BBC twin T70's

[Z06killinsbf]

I sold my dad a T70 turbo a while back for a project but now he is talking about getting a second one and running twin T70's on his 468 BBC. Would this be a good match? I think it's the .68 AR housings.

[Sleeper]

To small of a turbine housing, at least that's me.

[War Machine]

If you need someone to build the turbo set up let me know!

[naynay]

https://www.theturboforums.com

[Acrotom]

A pair of 70 mm turbos has a lot of potential. What is your dad's performance goal?

The .68 turbine housing is probably too small for a high horsepower application, but may work fine depending on what he wants to do. If he wants to limit the power output, but have quick response, the .68 housings may be just the ticket.

Hope this helps a little. Let us know what he does, and how it works out?

Tom

[91cavgt]

2 words.


Torque Monster

[Sleeper]

what type of block as well?

like Acrotom said twin 70's will make some power. That type of power is out of my knowledge zone. haha im a 700 and under guy.

[Z06killinsbf]

He wants the most power he can get, cheapest budget to do it in, and be cleanly packaged. Right now it has ported stock heads (not sure if oval port or what) solid .560ish cam basic mods on a 125 shot and he wants more. It's also a 4 speed and 3.42's. Stock 2 bolt truck block I believe. I could ask him for further details if needed.

[Acrotom]

He wants the most power he can get, cheapest budget to do it in, and be cleanly packaged. Right now it has ported stock heads (not sure if oval port or what) solid .560ish cam basic mods on a 125 shot and he wants more. It's also a 4 speed and 3.42's. Stock 2 bolt truck block I believe. I could ask him for further details if needed.

From the description, I get the impression that this is a somewhat mild street car.

Twin 70mm turbos have the potential to make 1500+hp. It will take a pretty big budget to build anything at this performance level.

If the car will remain a mild street car, these turbos will do a fine job, but they will not be used to their potential. Try out the small turbine housings and be prepared to upsize them as the power requirements increase.

Since he already has one turbo, it makes sense to just get another one like it and proceed with the build.

Good luck with the project,

Tom

[turbostang]

It will likely work fine, especially at mid range power.

A little quick math - Most of the MPT70's in mustangs are on 302 cubic inches, with the .68's. My own car made around 600 to the wheels. Spooled quick, like, real quick. (and ran 6.2x's).

468/2 = 234CI per side in the same .68 housings. That particular setup is probably even better suited as far as turbine backpressure/max HP usage etc.. compared to a 302 and a single .68 turbine.

This is all assuming you're using a "T70" that's either a MPT70 or a very close substitute and not some T6 dump truck turbo.

[Z06killinsbf]

Yes, MPT70, cam is actually @ .595 but getting 1.8 rollers to make it .633. Should be decent from what y'all say. I'll tell him to go ahead (if he so chooses) to get the other one. I just wanted to make sure they wouldn't be too little or too much. Thanks