im sorry for not being clear.im not running sequential,like all 3 pipes to one turbo then the next.it would be one pipe or rotor per turbo.im saying if u have one turbo shutting down after 5 psi and the other one keeps going,wouldnt that run sort of sequential?i would be running them parallel,but each turbo would shut down or stop at a certain boost pressure.do u understand now?there is no way in hell i could run 3 pipes to one turbo then the next then the next.

 

i dunno if that would work well. that would mean each rotor has a different load on it, due to the differing backpressures. it would be better if you had 3 of the same small internal wastegate turbos, like the axia car. of course one big single would be a lot lighter too

mike

 

that is true mike ive looked into the t76.got any specs on this.i seen a compressor map on it and that was it.that damn thing was out of the roof.i mean u hear alot ppl say a t88 can support 1200 hp but i havent seen it.what is the specs on a t76 versus the t88?

true thanx for pointing out it would have different loads as far as exhuast pressure.but they would all be the same size turbo.like axia's

 

You can't stop a turbo dead in its tracks. If you design a complicated valve system which recirculates the compressors sequentially, then that may work.

Yes you can run three pipes into one, and then feed 3 turbos. Well, maybe you can't, but just about everyone else can (not that it's very smart, though).

If you want the turbos to "shut down", then that means that turbo 3 will be running the engine by itself at the highest boost level, right? OK, so therefore at 25psi, 9000rpm, and assuming 100%Ev you are looking at a flow requirement of about 129lbs/min (1688cfm) under ISA conditions if my quick calculations here are correct. This means that with a slight pressure drop from the intercooler and thermal density drop from compression, you will need something the size of a T-100 for turbo 3. If you really want all the turbos to be the same, then you will need three T-100's on your engine, LOL.

It takes power from the exhaust system to run the turbos. By splitting the exhaust up into 3 pipes, you now have only 1/3 the power to run each turbo. You would get basically the same problem if feeding all three turbines with a collected manifold. I seriously doubt that the engine will be able to turn a turbine at those flow and boost levels with that little power. I think that the only way around this is to also sequence the exhaust to the turbines (which would defeat the spool-up issue), or use smaller parallel turbos and forget the fancy sequencing.

Compressor maps:
http://www.majesticturbo.com/compression.html

 

iknow evil i just explained that. one rotor=one exhuast pipe=one turbo with an integral w/g.the integral w/g is how i would plan on stopping boost above a certain level.

i didnt plan on putting 3 pipes into one turbo then to the other then to the other.

rear rotor=exhuast pipe=turbo 1 with integral w/g
middle rotor=exhuast pipe=turbo 2 with integral w/g
front rotor=exhuast pipe=turbo 3 with integral w/g

i was just saying it would kind of be like a sequential parallel setup.they would all spool up at the same time.but each one would just stop producing boost at a certain pressure.

 

That's just too complicated of a system. KISS. Keep it simple stupid. That's my motto. Three turbos plus the plumbing is going to add 100lbs. over a properly-sized single. Less to go wrong, less to break. There are a few rustangs running T100's at the local drag strip. They are simply insane. Utterly crazy. They are easily putting 850-1000hp down and are uncontrollable at higher boost levels even with a back half chassis running full slicks. Their front tires are in the air for almost 1/8 mile. My neighbor wrecked his stang (running a T100, stroker block and SpeedPro engine management) four weeks ago. Totaled his car (worth $80K) and ran right THROUGH the cab of an EMS truck (was in the wrong place, not behind the wall). He was very lucky to walk away from that accident (which amazingly he did). I've since LOWERED my hp "requirements" (LOL) and I'm in the search for something bulletproof for roadrace.

I would stick with something proven and again simple, and put more R&D into drivetrain (and suspension) which is where I see most three rotor conversions lacking. Put the funds towards quality connectors, hoses, etc. instead of an overly complicated turbo system. I plan on using nothing but aerospace/F1 grade connectors from Deutsch Ltd. (www.deutschltd.com) and XRP hoses (HS79 components).

