Thread: going from s/c to turbo?

I’ve always been thinking about going turbo. Kinda want to set a goal of running ~380-400whp and/or be able to trap 120-125mph trap speeds. The items that are needed to go turbo im really not sure on so that’s why im posting this thread.
I know I’d need to run manifolds, prolly P-log and welded rear (ported) manifold and of course the turbo crossover pipe. I’d need a decent wastegate along with an electronic boost controller for ease of use, a specific turbo size, and bov. I was thinking of running a gutted M90 and instead of using an I/C to try and continue to use the devils’ own alky/meth injection. Also I read that the stock L67 MAP sensor would be useless, is the air/fuel controlled via MAF sensor instead? Also the turbo needs to be oiled, is there more than 1 oil feed line and where does it tap into, the oil pan?
No worries on the tranny as I plan on upgrading it to take the power. Can I still run on the 42.5# injectors for for my goal? Thanks in advance for your support!
Maybe make this a sticky for newbs like me? ^_^;

They sell turbo kits for your car... zzp makes the z7, and also they sell the statama turbo kit... this is your best bet if you wanna make some power with a turbo.
https://www.zzperformance.com/grand_...=410&catid=109
https://www.zzperformance.com/grand_...=411&catid=109

when buying these kits for a supercharged gtp you need the m90 blockoff. im pretty sure they have an option you can select on there to get that

yes i know zzp makes kits for our cars, im just asking if theres a likelihood of piecing together a custom setup myself. if not, i can always get a used kit in the classified section on the forums, but thats all in one chunk.

well of course theres ways to piece the kit together yourself... but it makes it harder to do usually and costs more in most cases. i would just get a kit thats already been proven to work well because turbos are really complicated systems

cartuning makes a nice turbo kit too. their are plenty of guys on this forum that are running way bigger turbos then in those kits. I know moderator UR LOSIN is running a gt45 turbo, which is huge.

There are a few other things you have to consider when installing the turbo:

- You need to Tee off the oil pressure sender and run a feed line to the turbo.
- You need to run a return drain line from the turbo to the oil pan.
- The MAF will have to be modified, or an AFC will have to be installed.
- You may need a smaller brake booster if the downpipe is 3", with 2.5" it should be ok.
- The PCV system will have to be modified to run non-metered air. The simplest way is to put a breather on the valve cover and block the stock PCV passages, but the best setup is to run a filter.
- The EGR must be removed, and existing passages blocked.
- You will definitely have to do some tuning.

Piecing together the system can be done, but as mentioned, it will be a lot easier to buy one of the available kits.

Originally Posted by 2000GTP

well of course theres ways to piece the kit together yourself... but it makes it harder to do usually and costs more in most cases. i would just get a kit thats already been proven to work well because turbos are really complicated systems

Actually piecing together a kit will come out to be a LOT less than just buying a kit from ZZP or wherever. Ya it will be a little bit more of a hassle but to save like $1000 dollars or more just by piecing together a kit is well worth it IMO.

i have an intercooled cartuning kit at 10psi, and i'm pretty happy with the kit as a whole

Just wondering but why are you only running that kit at 10 psi? Hell my 3.4" pulley hits 10 psi. Your kit's intercooled, you should be able to run quite a bit more boost than that.

Originally Posted by Smokin2000gtp

Just wondering but why are you only running that kit at 10 psi? Hell my 3.4" pulley hits 10 psi. Your kit's intercooled, you should be able to run quite a bit more boost than that.

But he makes quite a bit more power on that 10PSI. And he has higher compression resulting in more caution needed with boost levels.

Ah I didn't see that he had it on a GT.

Originally Posted by Smokin2000gtp

Just wondering but why are you only running that kit at 10 psi? Hell my 3.4" pulley hits 10 psi. Your kit's intercooled, you should be able to run quite a bit more boost than that.

honestly cause i dont need the power, and to save my half broken tranny till i can afford a proper rebuild. the car used to be at 15psi

there's a big difference between S/C and turbo psi, my GTP runs at 10psi as well and there's no question which car makes more power

Originally Posted by Sabrewings

But he makes quite a bit more power on that 10PSI. And he has higher compression resulting in more caution needed with boost levels.

actually my car is a bit odd, after the engine blew it was rebuilt with L67 pistons (but still has L36 heads)...so it's medium compression?

Originally Posted by f0rge

honestly cause i dont need the power, and to save my half broken tranny till i can afford a proper rebuild. the car used to be at 15psi

there's a big difference between S/C and turbo psi, my GTP runs at 10psi as well and there's no question which car makes more power

Ah gotcha, a broken tranny is definitely no good. Ya I know a Turbo will always make quite a bit more power at the same psi since you're using exhaust gases to create the boost instead of power from the crank, I was just trying to point out that if my car can support 10psi with it being supercharged and non-intercooled that you should be able to run quite a bit more boost than me with your setup.

Originally Posted by f0rge

actually my car is a bit odd, after the engine blew it was rebuilt with L67 pistons (but still has L36 heads)...so it's medium compression?

I believe most of the compression comes from the rod length and not the pistons.

hmm interesting facts here guys, thanks. if i ever piece or get my hands on a turbo kit the only pieces or areas i still would have issues or confused about is the oil lines going in/out of the turbo.

i can tap into the feed line with where the oil pressure sender is correct? what about tapping into the oil pan, wouldnt i need to drill/tap a hole for it?

i can block the pcv passage area where the tb is at with metal epoxy? and run a breather/catch can off the valve cover?

i might skip the i/c and just continue running my alky with a larger nozzle.

the tranny's been rebuilt by trannyman with 3.29s, 300M input shaft and a 1" gm chain

does the MAP sensor at this point switching from s/c to turbo obselete then?

if anything i'll run at a max 14-15psi since i dont want to blow my 160K mile headgaskets

what else is there that i havent covered yet?

The oil return line can be put where the oil level sensor is in the front of the oil pan. you can get an adaptor that just screws into the pan....and run the dain directly to it. You'd just have to delete the oil codes out of the PCM.....and keep an eye on oil level the old fashioned way..................

can someone post a pic of where the oil level sensor is at? is that where when u install an oil perssure gauge and screwin the oil sender unit? if so, u get a "T" fitting and both lines from the "T" fitting would supply both the feed and return line for the turbo correct?

i read that swapping to a turbo the original/factory pcv system needs to be blocked or plugged and run something like a valve cover breather or a valve cover breather with a hose and have it circulated back to the pre-turbo inlet. why is that? should i epoxy the hole for the pcv that goes into the throttlebody from the m90 casing?