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I have been thinking about this for a while now and am interest to know about Turbocharging the Boss 5.4
I know most people that want boost in the 5.4 go for TT or a supercharger, I'm yet to see a single turbo on one, why is this?
I'm not considering this for my car right now, but some information on it would be handy. If you have any ideas what could work and what couldn't that would be great.
Thanks.
A Single turbo would offer very little and be a complex thing to install from an exhaust perspective, 2 low mounted turbo's would be a better option or simply a blower.Quote:
Originally Posted by ToCo
The turbo is a pump - the gasses from the engine drive it and it relies on volume/temperature of the gas for it's efficiency. The turbo preferably should be mounted as close to the exhaust valves/manifold as possible.
Now to your question ... a turbo needs to be matched to the volume of air the engine requires. A 5.4L motor at 5000RPM and above needs an lot of air. If you have a single large turbo to provide this air, then using just 2.7L of the engine's capaicty is going to make it inefficient right at the outset (ie not going to have the physical capacity to provide what the engine needs.)
Looking at it from the other way ... if you use a smaller turbo to operate effectively with 2.7L, then the volume of air provided will only be effective on a 5.4L engine running at half it's max revs.
That's not to say it can't be done - it has. But the trade off IMO is not worth the money or effort. If you only want to run low boost, say 4 or 5 psi at 4000 rpm (and above) then a single turbo will do the job.
Another consideration is the heat generated at the exhaust valve - if you have a turbo on one bank you have lots more heat on that bank. I don't see this as desirable. Uneven temps across the engine from one head to another has to cause problems.
So ... two turbos? Well yes, but with a BOSS where do they go? Physically you have a big issue. It is impossible to have them positioned where they need to be - as close to the heads as possible. Going low mount will drop efficiency by as much as 50%. And it increases lag too! Again, it has been done .... but you have to ask yourself (well I do) WHY? ...
Honestly the most cost (and power effective) way is a supercharger on a BOSS motor for many reasons.
Thanks for the info there fellas, I actually understand what you posted there too MisterAU, cheers.
I guess thats exactly why no one has really done it before, its really not effective at all for the money it would cost. I think I will stick with NA at the moment then!
mr cve turbo'd his 3v ba ghia, with pretty decent results iirc.
ran in the 11s, 300+ rwkw. full sleeper spec too.
the main reason is space...
plenty of single turbo LS1's, LS2's etc.
in terms of air volume, they're pumping more, so turbo size isnt the problem.
Engine bay space is an issue for more street setups.
low mounting turbos typically has space concerns aswell, you don't want them hanging too low, for obvious reasons, coupled with the need for oil return/pump to sit even lower.
saying that, Mr CVE had his 3V, with a single mid mount turbo.
He's also done another 2 since, and all had results between 300rwkw and 370rwkw on relatively low boost.
I'll be doing mine soon, just sourcing injectors.
I also purchased a mid mount single Turbo Boss 260 setup last year, the 260 was installed in a BA Ghia.
So its been done, its just not overly popular.
a lot of the numbers quoted in this thread seem incredibly inaccurate.
A single turbo on a V8 doesn't mean just running it off one bank, There is a cross over pipe so the single turbo runs on both banks, there are complexities in piping obviously. but in terms of 'offer very little' theres no reason to assume that.
if the turbo is correctly sized for the application, it will be just as good as a pair of smaller turbos.
A couple of years back we were looking at a new project car and were thinking of either a turboed Windsor or a Boss and concluded (after a lot of quoting and research) the Boss engines have a few issues that limit you. Mainly it was the block it self that was just to big, this left very little room for piping and mounting turbo/s etc, so even if you find a way to squeez them in the engine bay won't allow you room for a decent air intake and other piping, and what the point of a turbo if you can't let it breathe! You will have to modify the engine bay to MAKE extra room. So in esence it can be done, it has been done but some serious mods to the actual engine bay to gain the full capacity.
This is primarily why we looked at an EL, twin turboed it and that was low mount turboed too and had no problems with piping or room or power output! If I had my way it would have been supercharged but twin turbo windor was unique and he won that argument!
That's a personal experienc, hope it helps.
Its a pain in the ass to single turbo a V engine, they have odd manifolds with two banks going into one with a cross over pipe.
Also I just realised this thread is 2 years old, go me.
People who say there's no room to turbo a boss aren't trying hard enough.
http://i1296.photobucket.com/albums/...ps15997da1.jpg
Nice, a blower in the valley may be easier but damn that looks impressive.Quote:
Originally Posted by defective