This just got interesting. Would love to mod my GS460 and add a few HP if possible.

 

You can easily build a small remote mount turbo setup, to keep the initial cost low at first run cheap ebay turbos. Mount the turbos in the rear, use a scavenge oil pump to feed oil to the turbos, maybe a pair of t3/t4 turbos will spool nicely in the back. The good thing about remote turbos is that you wont need to build an exhaust manifold, just weld a flange on your exhaust tube and mount the turbo's.

For $1,000.00-$2,000.00 grand you can build a basic turbo kit, 9-12psi of boost, on stock injectors. Once you get the kit dialed in and the turbo's sized properly then you can spend the big buck on a more long term reliable turbo like garret or a borg warner turbo.

 

It's not that simple to do rear mount turbos for 1-2k. It will be a hack job and be unreliable. From a tuning standpoint, it can definitely be dialed in with a reflash. Although 9-12 psi may not be achievable depending on turbo size. The 460 factory fuel system can safely run 500+whp

 

I think it can be done, here some pricing off ebay.

Precision turbo waste gates are $250 each x 2= $500.00
ebay turbo t3/t4 $130.00 x 2= $260.00
turbowerks scavenge pump $249.00
blow off valve $100-200
intercooler tubing $200
AN fittings $100
Metal tube/brackets $150
Couplers $100
DW fuel regulator $150

The reason why I put china turbos is not for long term. Using cheap turbos will help size up the right size for when you go to tune the car. Then when you work out all the bugs. You will know what size turbo is best for that hp goal.

You can also join your exhaust into a collector and run 1 single large turbo thats a t4. For just 9 psi you dont need to run an intercooler, plus being a rear mounted turbo, the turbos would run cooler, and with the charge pipes being aluminum.

With any custom build, it can be a total unreliable/hack or it can be a clean well engineered design. That all depends on the builder, and how good he can fabricate and weld.

 

On projects like these, whatever you think it's going to cost, double it. Little things add up fast. Your list doesnt include air filter, filter shield, t-bolt clamps, vacuum lines, fluids, welding/fabrication cost, tune, boost controller, external trans cooler, gauges or some way to monitor, etc. Just to name a few. And t4 is too small for a 4.6 v8. What sounds good on paper usually doesnt pan out that way in real life otherwise everyone would do it.

 

I agree with the double cost of custom projects, but you can help lower the prices by using used parts. As the majority of the parts needed are generic. Plus there ways to cut cost. Like not using an fittings on everything, but instead use hard lines.

Do you really think a t4 is too small?? Guys run them on 6.2 6.3 LS motors and make over 1000hp on a single t4 turbo flange.

If you have the skill set to build a turbo go for it. You are able to tune it, hell build a kit then sell it once its dialed in and build another off that original kit. A twin turbo set up would be pretty sweet in a 460. Worst case scenario the engine grenades, these engines are a dime a dozen at the junkyards. Pretty sure you can scoop them up for next to nothing. You will be the first 460 with a twin turbo, thats pretty sick!

 

At one point I wanted to supercharge the car, however I publicly listed it for sale yesterday!

 

Cool! I remember a member named Designo, he supercharged his 460. If I remember correctly wasnt able to dial in the tune properly.

 

Correct. When he was supercharged, the ECU wasnt able to be tuned yet