Twin turbo carbed SBC
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TECH Apprentice
Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
Twin turbo carbed SBC Ok, i think I've decided in order to make the amount of power i'm wanted and to be able to drive my truck on the road i'm going to need to be FI. Seeing as it's carbed and i'm NOT going efi, my first thought was roots type blower, but i want something different. So how does twin T66s with dual Holley dominator 1150s sound?
Here's the setup I was considering:
L98 corvette heads with 2.02/1.60 valves ported out to almost the max
forged 9:1 pistons
forged 327 crank
forged h-beam rods
300/305 245/250@0.050" .505/.520" (give or take)
single plane dual carb intake (duh)
Shorty headers upside down and left/right swap
turbos somehow into steel box above carbs as small as possible while equalizing flow
about 12-15lbs on pump gas 20-25 on 108.
Any thoughts? Tips?
Thanks.
Here's the setup I was considering:
L98 corvette heads with 2.02/1.60 valves ported out to almost the max
forged 9:1 pistons
forged 327 crank
forged h-beam rods
300/305 245/250@0.050" .505/.520" (give or take)
single plane dual carb intake (duh)
Shorty headers upside down and left/right swap
turbos somehow into steel box above carbs as small as possible while equalizing flow
about 12-15lbs on pump gas 20-25 on 108.
Any thoughts? Tips?
Thanks.
My buddy has a 350 sbc thats EFI w/ Gen7 and a 76mm tb...he runs twin T-76s and maxed the dyno at 1500 rwhp. I dont think you need to carb the motor. He street drives it about 150 miles per week...runs low-mid 8s 160s-170s depending. 1970 Camaro.
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dual 1150 dominators, rofl.
You do realize the fastest blow-thru carb car in the world is running a lightly modded single 750 holley, making 1500+ horsepower and running in the right? You do realize that 2 carbs makes it a son of a bitch to tune, and that dominators suck for blow-thru apps?
If you want to run a decent amount of boost on pump gas I would run less than 9:1 compression, I would run a LOT bigger stroke than a 3.2" crank, less duration and a LOT more lift on the cam, and you're probably going to want to rethink twin T66's. I ran twin .68 A/R T66's on my old setup with a 377 and I thought it felt a little sloppy for driving on the street, nevermind in an off road truck with 331 cubes. I shifted my motor at 7500 too, just something to think about.
Forgot to add. The cam in my 377 was 240/232 @ .050 I think, but the lift was near .700. The duration doesn't do too much for the power, basically just shifts the powerband. With a 240/250 @ .050 cam, TWIN dominators, and T66's on a small 331 inch motor that sounds like something that would make power to 8500+ RPM's.
You do realize the fastest blow-thru carb car in the world is running a lightly modded single 750 holley, making 1500+ horsepower and running in the right? You do realize that 2 carbs makes it a son of a bitch to tune, and that dominators suck for blow-thru apps?
If you want to run a decent amount of boost on pump gas I would run less than 9:1 compression, I would run a LOT bigger stroke than a 3.2" crank, less duration and a LOT more lift on the cam, and you're probably going to want to rethink twin T66's. I ran twin .68 A/R T66's on my old setup with a 377 and I thought it felt a little sloppy for driving on the street, nevermind in an off road truck with 331 cubes. I shifted my motor at 7500 too, just something to think about.
Forgot to add. The cam in my 377 was 240/232 @ .050 I think, but the lift was near .700. The duration doesn't do too much for the power, basically just shifts the powerband. With a 240/250 @ .050 cam, TWIN dominators, and T66's on a small 331 inch motor that sounds like something that would make power to 8500+ RPM's.
Last edited by eviltwins; Sep 28, 2004 at 10:54 PM.
hope you dont wnat power brakes with that puny engine and HUGE cam - it is way too much for that size engine
go with a 383 8.5-9.0:1, 10-15 psi, 3.73 gears, and a 205/225 @ .050", and afr 195 heads
go with a 383 8.5-9.0:1, 10-15 psi, 3.73 gears, and a 205/225 @ .050", and afr 195 heads
Thread Starter
TECH Apprentice
Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
while, yes, this is a truck i'm looking for topend. maybe dual holleys was thinking a little much, ok, how about a single holley 800.
and more lift less duration isn't possible without a roller camshaft and i refuse to trust retrofit lifters with the kind of RPM i'm looking for and I don't want an 87+ block so solid or hydraulic are my options.
I initially thought about a 377, but i think a 331 would just be more what i am looking for... capable of 8000 rpm and all the horsepower i'll ever want.
if i do end up using the truck off orad it's going to be nothing but mud bogging- WOT for 1-2minutes, but for now, it's going to be seeing stret/strip use.
and more lift less duration isn't possible without a roller camshaft and i refuse to trust retrofit lifters with the kind of RPM i'm looking for and I don't want an 87+ block so solid or hydraulic are my options.
I initially thought about a 377, but i think a 331 would just be more what i am looking for... capable of 8000 rpm and all the horsepower i'll ever want.
if i do end up using the truck off orad it's going to be nothing but mud bogging- WOT for 1-2minutes, but for now, it's going to be seeing stret/strip use.
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Thread Starter
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Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
Most people don't consider aluminum to be iron, but call it what you want. initially 750fwhp is my goal. from there i'll see where i can go, but my base goal is 750.
why are you trying to be such a jerk about this?
why are you trying to be such a jerk about this?
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Bowtiered - I don't think he's trying to be a jerk. I think he's just a little aggressive with striking you back into reality. He is right on par with saying/implying you're going a tad overboard with the parts you have and equipment/power you're looking for.
