Turbo Suggestions for BBC ?
 

I'm helping a buddy turbo his 65 nova. He is building a 8.8:1 compression 496 stroker for it. He wants to go with a single turbo setup hoping for 1000 whp. Would a GT45 (.69 AR compressor/1.05 AR Turbine) be big enough? He said he can get a used one pretty cheap. If not, any suggestions. Holset?

Re: Turbo Suggestions for BBC ?
 

Two would be enough. ;)

Jesus man a 496 anything shouldnt have a problem putting 700+ to the ground, an extra 300 from a tiny huff of boost isnt a stretch. Hope the rest of the car can take it...

Re: Turbo Suggestions for BBC ?
 

I was just worried that the exhaust AR would be too restrictive for all those damn cubic inches.

Re: Turbo Suggestions for BBC ?
 

T6 exhaust side required for sure.

I would look in the 88mm - 91mm size range, yes I realize that this is way overkill, but it will at least get out of that motors way when not in boost.

Re: Turbo Suggestions for BBC ?
 

hx55 will get you there

Re: Turbo Suggestions for BBC ?
 

What about one of these guys?

http://cgi.ebay.com/ebaymotors/Huge-...QQcmdZViewItem

Re: Turbo Suggestions for BBC ?
 

That's a big bitch

Re: Turbo Suggestions for BBC ?
 

--i'm a retard

Re: Turbo Suggestions for BBC ?
 

Learn how to keep cock out of your mouth.

Re: Turbo Suggestions for BBC ?
 

It would work fine, over kill on the compressor side (good for about double what you are after), but its not like a 496 doesn't have enough torque to shed the tires on the street all by its self anyway.

The hx55 with the big exhaust side would be enough turbo, but I would goto at least a an hx60, and probably right to that 82, if you have the room.

Re: Turbo Suggestions for BBC ?
 

That is about the least important thing on a motor like this, thanks your a real benefit to have here. :1

I can think of about 15 compressors off the top of my head that would work fine, but the turbine they are attached to would choke the ---- out of that motor. 4294 for example.

Re: Turbo Suggestions for BBC ?
 

you could just run a small turbine with enough compressor size to support the motor but build the manifolds etc to utilize large wastegates (at least 2x) to get the most flow out of them, then the motor will make boost right off the bottom but the wastegates will keep the restriction down to make power

Re: Turbo Suggestions for BBC ?
 

This sounds like it should work, but in fact when you run a drive pressure gauge, the drive pressure is the highest when the wg is OPEN. So you end up with the same problem of heat build up and detonation issues as you would with a small turbine and small turbine housing. IMO run the biggest turbine side you can, that will still allow the spool that you require, this is probably different then the spool you want.

I have had a few bbc/f/m vehicles, and I NEVER thought they needed more bottom end. Every honda or car I have owned under 2L could use more bottom end, but I will always sacrifice that for a good turbine to compressor balance / top end smash you on the highway.

Edited for clarity

Re: Turbo Suggestions for BBC ?
 

Well, he seems determined to get that GT45. It has a 1.05 AR turbine so I think when I build the manifolds, i'm gonna use 2" SCH 40 instead of 1.5". That should give it a little more breathing room. That in conjunction with what accordepicenter mentioned about large wastegates, it should work out all right. I was so hoping he would jump on the HX82. That would be badass.

Re: Turbo Suggestions for BBC ?
 

Is that GT45 a T4 or T6 1.05 there is a big difference.

Re: Turbo Suggestions for BBC ?
 

Yes, since a T4 would def choke off anything with that displacement. There are stock LS1's running that GT45 that spool off the line, and run 10's on like 15 pounds....

Re: Turbo Suggestions for BBC ?
 

Its a T4 divided turbine. He's gettin it this week I guess. Its brand new and he's gettin it from one of his buddies for $400 :o. I'm think i'm gonna try to get him to sell it and get something bigger or get another one and run twins. Twin gt45's would get it done.

Re: Turbo Suggestions for BBC ?
 

Or just get him to buy a T6 exhaust side for it.

Re: Turbo Suggestions for BBC ?
 

I thought about that. What all do I need to know in order to find one. Just inducer and exducer dimensions, right?.

Re: Turbo Suggestions for BBC ?
 

Yup, or the actual numbers off the turbo, if it is a genuine garrett.

Re: Turbo Suggestions for BBC ?
 

S480