After much deliberation I've decided to forgo the bigger cubed motor in favor of forced induction....as both are going to cost me roughly the same amout to do and the twin-turbochargers are going to net me ALOT more horsepower than the 408 I don't really see it as much of a competition....

Here's the setup:

* 2 Turbonetics T3/T04E .63 Trim turbochargers (I've been assured these WILL work....see below)
* 2 ATP T3 integral wastegates (these things are BADASS !!)
* 2 ATP adjustable WGA's (7-14psi)
* 1 TiAL 38mm BOV
* 2 Buick GN FMIC's (almost a perfect fit side by side in front of the radiator)
* 1 SMC methanol injection kit
* 8 72 lb/hr injectors
* 1 Walbro 255lph in-tank pump
* lots of silicone couplers, v-band clamps, t-bolt clamps, and piping...and a little bit of luck

I've been assured that this setup will support ~750hp if I choose to go that far....I know that everyone is going to think the turbos are too small but these are the same turbos that APS is using to make ~650whp in LS2 GTO's and Monaro's, I'm not going to spin this thing into the sky....5500-6000rpm is the max this will see and at that flow rate I'm right at the edge of the choke line at 15psi, as I'm looking to max out around 10psi I'm still well within the limits of the turbos.

The ATP T3 integral wastegate......





This thing is about as BADASS as I've seen in an integral wastegate....this will work as good as ANY external wastegate and makes exhaust routing a piece of cake !!!

The 72lb/hr injectors are probably overkill but I DO NOT want to have a lean out problem because I don't have enough injector, I know the 72's are harder to get to idle than the 60's but I'll deal with the funky idle issues to ensure I have enough fuel flow at WOT

The Buick GN FMIC's are 12x18x4 each...the inlets and outlets are on the same side of these so I can mount them sideways in front of the radiator and have an inlet and outlet on each side of the radiator for easier pipe routing

Let me know what you guys think !!

 

Dont know **** about turbos but sounds like you are going to have a nice setup for sure

Should be good enough to take out Grippy

 

Since you are already doing an intank, would an inline not be of any benefit? Also I would think that the 60's along with your meth kit would be more than enough fuel for a stock displacement 6.0 with 600-700rwhp or so, but I agree with your point of going bigger now as opposed to running out of fuel. Im going with a bigger 50mm Tial BOV as its cheap insurance. Do you think 2 GN intercoolers would be easier to mount and more cost efficient than 1 OBX?? Are you going to use manifolds or have headers made? Im very interested in the progress of this. The off line TQ on 2 turbos that small will be insane!! How do you think that setup would compare with the STS GT67 or GT70 that everyone else including myself will be going with? Very cool project indeed!

 

I'm not sure an inline pump would be of any benefit....the in-tank will flow enough to keep 72# injectors happy at 90% duty cycle

The 72lb/hr injectors ARE overkill.....but I'd rather have overkill than have to replace either them OR the engine due to them being too small.

EVERYONE I've talked to says the 38mm BOV is more than enough to keep boost pressure under control during 100% throttle transitions....and some of those people are running 20+psi

I'm not sure that GN intercoolers are more cost efficient or easier to install....I'm using them primarily because of the inlet/outlet routing and size (I can fit two side-by-side in front of the radiatior perfectly)

I'm going to be using my existing Pacesetter shorties with custom-made DP's....the turbos are going to be low-mounted APS-style beside the transmission. Eventually I'll fab up a log-mainfold to keep exhaust pulse timing equal but for the moment the shorties will do fine.

the mounting will look something like this....remember, this is on Holden Monaro NOT a truck but it will at least give you an idea:



I know the off-line torque will be better with the twins than with a single turbo....how much better and how this will compare to a single GT67 or GT70 I can't even begin to guess. I'm apparantly the first person that has tried this in a truck.....most people in the F/Y-body world agree that the T3 exhaust housing will work great at lower boost levels (under 15psi) but all of those people are working with sub-4000lb cars, I'm going to be using this setup on a 5600lb truck.....I KNOW the extra load on the engine will cause the turbos to spool faster than they would on a car but once the truck is in motion it shouldn't be much different in efficiency than the car setup. Worst case scenario I'll have to swap out to larger A/R exhaust housings to slow the spool down a little.....and that's so easy that I'm not even going to worry about it until it happens

 

 

That is a bad *** setup and thats awesome that you are willing to tackle something no one else has tried. How far along are you? Have you gotten the turbos yet? Im not too knowledgable on turbos, but are the ones you are going with inexpensive or are you going with high end turbos?

 

I already own the turbos but they are .57 trim, I'm replacing the exhaust turbine housings with larger A/R housings to make them .63 trim for a slightly slower spool....thes e turbos new would run about $695, I aquired a brand-new pair of them from a friend in return for some work I did for him over the holidays.

As for how far along I am.....I've already mapped out the hot and cold side piping using PVC pipe and fittings as a template and have handed those over to a local metalworks to have them duplicated out of mild steel exhaust piping which I'll have ceramic coated. The Intercoolers are going to be the longest in getting not only because I'm going to have them custom made from a standard template but with a bigger core but also because they are almost $700 each brand new. Most of the rest of the stuff is either in the "getting ordered" or "already here" categories.....as soon as a I find a place that sells 72lb/hr injectors at a semi-reasonable price I'll be ordering those too

I'm looking for this to be a semi-long-term project.....I'd like to get it done before the end of the summer but we'll see how things go

Thanks for the words of encouragement !!!, I'm probably going to be looking for alot of help from people in the near future (that means YOU grippy !!!)

 

what? help the competition?

Anytime bro

 

Now that I think about it grippy the only real help I'll need from you is making sure my tail-lights are still working

Seriously though....You said you were willing to help me with my heads/cam swap, I had to take a rain-check on that so I figure I'll try to drag you down here during the middle of summer to play with hot exhaust parts

 

You will need two 255 lph fuel pumps to keep up with those injectors and that much rwhp.