You REALLY only need 2 stock GN turbos (read:cheap) or 2 TE-44's to hit 600 - 700 hp on low boost (15-20psi). On top of that, you really only need a 650 or 750 carb with nitophyl floats. A cam... well I'm putting either a single pattern .465 or .488 in my Monte. Boost is what will make your power, not the cam. As far as compression, you will be okay with 9:1 but would be better off with 8:1 or even less. With 9:1 compression, no intercooler and 12psi of boost, I doubt you will see that on pump gas without some MAJOR knock and a blown motor.
Keep asking questions, that's the only way you'll learn.
You REALLY only need 2 stock GN turbos (read:cheap) or 2 TE-44's to hit 600 - 700 hp on low boost (15-20psi). On top of that, you really only need a 650 or 750 carb with nitophyl floats. A cam... well I'm putting either a single pattern .465 or .488 in my Monte. Boost is what will make your power, not the cam. As far as compression, you will be okay with 9:1 but would be better off with 8:1 or even less. With 9:1 compression, no intercooler and 12psi of boost, I doubt you will see that on pump gas without some MAJOR knock and a blown motor.
Keep asking questions, that's the only way you'll learn.
Thread Starter
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Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
ok, so how about i keep my current cam (280/280 224/224@0.050" .465/.465") with two stock GN turbos. and an edelbrock 750, or are edelbrocks not good for blowthru applications? I'm assuming a drawn through carb isn't feasible with turbos is it?
alright, maybe a 355 would be a better option then too?
how about a 355 with the above and the GN turbos.
as for plumbing could i just use heavy gauge stainless 3.5" exhaust pipe?
ok, now how about some suggestions, i guess i need to get more with it in the FI department.
alright, maybe a 355 would be a better option then too?
how about a 355 with the above and the GN turbos.
as for plumbing could i just use heavy gauge stainless 3.5" exhaust pipe?
ok, now how about some suggestions, i guess i need to get more with it in the FI department.
Now you got the idea. I don't know too many people using the Carter AFB (edelbrock) style carbs for blowthrough BUT that doesn't mean you can't use it. Try it, if you get erratic results under boost, switch to a Holley style. The Demons come with the Nitophyl floats. The 3.5" piping is too big IMO, stay with around 2.25 or 2.5". Go too big and you lose velocity and sometimes pressure.
keep in mind how heavy this truck really is @ 4500 pounds.
with the engine you are building it still wont have any acceleration.
you need lots of torque!!!!
i built a 355 for my s-10with everything done internally, and a 383 with stock cam, afr heads for my brothers 86 t/a, and the t/a weighs more than the s-10.
THE T/A IS FASTER DUE TO THE AWSOME TORQUE CURVE - PEAK TORQUE IS @ 2000
trust me it will be alot more fun to drive
with the engine you are building it still wont have any acceleration.
you need lots of torque!!!!
i built a 355 for my s-10with everything done internally, and a 383 with stock cam, afr heads for my brothers 86 t/a, and the t/a weighs more than the s-10.
THE T/A IS FASTER DUE TO THE AWSOME TORQUE CURVE - PEAK TORQUE IS @ 2000
trust me it will be alot more fun to drive
Launching!
Joined: Jan 2002
Posts: 275
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From: Bardonia, NY
Based on your vehicle, the parts you want to use, and your goals, I really think you would be hard pressed to do better than the following setup:
http://innovativeturbo.com/cgi-bin/h...2402913257585?
Use that kit, an intercooler, carb hat, and custom plumbing and you'll be golden.
http://innovativeturbo.com/cgi-bin/h...2402913257585?
Use that kit, an intercooler, carb hat, and custom plumbing and you'll be golden.
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Joined: Nov 2001
Posts: 4,857
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From: Austin, TX
Lets not reinvent the wheel.
For all this talk...just go to www.turbomustangs.com (or www.turbogms.com)
For all this talk...just go to www.turbomustangs.com (or www.turbogms.com)
Thread Starter
TECH Apprentice
Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
Originally Posted by Pro Stock John
Not a bad package.
I would go no higher than 8.5:1 for pump gas.
I would go no higher than 8.5:1 for pump gas.
also, i don't want to buy a kit. maybe it would be smartest if i were to, but i'm one of those people who wants to say "this is my design, my fab, this turbo setup is MINE" maybe that's dumb and won't come out as well, but i just feel better about myself when i do the setup from scratch. i mean, i guess that kit is pretty much scratch, but if i used turbo headers as opposed to manifolds, wouldn't i have a quicker spool and a lot less backpressure?
Thread Starter
TECH Apprentice
Joined: Nov 2003
Posts: 330
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From: Winston-Salem, NC
tell me about stock GN turbos, I know nothing about them. I know little about turbochargers in general other than how they work, i don't know numbers or %. That's why i'm trying to take a year or so of researching this before i dive into anything.
can anyone define or give me a place to have them defined the following terms
efficiency (intercooler) also give me some numbers that i would expect
surge flow and what is realistic number for this application
pressure ratio
efficiency (not intercooler) and another realistic number or range of numbers
thanks, LS1Tech rocks!
can anyone define or give me a place to have them defined the following terms
efficiency (intercooler) also give me some numbers that i would expect
surge flow and what is realistic number for this application
pressure ratio
efficiency (not intercooler) and another realistic number or range of numbers
thanks, LS1Tech rocks!
Launching!
Joined: Jan 2002
Posts: 275
Likes: 0
From: Bardonia, NY
Originally Posted by Bowtiered
also, i don't want to buy a kit. maybe it would be smartest if i were to, but i'm one of those people who wants to say "this is my design, my fab, this turbo setup is MINE" maybe that's dumb and won't come out as well, but i just feel better about myself when i do the setup from scratch. i mean, i guess that kit is pretty much scratch, but if i used turbo headers as opposed to manifolds, wouldn't i have a quicker spool and a lot less backpressure?