Turbo vs. TT Question (Boosted&Skyline)

[GTStang]

This question is open to anyone but I figure are resident Turbo-lovers Boosted and Skyline will help me the most.

I think for my newest project motor I'm want to turbocharge it cause it is the one thing I have not played with yet. My first big question is like the title says what do you think of a single turbo vs. a TT set-up. I know with the new turbo's the turbo lag has been greatly reduced and cause of only having one it's a simpler install and usually cheaper. But for a serious Street set-up does the TT have any advanatges these days vs. the single turbo?

Next would be I have seen people do both for Turboed Ford's would be MAF or Speed Density set-up?

My idea at it's rough stage right now is 6-10psi air-cooled set-up(I want to keep the boost mundane) and I still want good low-end torque(I'm not saying turbo cars can't make torque). So maybe some quick set-up ideas you would do to meet these requirements if you have some would be appreciated.

[Cobra01TT]

One bigger turbo will make more power than two smaller ones. Turbo lag shouldn't be that great an issue since its a V8. Most of the kits that I've looked at are about twice as much for a good twin(double almost everything), and much harder to fit and install. Most(I believe all) of the pro drag racers who run turbos run huge(102-106mm) singles.


What I've heard is that if you convert to a blow through MAF that will be the best set up.

In the Hot Rod article on Battle of the Boost, the turbo made more torque(100+) than certifugal all across the range untill redline. It also made much more HP untill the centrifugal caught up less than a grand off redline.

I started wanting to get a twin turbo kit from www.inductionconcepts.com with two 60-1 Hi-Fi turbos, but that was far too expensive for me. Right now I'm looking at getting a kit from www.proturbokits.com, and upgrading to a T-66.

If you look at the Induction Concepts website, they outline everything they put in it, so you can use it as a guide to find parts. They use pretty much the best parts out there, and it is a extremely complete kit.

[boosted331]

Originally Posted by GTStang

This question is open to anyone but I figure are resident Turbo-lovers Boosted and Skyline will help me the most.

I think for my newest project motor I'm want to turbocharge it cause it is the one thing I have not played with yet. My first big question is like the title says what do you think of a single turbo vs. a TT set-up. I know with the new turbo's the turbo lag has been greatly reduced and cause of only having one it's a simpler install and usually cheaper. But for a serious Street set-up does the TT have any advanatges these days vs. the single turbo?

Next would be I have seen people do both for Turboed Ford's would be MAF or Speed Density set-up?

My idea at it's rough stage right now is 6-10psi air-cooled set-up(I want to keep the boost mundane) and I still want good low-end torque(I'm not saying turbo cars can't make torque). So maybe some quick set-up ideas you would do to meet these requirements if you have some would be appreciated.

IMO a single is a more cost effective setup from 300-1250 horsepower, then after that I would think about twins. A single PT76-GTS will make 1000 RWHP, which is more than you ever need in a car, and has very little lag. Past 1000 RWHP it's kind of a gray zone, something like a PT91 is too big to be streetable (IMO) and something like a large frame T88 might not make as much power as you want. Twins are great because they are easy to adjust how much power you make and when they spool, because you can pick from .58, .70, .81, and .96 A/R exhaust housings for twins, whereas with a single T4 you're basically limited to a .81 or .96 otherwise it gets very restrictive.

You can run a MAF setup, which is very easy to do. Get a big MAF calibrated for some 55's, and a good tune and your car will run like butter. Speed density requires something aftermarket (speed pro, accel DFI, AEM, etc) and is generally more expensive and somewhat overkill for a typical street car.

What kind of a motor are you running, 5.0 or 4.6? For a nice mild street setup i'd go with a PT67-GTQ with a .81 or .91 housing, as big of exhaust/downpipe as possible, no smaller than a tial 38mm wastegate, a good bov and an intercooler.

When you're putting together any kind of an aftermarket turbo kit, you really dont have to worry about turbo lag. I'm running a T76-GTS with a .96 housing, 3.5" downpipe y-ing off to dual 3.5" dynomax race bullets, on a true 302" motor (4.00 x 3.00, with a 5.4" rod so it revs like hell) and it makes 17 pounds of boost by 3600 rpm's. Lots of fun on the street with a stick!

[boosted331]

Also, don't listen to what people tell you about how "laggy" it will be with low compression. With a 16CC dish piston, and 72CC heads i'm sitting at 7.25:1 compression, and any downfalls from that low compression is more than made up for by being able to run 20 pounds of boost on 92 octane.