Hey, all you out there with 20Bs, how much boost are you running? I was just talking to someone that said that you cant really run much more than 7PSI without getting alot of flex in the eccentric shaft, on a 20B.

 

Whoever told you 7psi must have been pulling your leg. Something like 27 psi sounds more reasonable. 7 psi is actually less than the STOCK boost pressure.

I can't answer your question as to how much a stock 20B can handle before eccentric shaft flex becomes a problem, but if I had to throw out an "educated guess" I would say definitely higher than 24psi. (assuming stock RPM limit)

 

The e-shaft flex has nothing to do with how much boost you are running. It has alot more to do with the high hp #'s. Remember 24psi on small turbo will be completely differant than 24 psi on a larger one.

 

I'm runing 15-16 psi right now with a T76 on the stock port... I'll be putting together my other poted engine soon and should be runing a max of 20psi, but I probably won't need over 13-14 if I wan't to be able to control the car..

 

I am getting 9 to 10 with the stock turbo's
stock porting etc.
matt

 

Tell us who this person is so we can avoid them...


-Ted

 

mine runs 7psi right off the wg spring....

 

14 psi on GT-40 turbo currently making 470RWHP on 91 pump gas.

 

1 bar (14.7 psi) with stock turbos. However, that falls off a bit, since the stock turbos just can't keep up with the demand.

 

yep that all makes alot of sence. You guys have restored my faith in building a 20B FD.

 

Ha ha ha ha. Thats a good one. Did he explain how how the shafts still hold together when they have 30psi pumping through them at over 1000hp.......???

Back to reality. I am running 12.5psi front turbo, 8psi rear. Or at least thats what the sticker says on the RE-Amemiya ECU I just got from Japan.

Installing into the Cosmo on Friday. Pics & story from the dyno session to come.........

 

id like to hear more about the RE ecu!! that is one route that im considering taking. what other mods will you be running besides the RE ecu?? thanks, heath

 

I too am very interested in hearing more on these ECUs. Which one did you get, Dave, and what are the changes it supposedly makes? I couldn't glean much info from the RE-Amemiya site due to the dodgy engels when translating through babelfish.

 

not to sound stupid but is this ecu better than a stand alone ???

 

I bet that turbo is awesome for street use on the 3 rotor engine!

How soon do you get 14psi? I bet its practically right away!

 

1 bar (14.7 psi for guys who don't do bars) with the stock turbos. However, boost falls off after about 6200 rpm in the upper gears.

 

Hey George, care to share any info on your ownership experience with your 20b? How many miles have you put on since the conversion? How reliable has it been ect?

 

Sure. I've got about 45,000 miles on it. It's more or less a daily driver. (I usually don't take it when there's snow or rain, since a convertible just isn't as much fun in that kind of weather.)

Reliability has been equal to or better than the stock convertible and substantially better than the 3rd gen I used to own. The motor, itself, is like an anvil--can't break it. The only 20B-specific problem was a failed crank sensor for one of the Tec II units. Even though the car had about 38,000 miles on it, at that point, Peter Farrell replaced the sensor at no charge.

I can handle these maintenance costs.

Things that are not specifically 20B issues, but are related to the conversion:

I thought I was having a serious design problem on the cooling system. It turned out that only one of the three fans was working. Soldering the junction box where they came together solved the problem. The temperature stays a nice 192 degrees now.

The differential mount keeps breaking. I have learned that someone (Mazdatrix, I think) offers a competition upgrade. The next time I need to replace the mount, I'll try one of those.

The rear tires seem to wear out pretty fast. Considering that I don't do any drag racing and generally make an effort to NOT spin the tires, that's annoying.

I suppose the big news is that there isn't much news. I like that. When Peter and I were discussing design criteria, we agreed that reliability had to be at the daily driver/stock vehicle level. Giving credit where credit is due, Peter and his (at that time) employee, Mitch Piper, did an outstanding job of making a solid, reliable upgrade that is all smiles and no problems.

 

so how many HP are you putting down with this reliable setup? care to give us the skinny on whats been done to the motor? im glad to hear the 20b has been reliable and im happy to see that youve already put 45K on it!! thats super! it gives me hope -heath

 

The motor and turbos are stock. The motor was rebuilt by PFS prior to installation. Engine management is handled by twin Electromotive Tec II units. (one Tec II couldn't handle the number of controls for a 20B. A Tec3 can.) An Apexi boost controller is set to 1 bar, which "overdrives" the stock turbos quite a bit. However, given the acceleration, the period of time they are overdriven is fairly short.

On the PFS dyno, we got 368 hp and 425 lb./ft of torque at the wheels. Allowing a 15% drivetrain loss, that's about 427 hp and 478 lb./ft at the flywheel.

Many in this forum will wail and gnash their teeth over the "lost opportunity" to get 1000 hp. I have found that with my current capability, I already go from zero to illegal in a heartbeat. For street or autocross, it's like going rabbit hunting with a bazooka. On a road course, I can go way faster than my brakes will ever survive. It is sufficient to my needs.

With that said, IF no one buys it by June 1, I'll just be forced to keep it...and improve it. (sound of maniacal laughter) No specific plans, but a big brake kit and a Tec3 would make it pretty close to perfect. In another 100,000 miles - whenever the motor finally needs a rebuild - as long as the motor's apart anyway, porting and adding a big single turbo would be cheaper than buying a new car. Right?

 

i agree with that. i like my velvety smooth big motor, it just feels like its not working at all