Pedestrian X

Just liek the title says, I was just wondering what mods internal/external would need to be made to run around 11-13K redline. like stationary gears? balancing? clearenceing? E-shaft strengthening what else to make it as reliable as possible? And this isent for constant high RPM like race car but just average usage.

1rx7owner

Alot of money.

Pedestrian X

thanks for you contribution.

fatboy7

Seals. Past 8500 the stock one won't cut it. I won't claim to know much about the different seals available, but I know that seals is what will ultimately detirmine the effective redline (ie, not just will it rev high, but how long will it rev that high before it causes appreciable damage). Balancing, and clearancing is a must. Stationary gears most likely, but the seals..... to get any good use of the engine.....

O 16581 72452 5

Bridgeport makes for the highest redline while still making power, street port for about a 10.5k redline... a header will make the powerband last until 7.8k

WackyRotary

Porting determines what your redline will be. What is your rational for throwing a number out like 13Krpm?

The lower you can rev it to and make the engines max
power, the longer it will last, and cheaper it will cost to build internally. Going to a bridgeport is were carbon apex seals become nessessary since the power is built 6-9000rpm, so I hope you have at least that extent of porting.

I can't see any reason to rev to 13krpm except on a mis-shift on a full race perpheral ported engine. Even these engines power peak fall off by that rpm.

MikeLMR

I would have thought even a PP would start to drop off in power at that sort of Rpm. As a guide the power band for the 4 rotor used in the 787B dropped off at 9000 ish Rpm.

I imagine you can get a rotary to run that fast (you can get a piston engine to >18000rpm FFS) what would be involved is another matter ... lighter rotors ? stronger E-shaft ? bigger/better bearings? Huge ports etc. etc.

Mike

O 16581 72452 5

I meant 8.5 with a streetport i know it's not 10.5.

Rotortuner

Most PP engines run up to about 10-11k But not mutch past that. The pp12a will runa allright to 11.5 but then fall off drastically. There is really no point in going past 11.5 . I have heard of some wild mega bridges that run up in the high revs too. Once you start revving that high the shafts start to flex and the rotor tips can touch the side plates plates. The 2 rotor engine will pull higher rpm sice the shaft is shorter therefor decreasing the chances of flex. This is why 3 and 4 rotors are rarely used as a high rpm road race engine, with the exception of the 787b which had mega bucks put into it.

CJG

Pedestrian X

i was just curious.

fatboy7

Also remember that the 787B was designed to be a fuel saver, and last the whole 24 hrs at high rpm. Its lowest BSFC was at around 6k. Its varible telescoping intake was tuned for opperation from 5.5k to 7k or thereabouts. Mazda went to a four rotor, cause they couldn't build a turbo 2 or 3 rotor to be reliable enough, or it would be a gas hog. I'm sure they also played with high rpm NA 2/3 rotors, but they have shortcomings as well.

abeomid

Well since you asked for it,

Peripheral Port is needed for sure.
Carbon or Ceramic Seals (3mm).
Hardened gears.
Race pump with really high pressure (dry sump)
Flywheel and clutch assembly that will take such a high RPM (will cost you a fortune)
Tranny that will take such high RPM (will cost and arm and a leg)

So overall you are probably looking at over $20G. and that is probably 10.5-11K RPM, u won't be making too much power over 9500 but u can rev it that high so u don't need to shift.

Wankelguy

The old 10A motors would rev to about 10K pretty easily. Maybe start with one of those and a garbage truck full of money. Or you could just hang your head out the window and make a really high whining noise.

KYPREO

OK....there is a race car in Melbourne that runs a 13B BP built by Rohan Ambrose who is THE natural aspirated rotor guru. He owns Guru Racing, which you may have heard of.

His Improved Production class BP makes 313rwhp@12K rpm or so. This engine is WAY MORE powerful than most PPs out there. Due to class restrictions, he can't run PP. It is running almost 400hp at the engine.

Basically, the port specs are secret as is induction, but you would need quad throttle body injection, with tuned, preferably adjustable intake runners to be able to fill the chambers at those rpms.

Then for the engine, you will want a billet two-piece eccentric shaft, isotropic finished, which is a process that gives the surface a polished like finish - basically all the parts are finished with that. Stationary gears, you will want CUSTOM gears...hardened s6 gears is not enough as the gear profile is still poor and cause harmonic problems. You will need better seals for sure. You will need lightened rotors, which have been clearanced, and you will want the whole thing balanced. You will want a BEEFY dry sump system, as the factory oil pump will foam up the oil very quickly at those revs.

You will need a chromemoly flywheel and ultralight clutch. You will need a box with dog-cut gears which have also been hardened. You will also want a lightened tailshaft.

You can make power at 12,000+ BUT this car doesn't usually use those revs in races obviously. You can build a car that will do it, but you will need all the right gear, Guru makes it all and does a lot of its business in the States....

Check out their website:
http://www.gurumotorsports.com/

j9fd3s

iTrader: (3)

the racing beat imsa gtu cars had a redline of 12,500 in 1981. theres a car and driver road test of it

mike

KYPREO

For those that are interested, here are some pics of the engine and the SERIOUS intake.

j9fd3s

iTrader: (3)

that there is right sexy

mike

KYPREO

Also I should point out that 12,500rpm was not the redline, it was where the dyno run ceased, in other words it is a peak power figure, but it was still making power, and the torque curve was remaining flat. Even with all that hi-tech gear, you wouldn't want to keep it above 12.5K rpm. It had accidentally seen 14K apparently, but it was only there for a quick burst.

GtoRx7

iTrader: (5)

All I can think to say is- "Damn"

hybridracer

Your also going to want a ballistics blanket or a shatter sheild for the flywheel. Id had to see one shatter on you at that high of an RPM. Needless to say you would probably be torn to shreds.

KYPREO

Ditto!

This is also part of the reason you want to lighten your flywheel and clutch. To give you an idea of how light, the Guru engine's flywheel and clutch weigh a total of 16lbs (flywheel AND clutch).

Someone in the same racing series had a flywheel go through the bellhousing, and it almost sheared his legs off

Keaponlaffen

is it just my imagination, or did no one mention clearancing the rotors?

KYPREO

I said it!

Lt. Dan

Here's another way: Remove rotary engine, install Hayabusa Motorcycle engine. More horsepower, and you'll get your 13K rpm.....

Dan

Pedestrian X

wow, thnx. i dont really want a 13K redline, i was just curious as to what it would require. thanks everybody :]