Single T70 Too Small? Piping and Velocity Q's as well

[avexhype]

What's the smallest turbo I can efficiently run on a 5.0? I have a 12' A6 GT and am thinking about piecing together a kit myself. Space is a major concern. I will do my best to not cut or modify my engine bay and retain all stock components.

I was thinking a T70 with a .81 a/r turbine housing would be nice and compact enough to not take up too much space, but still make decent power. I had one on my old 2v GT and it made 500rwhp on 14lbs, no other mods but fuel and a forged shortblock.

I just need something that will support 750-800 rwhp max without choking the engine.

For hotside piping, is 2.75" from the manifolds to the turbo too small? I want to keep velocity up, but i understand these 5.0's like to exhale and valve float may be a concern with too small of a hotside.

I plan on a 3" downpipe Y'ing out to the stock OTA pipes. Will I be okay, or do I need to go bigger?

FWIW, I've scratch built a kit in the past before. I just need to understand the flow dynamics and limits I can work with on a Coyote.

 

[2003mach1]

I'd be more concerned with the turbine on that turbo being too small. You know the size of it?

 

[avexhype]

Actually, how about these for examples:

No specs, but it looks between a T70 and t76:
http://www.on3performance.com/shop/on-3-gt45-turbocharger/

OR

http://www.on3performance.com/shop/on-3-performance-76mm-t-4-turbocharger/
Cold Side

Compressor Wheel 76mm
.80 a/r
4” Inlet and 2.5” Compressor Outlet
Inducer- 76.71mm
Exducer- 102.36mm
Exhaust Side

Exhaust Housing T-4 Flange
.96 ar Exhaust Housing (.68, .81, 1.0 divided, 1.15 divided $30 charge for swapping housings)
3.0″ Vband outlet
Inducer- 74.5mm
Exducer- 65mm

 

[Slowb00st]

You need to go bigger than a 65 on the exhaust side. As I recall on3 tried to make a single kit and it did not perform as expected, so I would say away from their turbos for single setup.

 

[avexhype]

By .65 are u referring to the exhaust housing or the actual turbine wheel size?

 

[Slowb00st]

By .65 are u referring to the exhaust housing or the actual turbine wheel size?

I was referring to the wheel size, in this case the exducer. But in the other hand I would also consider a T4 .65 A/R housing too small also.

 

[Aaron@JPCRacing]

Turbine housing is a little small. Your going to have valve float issues with that turbo at like 600hp.


If you want I can get you setup with a precision turbo for a couple dollars more and you'll be alot better off.
As far as piping size goes those sizes should work fine

 

[avexhype]

Aaron, would a .96 housing be the minimum then?

Im interested, especially if it's still in my price range... could you PM me with some recommended turbos and sizes for my application? As I mentioned, 750 rwhp max is fine, compact dimensions are the most important thing at the moment for me.

 

[Aaron@JPCRacing]

The A/R isnt as much of a factor as the turbine wheel size. But yea I'll PM you some options and recomendations

 

[avexhype]

Thanks. I get confused and am still learning about the technical specs of turbos. Housing, inducer, exducer, etc.

I got it now.

So what's the minimum turbine inducer/exducer I should consider? Will anything in the t4 category work, or should i be looking at t5/t6?

 

[T's03GT]

For a single setup I'd go T6 Borg. Plenty of people on here running that with zero issues.

 

[wakebum2507]

For a single setup I'd go T6 Borg. Plenty of people on here running that with zero issues.

Don't be a smart ass.

 

[jn2]

Go with a BG EFR 8374 or a EFR 9180

 

[T's03GT]

Don't be a smart ass.

Don't you back talk me, mister.