifying then and not tuning them correctly
d. pushing them past their limits when modifying them


Consider this, it has what? 145 HP in it N/A for then a turbo is added and it makes close to 200 hp. My TII makes over 400HP it has more than doubled the cars intended HP rating. (or close to tripled the n/a)
But, to some 400+ HP is not enough they need 600 or 700. Guess what? They rebuild a LOT of engines. To get 400HP from a 1.3 litre engine is amazing to me. Some feel the need to find the envelope. Unfortunatly it has caused the rotary to get a bad rep.

I Agree. Most people drive it like they stole it! Pretty much, every car I've found for sale that has over 85K miles on it has had a rebuilt motor. Yes it's a missconception that the rotary can't last that long but anyone that tells you that it dosn't require more care and maintanance to keep it going strong is a fool. Rotary engins ARE more delicate than piston engins...all it takes is a hint of detonation and you're done. Anyone dissagree?

[dayna240sx]

Yes i disagree, you are being far too ambiguous. IT is ture that many 3rd generation RX-7's need a replacement engine around 80K miles. Mostly due to poor-break-in, and heat issues near the rear side housings where the turbo's are.
and yes to TURBO rotaries detonation is far more serious than to other types of cumbustion engines..

However, when you step into the world of N/A rotaries it is a completely different ball game.
there are many many VERY high mileage N/A rotaries out there. I've personally owned an 87 sport model with 236K, and an 85 GS(L) with 186K


To answer some questions here concerning high high he should rev his engine.

For example in my WRX. peak power is at 6000 rpm.. in first gear however i shift right about at 7000 rpm not because there is more power there (actually less) but when i shift into second i am already in my peak power band.
He'll simply have to experiment with his specific car to see when his shift point will be.. In all my RX-7 race cars I have taught myself to shift when i hear it beep at me.

Quite to the contrary, driving a rotary like a grand ma will only harm things, Rotaries do not like being lugged (driven and low RPMs) they need atleast a 6K rev nearly everytime you drive it.

To add to this point how high he would rev his engine has nothing to do with engine management.. the stock engine management will properly map his n/a engine to well beyond 8K.

The problem would be his stat gears and older bearing.. the higher you rev a rotary the more stress it puts on these parts. in the range of 3500-3750 RPM you are putting the least amount of load on these parts, even less than at idle. 6750 RPM you have less load than the rest of the range from 5500-7500, then at 10125rpm you have less load than 9K rpm.. as you can imagine it is a non-linear scale.
Formula 1 engines rev to 16-17K RPM.

I have personally built a 13B that would goto 13K. with hardened bearing and stat gears it was fine.. it was also p-ported so it could breathe far past the usual 6-8K rpm's a stock port utilizes.

Welcome to the forums! AreaT51R, please be less ambiguous when you make broad statements about rotary reliability.

[ShortyDTP]

Is it true p-ported don't last that long?

[J-Rat]

Originally Posted by AreaT51R

Bull Shit it's not uncommon! Most RX-7's need a motor rebuild at around 80K miles. Your dad must have driven like a grandmother!

My 87 N/A went 212,000 on the original motor. I should know, I was there when it was purchased in 87.

[Soyo]

Originally Posted by ShortyDTP

Is it true p-ported don't last that long?

from what I hear, they have very short engine life, the shortest of all the rotay ports. a J port is said to have a life span of 6-12 months, and the P port is supposed to be even shorter... if your wanting to keep your engine for awhile go with nothing more than bridge port I'd say