Questions: Adding a turbo to a NA 231

[nicad]

Hi all. I am quite familiar with engines, but never any experience with forced induction.
I have a 1987(?) Buick "Regal" 231 in a Porsche 914. It is a street car only- not used for race or drag.
The rods are billet aftermarket. The heads have been gasket-match ported and have been modified to accept stud-mounted roller-rockers with slightly higher ratio than stock. It has a "medium" street cam in it, and a 4brl Weiand single-plane manifold and a Holley 390cfm 4brl carb. The entire rotating assembly has been blue-printed and balanced.

It currently runs out of steam around 6000rpm-- due to either the 390cfm carb or possibly weak valve springs. The valve springs will be addressed at some point. I would like for it to get to 6500 or maybe 7000 rpm.
I am currently in the process of replacing the distributor and Holley carb with a Megasquirt-II TBI (500cfm) + EDIS ignition system.
From what I understand this setup (either Carb or TBI) should be around 200-220hp at the crank.
They say the 901 transaxle on the Porsche 914 can handle up to about 300hp (??? trq)

So, I am toying with the idea of putting a turbo on it and getting it up to that 300hp. From my limited research, I will need about 10psi boost to get it there.. Is that close to correct? Since I am not trying to build an all-out fire-breather, I would like to be able to have quick spool time (low RPM torque) and also not break the bank. I would also like to get away without an inter-cooler if possible, since space is quite limited in the mid-engine setup..
I would like very much if someone could recommend some Turbo brands and turbine/compressor/housing numbers and trims. I am still new at this, but trying to learn fast-- so take it easy and explain as much as possible for me.
thanks-

 

[mat231v6]

if you want to go old school then you could put a drawthru turbo on. this pic is not my motor. if you want to go this way go to the before black section on this site. you can always go and get all the 87 stuff and hook it up. With the before black stuff you will have a carb and it doesnt cost much to change the car over.

 

[nicad]

Thanks for the pic and information, but not really interested in a draw-through setup. I have seen others do a blow-through into the TBI, and I think that is what I would want to do. Just really looking for turbo specs to get close to the goals that I am after.
Thanks again tho.

 

[mat231v6]

ok

 

[mat231v6]

see this link http://www.turbobuick.com/forums/before-black-non-sfi-tech/294806-repeat-procedure.html
here is someone to talk to. he did a blowthru with a carb he might know how to do it with a tbi. here is his contact info. http://www.turbobuick.com/forums/members/warwagon.html

 

[charlief1]

Welcome aboard. If you'd like to do blow through Matt's right, you need to talk to Adam (warwagon) about it. He's pretty much got it down so he can help you figure out what you want to do.

 

[Nasty Wendy]

I'd be willing to bet you that if you build a 300hp turbo 6 it will break the f#*& out of that transaxle. Torque is the force that breaks everything from tires to transmissions to 'the bank'. That 300hp rating wasn't given to that transaxle with the amount of torque in mind that a Buick Turbo 6 capable of making 300hp makes.

 

[nicad]

Realistically, I am starting to bet on Nasty's outcome. :-/
And I don't exactly want to goto the beefier 915 transaxle = $$$$!!

I guess I need to keep looking at what all can be done to up the power out of the N/A setup. I am sure there is quite a bit of room for improvement there. But that will call for another thread in another area of the forums here.

Thanks again yall for the input!