sefus having a breakdown

[sefus]

lets see if i can edit this alittle bit.
i have a 68 stang 200 c4, low miles on the car, think it isn’t the original engine with a rebuild, perfect interior, friend with freshly rebuilt 4000 mile 200 out of a 65 he will give me for cheapbut i dont know if his a 7 main or not.
i want a turbo car again and this would be the one to do it to. I’ll be going with a fully prepped 250 head, 1.6 rockers, valves, springs, porting...the works. I want to stick with a 2bbl but not sure what cfm to go with? I heard from someone that 550 would be the limit before over carb but that sounds high from what I’ve read. i'll need to prep the short block with strengthened internals: rods, pistons, bolts plus a balance job. is there anything else I'm missing?
I'll use the c4 with a shift kit but where can I get a bigger converter for the smaller 6cyl housing? Are there lightened fly wheels available?
for the turbo system specificly i was thinking of a boost referenced fuel pump(from summit) and fuel pressure regulator (nessasary ?). i thought a t3/4 hybrid would fit about right. not going to bother with an intercooler just yet.

And for the guys who have already turboed theirs: was it worth it? Post your best combos, your thoughts, your questions, everything. I cant tell you guys how much I appreciate all this. Thanks

-sefus

 

[rbohm]

8) you are kind of rambling and asking alot of different questions, it is hard to follow what you want to do. try asking the questions one or two at a time on related topics.

 

[xctasy]

Hey, I thought I'd posted it!


I'd look at the 200 six, use the log head, and run triple TBI throttle bodies, SDS computer, and a TO3 turbo, with an EVO Mitsubishi inter-cooler. Stick with the stock C4 casing, and just up grade to a higher stall automatic (3400 rpm), then shove 12 pounds of boost on a car with a 62 cc 250 head from an unleaded Granada/ Maverick. Go for 7:1 copmression. Run a 264 degree or so( at lash) hydraulic cam. Swap to V8 mechanicals or raid a Granda/Maverick or even a Versiallies (sp?) which had disc brakes all round.

Diff should be around 3.55 or so, and get wheels. AsaStang67 did a post a while back on backspacing and tire size. MustangSix has done several as well.

Most important thing is to keep away from exotica, then look at making it trick last. A turbo with only a 9 pound boost will easily hit the 260 hp mark if you could get 160 hp normally aspirated. With 12 pounds, you'd be banging on the door of 280 hp. Enough to push a 2800 pound machine to low thirteens/ 100 mph+ quarters.

For me, I'd be looking at spending money on getting a ductile iron exhast cast, or make two tube exhast manifolds. You don't want a lot of under bonnet heat. Water injection should be considered.

Most of all, after you've got feedback, draft it all up, and get a turbo guru to do the build-up to your spec.

 

[sefus]

i really dont need any sort of computer, it will be a simple carb set up off a single out header. thanks for your thoughts. any others after i edited my original?

 

[rbohm]

8) looks like you have things pretty well planned out. the flexplate is already light enough, but i havent seen any light weight flywheels for the little six. if you use a draw through system, i would recomend a 40 dcoe weber carb as it is quite tunable, and well suited for a turbo application, especially a draw through. why would you want a larger converter, unless you are thinking higher stall speed, then you are looking at a smaller converter. if youuse a weber in a draw through setup you wont need a boost referenced fuel pump, but you will need a pressure regulator as webers run on only 3 psi max. if you use a blow through system, then you use the boosted fuel pump and a 350 cfm carb as that is about all you need even with a turbo. the only other thing you are missing is the ignition system. a dual advance dist, with a good electronic ignition, and a boost retard system.

 

[sefus]

woops forgot to mention ignition. ive got a 6a box on my mopar right now so i'll use that on the stang cause i wanted to upgrade anyway. i'll use msd if they make it for as much as possible but yes the ignition will be taken care of too.
i was looking for a higher stall rpm than 1300 or so (thats what the stock is right) somewhere near 2600 if possible.

can someone give me some ideas on what would be better: blow thru or draw thru? i know that puddling can be a problem with the draw thru systems, so i was thinking more on blow thru, but is it something to worry about? thanks guys.

 

[rbohm]

8) for a converter i recomend the B&M holeshot. it acts like a normal converter untill you stand on it, then it gives you a higher stall speed, about what you are looking for.

draw through system;
pros
no need for boost referenced fuel pump.
no need to seal the throttle shafts.
better mixture homogenization(per smoky yunick).

cons
longer route to cylinders.
possibility of fuel falling out of suspension.
more complex plumbing.
more complex throttle linkage.
cannot use a popoff valve
requires a special bearing seal to prevent fuel entering the oil.


blow through system
pros
easier plumbing.
carb in stock location, so shorter route to cylinders, and throttle linkage is stock.
reduced possibility of fuel falling out of suspension. can use a popoff valve if desired.
no special bearing seal required
cons
must seal throttle shafts.
mixture homogenization not as good.
must use boost referenced fuel pump.