20b single turbo choice
 

***mods dont move it yet ,please.
this forum gets alot of action.***
T66 was the first thought
t72 ported to a t74 is where im at now.
its called "PLUTONIUM TURBO " @ http://www.mjmturbos.com/
...with a goal of 6-800whp i think this can be done. I know this car is not going to be streetable w/ anything over the min. 3bar (about4.5 psi) with almost any single turbo setup.
the t72-t74
http://www.mjmturbos.com/images/KICKASST72T74.jpg

have you looked into a turbonetics t76

Ill be going with GT42R for my 3-rotor.. Sean (A-spec Tuning) is obviously making me a manifold for it..the GT42R single turbo kits for the 20B's will probably be for sale this summer

good luck!

Steve

Sweet...just in time for my 20B project!

Re: 20b single turbo choice
 

What to you mean by 3bar (4.5psi)?
3 bar = 43.5 psi
Are you planning on running that much boost?!?
Unless you are race porting the engine, why won't it be streetable?

he said .3 bar

gt42r kit! hmmmm. that sounds good to me and good timing also

GT42 is a monster, wont its be laggy ? (yeah i know its on a 3 rotor, but still!!!!!) Then again, maybe it will still get good boost response. Why not a GT40R with the 88 trim wheel? (the big one) Wouldnt that be a fast street turbo on a 20B ?

People have run the GT42R jsut fine on 13Bs, I see no problem with it being on a 3 rotor, probably would spool really good. What wastegate that is big enough to control the boost for that turbo is going to have a spring for 4.5 psi?

the 4.5psi is going to be for breaking it in then stock boost (.5bar) will be used until a tranny upgrade is done

also
any vendors to recommend?
the gt42r seems to be a bit large when comparing it to the t78's.

the t66 will make 515 rwhp and is a bit on the small side but would be very driveable...

i noticed you mentioned mjm... i had some dealings w them last year (2 turbos) and would not ever deal with them again.

i suggest you call kevin draper at majestic turbo in waco tx. i have previously mentioned him on this forum. kevin is above all a racer. he built the turbos for the Racing Beat Bonneville RX7, the fastest RX7 on this earth.

kevin not only is familiar w the rx7 and all the usual turbo hardware but he has come up w some additional mods (how about taking 4 ounces of the turbine wheel for instance.... or his bullet hub for the compressor wheel which increase flow a bunch)... very fair as to pricing.

he has a suggestion for you on the 20b. my friend has a 20b fd w a t66 and kevin is planning a diff turbo for it.

as i always say, i am sure there are other good turbo shops but i know Kevin is the real deal. as to mjm, i would be very cautious, ask your guy if the turbo will be built in Buhl Alabama, get your track shoes on if it is.

howard coleman

Just fine is a vague description. Full boost at 6000 rpm may be "just fine" in one persons book, but thats unstreetable in mine.

Who uses a gt42 on a 13b? If we knew hard numbers on how it stacks up on a 13b, maybe it would be easier to guess how it would work on a 20b. I have no doubt that a 20b would spool it, but the question is WHEN?

Magnus Motorsports runs a GT42 on a 13B (540 rwhp streetported) with good results. He had posted some information on spool time, specs, etc but I'm not sure which threads those are in anymore (somewhere in the Rotary Performance forum).

It could be a near perfect turbocharger for a streetported 20B if the specs on it are suitable.

note: it said min. 3bar, so i thought it meant minimum 3 bar, not .3 bar. typo, but i should have caught on anyway. :)

https://www.rx7club.com/showthread.p...highlight=GT42

Heres a quote about their GT42 that is using a smaller turbine.

"We went out for some roll on tests just now.

listen carefully:

From a roll starting at 1000 RPM in 4th gear, full boost at 3700 - 4000(14psi) 7 psi by 3000 RPM.

this is a mild street ported engine."

Thats with the larger turbine that I think is still smaller than the smallest turbine offered with the GT42 from Garret. The kit is from Magnus Motorsports. Keep in mind this turbo isnt efficient until much higher boost so if you are only going to be running 15psi or so, it would be a better idea to go with a GT40R, but if you want to run 20+ psi the GT42R would be a killer turbo for a 20B.

:)

that GT42 info "ice mastr"...
7psi at 3000rpm? AWWWW boo hoo that's on a 13b single turbo setup. :( You mean im going to have to deal w/ 7psi coming in sooner? Oh what a freak'n shame!!! (20b setup)
more info...GT42 vendors and housings your refering to.

Excellent answer!

I was kinda thinking that a GT40R with the 88mm wheel (which is like a greedy T88 i believe) would be an awesome "15 psi and lower" turbo. GT42R is the "above 15psi" turbo for the 20b that would crank out big numbers....

Anyone else care to comment?

order a gt42 from www.magnusmotorsports.com marco has just the thing for you :)

Gt42R would be a good choice I can set it up to be exactly how you want it if interested.

-Sean

GT42R 2700.oo not worth it if its going to cost me that much. remember 1 bar max. more will be impossible to make down the lane

You know I feel the same way you do. I too was thinking about the GT42R for my 20b but if it's only good for psi levels higher than 15psi, then I'll guess Ill have to find something smaller and more efficiant at lower boost levels. I could care less about hp bragging rights. I'm trying to build the all around perfect street machine, not a dyno gueen.

im with you t-von, streetability and hp curve is more important to me than peak hp. That makes the GT40R-88 seem like its a pretty good match for the 15psi and less crowd ( i could be wrong on this one).

Im pretty much locked on a T76 at this point... clipped,lightened balanced,bullet tipped...if i feel the need for another turbo just shoot me.

i wish i had a 20b but to expensive

Wouldn't a T-51SPL work just fine as well?

Zach

I recently bought a 20b cosmo and was going to overhaul the engine and put it back in the cosmo with a bb t51 r kai. Just after I pulled the engine I bought a full tune 20b fc. It has a t88 33d on it. The engine is completely normal with 13b exhaust housings. I drove it the other day and never driving a car like this before it took me by surprise. I was to busy watching the road to look at anything else but it was very responsive. Nothing like what I was expecting. Full boost was 1.4 and I didn't rev over 6500rpm's. I know it's not much help without actual full boost #'s but I thought i'd throw that in anyways. Also first and second gear where useless under boost. Whats anyones thoughts on the t51 r kai? Thanks.

-Destin