So here's the deal, I have an '87 F-150, 4x4 with a 5.0L and an AOD. Recently I aquired a Garrett T-3 Turbo from my brother's dead 86 T-bird(I have two actually but I thought that'd be too much and I'd have to swap out pistons). I bought a set of headers from an 85 Mustang and plan to build a pipe with a turbo flange (I've got all the tools and I'm a very capable welder).

I was just wondering if any problems would occur regarding balance. Would putting a turbo on one side and not the other cause back-pressure issues or even cause one side to wear faster then the other? Also, as far as the intake goes, would it matter which I dump the boosted air into?

Before I spend the hours to make, modify, and modify a system to get this to work I figured I'd ask here and see if maybe even someone has done this to their truck and had any tips.

My basic reasoning for this is:
1. Performance, always want more power
2. Better fuel economy (in past experiences it helps alot)
3. Why not? It's just sitting around!

Anyone have any input on this? Ideas? Any thoughts will be greatly appreciated.

 

I would never create backpressure on one side, and not the other for the reasons you're concerned about. You can put the turbo further down the exhaust system, at where the "Y" pipe meets the cat if you want to join the sides somewhat easily, and that might be a great solution for you.

I think a single T3 off a t-bird is too small for your engine, you probably need two.

T-birds or what, 2.5L? And you have a 5L

 

The T-bird is a 2.3L but that garrett can put out 16lbs of boost... the compression ratio on the old thunderchicken is alot less aswell so I thought two would be too much. I don't have a Y-pipe anymore... true duals.

 

Boost capability at what CFM?

a 2.3L engine, 7000 RPM can easily require 600cfm from the turbo.

A 5.0L engine at 5000 rpm, can easily require 900 cfm from the turbo(s).

So if you think the tiny factory sized turbo off the 2.3L engine can do this, by all means fabricate away.

I can assure you that it cannot achieve what you want on the intake side. It's simply not big enough. While you suggested driving it from one side of the engine on the exhaust size, it's at least 1/2 as large as you'll need on the intake side.

Since you have "true duals" fabricating both sides and having two turbos shouldn't be a big deal. Been there done that several times.

The way to ballpark this for yourself is with my simple, monkey-math formula:

 

Yes i guess its something to think about... I just don't want to hurt more then im helping. I guess I can always start with one and go from there.

 

Yes you can. However, I'm really trying to reinforce after all that work, with the turbos that you're thinking of, one will be most disappointing.

Just trying to save you some grief, that's all.

 

Yea, putting it all on then pulling it all off again IS alot of work that I don't really need to do but... the other turbo happens to be on a running engine thats just taking up space in my shed. The engine has less then 100 miles on it and I'm thinking it would be a shame to leave it turbo-less...

What I could do and thought of is make the flanges and have it all set up to run two turbos but just make another piece of pipe I easily remove later if I have to. That way, I only need to put it all on once... after that it's just pieces.

Do you have any recommendations for what to use for an oil pump?

 

Engines in sheds do not need turbos. When it comes time to use that engine you can always get another turbo.

I made my own twin-turbo exhaust system using 7/16" plate for the turbo flanges, 5/16 or 3/8 for the header plates, and ordinary "black pipe" for the runners, which I sectioned into trapozoids so I could "bend" them. Not necessarily the most optimal design in the world however it absolutely will flow better (way better) than the stock log manifolds, and it puts the pair of turbos very close to the throttle body meaning that the exhaust side, and intake side, are incredibly short.

Here's what I did, step by step more or less:

http://frederic.midimonkey.com/f350-...manifolds.html

And a picture of one of the turbo manifolds:

http://frederic.midimonkey.com/f350/IM001584.JPG

Ignore the cheesy round exhaust ports - they're undersized for a reason - to give me plenty of material for port matching to the heads, once I finish getting the heads shaped the way I want them to be.

I drilled and tapped a hole in the oil filter housing which will feed hoses that in turn feed the turbos. The returns will go from the turbos into the side of the block, where I've drilled and tapped a hole on each side of the block just above the oil pan, so the oil goes in, falls into the pan, and gets recycled.

I'm using a high volume oil pump rather than a high pressure pump, so the additional oiling requirements of the turbos is definately covered.

I may revisit this once I dig out my dry sump bits... just haven't located them as of yet.

 

Thanks for your help, I got something to go off now... I'm still thinking of using existing headers and just bolting on a flange... I don't want my turbo and engine to share oil, I've had past bad experience's where one wrecks the other and I'd just sooner avoid that.

I got some pipe ordered and I'll start working on it when it gets here. I'll post things when I get something accomplished I guess. Thanks for the idea's and suggestions.

 

That turbo is too small to run singled on a 5.0. Listen to Frederic.

 

But one is better then none...

