Kevin T. Wyum

You're kidding right?

TT_Rex_7

If you have corkys book, read it and simple math will figure it out, although I think you have to calculate it as a 4 cyl. 2.6 liter.

-Alex

Mark'sMazda

I have the book, have read and re-read it.

I was just un-sure of what to plug into the forumla for a 13b. I also made the assumption, of 2.6L 4pot, then noticed that's just under what corky recomends for a twin setup on an otto cycle.

Im looking foreward to seing the car, hopefully in action, at the rotary revilution.

SnowmanSteiner

Well lets think about this. You are running half the exhaust to two different turbos. Let's say the turbos are exactly 1/2 the size of some specific single turbo. Each of the twin's is recieving half the exhaust. Each of the shafts is half as heavy and the wheels are half the diameter, so it takes less energy from the exhaust to spool them, but each one has to be spooled which pretty much equals that of the single. In complete theory disregarding any type of friction, you are taking the exhaust splitting it in two, each turbo requires half of the exhaust that the single needs, but you have two, so they are about equalled out. Obviuosly this is all theory. I personally used to be a fan of twin setups but I'm not too sure about the benefits anymore, that's why I look forward to the results.

- Steiner

Kevin T. Wyum

"In complete theory"

That probably should have been incomplete theory : ).

A. The twins are not half the size.
B. A combined header, single turbo, will actually reduce the total amount of exhaust energy relative to two completely divided tubes and turbos.
C. I don't think you understand what I meant about rotating mass and distance from the point of rotation. It's not a linear relationship as you're thinking. It takes more effort to accelerate 1 large wheel than it does 2 small wheels.
D. Things don't equal out. With appropriately sized twins you will have faster spool, READ IMPORTANT, and the same top end flow as a large single.

The downside is you'll have a few pounds of additional weight and complication of all the coolant, oil, exhaust and intake lines/tubes and if equal quality a higher price.

If we want to nitpick there will be the additional benefits, minor as they may be, of more surface area to exchange heat in the center sections meaning likely longer turbo and system life, additional coolant and oil volumes to the system. They will likely run cooler.

I'm not holding my breath for these particular turbos to be a great example as the headers don't seem to be equal length and from what I can see of the exhaust side I'd rather have it done a bit differently, same with the wastegates. Of course price is a major reason for some of these things and on that basis it definately looks very worthwhile for the price. I'd still bet with the right exhaust housings they'll perform much better than an equally rated single.

Oh and the reason some big blocks use large singles, because they have so much torque and low RPM oomph that spool doesn't matter to them, they're looking for extra power after they're up and moving. Ask someone why they have staged nitrous systems. : ) I can't believe someone said people make twin systems based on looks. sheesh.


Kevin T. Wyum

SnowmanSteiner

First off, thanks for immediately making snide comments. Next what I ment by in complete theory, was to take everything into theory, ie. no friction all gases and other elements act ideal. I did not mean that it was the complete end all of theories, misunderstanding but thanks for the insult.

A. I realize that these turbos are not half the size of any turbo, that's why I said "Let's say the turbos are exactly 1/2 the size of some specific single turbo." which means that we are simplifying things by taking an easy ratio. Again misunderstanding whatever.
B. I don't understand this, you'll have to elaborate further, I can't just assume it's right.
C. I don't think we are thinking the same things on this either. They way I am looking at it, is in a torque perspective. Ie. force x distance. Regardless you're final statement is correct, it does take more force to spin one larger wheel vs two.
D. The fact that the two turbos will spool individually faster is understood. But I have been told varying things on this subject, ie. some have said that the actually boost pressure that is made is the combination of both turbos, ie. if they are each producing 7lbs, then total they will produce 14lbs. But I've heard the opposite as well, that if they are both making 7lbs, then together they are still only making 7lbs unless you run an individual ic and runner all the way to the port.

additional turbo life, possibly, you also have to take into account that they are going to give off more heat than a single, by the same pricinple more surface area. More oil doesn't neccessarily mean that they will run cooler, oil can only absorb so much, and as I'm sure you know, there is a maximum point to where too much oil just isn't adding any benefits. Again it will take more oil to cool the system so the increase in amount of oil in the system should ballance this out, because you don't want to overflow what the stock system can take.

In my opinion if you want faster spool there are many devices on the market that can offer it at price that is much less than this. But as stated before some people want to do something different, which is why I think this kit has been developed.

- Steiner

mitchiemitch1

lol

milkman2k52

lol @ steiner

88fc3sw/HX83

damm double pump

88fc3sw/HX83

I'll take one of those, if the price is right

z8cw

These 3071s are really expensive. You are looking at an additional $600 per turbo...ouch.

SnowmanSteiner

Well I think we both misread what we posted. Just trying to clear things up. Besides it's better to have different perspectives when judging or looking at a system like this. I'm merely offering what I can, and what I can understand, not anything definitive, just my perspective. It's all constructive which is what matters.

- Steiner

RacerX_IU

i want to see how you guys are planning on plumbing from the turbos to the intercooler

ijneb

Either two in's on the intercooler or a pipe that y's off similar to stock, but more of a Y than a T.

RacerX_IU

^ i just want to see it!!!!!

krautrocket

disco potato to the rescue ... x2

LT1-7

Disco Potatos and even the GT3071R turbos use the same exhaust flanges as the GT28R's. So really, all we would need to do is swap the turbos. We're looking into making a twin GT3071R, GT28RS, and GT2871R kits. These should be the bad asses of all systems and still be in the price range for most people.

2.0L 1st Gen

Finally someone comes out with a decent twin turbo set up! Ive always liked the simplicity of internal wastegates. Looks like a great set up.
Good Luck!

Xcessive

Hey John, I have a pair of GT30rs, shall we try them on the 7? Also I have HP tuners ecu
program firgured out and it rips!!! Ralph

LT1-7

Ralph, you know me!! I'll try anything and everything. Why don't you give me those 30R's and we'll see what we can come up wth Talking to Precision today and they estimated 600rwhp with twin 3071R's. Reading the maps, it looks like these turbos are good for over 30psi. Of course these are just estimates until we can run them on a car that can handle the power. You have strait 30R's right? Those would be unreal on a 7!!

I think we're gonna try HP Tuner on the turbo Trans Am. Probably be a couple months before we can dyno it though. When do you think you can start dynoing again?

darkphantom

iTrader: (2)

I will say that twins are safer than single turbos. but twins have too much heat than single.


i bet you could produce 500hp on twins eaiser than you can on a single

z8cw

Looking for some confirmation here but that is what I think.'

Stock port, flows max of 40 lbs/min at 15 PSI, 46 at 20 PSI, 58 at 30
Street ports (big range but best I've seen) 47, 54, 68
Bridge port (big range again) 51, 57,71
PP 58, 66, 82

Looks to me that most twins are overkill for stock or not so great street ports. I would think the 28r is probably the best choice for most.

t-von

iTrader: (8)

A bridge may never pass emissions (regardless of turbo) because of the larger overlap it creates. With the exaust and intake partially open at the same time, the exhaust will draw in some of the un-burned air intake mixture. This will cause more gas to be burned in the exhaust itself.

t-von

iTrader: (8)

Does the kit mount the front turbo low enough so that the stock smog pump can be used? If so, this would be a really nice benefit compared to a single.

Rotarded

Coming Soon???