Allright right now i have a 2001 GT with an Accufab throttlebody and intake plentum, a JLT permormance cold air, and a MAC catback. I was wondering, i have come across a good bit of cash and i want to turbo! Can anyone help me out with a list of everything i need to do 1st to prepare my engine/car for a turbo??? ex.) cams, port & polish, monifold....
I just wanted some opinions from people that know what they are talking about....Thanks!

 

first forge the bottom end, then get some good flowing p/p heads with stage II turbo cams, then get rid of plastic intake and to round it up upgrade your fuel system and get a tuner and have car dyno tuned

 

let's see. Forged bottem end. Cobra gas tank with Ford GT twin pumps, you are most likely going to need a tubular k-member and a-arms along with coilover set up. I would say not to do the heads and cams yet unless you have the 2500-3000 dollars to drop in it right now. You are going to need a built tranny and rear end... Well I should of asked first off how much money are you trying to spend and how much power do you want?

 

honestly, it depends on how far you want to go. a good turbo set up, and a decently prepped engine/trans is going to cost you $10+K, its nothing to just go ahead and do unless you plan on being prepared anything.

One of the most important things to remember with turbo's is that you're going to be running a ton of strain on the entire valve/drive train, and unless you build the engine to handle it, you won't be able to run enough power to see the advantage of using a turbo.

The stock engine might handle, quite honestly, on a great tune, 390RWHP, and I would say honestly, no more than 420lb-ft of torque at the wheels. The torque rating is significantly more important than the horsepower rating, because technically horsepower is just a function of torque, and the torque curve will give you a little more information on how much stress you're putting on you're engine/drivetrain.

If you size a couple turbo's nicely, or even one nicely, you will have very little spool time, less lag, and alot more low end torque, which can be a good/bad thing. Remember, if you're running 400lbft of torque at say 4200RPM, and you can actually hook up (if you're running sticky tires), you're putting a great deal of stress on everything, the load on the engine is higher, the stress on the axles/differential is far higher.

The main problems associated with turbo's that I see are Spool time/heat. I don't think people consider how much heat turbo's actually create, and it might slip their mind that the hotter the air is that is going to the engine, the more likely you are to to do damage to something important because of detonation/preignition.

all that said, lets go into what you should consider if you're actually going to go with a turbo.

If you're okay with staying under 400rwhp, then you can probably stick with the stock bottom end. I would still suggest ported/"aftermarket" heads. Remember, the more efficient you're engine is, the more air the heads/intake/exhaust can flow easily, the less manifold pressure you have to run to reach you're goal.

Lets say that your' goal is to get to 390hp, while that is perfectly possible to do on the stock heads/intake/exhaust manifolds, on the stock pieces you might be running say 8-9PSI to make those numbers, whereas with ported heads/ and a set of well flowing headers will probably get you to that 390HP on less manifold pressure, which is literally, by every meaning of the word, less stress on engine components.

So, if you're planning on sticking with the stock rotating assembly, I would have to say that a good set of ported heads, either the Stage II generic form of a Blower/Turbo camshaft, or a custom ground camshaft, and usually whatever headers/manifolds come with the turbo kit, if you're going with a kit.

If you're planning on getting bigger numbers, you're going to have to replace the whole bottom end, ie Crankshaft, Rod's, Pistons etc. If you're looking at getting significantly more than 600hp at either the crank/wheels, I would preferably reccomend a forged crankshaft, whreas, if you're only looking for 450-600hp, the stock piece will be fine. You're going to have to replace the rod's with a decent set of forged rod's, manly, eagle, there are quite a few brands out there, and then start looking at forged pistons.

Since you're going to be running higher temps than you would if you were using a blower, you're going to have to run a lower compression, preferably somewhere around 8:1-8.5:1 compression, so a dished piston will be in order, and again, there are quite a few brands that produce such products. In my Engine, i'm running basically the same pistons that came in the 2003 Cobra, which are Forged Mahle pieces, but again, Eagle, Manly, all good brands. For a crankshaft, if you're going to go forged steel, you can simply get the stock piece out of a 1999-2004 Cobra (I believe the 99-01 cobra's have a forged crank as well).

If you prefer not to assemble the engine yourself, you can have a machine shop do the work, in which case you'll need your' block bored over at least .0020" so that you have a clean cylinder wall as a base, or you can buy a shortblock from a place such as MMR, or Livernois (I believe they are still around), which is basically everything except the heads/intake. I'm not sure if it comes with a timing cover, hopefully a member who has purchased one will come in and clarify.

So once you have the engine together, since you're running a turbo, if you plan on doing any street driving, or anything other than just running at the strip, I would defininately upgrade the stock radiator, I'm fairly sure the flow numbers are far too subpar compared to a Fluidyne to support a street car with a turbo.

You're going to have to run an intercooler no matter if you run 1 turbo or 2, they produce so much heat, it's a requirement. If whatever kit you're looking at doesn't come with one, I would suggest a Treadstone piece, the one I purchased seem to be a very quality piece, all the welds are nice and pretty (one of the engineering terms I use alot). but seriously, the welds are very clean, no holes.

If you're looking at a single turbo kit, I would assume, on the bassis that our engines are soo tiny that you will be looking at a straight line, basically a strip/street monster, whereas a twin turbo system would probably be more oriented for open tracking, circuit racing, to cut down on lag. Either way, you will have to carefully size the turbo(s) so that you don't spend too much time waiting to get to full boost. I've seen Twin turbo car's run 12PSI and see full boost at 2500RPM, and I've seen guys run a single hairdryer and not see full boost on the street until 4500rpm+. The size of the turbo really depends on how much power you're looking for, and how much time you're going to spend on the street vs strip/track. A bigger single turbo if you're looking for bigger numbers, and are going to spend a ton of time at the strip, whereas a couple smaller turbo's (say 55mm) if you're going to spend alot of time on the street or open lapping at your favorite track.

As you can see, there is a hell of a lot that goes into a well built turbo kit, if you have any other questions, just ask.

 

^ what he said lol i didn't even read it but he knows his ****, and theres a whole book of it lol.

 

Suggestions on where to buy?

I am also looking and don't want to change the internals or exhaust. I am looking for 350 ish so as to not push the limits. Any suggestions on which turbo/kit to get?

 

wow 2000az that was alot. but ya it depends too on how much power you want. if your going to boost alot then build some things if your gonna take an easy(which i doubt) they you wont have to build as much.

 

umm, you will have to change the exhaust, thats how the turbo works

 

Right......I mean I need the cats still in place, and the catback to remain stock.

Now how about a turbo suggestion or place to shop from? I search google and don't come up with much other than twin kits in the $6K+ market. That isn't what I'm looking for. Are there no other real choices perhaps?