81WideMariah

iTrader: (8)

so here's the deal guys...starting the research for my new project, and i've been doing some searching but unable to find any hard numbers.. specifically i'm looking for the a/r and trim sizes that fellow members are using for there 12a carb/turbo set-ups. I'll be using a t3/t4 hybrid or just a standard t3 due to the ease of fnding parts and relative in-expensiveness of the unit itself. I'll be using a sidedraft set-up from Robert@Rotary Shack and intercooled running around 10 lbs for daily driving and 12 lbs for high boost runs also i'll be using a HUGE 24x12x4 intercooler so I need to take pressure drop into account.

Thanks in advance for the help guys, also if anyone thinks I'm off course with my choice in turbos i'm open for suggestions/oppinions.

13BT_RX3

A 12a is only ~11.8% smaller in displacement. A turbo setup to flow to 7000 on a 13B would flow to 7934 on a 12a. A setup for a mild 13B should work. It would basically operate the same in every way except the rpm operating points would be higher.

81WideMariah

iTrader: (8)

so... I'm thinking about a t3 with a 50 trim on the cold side and 48 a/r on the hot side... since this is not an all out drag car and I drive it every day i'm looking for the most torque through the powerband and trying to keep the "peakieness" of a big turbo away.... in summation quick spool, with good mid range, and peak horsepower is not important

Man_in_black49464

iTrader: (1)

The best swap is a DSM Stock Turbo, out of like a talon or eclipse + they are "a dime a dozen" so they are cheap and easy to replace if they break.
I think the mitsu guys call them the 14b turbo ???
I would go with a stock 16g turbo out like a 95 Talon they offer good mid range on the rotary, and are really easy to find.

81WideMariah

iTrader: (8)

i thought about going the 16g route too...just not a big fan of internal "flapper" wastegates... every turbo engine i've tuned that had one always had issues with boost creep...hmmm...what if i ported the wastegate....

trochoid

iTrader: (6)

Find an S5 turbo, have it rebuilt, they can be upgraded also and yes, port the wastegate. On the TIIs, porting the wastegate is an integral part of a 3" exhaust upgrade, along with an FCD.

Unless you want instant spool by 2500 rpm and be dead out of breath by 6k rpm, stay away from turbos from other cars. What has Robert recommended for your needs?

7SpringsMisfit

kinda off topic but what kinda whp are you expecting to get from the 12aT?

81WideMariah

iTrader: (8)

i was thinking about the s5 route too...just thought there may be something more readily available or cost effective... like we said earlier the 16g,14b, and t3/t4's are all extremely easy to find and relatively inexpensive, i mean you can find them on ebay all day long for just a couple hundred bucks... i'm curious though what's your reasoning behind turbos from other cars running out of breath at 6k? I figured that a t3/t4 that can operate at near 25 psi before it becomes volumetricaly inefficiant should have no problem pushing half of that with my desired 12 lbs of boost...the only drawback i could see is turbo lag from one of those big snails... i'd be interested to know what the specs on an s5 turbo are, and then i can try to match something with a similar compressor map.. you're also probably right on point about me getting ahold of robert, seeing as he is the guru of all things carb/turbo... but of course i've yet to contact him... i really like feeling out all the members of the forum first, i mean there's enough gray matter in this post alone to sort out more than a few problems, more so i kinda like to take the road less traveled... find a diferent way to acheive the same results, with the intentions of making it less expensive/ more efficient. if i can get an idea of what kinda A/R and trim sizes i need i can better sort this out.. i mean i could pick up one of those $500 ebay honda turbo kits with the intercooler, bov, turbo plumbing, etc.. sell the pieces i don't need manifold intercooler piping etc and probably walk away with a near "free" turbo kit... see where i'm going with this???

81WideMariah

iTrader: (8)

i don't think 225-250 is out of question... i do have some great supporting mods already..porting, flywheel, exhaust.. i mean i'm running deep into the 14's and have clipped the 13 sec mark twice on the set-up i have right now so i don't think 12's are out of the question with traction limiting of course... then again my car isn't built for drag racing, more for "spirited street driving"... lol, but the track is always a good benchmark to check the efectiveness of modifications...

7SpringsMisfit

ha not too shabby when my 12a is at about 115 id say

trochoid

iTrader: (6)

I'm not up on turbos,so don't take what I say as gospel. The exhaust flow from a rotary is so different from a piston engine, piston turbos are rarely big enough. For a TII turbo upgrade, it starts with a TO4B and goes up from there, discounting the hybrids, which are built with TO4B parts.

