twin mitsu 2.5

[4cefedomni]

i'm trying to go twin mitsu's on my omni with 30-35 psi in my sights. Just curious what i will have to do to the wastegates to hold that much pressure. and if its not possible then how i could modify them to work with an external wastegate (i'm making my own header so it is a possibility). the reason i'm going with the mitsu turbos is that i have five of them and i got some rebuild kits for them for $100 each so these are the turbos i'm using please don't tell me i should go with a hybrid or something. thanks

[Ground Rat]

I'm kind of new at the TD thing, but isn't 30+psi way out of the mitsu's range? If you are getting 15psi a piece on those turbos, aren't you still at only 15psi, just more CFM? Also, how hard would it be to spool twins on a 4cyl?

[cordes]

You will probably kill those little things at that boost level, and toast your motor with scorching hot boost.

That being said, let me dig up the link to Carl's web site which details his TT mitsu shadow...

ETA: Link

http://66.78.24.116/index.htm

[4cefedomni]

i'm not sure myself i've never done it before but if one is good for 15psi then 2 should do 30 right? and the twin mitsu thing has been done once to my knowledge in a dodge shadow i believe it was Brian Slowes. If memory serves the lag wasn't that bad and it was capable of some high boost numbers. I hope mine will work well if not i build a new header and get a bigger turbo but right now thats out of my pricerange and i already have the turbos.

[Wink]

Look at the mitsy compressor maps. None of the TD04 or TD05 maps will go to 30+ psi. If they can't get to that pressure, then two won't be able to. They will just be able to flow twice the amount of flow per psi. That's all.

[cordes]

I posted the link.

15PSI from turbo1 +15PSI from turbo2 does not = 30PSI.

pressure does not work that way.

If your intake manifold is seeing 15PSI, that is what both turbos are putting out 15PSI. You will be flowing approximatly twice the air though.

You might want to take a look at the home made alky setup on carl's site too as that would go a long way in keeping your motor from becoming an ashtry maker.

ETA: Made the formula a little less confusing.

[Bardo]

thank god someone found it cause i was racking my brain looking for that link cause i wanted to do the same thing about 4 years ago and found out its not worth it

[turbovanman²]

I don't think its worth the hassle. Granted time is free but heck, for the effort, you could buy the proper turbo and not break a sweat. Carl went back to a single turbo I believe.

[4cefedomni]

well call me ignorant if you want but i have the parts to do it this way so this is how i'm going to do it if it works awesome if not then i need to try something else but i do think that 2 turbos will be able to reach higher boost than 1 turbo and there is also the awe factor of pulling up in a twin turbo car

[Ground Rat]

well call me ignorant if you want but i have the parts to do it this way so this is how i'm going to do it if it works awesome if not then i need to try something else but i do think that 2 turbos will be able to reach higher boost than 1 turbo and there is also the awe factor of pulling up in a twin turbo car

You won't get more boost w/ twins unless you run them in series, but you won't need to since you'll be moving about twice as much air at the same psi.

[WVRampage]

piggy back them like a deisel truck then 15 on one turbo then 15 more from the next. so the outlet of one goes to the inlet of the other,mount one turbo right under the other one on the dp then youd have twins with 30 psi. Even beter yet you could use lower boost and be well with in the limits of the mitsu. Same as above must have been posting at the same time.

[Ground Rat]

piggy back them like a deisel truck then 15 on one turbo then 15 more from the next. so the outlet of one goes to the inlet of the other,mount one turbo right under the other one on the dp then youd have twins with 30 psi. Even beter yet you could use lower boost and be well with in the limits of the mitsu. Same as above must have been posting at the same time.

I've seen up to three turbos on a diesel set up like that, the last was pushing 150psi. I've never seen it on a gas motor but don't see any reason why it wouldn't work. I don't think the same size turbos would be a good idea w/ that kind of setup though; the idea is to quickly spool a small turbo so it can quickly spool a larger turbo.

[Ondonti]

you can put one or 500 mitsus on your engine and it will never boost past 2.7 bar......unless you like getting pieces of turbo implanted in your face.

[TrrboJeep]

you can put one or 500 mitsus on your engine and it will never boost past 2.7 bar......unless you like getting pieces of turbo implanted in your face.

It is great to create.. even God thinks so. That being said, you must realize that, as stated above, 2 turbo's each making 15psi of boost, will only net 15psi of boost pressure in your intake!

What others have found by creating exactly what you are going to try, is that

a.) the turbo lag associated with using 2 cylinders to spool a mitsu will be immense.
b.) the mitsu's will never be able to achieve 30+ psi of boost.
c.) although the "AWE" factor of twins may be there initially, after one race with someone cleaning your clock, it will quickly fade to something else.
d.) The best form of "AWE" occures in how your car performs, not how it looks.

