turbo selection 2jz

[indeecent]

Alright so its personal preference.

I was under the impresson that if you get 2 turbos that have the combined area of the single, due to the reduction in the radius of gyration would spool up quicker...

Or in practice does this rarely work?

And if you price turbo's the smaller ones from garett have dropped substatially in price. The Gt28's go for around 1250 at my nearest turbo shop, and are what im planning on putting on mine. But everything is still in the entry stage so am trying to learn as much more as i can.

[JustCallMeOrlando]

The reason is because a big single is FAR cheaper than two smaller turbos, and if well-chosen it can be every bit as responsive. Aftermarket twins are for the "because I can" factor only, don't expect it to perform any better than a single though.

Surely the same principle applies to aftermarket turbos as factory ones. They wouldn't have used twin-turbos if there wasn't a benefit. As you said, it's much cheaper to go single. Surely a properly setup twin-setup should have the advantage for a given power level.

[Draven]

if you aim a little lower you can go a gt30r.
it will spool up very early on a 2j, max out a fraction over 300rwkw... you may not like the feeling of hitting max power at about 3500rpm and then just carrying that power level through to 7500 tho

[Joshstix]

Surely the same principle applies to aftermarket turbos as factory ones. They wouldn't have used twin-turbos if there wasn't a benefit. As you said, it's much cheaper to go single. Surely a properly setup twin-setup should have the advantage for a given power level.

Take a look at the 1JZ's. Toyota dumped the twins and went to a bigger single turbo for the latest generation. They also halved the revs at which it makes maximum torque, yes I know VVTi helps here. It doesn't look like Toyota really thought twins were the go for that use though.

Sequential twin turbo's are either terrible to drive when they step from one turbo to two or so stupidly complex that they fail too often. Simultainious twins are a fairly old school concept that was used by very few manufacturers also indicating it's not exactly a cut and dry better option.

[Norbie]

The difference is the modern turbochargers available to us now which are miles ahead of what was available when the 1JZ was released. You can acheive better power AND response replacing 1JZ stockers with a modern single.

Yes there are probably gains to be had by using a pair of modern turbos, but the benefit would be minor (if there is any benefit at all) and not worth the significantly greater cost. You'd acheive a better result with a 25hp shot of N20.

[JustCallMeOrlando]

Oh I don't doubt the advances in turbo technology have more than made up for the perceived benefits, was more saying that while everything has improved, the basics still stay the same, although their effects have been reduced.

[6BOOST]

Surely the same principle applies to aftermarket turbos as factory ones. They wouldn't have used twin-turbos if there wasn't a benefit. As you said, it's much cheaper to go single. Surely a properly setup twin-setup should have the advantage for a given power level.

The factory twins on a GTR make full boost around 4000rpm. A TO4Z makes full boost on some GTR's around 4000rpm, a GT35 DEF is on full boost by 4000rpm, and power wise shits all over the stock twins. The old school thought that twins were better came from the fact that before the advent of ball bearings and new turbo designs, people were going straight from twin ball bearing T28's, up to old school TO4's and T88's. Check out the american supra sites, they rarely use twins, and the general knowledge now is that a single turbo generally of comparable power output to twins of similar combined power outspools its twin cousins.

6BOOST

[1JZ.747]

You'd acheive a better result with a 25hp shot of N20.

now your talking norbie

[JZA70 R]

good info here.

[MS-75]

Yep-spot on info.

I'm running a GT42 (102 major dia. comp,non-roller) at 23-24psi and getting 610rwhp through an auto.