Latest update: I am corresponding with Steve Kan, owner of Gotham Racing. He is checking with BNR to see what they can do with the HT-10. When he gets back to me, I'll post the results here.

You're absolutely right about saving the cost of the custom manifold. While the upgraded twins probably won't have the peak horsepower of the big single, I don't think we would feel terribly shortchanged.

 

My thoughts exactly! Plus these would spool-up much faster than a big laggy single.

 

Chuck the twins - they are a piece of **** designed for low end power and don't flow very well at high RPM's.&nbsp Either go single turbo or triple turbo...


-Ted

 

RETed a 20b conversion doesn't have to be any more expensive than it already is. You make it seem like the stock twins on a 20b are incapable of being properly upgraded. We undstand that they were never designed for high boost and don't flow very well. Please share your experiance! Is it the turbos themselves, the manifold, or both? Also do you feel the same about the stock twins on a 13b?

 

still looking forward to this

matt

 

I took the pic today because i got my turbos back on after i rebuilt them so tonight i will try to post them.

 

It depends on what your idea of a "project" is.&nbsp I think my idea of a "20B project" is something that will at least make 600hp...to the wheels.&nbsp I find anything less than that to be a "waste of time and money".&nbsp Why?&nbsp A 13B is fully capable of producing under 600hp.

There is an SAE paper http://www.sae.org/ that has a pretty good write-up on the Mazda sequential twin-turbo system.&nbsp Although it's more geared towards the FD3S 13B-REW turbos, the Cosmo twin turbos have very close similarities.&nbsp I do have an extensive Mazda service manual that goes into gross detail on how the Cosmo system works (there's an extra "stage" versus the FD3S 13B-REW).&nbsp If all that fails, it's just simple logic that tells you..."how do you divide 3 rotors into 2 turbos efficiently?"&nbsp It just can't be done.

I understand that there are owners out there who are looking or trying a "budget" 20B conversion.&nbsp I apologize my comments don't that those into account, as mentioned above.



-Ted

 

where did you get the parts to rebuild them?

matt

 

The Mazda/Hitachi turbos are based on the Garrett line of turbos.&nbsp Any turbo shop that handles Garrett turbos should be able to get parts to rebuild these Mazda/Hitachi units.


-Ted

 

As has been said, before, by many people, horsepower isn't all there is. From one end of the country to the other - literally (Peter Farrell and Jim Hagerty) - those who have gone to a 3-rotor say that it's a whole different experience.

One owner of a modified 3rd gen said, after driving my car, "It's like my car is working so hard, and yours is just taking it easy."

Speaking for myself, the 478 lb./ft. of torque produces sufficient thrills. The car goes from zero to illegal in a heartbeat. For a daily driver, the cost of getting extra horsepower would truly be a "waste of time and money", allowing me to qualify for a ticket 1.3 seconds sooner.

Each of us defines a level of desirability and acceptability. Sometimes that level is set by money (the budget conversions), sometimes by ego (The Black Car that PFS took to the Supertuner Shootout), and sometimes by some arbitrary, personal value (600 hp). As the popular saying goes: It's all good.

FWIW, if you want to set your goals high, Peter Farrell said that 1000 hp is attainable out of a 20B, if it's modified in the same way his 700-hp 13B-rew was.

 

Just for curiousities sake... how has PFS done their 700HP 13B-REW? Is there a link available or similar post?

 

You still havent sold your 20B Attila? Is it still up for sale (not like I am interested in buying it with the chunk of change that I don't have laying around)?

 

Ahhhh now I understand your point. But isn't that article only talking about its sequential operation? From what I understand, people who had done 20b conversions in other cars where unable to run the turbos sequentialy with an after market ecu. I think it had something to do with the 20b being only available with an automatic(can't remember). I guess that extra stage you where talking about also has something to do with it. Therefore, odviously I plan on running non sequential.