If you truely want twins, you need to stage the turbos as stated above. Use one mitsu to spool a larger turbo. But, even that is not the ideal setup for a TD. But heck, since performance is not a concern, I'd say go for quads! You did say you had 5 mitsu's. Run 4 and you'll have one for a backup! If twins look impressive, think how jaws would drop when you popped your hood and folks saw 4 of them in there!

Don't hate us for saying this, we're only trying to help. You see, by doing this you will be reducing the performance of your car, and making it less fun to drive, all for the sake of some looks. It's kind of like the kids who wear their shorts/ pants down to their knees, they think it's cool, but the practicality of it defies the form and function it was designed for. You can no longer run, jump, sit, squat, and your constantly grabbing onto them with your hands to keep them from going all the way down to your ankles and exposing things!
We just don't want you exposing things that shouldn't be... thats all.

[Subliminal]

I think Carl went 12s, maybe even 11s with his tt setup, which wasn't much more than stock, if i remember right. I asked him a while back if he'd do it again, and he said probably not. He did it because he had the parts and it was free. He said the plumbing was a nightmare, though. And you have to have access to a welder to weld the manifold...

And Joel, I don't think he had any problems spooling the turbos, either. The rest of your points look pretty good, though.

d

[Wink]

... and there is also the awe factor of pulling up in a twin turbo car

That's the only reason I'm fabricating my custom manifolds for my V6. Most are adding a single turbo to them. Where I single myself out with having the only twin turbo project on the drawing boards at the moment.

I was told this and I'll pass it down to you.

Don't let others tell you something can't be done. If you have the ability to do something, then do it. If it works, then flaunt it. If it doesn't work, then learn by it. The only thing that you loose by trying is your hard earned work.


With this said, go out and prove everyone wrong and have fun with the project.


Now I get to play devil's advocate......

If you're planning on running the turbos in parrallel, then the setup has already been done and proven to work. However, it didn't work as well as hoped or the owner grew out of the setup and wanted higher boost. But, if you were to run them in series, like some of the deisel setups I've seen, then I don't see why you can't reach your goals. It will just take a lot of patiece to pull it off.

Good luck,

Wink

[turbovanman²]

Where not telling him NOT TO DO IT, just telling him its not worth the hassle and the fact that 2 turbos don't double the boost, and he will never hit 30 psi or more. If he wants to do it, knock himself out,

[Wink]

Where not telling him NOT TO DO IT, just telling him its not worth the hassle and the fact that 2 turbos don't double the boost, and he will never hit 30 psi or more. If he wants to do it, knock himself out,

I realized this. That's why I mentioned the sequential turbo setup. But, you have to admit, once someone gets something in their head, nothing short of finding out for themselves will make them understand.

I only posted that because of the "cool factor" he wants. But I totally agree that with two mitsu's in parrallel, he will not be able to attain that kind of boost, period. But I'd like to see someone try out a sequential twin set, just too see if it would work.

I do have one question about this, if anyone absolutely knows....

When you push compressed air into a compressor, will the pressure side of the maps increase exponentially with the pressure of the inlet? Or will that not matter, and you just won't see above the boost pressure that the maps show?

I just thought that if you pressurize an already pressurized mass of air, it would compound the pressures. Set me straight someone!!!! Please.


Wink

[TrrboJeep]

I asked him a while back if he'd do it again, and he said probably not.

That is one of the most often ask questions I hear, in regard to turbocharging my Wrangler... "if you had it to do all over again would you add the turbo, or just swap in a V8?"
I always reply with "I'd add the turbo" Why? Because everyone else does the swap. It's not unique, they're everywhere, and lots of people have them. I know of no one with an intercooled turbo setup on a 4 cyl. Wrangler!

So I guess, I'm the pot calling the kettle black! Live your dream... throw on the twins and run a safe amount of boost, so the mitsu's can live long and prosper! I wonder how much boost Carl ran on his setup?

Wink, your twin setup is a horse of a different color. On the V6 small twins actually have a performance edge on a low boost application. You'll spin them up quick and get some good low end grunt and low rpm boost. I think no one is working on that setup only because of the complexity of it, not because it is poor from a performance standpoint. I've been following the posts and pictures on your build up, and I think it's gonna be a sweet setup, with a lot of balls when its done!

If you choose to proceed with the twin mitsu's, be sure and post some pictures as you progress. We can't get enough of this crazy stuff around here!

Oh and BTW, I got no clue on the pressurizing pressurized air???

[4cefedomni]

that is correct thats why hooking turbos in series is called compound turbocharging. but what i don't get is if i have them in parrallel and now they are flowing twice as much air the engine can only take in so much the rest would build up hence more pressure. and the setup i plan on running is to have cyl 1,4 run independantly from 2,3 both on intake and exhaust side that would make it seem like a big turbo on a small engine and big turbos should be able to get high boost pressures. on the intake side i plan on having 2 throttle bodies feeding 2 cylinders each with an intake that looks similar to a header( like whats on a toyota vvti motor if you have seen one).