The smaller piston turbos can cause more tuning issues than a rotary specific one simply because of the efficiency ranges and heat generated. So what if a DSM turbo can push 25 psi, how much cfm at what psi/rpms is the key. The DSM turbo may supply enough cfm at 20 psi, where a roatry turbo may do it at 14 psi. Which one is the better choice? If your answer is the DSM because it's cheaper, that's the wrong answer. Why?, because the rebuild from detonation will cost more than buying the correct turbo to begin with.

Spend some time in the single turbo section. While you won't find a lot regarding the 12As, it will give you a better understanding og turbos for rotarys.

81WideMariah

iTrader: (8)

i get what you're saying trochoid...and hope i didn't come of condescending....i do understand that rotary exhaust is different in many aspects in comparison to piston exhaust, just didn't realize it to be that drastic o a variable aside from the temperature aspect... i think i will go piddle about in the single turbo section as well...i guess what i'm trying to accomplish here is getting lost...i just figured that we had more than a handful of guys here running turbo 12a's and i know they al can't be using the t2 turbos...just wanted some people to chime in with what they are running and the specs so as to help me along with my decsion..

trochoid

iTrader: (6)

NP, the figures I stated are not real, they are there only to make a point and not to be taken to heart. I have bought 2 turbos so far for may swap, plus the other 3 TII ones I have on hand, and none of them will meet my needs in thier present states. I'm looking at 900 minumum for a decent new turbo and that's for a journal bearing one. A BB turbo will cost will cost more than a full rebuild kit and all the parts needed to fab up the intercooler.

81WideMariah

iTrader: (8)

yeah...i'm sure that a bb turbo is out of my price range as well...just don't think it's necessary for my use..

bad 83

iTrader: (3)

I think you are setting some realisctic goals for yourself. On a stockport with a S4 turbo, you can clip the 225 at the rear wheels with about 12 pounds of boost. I personally didn't want to go with a S5 turbo, because I wanted to keep everything nice and tucked beside the engine. I have noticed guys mounting their turbos more forward and higher up, without useing the water port, and can't figure out why they have overheating issues. Anywho, here's my setup, and I'll say that snapping second with a posi rearend will definantly put the fear in ya! I am real happy with my setup, and I have room for upgrades later, if I deside to port the engine later.

http://www.youtube.com/watch?v=PNG6J...elated&search=

http://www.youtube.com/watch?v=ZIjR8...elated&search=

81WideMariah

iTrader: (8)

nice set-up, she sounds mean too... i like the fact that you've got turbo nice and low...and i have noticed the set-ups as you described with the turbos high and forward... now that i have someone chiming in that's running the type of set-up i'm thinking about... i might be able to get some hard numbers about your s4 turbo.. do you have any idea what size it is?(garret equivlent size.) what the a/r on the hot side is and the trim on the impeller...i have yet to hear anyone rattle anything off in that respect... if i could get an answer to those questions it would help me to explore my options better... i need a base to compare off of...we know that the s4 and s5 turbos work for the 12a..as they should seeing as how the 13b is identical to the 12a less the increase in displacement... and i refuse to beleive that there are no other similarly sized turbos out there that i don't have to buy used, are easier to find, or less expensive... also most any turbo should have no problem keeping up with the exhaust temps of any "healthy" running rotary... i feel like too that if we can get enough input on this matter and some good hard facts that this post could possibly become an archive.. as how this question must pop into the head of most 12a owners from time to time... i guess what we're trying to do is find the "most effective" turbo for a DIY turbo set-up... what ya think guys?

trochoid

iTrader: (6)

If you want the answers on the TII turbos, spend some time in the 2nd gen section. I have run across the specs posted there. I know ReTed has posted them before. Your question and where you are going with it comes up in the 2nd gen section frequently, almost as often as our top 3 newb question. lol.

You will find a great deal more info on turbos in general there than you will ever find here. Newbs who just purchased an NA FC want to turbo worse than the ones here do

I have an S4 unit apart, when I get a chance, I can get the general measurements of it.