I just bought a 20b today for my 3rd gen(a "D" series 133). I should receive it some time next week.('') The goal with my project is to put down 650 reliable rwhp while being very streetable,reliable, and on a budget. Thats why I want to retain the stock twins(less fab work). Also I will do alot of fab work myself. If the guys at Pettit Racing can get 550 hp from slightly modified twins at 14psi, then I should easily hit my goal having BNR upgrage my twins to stage 3 spec with more boost. With these twins flowing like a big single and spoolin fast like sequentials, I will have the best of both worlds(A great looking car,tons of torque down low,and an exhaust note to die for). I love the 13b but, I can't stand their loud raspy exhaust notes on fully ported, open exhaust setups(which are needed for really high hp numbers). I would never be able to enjoy my music while driving. Oh and dont forget about that lumpy idle(no thanks). Like I said above SPOautos's 13b dynoed around 470 rwhp at 17 psi non-sequential, and is putting down similar hp #'s as Nocab72 with his big single. Also SPOautos car has all the bolt on mods and a "regular" street port. Just like Attila's friend said " Its like my car is working so hard, and yours is just taking it easy".





Trey

 

IIRC, a T-78 single turbo, porting and a hundred-shot of NOS. Go to http://www.pfsupercars.com/ select the link for "Race History", and scroll down to the paragraph beginning "As interest in the sport of Import Drag...".

Hope that helps.

 

No, I haven't sold it. It seems that everyone who wants a 20B really wants to build his own. This suggests to me that there are a disproportionate number of masochists among 20B wanna-be owners.

Yes, it's still for sale...for 13 months and 2 days (until the twins graduate). Once they are out of college, it's mine forever. Maybe I should advertise it as a "Limited Time Offer".

 

[gameshow voice] get it while they last, we've overstocked and must sell to the bare walls!

mike

 

Yeah, the stock Mazda exhaust manifold was optimized for low end power and at under 10psi.&nbsp This would be too restrictive for most people.

The stock Mazda/Hitachi turbos are just too small and restrictive.&nbsp Those who have gone big single (on a 2 rotor, mostly) understand how much power is "freed" when going with the conversion.&nbsp If you stare at the exhaust manifold and think like a has molecule, you realize that there has to be a better design than all those 90-degree passages. The 20B runs it's primary turbo from two rotors (front and center?) and the secondary gets it's own turbo - this is just bizzarre.

I don't know how many single turbo 20B owners we got here, but maybe they can chime on on how their cars haul? I don't suppose we have anyone who has experiences before-n-after a stock twin to single conversion?



-Ted

 

This is what the valve looks like i will post another pic tomorrow of were i put them.

 

i have a feeling that mine would be faster without the turbos, and there wouldnt be that 100+ pounds on one side of the car either

mike

 

Only one left!

 

A friend of mine has a 20B in his FC running a T76 on the stock ported engine. At 1.15 kgcm of boost he launches at 2750 rpm and the car goes like it was just shot off the catapult of an aircraft carrier. I just purchased a 20B and I will be porting and rebuilding it then doing all the mods needed to stick it in my FD here over the next few months by my self. I eventually intend to make 750 hp to the wheels, but I'm going to start out with a consevative 550-600 hp. Any links to mod's needed or installation of a 20B in to a FD would be greatly appreciated as I can fabricate just about anything if I've go a picture of it..

I've also heard of 450-550 hp ported 20B's running N/A over here in Japan.

 

Experiment away my friend. I may be following your lead because, I too will be doing most of the work myself. I need a couple more months of saving so I can buy all the stuff I'll need.

 

no problem, I'll take pic's etc as I progress.. I'm going to probably use the rear plate from a fd and open up the 2 dowel pin holes for the larger bolts. Then make FD mounts that will bolt to the stock location, but lift the engine about 1/2 a inch. I'm also going to tie the stock mount in to the intermediate housing stock 20B mount for increased rigity and use 1/4 aluminum plate on the oil pan to also reinforce the engine and keep it from twisting... I think all of that and the exaust manifold should hold things together pretty well.. I may sell the TO4 Manifold, Wastgate and T45S turbo kit that is on the 20B Cosmo I bought because I plan on modifying the T51R V-band manifold that is on my 13B right now.. I really like the V-band, one 10mm bolt and the turbo is off the car..

 

you ever take that other picture

matt

 

My engine is apart but i will try and get a pictures to show you where it go's