If boost control is a big issue, any of the modern controllers can be programmed to produce x amount of boost in "normal" mode and can be programmed for y overboost when needed (like when chasing down a twin turbo Lingenfelter ZO6 down Sebring's back straight:-)

I think I'm at the point now where I'm seriously contemplating the purchase of another FD body to do the conversion to. I think it'll make things much easier and less painless as I'll still have an FD to mess around with. I could even use my current FD as a rolling test bed for parts I plan on using with the three rotor conversion.
Michel

 

Wow.

You really have no idea how turbos work, or how engines work, do you?

 

look at axia's turbo setup the pic explains it self.im tired of trying to.they did exactly what im tryin to tell u guys.u keep thinking im going to run all 3 pipes to one turbo then another im not.

but hey michel that is true with the suspension.i will be seriously doing good drivetrain and suspension setup to support this engine.i will use good quality connectors for ex. earls, and steel braided lines.

there is hotrod and nascar shop i found on a back road a little ways down from here.ive started talking to them on this subject as far as rear end support and suspension technique.

i've talked with vosko a little bit about the t76,but ive also looked into this turbo made by lateshift engineering,called a t90.it supposedly spool time is similar to a t78 but will support 1400 hp.

and peejay i dont, i really dont.arent rotaries electrical?they r a big alternator right?let me guess on how the turbos work it shouldnt be too hard?i got the rear housing(i guess u would call this the iron thingamajigga)hooked to a air vent to the front lip and the faster i go that forced air spins that turbo like crazy.give me a break and dont insult my intelligence.someone misunderstood what i was trying to say.also look at racing beats tri turbo 3 rotor.3 parallels,3 seperate exhuast pipes.i was just trying to explain that if with integral w/g's u could set each turbo with a higher boost interval.

but like michel said i should KISS.

 

No, he obviously doesn't have a clue, but I'm still trying to help him out. Unfortunately, I haven't been too successful so far.

OK, let's try this again, but more slowly. You are going to have one turbo per exhaust pipe - OK, no problem there. Now, tell me how you think you are going to "shut off" the boost on each one. Do you think you can do it with wastegates, recirculating with a TBV, venting with a POV, stopping the turbo with a brake, rerouting the exhaust, what?

More questions to follow once you explain that.

 

i vote for a stick in the turbine.
seriously if it light weight your after, you will eventually come to the same conclusion that mazda did with the fd. 2 rotor is a lot lighter than the 3 rotor. also for the same reason you will end up wth a single turbo.
the problem with the 3 turbos running different psi, is how do you keep the 5psi turbo from blowing all its air through the other 2, and then when they spool they will blow all the air thru the first one (i "tried" this with the stock twins it will do it)?

mike

 

evil ok im sorry this is what i was saying. 3 td05's would have 3 seperate integral w/g's.3 seperate boost controllers right?well,how do u control boost on a single turbo?with a wastegate and a boost controller correct?yes,now if i applied this to 3 smaller turbos with integral w/g's u could adjust the boost seperately right?

but im thinking about weight savings now so i will stick with a single for now.but ask whatever u feel?

just think though,3 seperate turbos,3 seperate integral w/g's,3 seperate boost controllers,3 seperate boost gauges.

 

No, you cannot. The flow from the turbos with shut wastegates would force the turbo with the wastegate open to go into surge as airflow is stifled and possibly even reversed.

 

hmm.good point.that would of never been mentioned unless u said something.that one is a complicated mess.thanx.

u think i could take my t78 and have it worked on to flow more air.or is there anyway in hell it can support more than 650hp?this is all ive ever seen proven as far as numbers go.

 

Yes, and besides that it wouldn't work.

Here are some turbo basics:

For a parallel system, you can stack volume, but you can't stack boost: Turbo #1 cranking out 5psi and 200cfm + turbo #2 cranking out 5psi and 200cfm = 5psi and 400cfm total output.