 

You hope

 

This question I have comes to mind, and seems most appropriate in this thread, here it is.
Theoretically, we will say the 2.3L-T maxes out stock at around 6000rpm, its around there somewhere. The air capacity into the engine is 245cfm, more will be needed to make boost.
A 5.0L will flow 245cfm at 2800 rpm, maxing out the single 2.3L turbo.
Say the 2.3L starts making boost at 1500rpm. At 1500rpm the 2.3L flows 61cfm (again more needed for boost). The 302 flows 61cfm at 690rpm, so you would be boosting on idle untill 2800 rpm. The 302's powerband is higher than that.

Ok, those are the facts....So here is the question, could you run an external wastegate big enough to bypass enough exhuast past the turbo so it wouldnt be choking the engine, allowing you to still run the engine into its peak power range?

Im sure the power would still drop off after loss of boost, and doing so wouldnt really be beneficial to performance, but I just had to ask lol.


OT- how much extra CFM over the amount the engine is drawing in, does it take to create 1# of boost?

 

Calculating Airflor Requirements

cfm = (cid x rpm x VE) / 3456
cfm = (302 x 6000 x 0.85) / 3456
cfm = 445.66


Calculating Pressure Ratio

pressure ratio = (boost psi + 14.7) / 14.7

If you want 10psi of boost, the pressure ratio is:
pr = (10 + 14.7) / 14.7
pr = 1.68:1


Temperature Rise

A compressor will raise the temperature of air as it compresses it. As temperature increases, the volume of air also increases. There is an ideal
temperature rise, which is a temperature rise equivalent to the amount of work that it takes to compress the air. The formula to figure the ideal
outlet temperature is:

T2 = T1(p2/p1)^0.283

T2 = outlet temp degrees R
T1 = inlet temp degrees R
degrees R = degrees F + 460
P1 = inlet pressure absolute
P2 = outlet pressure absolute

If the inlet temperature is 75 degrees F, and we want 10psi of boost, to figure out T1 in degrees R:

T1 = 75 + 460 = 535 degrees R

The P1 inlet pressure will be atmospheric in our case and the P2 outlet pressure will be 10 psi above atmospheric. Atmospheric pressure is 14.7
psi, so the inlet pressure will be 14.7 psi, to figure the outlet pressure add the boost pressure to the inlet pressure.

P2 = 14.7 + 10 = 24.7psi

Now we have all the variables and we can figure out the idea outlet temperature.

T2 = 535(24.7 / 14.7)^0.283 = 620 degrees R

the convert back to degrees F
620 - 460 = 160 degrees F

The above formula assumes a 100% adiabatic efficiency (AE), no loss or gain of heat. The actual temperature rise will certainly be higher than that. How much higher will depend on the adiabatic efficiency of the compressor, usually 60-75%. To figure the actual outlet temperature, you need this formula:

IOTR ÷ AE = AOTR
Where:
IOTR = Ideal Outlet Temperature Rise
AE = Adiabatic Efficiency
AOTR = Actual Outlet Temperature Rise

Lets assume the compressor we are looking at has a 70% adiabatic efficiency at the pressure ratio and flow range we're dealing with. The outlet temperature will then be 30% higher than ideal. So at 70% it using our example, we'd need to do this:

85 ÷ 0.7 = 121 degrees F Actual Outlet Temperature Rise
Now we must add the temperature rise to
the inlet temperature:
75 + 121 = 196 degrees F Actual Outlet Temperature


As air is heated it expands and becomes less dense. This makes an increase in volume and flow. To compare the inlet to outlet airflow, you must know the density ratio. To figure out this ratio, use this formula:

(Inlet deg R ÷ Outlet deg R) × (Outlet Pressure ÷ Inlet Pressure) = Density Ratio

We have everything we need to figure this out. For our 302 example the formula will look like this:
(535 ÷ 656) × (24.7 ÷ 14.7) = 1.37 Density Ratio

Using all the above information, you can figure out what the actual inlet flow in CFM. To do this, use this formula:

Outlet CFM × Density Ratio = Actual Inlet CFM

For the 302...

445.66 CFM × 1.37 = 610.55 CFM Inlet Air Flow

That is about a 37% increase in airflow and the potential for 37% more horsepower. When comparing to a compressor flow map that is in Pounds per Minute (lbs/min), multiply CFM by 0.069 to convert CFM to lbs/min.

610.55 CFM × 0.069 = 42.12795 lbs/min

Now you can compare these results with compressor maps of turbos you are considering and determine how suitable they are, or aren;t. Play with sevearl adiabatic efficiency numbers and pressure ratios until you have good results. Twin turbo systems would require each turbo to do half the work, whereas a single turbo system would be required to do all the work.

So there ya go, all the math necessary to answer your question which was... "how much extra CFM over the amount the engine is drawing in, does it take to create 1# of boost?"

 

thanks...this is going into my bookmarked pages.