agh, im gonna pull my hair out finding this stuff. anyways, can anyone give me the stock specs of the 20b...heres what i need.

volumetric efficiency
good running compression ratio
operating RPM range
optimum fuel(91 92 93 98 100 etc)
etc

 

WHY?

Stock rotor compression is 9.0:1.

You cannot use formulas that utilize piston engine displacement.


-Ted

 

StealthFox,

Interesting question.. Sounds like a newbie wanting to be smart.. or someone who never owned a rotary car.

My favorite question are operating RPM range and optimum fuel(91 92 93 98 100 etc).. Youve forgot 94..

Just giving you a hard time..

Goto Evil Aviator's sticky..

 

wow, thanks A LOT herblenny, if you are to criticize at least give good advice/ a good reply as his thread didnt contain those bits of information.

anyways, i never did say i know anything, or did i attempt to, im gathering information... i am a newbie in need of help. ALSO, i never said i owned a rotary car...

ALSO, i need the stock engine horsepower...i believe it was around 270 or something?

 

Wow, Too much drama.

 

You can say that again! Good luck, because you will really need it.

I have been unable to find VE numbers published by Mazda. Please post them if you can convince Mazda to give them up. VE varies with rpm and load, so you would be looking for a chart rather than a single number.

Same as a 13B. See Chapter 1 of an 86-On RX-7 Factory Service Manual for the procedures and corrections for a compression check.

Stock redline of a 20B-REW as installed in a JC Cosmo is 7,000 rpm. I think the idle rpm was the same as a 13B.

All I have been able to find is an unofficial Cosmo owners' website specifies "Premium". If you find an actual number for the JC Cosmo minimum octane rating, note that you will need to convert the Japanese RON into the US PON.

The Cosmo brochure lists 280ps @ 6500rpm, 41.0kg-m @ 3000rpm (276bhp @ 6500rpm, 296 ft-lbs @ 3000rpm).

 

Evil Aviator.

to you.

 

Just read through the "Cosmo owners manual" & its says the following............

"Regular or Premium unleaded"

REgards

 

thank you

 

That will be quite a disappointment to those who like mid-grade.

 

not to mention if your running a larger turbo too heheh

 

Well, I have a paper with some VE numbers they were playing with on PPort motors, but yeah. Of course, if you had a torque curve of an NA motor it wouldn't be hard to compute VE at varying RPMs at WOT, but I haven't seen one of those either.

 

Could you post that on the forum?

Wouldn't you also need corresponding BSFC and AFR numbers?

 

Don't have the paper in postable form right at the moment... have to dig it up and scan it. It comes up with some interesting numbers though for what happened after they optimized port timing (and come up with timing numbers I've not seen anywhere else)... and then considering they start looking at the effect of variable runners. And that it was published in '91.

And yeah, BSFC and AFRs would be necessecary to be exact, but you could make some assumptions from other rotaries and come up with data that's pretty close. Or at least useful.