Hi guys first post here. I currently have just stroked my 440 out 512 with a 440 source kit.
I'm thinking of putting a set of twins on there just for even more overkill. I'm not sure what to run as for turbo sizing. The car is going to 99% street driven due to not having a track close to my town. I want more power down low but still be fine to be able to cruise on a highway. I have trickflow 240s as my head's and from what I have read from other builds with a hyd roller cam and it's around the 600hp depending on the intake that is used. I've seen people use Garret 3076 but that was for a standard 440. Wondering how much difference the extra cubes will make to that.

 

What is the power goal?

 

800-850.
Was having a browse on the Garret site and it recommended GTX3576R.

 

The fine details are also confusing me.
Eg. Like the inlet size T3 or T4? I'm thinking T3 due to quicker spooling?
A/R ratio. A few different options here.

 

The matchbot application on Borg Warner's site is a good tool to check out. There's a thread on here about how to use it.

 

It shouldn't take much to get 800 out of a 512 with decent heads, a pair of S362 with the .88 open t4 would be plenty and spool fine. You probably don't really want instant spool with that many cubes, it's going to be a traction mess on the street.

 

what Ben said

 

Your probably right. The reason I was looking down this path is my friend who is doing my exhaust was keen to make a setup for a twin turbo. I know it sounds silly but I'm getting that work and materials for nothing so I thought fuck it. But might be just too much to handle.

 

Not silly on my end. If you enjoy tinkering and learning , do it.

 

I've got twin T04e's on a 426 Wedge, they're putting out WAY more than 850 no problem. They start to spool at around 1800 but will cruise nicely out of boost if I keep my foot out of the pedal. They're probably a LITTLE small for the engine, but I don't spin it out to redline anyway. Its fantastic fun on the street.

I will second what BEN said though, if I stomp it right outa the gate it's very hard to keep stuck. Rolling romps are epic though

 

If someone is going to do the hard part for free jump on it. Go just a little big on the turbos to let them come in slower, and you have overhead for the future. If you decided to race it you would be a stall convertor and wastegate spring away from a monster.

 

Would it be better to just put a big single on there in that case?

 

I like twins for it, you are in a sweet spot for twin T4 turbos, or even big T6 frames. A pair of S475s with t4 exhaust sides would be super sexy under the hood if you could make them fit. No one needs to know it's low boost, and s475s can be had cheap.


You could do a single but it would need to be really big. A monster s500 or gt55's is still small for the combo.

 

Yeah twins would look a whole lot cooler. Ice just had a quick browse online and I've added a few pics. Would this be the turbo? Most suppliers are using this brand. Keep in mind I'm in Australia
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Those look right, I am not familiar with the Australian brands though.

 

Think it's the Chinese knock off brand

 

I would get a real Borg Warner S475. I looked at the Aussie eBay and they have T6 s475 BW turbos for the same price as that Chinese knock off. Order from the states if you have to, but you should be able to find them down under.