Advice on planning out Grand National turbo setup?

Hey all, I'm trying to decide whether I should go high compression with my 200, or go turbo... so I'm trying to map out a plan for a relatively cheap/simple small turbo setup before making up my mind. This is just a street car, so I'm looking for good low/midrange performance and reliability, but I wouldn't mind taking it to a track sometime. My goal is to get near 200hp.

Here's what I've already done to the engine:
Bottom end - stock '66 200 (rebuilt), .030 over. Comp Cams 260h cam.
Head - large log with direct mount 2v adapter, 1.75 intake valves / 1.5 exhaust, 3-angle valve job and mild polishing, dual springs with dampers
Exhaust - headers to dual 2" pipes
Ignition - DSII with MSD 6A
Carb - Autolite 2100 1.08
Compression should be about 8.7:1.

Plan:
Turbo: I'm considering a TB0330 Grand National turbo... I can't find a map for it, but engine size isn't too far off and it was built for carbs. Appears to have an internal wastegate of about 7psi.
Carb: I'd like to keep my Autolite 2100 if possible. Do I need to do anything else other than putting in a nitrophyl float and get some richer jets?
Ignition: MSD makes an expensive boost controller that works with the 6a... but can I just limit my total timing with my DSII instead?
Fuel: At 7psi do I need to do anything special here? Can I keep running the stock mechanical pump, or do I need to go with an electric one?
Exhaust: Split the downpipe into my current dual 2" pipes
Intercooler: As a first pass I was hoping to not put one in to keep costs down. If I decide later to swap turbos and go with higher boost, I'll add one in. Would I notice a big difference without one at 7psi?

Sorry for all the beginner questions but I'd really appreciate any advice... I'd love to do this if I can convince myself it's worth it.

-Nick

The TB0330 turbo is rated at 34 lbs/min and I suspect that to be at a pressure ratio of 2. It was used with sequential EFI and intercooling.
It will be a little on the large side for a non-intercooled 200 hp application.

It will be tough to reach 200 hp without and intercooler.
If the engine has a VE of 65% at 5500 rpm it would take 12 lbs to make 200 hp but the air temps would be around 235 degrees.
Add a 50% efficient air to air intercooler and it takes 8 lbs of boost to make 200 hp with air temps at 135 degrees.

In answer to the question concerning the power difference with and without intercooling:
At 8 lbs of boost there is around 20 hp difference between using a 50% efficient intercooler and no intercooler if all other things are equal but that's not the case.
The problem is the higher air temps going into the engine without intercooling require additional timing retard and the air/fuel ratio must be richened to prevent detonation which decreases power further.

There are some here that have had good results with methanol/water injection.

The MSD 6AL-2 Part# 6530 allows you to program the advance curve and on a separate graph you can program the boost retard curve as well as the vacuum advance curve.

A boost controller works with an external wastegate that has two ports where there is access to the chambers on both sides of the diaphragm.
Again there is a thread somewhere with an ingenious method of adjusting the boost on a single port internal wastegate.

The TBO3 is fairly unique - Early carbureted Turbo BOP (Buick/Pont/Olds) turbos' are built specifically capable of Draw-Thru fuel/air turbocharging. The BOP systems used a specifically built Rochester Q'Jet 4BBl with the TBO3. The Fuel Injected Grand Nationals and virtually all modern systems Blow-Thru only air though the turbo benefiting reliability on all levels.

The early BOP TC systems added some performance punch to the V6 engines that GM division seriously developed.

Rather than start from scratch, I used the pushrod / carbureted (V six 231 cid engine) BOP turbo system on the small block six 250 . So far it is completely drivable and adds a whole new experience to "driving a little six".

have fun

TBO3 based Draw-Thru BOP setup - my 74 Maverick 250 work zone :

/ .

Ah, interesting... didn't know that intercooling had an effect on the amount of boost you needed, I thought it was just to lower temps to avoid detonation. Looks like I'll need to go that route then, since I'm not sure I want to be running over 10 lbs.. at least not initially.

powerband, that's a very cool setup. What did you have to do to adapt it to the intake manifold? Is your intake stock?

Good to know about the early turbos being setup for draw-through though... I think I'd like to do blow-through though, so maybe I'll look into the 86-87 one instead (TB0348?). Or I can just look for a generic T3 I guess. The only reason I was leaning towards the GN ones is that the speed shop that would be helping me with this is run by a Buick guy, and he's got some stock ones laying around.

When the air is cooled it condenses and the pressure drops.
You get more air by weight with less boost pressure which equates to more power.

It would be best if the turbocharger compressor inducer size was 47MM or less for your application.

Also there are much better turbochargers available than the old tech GN turbos.
The newer turbos are more efficient and produce boost at much lower air temps.

That makes sense when you put it like that. Curious, why only 47 though? I was going off a chart by Turbonetics that was posted somewhere on here that recommended either the largest T3-Super 60 or a T4-S3 for a 200 running 10 lb or less. It didn't explain why though, and it was very generic.

I ordered the MacInnes book on turbochargers that people seem to recommend a lot, so looking forward to reading through that when it gets here...

A T3-Super 60 has a 48MM compressor inducer and will support just over 300 hp at 22 lbs of boost.
Sometimes a turbo is listed by the outside diameter of the compressor wheel (Exducer) and sometimes by the inlet size or Inducer. I was using the inducer size with a 47MM limit. Close enough.
Companies like Turbonetics offer different housings that allow the turbine to be run harder with less exhaust restriction or back pressure and will increase the turbos performance.

In general it takes 1 lb of air per minute to make 10 hp.
If you are looking to make 200 hp then the turbo must be able to flow at least 20 lbs/min. at the target boost level.

As you know if the turbo is too large for the engine's pumping rate, it can surge and be damaged.
I've been there once when a rocker arm broke and one cylinder quit pumping.

If the turbo is too small and cannot keep up with the engines pumping rate then it can go into the choke zone and over rev and be damaged.

The engines ability to pump air is limited by the port flow of the cylinder head.