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Discussion Starter #1
I'm wondering if it is possible to convert our turbo engines to run like the Supras do. We run tandem and they run sequentially (one after the other) right?? Would it be possible to change our turbo setup so that we could run like the Surpras do? Any help would be great- thanks.
-Shaun
 

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Run a search for "Single Turbo." This topic has been debated over and over. At least one car has done it, but hasn't really been run yet. The general consensus, however, is that it won't help.... although its certainly not fact.
 

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i thought someone said that only the rx7's ran sequential
 

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More Than Meets the Eye
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The only time sequential would help us is if we had larger turbos to begin with. The Supra's stock turbos are equal to our 15g upgrades.

Still, our engines spool faster than any turbo car out there. Come on - our peak torque figures are at 2500rpm - that's even lower speed than v8's.
 

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:rolleyes:

:confused:

:mad:

*looks at the thread starter like he is about to die*

:rolleyes:
 

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lol you must enjoy confusing me, racerRT :D
 

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Whatever Man
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I think it would be a terrible idea. Most people with sequential turbos try and get away from the sequential since it inhibits power so much.
 

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Discussion Starter #8
John M said:
The only time sequential would help us is if we had larger turbos to begin with. The Supra's stock turbos are equal to our 15g upgrades.

Still, our engines spool faster than any turbo car out there. Come on - our peak torque figures are at 2500rpm - that's even lower speed than v8's.
Does anyone know why the stock Supra turbos would be so much better than ours are? And if they are- couldn't we switch out our turbos for some stock Supra turbos and save money rather than just upgrading to 15G turbos.:confused:
-AM i really confused or what?
-Shaun
 

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More Than Meets the Eye
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The same reason they came with 550 injectors, a big fuel pump, and huge fuel lines. They designed the car for serious hp where Mitsu decided 300-320 was plenty.

No we can't bolt theirs on. Nothing is even similar between the two.
 

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Discussion Starter #10
ok- i got ya- thanks a lot guys. Maybe i should have bought a Supra to start out with-lol
Anyways- talk to ya later-
Shaun
 

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DStealthTT said:
ok- i got ya- thanks a lot guys. Maybe i should have bought a Supra to start out with-lol
Anyways- talk to ya later-
Shaun
If u want a 2JZ-GTE, then ... uh ... yeah, a supra might have been a good choice :D

.jon
 

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Discussion Starter #12
lol- you're probably right
 

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A note about the 2JZ-GTE.... First, the solenoid valve that controls the wastegates, is horrible. Second, bad turbo construction - I hate the CT25, the oil feed lines are too small, as well as the coolant lines. Third, While inline is good, iron cranks are bad, so are the crappy rods they use. Fourth, because of #1, they have rather large overboosting problems. Fifth, Too high compression ratio for the amount of boost they're pumping in. Sixth, Rear wheel drive.

That's just my opinion (and the same opinion of a very large amount of mechanics at the dealership I work at). A few years back they took a few TT supra's out to DIA for a show, and ended up replacing the engines in two of the four.

Personally, I like our twin setup, and as someone stated already, quite a few people who are looking for large amounts of power, tend to stray away from the sequential setup. :)
 

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our cars will never run like supras with a sequential setup as the supra has a straight six.....does it make more sense and sound easier to you to
A) cram a whole lot of air in one end and blow it out the other of a relatively straight shot through a straight six or
B) cram a whole lot of air in one end and out the other of two banks of 3 cylinders each and all the extra whooshing around the air is obliged to to as a result of that?
not saying our cars can't be as fast, but for a turbo car, the straight six engine is much more efficient. why would you want to go sequential, if you want to do anything other than twins just get a large single. keep in mind you'll have less low end output as a result of the turbo taking longer to spool.....
or you could stick with somewhat smaller twins an has them spool at lower rpm levels simultaneously and producethe sam amount of boost as a larger single. i think. i don't know too terribly much about turbos an this is just theory to me.
 

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I say, our system works just as well (if not better) than the sequential setup. Why? We use two small end turbos to decrease spool time, while achieving the same amount of boost as a larger single turbo. That's the whole idea of twin turbo to begin with. Two small = One large w/ less spool time. The Sequential setup uses one small and one large - smaller for low end with little spool time, large for high end to be engaged at the time the little one peaks out. And if you ask me, I don't understand how a Supra can come stock with 15G's (two of them I believe) and still decrease spool time, using one for low end and one for high end. If it's truly sequential, then that's how it would work.