Qbuilt

This would be great if it makes it to the archives.
I am currently running a 12a turbo myself and it is hella fun. Im using the s4 turbo/manifold with a 2" spacer(out and forward). Im using a weber 45 sidedraft which could still use a little tuning, but my car is still great for everyday driving and has tons of power. Im only running about 6-8 psi, non-intercooled, stock timing, well a little retarded, but still. Premium fuel and pre-mix and ive never had a hint of detonation. I also drive the crap out of my car. I dont know if you should really put all to much effort into finding other turbos/kits on e-bay. It just sounds like to much work. Besides the e-bay turbos DO NOT have a good reputation for reliability on honda civics, whats going to be the case when you throw some rotary heat at it???
S4 turbos work, spool at 2-2500rpm, make great mid-upper rpm power, cheap( i bought 2 and a manifold for $250cdn). Im sure you just really want to find a better way and im not doubting the possibility, but i really think its going to be hard to find a cheaper, more reliable, proven setup then the s4 turbo.

trochoid

iTrader: (6)

As far as the eBay turbos, stay far far away from the XS Power ones. The Master Power ones, made in Brazil, however, have been met with some very favorable success.

81WideMariah

iTrader: (8)

sounds like a blast i can't wait to start up my project i'm at the point were there's not much else i can do less tearing the motor open for bigger ports to make more power..and i just can't see myself doing that to an engine with less than 40k miles on it... i didn't realize that the t2 turbos can be had for so cheap, maybe everything is just a premium down here in Lil San Juan...(read Florida). I mean that I know of there arew only 2 junkyards in the whole central florida area that even have a couple rx7's laying around and they've all been stripped of any turboey goodness .. hence i guess that's why i'm trying to go the route i am. Granted I'm sure there's one or two members on here (trochoid, ahem) that would probably part with one of there turbos for a humble fee. But as testament to Trochoid's methodical ways...it is better to do it right the first time (and cheaper.) So we can considered this a bit of an instruction manual if you will...to help all those to follow behind.. i'l keep this thread going until i can find some hard numbers on the s4/s5 turbos and then investigate equivelants and post those nukbers there too... I guess it's important for us to all understand that we all come from very different parts of the world and availability of parts may be different.. also as simple economics go price is determined by supply vs demand.. and seeing as how i live in "the land of the rotor," the fabled land of quality gas, no emissions, and plenty of ricans to help you sort out any rotary gremlins, there seems to be a huge demand for said parts..i mean, my buddy paid 200 dollars for a set of door panels off a junk FC because he couldn't find any elsewhere... hope that puts my quest into perspective for you guys... also realize that i'm still a little ways out from doing this project and i'll be purchasing bits and pieces over the next couple months because i to am just a working slave to my hobby... so there is time for me to get the hard facts here for everyone that's following this thread to utilize..

[QUOTE=TROCHOID] Newbs who just purchased an NA FC want to turbo worse than the ones here do [/QOUTE]

LOL... i really ddn't think it was possible...I'm no noob...but i want the boost BAD!!!

Sgt.Stinkfist

iTrader: (6)

a while back, when i was searching on the same question of turbo sizing, i came a accross someone in the 2nd gen section saying that a stock t2 turbo is pretty close to a T4/T04 w/ a 1.00 a/r exhaust. hope this helps

Siraniko

iTrader: (13)

size = in-between a T3 and T4.

81WideMariah

iTrader: (8)

sooo..then a t3/t4 hybrid should work pretty well...quick spool from te t3 turbine and good cfm from the t4 compressor... i was way off in terms of A/R though, i was going way to conservative if the above post is right... so IF theoretically, i couldn't find a s4 or s5 turbo for a decent price then i should be able to use a t3/t4 with a nice fat A/R... but i still need to lock down the trim number... I'm thinking about giving a call to garret and letting the do all the math and then i go on a google hunt til i find one that'l work

81WideMariah

iTrader: (8)

ok...did some more research...and from what i've gathered i should have no problem using a t3..a/r of .48... and either a 50 trim for the cold side..or if i want to leave growing room I can go with a Super 60 (60 trim)... this should flow plenty to get me to my HP goals... also like the idea of using a v-band for DP conection...makes life MUCH easier.. now i'm going to have to find the best deal....

out of curiosity.... i'm not sure how we should measure displacement on our engines... should we just go with the static displacement of 1.2 aprox?? or should we use the method used to class our engines in racing series.. if i recall correctly they multiply our satic displacement by 3... as there ar 3 faces to the rotor and the engine is constantly on a power stroke... what do you think guys? because i based the above numbers on the static displacement...

Sgt.Stinkfist

iTrader: (6)

for compressor flow, i had the best luck using 1146cc x 2 (2.3l or 140ci) for displacement