Pressure seeks equalibrium: Turbo #1 cranking out 5psi + turbo #2 cranking out 10psi = 5psi being crammed back into turbo #1 until it chokes out, and the remaining pressure reverses the flow of turbo #1 causing bad things to happen. You can't run the turbos at different boost levels if they feed the system at the same time.

Therefore, the way to take advantage of the better spool time of several smaller turbos vs. a single large turbo is to find several small turbos which can ALL operate at the desired boost level and have the combined flow rate required by the engine. This is the concept behind the Axia car. So if you want 3 turbos the same size, you need to select a size which flows 25psi (your posted number) and about 43 lbs/min (assuming 129 lbs/min required then 129 / 3 turbos = 43 each). If in doubt, then just ask your local turbo supplier what they recommend. I guess it's still not within your KISS requirements, though.

I don't know about the turbo, but here are other ways to get around an airflow limitation of the turbo and still make more HP:

1) Install a more efficient intercooler, especially an air/liquid intercooler with an ice chest. This will make the most of whatever air you have available.

2) Use a different fuel. For example, super unleaded has a best power AFR of about 12:1 and 19,000 BTU/lb = 1,583 BTU per lb of air, while ethanol has a best power AFR of about 6.5:1 and 12,500 BTU/lb = 1,923 BTU per lb of air.

 

yeah well see right now i have air to air i/c.but im getting rid of it for another custom intercooler with an ice chest for this project.right what i use is super unleaded.but to go over 15lbs i would need to go up in octance.i know

so the flow rate comparison of two of the same turbos at different lbs would be the same thing as flowing 2 different sized turbos.correct?like a t51 and a to4e?this i do know and understand.i just didnt think it applied to turbos of the same size.but i see now where it does.thanx.

have u ever heard of a 33b t78?i have never always 33d.but from sp engineering said it just helps spool a tid quicker.maybe i can have the turbo sent in and have a/r bumped up to a 1.00 if it will fit.and the compress side bumped to different blade.

 

omg, i thought you actually knew something about turbos, twin. maybe you should go read up about turbos and rethink your whole plan. you do understand that if you have one turbo per rotor they all have to be pushing the same amount of air or you'll have unequal pressure across all three rotors. dude, how the **** are you gonna have one rotor per turbo? that means you're gonna be dividing your power output by a third. after rotor one spools your 5 psi turbo, that means its not working anymore to supply exhaust energy to the other 2 turbos. what about the one rotor supplying the largest turbo, it isn't gonna have enough exhaust energy to spool it. if you plan on taking on the nightmare of plumbing one primary into the next, you're gonna need some sort of anti-reversion system to prevent what evil aviator explained. then you gotta think about some sort of block off valve to block off exhaust flow to the other turbos as you're spooling one. there's a reason why this has never been done, and its not for lack of resources or imagination.

 

yeah i know.thats why im going with single now.ive read that one book turbochargers 101.or whatever it is called.but i did not see anything in there about that.sorry i screwed up.i was ignorant of that fact.but i am knowledgeable now.thanx.like i said i only know what i read.or what i learn.i havent read this in the turbochargers book that u can find at book stores.i mean it tells alot of crap but not that.thanx.i guess i will stick with my t78 for now or go onto a t51r.

 

Not necessarily. Different-sized turbos would work in parallel if they were matched to produce similar boost levels at a given rpm and load. People run the 20B-REW's different-sized turbos in parallel, right? Granted, the turbos don't last very long in that configuration, but it does work. If there is too much difference between the turbos, then it wouldn't work. A large difference in the boost level of each rotor (or cylinder) will generally not work, either.

Sequencing turbos is an extremely advanced subject, and most books can only give you a very general account of how a turbo works. What you really need is a master's degree in engineering for a project at that level. I think you have a better understanding now, though, so that is always good. Hopefully, we can all learn a bit more every day.

These are some good turbocharger books:

Turbochargers by Hugh MacInnes (Really old 1980's technology, but it's a fantastic book on the workings of a turbocharger and written by one of the more influential turbocharger engineers in the US)

Maximum Boost: Designing, Testing, and Installing Turbocharger Systems by Corky Bell (Lots of opinions, some errors, piston engines only, but still the best all-around book for learning how to build a complete turbocharged system. Includes design info on intake, exhaust, intercoolers, etc.)

