Help with turbo selection please

[69charger383]

Alright, its not a GN but this site has probably the best information on turbos and related parts cause thats all you guys deal with really. I have a 2005 Lincoln LS, its a 3.9L V8 DOHC with 10.75:1 compression, please dont say it cant be boosted cause others have already done it, one guy runs an Eaton M90 at 9psi with an air/air intercooler and theres 2 rear mount turbo guys running 5-7psi also with air/air setups. I want a traditional style setup tho not rear mounted. Car weighs roughly 3700lbs, has 3.58's and is getting a 3000rpm stall, max rpm is 6600 but under boost Ill probably only take it to 6-63 maybe. I was considering the gt6152 turbo or maybe even just a stock GN turbo for now. It WILL be intercooled, air/water and possibly have an alchy setup as well for safety purposes. Would like it to have a decent spool time and round off nicely up top, not looking for peak numbers or a hard "hit" if you will. I imagine with the compression ratio of the engine even a larger turbocharger will have a good spool time? Not sure tho. Any input is welcome and appreciated. Thanks guys.

 

[RUQWKNF]

Sure I'll bite.

(3.9L DOHC V8, 10.75:1 CR, 6600 redline, 280hp, 286tq ? )

I definitely would not recommend a stock Buick turbo, due to the flow capabilities of DOHC setup. As the stock TBO-348 turbo can safely only support around 375 flywheel hp. Some have made more than this, but have run the stock turbo at dangerous levels of boost. IE: way out of it's efficiency range. What we really need to know is, what is your ultimate flywheel hp goal?

With the limited boost levels on true 93 octane at that CR level, going with a large turbo might not be the most efficient way to do this.

But for the sake of comparison, let's say you're trying to make 400 flywheel hp.
at 8-10psi. I would spec a dual ball bearing 6265E turbo, with the CNC'd billet compressor wheel, TO4E style compressor cover and one of the new .82 a/r V-band inlet, V-band outlet style turbine housing. It would easily support that hp goal at low boost levels. You would definitely need a wastegate that could keep up with this application, so I would be looking at a 44mm wastegate from the get go.
Hope some of this helps a little.

Patrick

 

[69charger383]

Well the guy running the Eaton at 9psi put down 407rwhp with a 1st gen motor(non-vvt, different intake setup) So Id like to be around that but with a nice smooth powerband. I put down 251rwhp with just an intake and exhaust and yes the DOHC heads/setup flow quite ridiculously, they have VVT or whatever FoMoCo calls it. I think I should be able to surpass his power output theoretically, the gen2 motor I use came with 30 or so more horsepower than his from the factory.

 

[yullose]

Meh... why play around with the small stuff ???

I say go right to a 70GTQ with a .85 exh housing.

Any lag might be useful as traction control.

 

[69charger383]

RUQWKNF whatd you got to say about twin stock GN turbos at 7(?) lbs on a conservative tune, 10lbs with meth if I can even hit that.. 400 at the flywheel would be pretty nice but Im trying not to break the bank just yet with a $1K turbo.. If I blow the engine Im gonna need a good amount to rebuild/beef it up and dont want to dump it all into the turbo system, plus if that does happen i might get another stocker and just run the 100 shot I got for it.. If it works well and nothing goes wrong, then I can upgrade it.. All replies welcome even if you wanna call me an idiot.. :wink:

 

[RUQWKNF]

Hmmm.
Two stockers at low boost might work. Even though it would basically be like two 2.0L DOHC 4 cylinder motors for each turbo, with the DOHC aspect, you should have no problems spooling them up and reaching your hp goals.
I would think 400hp on this low boost twin setup would be doable.
Now you just gotta find two stock turbos in excellent condition to start with.

Patrick

 

[69charger383]

Alright so Im dead set on running 2 stock GN turbos at a max of 10psi. Should I keep the stock internal wastegates or since this will be custom type deal go with some externals and if so what size. Engine bay room is quite limited so intake and intercooler piping will be 1.5-2in diameter merged to where the factory airbox used to be with a 3.5-4in single pipe or possibly straight to the front bumper and kept separate pieces. Im not gonna get too far into this, Ill open a new thread in the turbo V8 section when Im not so lazy.. Thanks so far

 

[Mr.Spool]

69charger383,not that the tt setup wouldn't be cool but what about a wet kit?so much easier on the wallet,the installation and plumbing and still make the power.this way you pop the motor your just not so far into the thing moneywise not to mention taking it apart timewise.spray works and its cost affective and space friendly just a thought.

 

[69charger383]

Ive been running a 100wet, I want something different and hasnt been done yet, plus I hate having to get the bottle filled and just not having it "on tap" 24/7.. I was considering going to a 150 but Id need a progressive controller for sure and Id have to get another tune and a higher rate fuel pump since mine gets maxed with a 125shot.. If I do the twins I still have to get the pump so thats void, still need a new tune, and I can sell the kit and make some money for this budget TT setup.. Not saying Im gonna break even, I expect to put more money into this..

 

[jhanson1750]

Looks like you have a basic game plan just remember to keep the Alky kit in mind with high base compression and boost it could save you lots of broken parts in the long run. Keep us updated on your progress, sounds like a neat project.

 

[69charger383]

Sure will, Ill start a thread in the V8 section this weekend with pics of the car and everything..

 

[69charger383]

So I got a hold of a MasterPower T70, .68 turbine for $125, what do you guys think? I know it can support the power levels I want, but Im concerned about that .68 exhaust side, too small, too big? would it be better suited as a rear mount turbo? Any input is welcome as always.. Couldnt find 2 good stock GN turbos and plumbing ect was looking to be a hassle.. 10psi max is what Im going for on Meth, FMIC, enough fuel and spark to keep it happy, Id really like to see 450 at the wheels which is 200 over what Im at right now.. 251hp and 274tq

 

[69charger383]

Anyone? MPT70 with a .68? Im no expert on sizing turbos but Im leaning towards it being too small.

 

[ITSNOTAGN]

it will work, kind of small housing but for low boost levels the backpressure wont be too bad. Will work fine for a front mount turbo setup, lots of guys run these on LS1s with the .96 housing but with your lack of displacement the .68 is fine, you can always go to the bigger housing down the road. spoolup should be great

 

[bison]

Id go with Patricks rec if i were you and scrap the twin turbo idea. Id plan on dumping in a lot of alky and running relatively low timing too. you should be able to hit 450+hp at the wheels if you take it to 6500 and run 10 psi. If you went with a higher than 3000 stall you could probably run a 68 trim ex and pick up some more hp over 5500

 

[bison]

So I got a hold of a MasterPower T70, .68 turbine for $125, what do you guys think? I know it can support the power levels I want, but Im concerned about that .68 exhaust side, too small, too big? would it be better suited as a rear mount turbo? Any input is welcome as always.. Couldnt find 2 good stock GN turbos and plumbing ect was looking to be a hassle.. 10psi max is what Im going for on Meth, FMIC, enough fuel and spark to keep it happy, Id really like to see 450 at the wheels which is 200 over what Im at right now.. 251hp and 274tq

The 6265 will make a lot more power than the t70 which has an old 76 trim ex wheel.