Rotortuner

hey thanks for posting the pics, I haven't seen those pics yet. Looks very interesting. So is there no IC on that or am I not looking close enough? Any ways do you know how much HP he is pushing?

CJG

rxrotary2_7

he uses NOS. i dont know how much he is pushing...but i would imagine somewhere close to 1kHP.??? each rotor housing has 2 injectors plumbed into the housing and an additonal 2 along the intake track. that 4 injectors per rotor.

Evil Aviator

Hey, no problem. I don't care if you were being ignorant, or if Blake is the King of France, I just want to know where to get a complete 13G w/ECU for $30K. :p

I'm kinda like Cookie Monster - no tact, no intelligence, no good looks, no talent, but you can bet the farm that I'm always after the cookie.

T is for Three-rotor, and Three-rotor is for me,
T is for Three-rotor, and that's good enough for me...

PS: And it would also be really nice if someone could tell me where to get an adapter plate for a T-56 so I don't have to spend $7K on a "real" transmission.

Jeff20B

iTrader: (13)

Hey Evil Aviator, Do you happen to know what gives the 20B its unique sound? Is it the 120º offset of the rotors when they vent out of the engine?

I ask because when one of the rotors in my 13B misfires, it can be heard as bass(my exhaust is quite open and I can hear any little misfire). The reason why is due to the 180º offset. It is like a woofer box with one speaker hooked backwards. The bass is canceled out, and this is how all two rotor engines run.

What happens when you're listening to a speaker box where one of the woofers are hooked backwards, and then you unplug it? The bass sudenly becomes louder. Then when you hook it up correctly, the bass gets even louder. Both woofers are in phase.

So what gives the 20B its beastly exhaust note? The 120º phasing? Anybody know for sure?

Evil Aviator

I don't know for sure. My guess is that it is mostly because the extra exhaust pulse of the 3-rotor would add to the cadence, which would also be a bit smoother due too the better balance of the 20B. I think that the sound of your misfires is based more on the exhaust gas velocity, the diameter of the exhaust ports, and the diameter & length of exhaust pipe. If you think of the whole system like a musical horn (trumpet, tuba, etc), with a mouthpiece the size of the exhaust port, and piping and bell the size of your exhaust pipe, then you would expect a very low tone. I don't think that there would be too much of a phase effect because, unlike your dipole speakers, the exhaust pulses do not happen all at the same time. Hmm, I guess that there would be some phase construction/destruction in the reversion wave, though.

Anybody else have ideas?

peejay

I think Blake and CJ are two diff'rint people.

So it's no big deal to run a turbo engine minus the turbo then, eh? Hmm... well that gives me an idea, but that's for a different thread.

HWO - Racing Beat sells a 20B conversion kit to convert a S2/S3 electronic distributor, it costs something like $500USD, I don't know the US-AUS conversion right now... But looking at the kit, it looks VERY home-fabricated, except for the reluctor, it looks like something I could make for pocket change and a little time. And could probably adapt a reluctor from a 6-cylinder junkyard dizzy...

Alternatively, couldn't one fire the leading and trailing plugs at the same time, use dual-post coils, and an electronic system set up for a V6? Probably not ideal but it'd work, no?

Jeff20B

iTrader: (13)

Yeah peejay, it'd work, but it would not be ideal. The last time I checked, the RB 20B dizzy kit was $550 US.

Thanks for your response Evil Aviator. I think each exhaust pulse of a 20B has a tendency to partialy cancle out the previous pulse, and then partialy amplify the following pulse. This is what gives it that growling sound. Or I could be wrong.

So, does anybody else know why the 20B has such a wonderful exhaust note?

Evil Aviator

Yes, all of the road racing 20B engines that I know of run in "V-6" mode, and fire both the leading and trailing plugs at the same time for more power. As far as I know, most everyone who races an NA 20B uses the lightened 9.0 rotors, so obviously the stock-compression rotors work just fine without the turbo. Here is the typical Rick Engman setup:
http://www.motec.com.au/drawings/m41.pdf

I will be using a Wolf3D 4.0 in "V-6" mode with my 20B, firing the plugs simultaneously just like everyone else. I am using a 20B crank angle sensor modified for the Wolf, which requires some of the teeth to be ground off - no big deal. I don't know what's up with the RB unit, but I like mine just fine.

