Turbo

[CrackerJack]

Because I thought posting in the regular LS section would bloat the hell out of this, here it is.

I've really been thinking about a turbo setup lately. I watched a few videos about truck setups for a friend and really am having a hard time figuring this out. Mostly what I have seen are exhaust driven turbo's. I heard rear mount turbo on here somewhere but have not looked into that. I was thinking maybe 6 lbs boost, not a lot but enough so the power is there.

Using a tool found on a mustang forum for what kind of turbo I should use this is what I got.

Using fairly close measurements of course

Engine size: 3900cc
Max RPM: 6600
Number of Turbo: 1
Intercooler: No
Turbo Boost: 6 lb

It came with the result of a Garret T3 with 60 Compressor Trim* And putting out almost 350 HP

*Dont know about Compressor Trim just yet.

This is just a simple calculator to help decide what turbo charger you should use.

Here is a link to what turbo I believe is what it called for.
http://cheapturbo.stores.yahoo.net/gat360trwar.html

Putting some though into it, I was still thinking of an exhaust mounted turbo but could not think of a great way to get it to work being that we have dual exhaust and all.

Further inspection got me thinking how to run the air BACK to the intake... Of course there is also the issues with fuel delivery and whatnot, but Im not minding that just yet.

Comments and whatnot appreciated! I'd like to get this planned out over winter and get a plan of what I need.

 

[pektel]

Okay, here's what I suggest.

Pay someone else to figure it out for you. This is not an amateur project, and should be left to professionals.

Or buy cam's turbo, and have a reputable shop install it. You'll have to redo the coldside piping, since the tb is in a different location, but that should be minimal in the grand scheme. You won't find a better deal.

 

[Quik LS]

IMHO, I would never run a forced induction setup without intercooling. for every PSI you squeeze the intake charge you raise the temp roughly 18 degrees. So a 5psi, you are adding roughly 90degress on top of the ambient air temp into the cylinders. In Texas, it's already 100+ outside most days. You will lose a lot of the potential trying to tune out the detonation from the heat, since the engine it already at 10.55:1

There were 4 people here with this done already, 3 were ILLS' work, one from way back. Steve and Cam are still selling their's.

There is a lot of work to do when boosting the intake of a car that was not factory boosted. Everything from the PCV, all the vacuum lines (EGR, brake, EVAP, ...), ...etc needs to be re-worked. Steve can talk to that, since he worked through a lot of it when the turbo was on his LS. At least with your Gen2 you do not have to worry about the air-assisted fuel injector issues.

If you want to build your own - hat's off to you, is there a particular design flaw with the current ones that you are trying to improve upon?

 

[pektel]

Lou, he has a gen 1.

And +1 about the intercooler. I was wondering why one would not, but don't know enough about FI to suggest anything regarding that.

 

[Quik LS]

yikes - sorry. If you have a Gen1 - then you are stuck redesigning the intake manifold. The Gen1 uses air-assisted fuel injectors, fed air through an air-rail that comes off the IAC. Since you will be needing to upgrade the injectors, and they do not make air-assisted larger ones (that I could find) you have to ditch the whole air-assist feature.

The issue is that the manifold is designed with the air-assisted injectors in mind. They have a longer snout, that is larger than typical injectors - so it is unlikely you will get a good seal with standard injectors (escepially under boost), not to mention that your spray pattern could be messed up by trying to shoot through bottom bung that is and inch thick.

Someone has to try it and see how much work is involved with the Gen1 manifold issues....

 

[CrackerJack]

I couldnt find any set-ups for an LS turbo and completely forgot to check members here. All I found was that they had it but gave no particulars on how it was set-up.

These cars are impossible to work with basically... Gen 1's really got the shaft didnt they? As for the intercooler I would run it, I just came up with numbers without because Im pessimistic about the gains anyway. I got all winter to figure it out though, I can't afford to buy it now, I just want to get a list of everything that I need. And it looks like I have to do some major modifications to the manifold etc.

Wish I had bought that damned Impala now....

Also, while on the subject, what are the major differences between running a turbo vs supercharger? Cost / benefit wise. If all this work is going to be done, is it worth just stepping up to a supercharger?

 

[pektel]

supercharger is belt driven, a turbo is exhaust driven. Both boost the intake charge.

The nice thing about the supercharger, is you can get it on llsoc. There are some extras (vacuum lines, fittings, etc.), but the majority is all in one boxed kit.

I wouldn't worry about the gains not being worth it. if you can get 350-375 at the wheels with this car, be satisfied. That translates to between 426 and 457 hp at the crank (I'm assuming 18% parasitic loss). Speaking of parasitic loss, I don't know how that is affected by the supercharger. Meaning, since it's belt-driven, I dont' know if there is further parasitic loss.

I still don't think I've seen final performance numbers, or timeslips from Lou's SC setup. So I can't tell you which one is better than another.

What I can tell you is Lou's setup has been WORKING for quite a while. Most who install turbos, on the other hand, seem to sell the kit shortly after installing it. Dunno why, but that seems to be the case.

 

[Quik LS]

Turbos are more effiecient since they do not use engine power to turn the compressor, like a supercharger does turning the rotor pack..

Turbos require exhaust flow to spool, and therefore need some engine rpm to begin to make boost, where as a supercharger will make boost sooner being connected to the engine's crankshaft. In this application - I believe it will be more about personal preference, since we are talking low boost levels, we can make more power with either option than the engine can handle.

When I look at the OEMs - most have been turbocharging 4 cylinders, and supercharging 8 cylinders for some time now. I own a turbo 4 in my Lotus, and a superchanged v8 in the Lincoln. The 4 cylinder revs higher and faster hence the turbo is a nice fit, the V8 is more torquey and hence a nice fit for the SC - just like the OEMs, turbo'd small hatches vs the SC'd Roush Mustangs.

However, there is a definate shift - turbos are coming. More and more are showing up at the strips, and Ford is bringing them to the masses with the Eccoboost line of engines - twin-turbos for V6 (V8 can't be far behind).

Cost is the other issue - a good set of turbos will likely cost as mush as the entire SC setup... but - maybe worth it.