Also, either way you look at it, an Inline engine will be more powerful, hands down. It has gravity on it's side during the power stroke. More power going down, turns into more power going up during the compression stroke, moderately compensating for gravity. When it comes to boost, it has gravity working against it (somewhat) during the compression stroke, and you're not looking for a whole lot of compression with a turbo car to begin with! So, in that sense, yes the straight six has it's advantages over us. On the other side of the coin, we've got a better balance between the two things (compression and power), resulting in a smoother running engine, and less compression problems. Less gravity working against us on the compression stroke, less gravity working for us on the power stroke. If you think about it, it kind of evens out. If a 289 cu. in. V-8 can make it down the track in under 10 seconds, so can I. If you're really curious about why our car's aren't in the 10's, then look at the tranny. Also, take the R34 for example. Half a liter less than our cars, and although it is an inline, those can still make it down the track in under 10 seconds. (god bless that driveline)

Sorry for the length, just my two cents.
 

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Discussion Starter #16
So TenshiVR-4, you're saying that our main limitation in getting 10's is our tranny. Could u explain that a little? Also, do u have any ideas for upgrading our trannys- and how much it cost?
-Shaun
 

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Stock transmissions and entire driveline in vr4's are CRAP. Ask any vr-4 owner. I've seen so many people that have replaced parts. From drive shafts, to output splines, gear synchronizers. The list goes on and on. A couple people even had the transfer case lock, which instantly locks all 4 wheels. One guy was going ~85 when it happened :mad:

Kormex makes a transmission, supposed to be stronger than stock. No idea how much power it can hold.

Some people have been using carbon fiber drive shafts, as well as output shafts w/ more splines (28 versus 38 sound right to u guys?).

.jon
 

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they aren't exactly crap, they just have to put up with a ton of stress and untill recently, internal parts weren't available, so that's why they WERE so expensive
 

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lostboi said:
our cars will never run like supras with a sequential setup as the supra has a straight six.....does it make more sense and sound easier to you to
A) cram a whole lot of air in one end and blow it out the other of a relatively straight shot through a straight six or
B) cram a whole lot of air in one end and out the other of two banks of 3 cylinders each and all the extra whooshing around the air is obliged to to as a result of that?
not saying our cars can't be as fast, but for a turbo car, the straight six engine is much more efficient. why would you want to go sequential, if you want to do anything other than twins just get a large single. keep in mind you'll have less low end output as a result of the turbo taking longer to spool.....
or you could stick with somewhat smaller twins an has them spool at lower rpm levels simultaneously and producethe sam amount of boost as a larger single. i think. i don't know too terribly much about turbos an this is just theory to me.
wtf?? Supra's have a inline turbo system (just like twins)... not a sequential....
and, you are pushing the air the same way, no matter if you have a inline, or a V engine... your still pushing it into the same big hole in the plenum.. and the air is equal going in.. and equal going out... no matter what..
Also.. a inline engine is not more "efficient"... catch up on some reading..
Also.. going single will not solve anything.. just that your torque curve will drop like a madman.. and you will struggle out of the hole every time..
A single turbo never produces the same amount of power, as equivlent twins.. no matter how you bull shit about making power, when it comes down to the basics.. two turbos will produce power more quickly, and have the same topend.. if not a slight advantage, due to volume of the manifolds and properly placed piping....
When it comes down to it.. it doesn't matter what the fuck you do, you can only do what the system is made for.. not what you think it's made for.
 

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TenshiVR-4 said:
A note about the 2JZ-GTE.... First, the solenoid valve that controls the wastegates, is horrible. Second, bad turbo construction - I hate the CT25, the oil feed lines are too small, as well as the coolant lines. Third, While inline is good, iron cranks are bad, so are the crappy rods they use. Fourth, because of #1, they have rather large overboosting problems. Fifth, Too high compression ratio for the amount of boost they're pumping in. Sixth, Rear wheel drive.


Ok I am going to raise the Bullshit Flag on you Tenshi.... I had a 95 MKIV......

THe selenoid that is fond in the car is actually adaquate for stock and D/P upgraded only cars, after that it is a POS

THe turbos are constructed fine for up to like 16 psi in sequential and when swithced to TTC very good for 18PSI. Most MKIV owners that blow their turbos are running sequential at 18-20 psi on a REGULAR BASIS.

I agree the oil lines are too small but so is the shaft its only 7mm, the coolant lines are adequate for BPU+ power

Umm.. crappy rods/cranks? I hat to break it to you most MKIV owners that go single/big twins are able to get almost 15-20K miles out the "CRAPPY" stock rods and crank :rolleyes:

We do not have overboosting problems on number one if EBC are installed according the listed directions on MKIV.COM Also the stock turbos are both the same size #1 is NOT larger than #2

Too high compression I do not think 8.5 is that high stock alot of us when doing rebuilds end up with that as our C/R..

Agreed rearwheel drive is no fun in the snow but that I why I have beater so neither SUpra nor my VR-4 will have to see snow.


Ok I am done with my rant/correcting ignorance
 
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