Jeff20B

iTrader: (13)

The RB dizzy kit allows you to have a true Leading/Trailing split if you want. But it still has to fire through a cap and rotor, and it still only has single Leading sparks.

Boostn7

Yep ! that's Sammy's car with that PP 20B running alcohol and a huge Turbo !!!looks like a T-100......BIG !!!

He used to have "Zapco" written on the side.

Car is beautiful and well built....made 1080 RWH awhile back and ran something like 7.7x or 7.8x@ 178mph...saw the timeslip myself.

He owns a shop called Mothers on Rt 46 and that's were I go use the dyno.

Later,
John D.

weaklink

Hey Evil Aviator,

if you ever run down a lead for a t-56 adapter, could you let the rest of us know???

Blake

If you've ever ordered from Mazda Comp, you'll know PNs are unnecessary. You just tell Steve, "I need the whatchamacallit next to the thingamajig." Those guys read minds and can find anything. Don't know if they'll sell a 13G to just anyone, but they are available.

Blake

Well, I'm not CJ (PP13BNOS) nor the King of France (though I've been told I do posess 'regal' qualities). I do own a 13B PP, which is in a project car. I am also a friend and business associate of Rob Golden (Pineapple Racing) and the creator of Rotary Engine Illustrated. I also recently wrote an article for New Zealand Performance Car on porting rotary engines, and will have one of my former project cars featured in the next issue of Grassroots Motorsports. Are those proper credentials for this forum?

As for an adaptor, why don't you just get one fab'd? And what "real" transmission do you have in mind as a substitute. Hopefully, you don't mean a dog box, like a PBS. Dog boxes do not belong on the street. Just my $0.02....

Evil Aviator

I don't know of anyone who has successfully fabricated one, and I really don't feel like contracting out ANOTHER custom part for my car. One of the leading transmission adapter businesses in the US wanted my friend to make one, and have me test it for them on my car, and then give them the results. I think I have enough "test" components on my car to worry about as it is. The PBS is out of the running because it can't handle the torque. I'm still considering Jerico, Zanes, Hewland, and T-56. The prospects for the T-56 are fading fast, though, because everyone I know who uses it misses 3rd on a regular basis. Supposedly there is a hydraulic fix for this, so I will see if it works when one of my friends tries it out on his Corvette. Hmm, I wonder if Soul Assassin knows that dog boxes do not belong on the street?

Since you know all those important and impressive people, why don't you write a stroy about all the 13G engines hidden in the secret Mazda Motorsports vault? This would be a very interesting story, and would clear up the myth that the 13G hasn't been available for about a decade now. I think that a lot of us would like to know when they will be released (like a time capsule?), and what the credentials are for getting one. I realize that I'm not important enough to get one now, but hopefully my clout will increase because maybe my post count will be high enough by the time one is released for sale.

Thanks for the advice on ordering parts. Some day when I know enough important people I may be allowed to order something, and now with your help I will not sound like a newbie. Thanks!

Scott 89t2

20B carb pics

http://www.1300cc.com/indy/jack13.jpg
http://www.1300cc.com/indy/jack01.jpg
http://www.1300cc.com/indy/jack06.jpg

http://www.1300cc.com/indy/jack02.jpg

j9fd3s

iTrader: (3)

Thanks for the advice on ordering parts. Some day when I know enough important people I may be allowed to order something, and now with your help I will not sound like a newbie. Thanks!

not that i know anybody, but if you were important enough they would come up with a 13g, i'd rather have a le mans 4 rotor though...

mike

Fc3sracer

Hey dont forget my favorite racer rafelito. He runs a two rotor bridge port with blow thru webers and nitrous hes in the 8's. Im thinking of putting blow thru's on a 13bt can anybody give me some advice on wether this is a good idea or not. I know where to get the carbs but im not sure how good this setup would be.

rxrotary2_7

i dont think anyone "forgot" him, no one mentioned him because the title of the thread was 20b carbed. for info on that, you may want to contact pac racing in Aust. they have a site, but i forget the address. they do a drawthrough system i believe and run 8's

faster7

I LOVE the duct tape on the "plenum." What I wouldn't give to have a racecar like that in my shop.... :-)

And just MAYBE Mazda will someday sell a 3 rotor car in the us....NA 20B Renesis would be just fine with me!