Custom turbo manifold question?
 

I'm not sure if this is the correct section, i would have thought this should go in Fabrication.

However that section appears to be mostly people showing off their work.


So, eventually i want to turbo my 2005 4.0 V6 Mustang, Not trying to get insane power, my goal is 300hp which 8-9 psi should get me to fairly easily. If i can reliably get more than that it will just be a bonus.

My problem is, the 4.0 while a fairly solid platform, Has virtually no aftermarket, so the manifold and downpipe I'm going to have to custom make, I made the mistake of calling a local speed/performance shop, Which tried to quote me $2000-$2500 just to fabricate a turbo manifold, Which unfortunately is just out of the question.

So i figured, we're talking about a header/manifold and a turbo flange after all. So i started thinking about how one could be made both efficiently and cheaply.

This is what I've come up with so far, i may be completely missing something but here goes...

If i was to get a set (or two) of these

Fits 2005 2009 Ford Mustang 4 0L V6 Performance Header Exhaust 05 06 07 08 09 | eBay

Simply use the driver side header on the passenger bank, the bolts and ports should line up normal, But would put the output near the front where the accessory belts are (roughly)


Then, If i was to attach a standard exhaust flange like this.

2 1 4 "ID Universal Quickfix Exhaust Oval Flange Repair Pipe Kit Gasket FX8016EX | eBay

Probably, not that size but just a reference anyway, then i could have a turbo flange welded to that and it should work. Or am i completely missing something?


The Downpipe is easier, i can get a more or less universal downpipe, The wastegate and BOV both have rather universal-ish adapters and pipes which could be used (or forced)

Just trying to get some advice on if i'm on the right path, or if my logic is flawed.

I'd probably just fabricate some sort of turbo mount up-pipe off the factory exhaust manifolds. Don't forget an expansion joint where it crosses over. I'd trust those to stand up to heat better than no-name Chinese tube headers. You might be able to flip them side to side to get a bit more room to put the turbo somewhere up front.

That's the second time someone has said "Cross Over" I must admit I'm oblivious to what this means, Does this refer to the merging of both exhaust banks?


Currently the car has dual exhaust, and i would like to retain that.

Does this mean something different?

So, Did a little googling, Answered my own question.

But i'm wondering is it a bad practice to drive the turbo off a single bank, Did some searching some say it will work, and some say it will create asymmetrical back pressure.

Is this a huge problem?

Will my only option for retaining true dual exhaust be twin turbo?

SAAB did this. It can work, but there are a couple things to consider:

1. You will need a turbo where the compressor and turbine are sized for this, since you will have a much smaller exhaust gas volume available than normal.

2. This will result in very different cylinder filling characteristics from one bank to the other. You will need an ECU with individual cylinder trim adjustment on both the fuel and the spark to tune this properly.

This seems like more headache than it's worth to me. There isn't a real advantage of this over splitting your exhaust downstream of the turbo.

Hmm, Yeah thats too much headache, While i know there isn't really a performance benefit to doing this.

My only real issue with merging the exhaust from both banks is, Well it is a mustang after all and i'm concerned about how it will change my exhaust note.

(And i just paid a few hundred bucks to have the true duals put in this year, So ya know cutting them back out is going to be annoying at the least)

Its suppose to sound aggressive ya know, Any insight?

I'm also trying to figure out if i will be better off buying a junkyard turbo (they are hard to find around here)

Or buying a new chinese copied GT30 like this

On 3 Performance 55mm GT30 Turbocharger GT3072 | On3Performance

I've read a bit and some say these "better" or at least more expensive chinese turbos "can" work if they are properly setup, one thing everyone says is "oil, oil, and yeah more oil" But i've also seen conflicting information too, some say if your oil pump puts out 60psi or more you still need to run a restrictor even on a journal bearing.

Any advice on that?

You're going to end up with some changes to the exhaust and a quieter exhaust note any way you slice it, just the nature of putting a turbo in the exhaust.

Your best bet for finding a V6 sized turbo used may be to check on Buick Turbo V6 boards for someone selling a used model.

Chinese turbos are a roll of the dice. I've seen some last tens of thousands of miles and some burning oil after a month of use.

I could live with the exhaust changes.

But i'm trying to come up with the best way to accomplish a single turbo system (i think twin turbo would be pushing the stock engine past its limits) on a car with nothing available on the aftermarket for it, And i'm trying to keep the cost at the absolute minimum i can while still doing it somewhat "right" to the point that its not going to break after a few thousand miles.

I really want to try to do this for $1000 or less, I'm sure that is going to be a challenge I can buy a direct bolt on supercharger kit for about $1900, So my $1000 budget is based on having to do all of the work myself.

If i was a decent welder this would be simple, But I'm terrible So any welding i'm going to have to pay someone to do.

And i guess I'm looking for some advice from the community here on how to best accomplish my goal with decent quality for minimal cost

If you've got to pay someone to fab this up, and that someone is not a buddy who will take a case of his favorite beer as payment - get the bolt on kit.

Or get a MIG welder and practice till you're ready.