Yeah Mike, I agree. I actually said that I suggested the DET unless you want to go over 300 HP. Because at that point you're going to have to start replacing things on either motor and since the DE is so much cheaper than a DET, might as well do it to that one. But if you want an out of the box solution good for 250 whp or more with an upgraded turbo, I still say go DET.
But if you're going to upgrade the turbo anyway and you want more than 300 HP... you'll need to get a new fuel rail, big injectors and a bigger MAF not to mention a T3/T04e-sized turbo.
But the important point here is that with a low compression motor like a DET, you can get much higher HP levels on pump gas than you can on a higher compression DE motor. This alone completely decimates any HP advantage the higher compression motor has. The difference in one point of compression (8.5:1 vs. the stock DE's 9.5:1) is about 10-15 hp. That's it. One pound of boost will make up that difference, and with lower compression you can usually go anywhere between 3 -5 psi higher on pump gas than you can on a DE motor.
So with a DET and upgraded turbo, it's possible to do 320+ HP at the wheels on 91 octane pee gas. On a DE motor with a big turbo with stock internals, you won't get more than 250-270 at the wheels before you start detonating. That's the difference.
This is why it's really important to know exactly what you want out of your car. You have to decide what kind of power you want, how much of it you'll want to be able to use on pump gas, how responsive you want it to be, etc. before you can decide whether to use a DE or a DET.
A DET will cost more money initally but then all you have to do is add bigger injectors, fuel rail, bigger MAF and a bigger turbo and you'll have a bitchin, made-for-turbo low compression motor capable of a crapload of HP on pump gas, far more than a DE with the same equipment.
But a DE is a fraction of the cost of a DET (or if you just use the one you have, it's free), and if you add the same components as the above example you'll save probably $1500 or so. However, you will probably detonate above 12-13 psi... maybe 14 psi if it's a cold night. So to get that 300+ HP you wanted, you'll have to run race gas all the time, and you can't do that if you're planning on staying smog legal because it will kill your 02 sensor. The only things you can do to solve this problem are to cool your intake charge any way you can. More efficient intercooler, water injection, etc. But even then you're still riding the edge of detonation all the time.
The only real way to solve it is to install lower compression pistons. Which brings us back to the DET, which has those to begin with but is a lot more expensive.
My belief is that if you want an engine capable of sustaining 400+ HP, it must be low compression... especially if you want to drive it on the street. People like Ryan Besterwitch have stock DE motors pushing 400 at the wheels... but he can't run that much HP unless he's running C16 (116 octane), so he can't push nearly that much on the street.
And if it comes down to replacing the pistons, why bother with a DET? The DET is so much more expensive that it makes a lot more sense to just get a DE motor and replace the pistons with low compression forged ones.
So there's a lot of ways you can go, it all depends on your needs and exactly what you want out of your car. I'm doing a DE motor built up with low compression forged pistons, and I expect to be able to push more than 350 whp on 91 octane pump gas. Hopefully I'll be able to test that theory later this year.
