Good god, I just got lost... agian.

[StarCraftLover]

Hi,

I have a 1997 GST with a Big16g turbo, and all the supporting mods. The thing Im missing are injectors, but Im just waiting to buy them.

I have some HKS cams, the 264/272 combo, and I want to install them. But I talked with alot of people and they simply told me to do a swap for a first gen head and then install the cams because of its much higher flow characteristics.

I said ok. I waited, talked with some other people, and they told me to port the hell out of the head and get like 20 more hp. I said ok agian, and talk with more people.

Some other people told me not to port, unless I wanted to get oversized valves, the porting wont do shit. So im like.. back to the drawing board.

What do I need...? Should I port without oversized valves? Or is it useless. Man, im so lost.

 

[Turbocharged]

Ive been contemplating the axact same thing. The 2G head is supposedly a more efficient design than the 1G head. For that reason, I have decided to get my 2G head ported with a ported 2G intake manifold and a 1G throttle body. Either way you decide to go, you should see substantial gains. The need to get oversized valves all depends on what your goals are. I remember reading that oversized valves arent really needed unless youre putting down some SERIOUS power. Also, it depends on how much you are planning to hog out of the 2G head.

 

[greyforestgst]

you need some sort of fuel modification

you could go the injector route, or you could go the propane route like i did.

either way you need more fuel than what the 440's can shoot so that you can run higher boost.

 

[Defiant]

Don't try porting unless you own a flowbench, ten heads to play with, and have been doing it for twenty years.

 

[Kingdom]

get 550/660cc injectors and install the cams at the sametime you do the inj. The cams will work with the 2g head and will be a noticable gain over the stock cams.


Do a 1g top end conversion, 1g head + intake mani + throttle body, should yield 20+hp. You can find them used in the classified and its not that expensive. Rebuild the head and if you can do a mild port job, not necessary buy might as well since its all out. I believe a mild port job on a 2g head will flow the same as a stock 1g head or are very close, its only when they are both extremely ported that the 2g head flows more. I havent seen any flow numbers to prove that yet, but it makes sense since the design is better. so if your not looking to make more than 400-450hp no need to port the 1g head, just rebuild it and go with stock size stainless valves and performance valve springs and retainers.

Oh, and at the end you will have less downtime. Get all the 1g stuff ready and do the swap which shouldnt take more than 1-2days.

 

[Ed98GST]

The "best" setup using stock parts would be: 1g TB, 1g intake mani, 2g ported head with 3- or 5-angle valve job, 264/272 combo installed (fork out the extra for some decent adjustable cam gears -- you'll be glad you did). Down the road you can hog out the 2g head even more, extrude hone the 1g IM, and port the TB. Of course, the flipside to using the 2g head is that if you can find a decent 1g head at a decent price, you'll minize downtime. You just have to decide -- do you want to minimize downtime or use the "best" combo of cross-year parts?
One side note: with a FWD, you'll never be running fast enough to worry about needing the flow available from the 1g head...I love my GST, but it'll never be a reliable high-horsepower beast. The ported 2g is all you'll ever need!

Unless you've had firsthand experience with a shop or know someone who has, I'd advise against having them install oversize valves. Some shops are squemish about installing them...plus, like was mentioned before, you won't really need oversize for any 16g turbo.

And like Defiant said, unless you're an expert at porting DSM heads, do yourself a favor and pay for a reputable shop or someone with tons of experience to do it for you.