 

thats the corky bell book.thanx.thanx for the info.and thanx for not being critical on my ignorance.i do wish to go to school but im figuring when and what?im thinking cars,but ive seen some friends of mine go through local colleges and they were dumb as a stick.been there for yrs and didnt know ****.im guessing i would have to go to like a nascar school.my guys at the nascar shop are inteliigent when it comes to that stuff.u wouldnt believe the thought process in putting one of those cars together.they told me it would be easier just to chop my front end off.make me a tube(which is light as hell)frame.lower the engine,push it back and keep the wet sump.plus there is alot of front suspension i want to work with,that is also the reason they suggested it.plus i could get to every part of my engine from any part of my car.they could make me a custom front end.basically to add as much downforce as possible,give me great steering geometry,a very low center of gravity,light front end, and a partial one piece that comes off with zeus pins in a matter of seconds.this is very tempting.i figured what the hell,if it will take me awhile to do this project, also why not to do it right the first,i should go for it. plus they will be installing a custom radiator which is about 3-4 inches thick and also has a built it oil cooler which u ccant see,except for the line going to the filter.that filter was huge too,the size of a damn t3/t4 turbo,no ****.

im also looking at other minor things on this project.
what to use for oil.i think i might go with 20w-50 synthetic.

im going with an all time running fan,instead of only coming on at a specific temp.i know this will burn the fan out.but the car will not be driven hardly ever.so who cares.ill just replace it when it does.

evans npg with water wetter as coolant.

lockhart phillips for all my steel braided lines.very good quality.me and my brother are using these one the race bike we are building(yzf-r6 for 600supersport)they come in any length.you get a very rugged braided flex hose.plus it gets a rubber coating of different colors.i will be using red.these are way better than earl's,i see that now.

im not sure which bushings would be best to go with though.i might go with poly urethane since there is already a kit for the car.but i will use half of it.cuz the front will be a totally different concept.

i will be doing the car differently i believe than what most ppl do.alot of like to just drop an engine in.i will be be building the car up first for the engine.that is like the rear end,differential,fuel tank and extra pump,redoing the interior.by then hopefully i can find a used core.i dont want to buy a whole engine when i will just getting rid of everything off of it.i know canman sells cores.but they are already rebuilt.i know one owner just bought a core for 300 bucks,bcuz the guy that was selling it didnt know its worth.lucky sob.

g-force has now told me that the gf2000 is for only drag racing,u can only upshift.for my applicatiion i would need to go with a gf5r.h-pattern.no thanx.i am now looking at quaife's.they can sell them 5 or 6 speed, sequential or nonseq.plus build the tranny pattern to fit any cars bellhousing.

 

hey, anyone know of any books on cart turbo technology? i read corky bell, i personally thought it was gay, not very informative. i've read some books on cart and turbo f1 cars, but they don't really talk about the technology of the engines and turbo system. those champ cars have the most advanced turbo systems in the world, and i'd like to read about them.

 

what technology?

 

intake and exhaust systems, equations for runner length, plenum design, header lenght and diameter, headwork, valvetrain, bore and stroke, valve angles, port shape, cam profiles, what materials they use, cr's, a/f ratios. you name it, i want the works.

 

that's not really turbo-specific.

 

yeah, i know but their motors are built for the purpose of turbocharging. knowing their intake and exhaust system designs would be very benificial imo. their motors are the most similar to import turbo engines (low displacement, high revs) so it would be good to know something about them. **** man, they redline at around 13k, make about 800hp from 2.6l on restricted boost, and have to last hundreds of miles per race. they're ******* sick.

 

thats why i keep telling you, you would be better off starting with a 100% tube frame. unless you have rules (improved touring, pro7), and with your goals, you would end up with a "better" car. instead of buying a bunch of kits, and have a hodgepodge.

mike