[fireturkey]

first off i am new to this, so bear with me. I have 2 questions...can i turbocharge my chevy 350 (carb motor). how do i go about doing this, i want to pull the turbo off an eclipse or something of that nature, not buy a kit. i need to know everything i can for this project, timing controlers ect. next question... i heard if you destroke your motor to a 302, you can run like 11000 rmps that sounds like it would be pretty sweet, would i increase 1/4 mile times? or would a 383 be the best option? thanks for the help!!

[ronb]

what transmission and gear ratio do you intend to use?

[fireturkey]

manual tranny not sure on the gears that i have

[ronb]

O;K are you ready for this? first off a manual tranny is not the best thing for consistant 1/4 mile times, or if you just want to see what it will do then o;k that tranny will work for a high rpm engine. a 383 makes power at low to mid range, usfull for towing or getting off the starting line(i would not turn it over 5000 rpm`s). however a 377 would be good for rmp`s up around 6500 and work better with a manual tranny. as for the turbo? i have been doing some research myself on this and can tell you that a turbo from an eclipse is to small for a V8, you will need one a least a to4 and yes you can use it wth your carb but you will need to modify it and get a carb relocation kit(you may find some on e-bay motors)? but the really hard thing to do is find the turbo exhaust manifolds(they are hard to find), then you will need a wastgate(very exspensive,around 200-300 dollars),after that you will need to intercool the intake charge(hope you have room for this)? and also a blow off valve and and and a boost presure gauge.

[fireturkey]

i have been doing lots of research on this, my friend has a honda crx turbocharged and he is giving me some help, my dad owns a machine shop so lots of my parts (exhaust) will be custom. the question is timing, you have to retard the timing. msd has a couple diffrent timing retarding units but which one do i use for my motor? also, do you think single or twin would be best. when i get the turbo off of the eclipse, i am going to get the intercooler and blowoff valve with it.

[ronb]

call msd and ask them! if you insist on using the turbo out of the eclipse you better use two! I believe you will be disapointed with the one?

[fireturkey]

good thinking on calling them. what would you suggest on pulling the turbo off of?

[ronb]

anything that uses a V8, maybe from a truck,and take the cooler from a diesel truck if you can fit it in? they make the best coolers. you will need a turbo with at least a 2 1/2 in inlet minium up to 3in or more.

[fireturkey]

alright thanks, i will look around and see what i can find. so over all what displacement size would you suggest? do you know anything about making a chevy 302? i am looking for the quarter mile and some stop light fun

[ronb]

the more cubes the better at low to mid range rpm. I use an automatic 700-r4 with a gearvender for 8 forward gears and double overdrive to push my t/a to 207 on the chasis dyno, the consept is to keep the rpm`s in the range of where the cam makes it`s power,in the 2200-3500 rpm,while still getting good fuel economy on the highway. as for you? the cheapest and most hp for your money would be the 383 stroker! for the price of a smblk rebuild you get awsome tork!

[fireturkey]

so will i be able to run a turbo with the 383? i bet that will be quick if i get that running. how much am i looking at money wise to convert my 350 to a 383? (preferably the cheapest way)

[Studebaker]

If you are set on using a turbocharger with a carb there are two ways, the draw through and the blow through. The draw through design draws the fuel/air through the carb and then through the intake side of the turbo and into the intake manifold. With the draw through it is not advisable to use an intercooler, you do not want pressurized fuel and air going through the cooler. This can cause major explosion. The blow through type design uses the turbo to pressurise the air alone then forces the air through the intercooler (really an aftercooler) and then through the carburator. This is a prefered design to use with port fuel injection as the fuel enteres the engine in the intake manifold not earlier. When using this design with a carb, the blow through design requires that the carb be inside a plenum or box that is pressurized by the turbo, this does not work very well with stock carbs because they over pressure the vents and the carbs don't work correctly. causes major fuel leakage, not good, can you say big pressurized fire! 57 t-bird superchargers worked this way but they had a carb designed to work with the system. When using a carb the cheapest and better way is the draw through design. Do your homework, this is nothing to attempt without a little research. Go and look a a few draw through designs like the early Buick , 3.8 turbo. they used a Q-jet and a turbo on top of the intake manifold. Good luck!

[Skylark_77_455]

I have an old book that I picked up at a garage sale called the ABC's of Hotrodding. They show a picture of a twin turbo SBC that was carburated. It looke as though they modified the factory air cleaner. It kind of looked like the Ram Air on the old Thunderbolts. I don't know any specifics though.

[deuce_454]

there are a couple of things to look out for when you do a blow-thru setup on a carb, first of all a holley carb meteres fuel from the volume passed, which means that when you blow compressed air through it, the mix is going to lean right out, so you need to mount much bigger secondary jets and back em down till the mixtire gets about right.

with premium gas and a relatively low compression small block you are able to run up to about 9 pounds of intercooled boost (an intercooler from a wrecked powerstroke ford diesel is about right in size for the volume air required

i can send you some step bu step pictures of how you weld up a pair of turbo manifolds, and give you some pointers on the compressor trin, turbine housing A/R ratio and housing size to fit your application. but i need to know the compression ratio, the displacement, max rpm, number of turbos you want to run, best available octane rating gasoline, and i can calculate the right ones.

so other than welding some pipeing and a pair o fmanifolds, all you really need is a carb hat from procharger and a pair of used turbos allong with an intercooner and some small items like blow-off-valves and some silicone hoze and you are set to build a 1000$ 550 hp 350 chevy, and pehaps a better clutch.. :-)

mail me at : jakob@regeur.dk and ill give you a hand with the calculations

[deuce_454]

and NEVER EVER build a draw through setup, it is impossible to intercool, throttle respons is terrible, the fuel gets into the turbos barings and destroys them in a few months, and one backfire and your turbos and ducting is history...