383 & a turbo - good idea or bad?
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383 & a turbo - good idea or bad? Okay guys, need some help. Did a few searches and didn't really find anything that gave a "definite" answer to my questions.
I'm looking at the sales from AP-Engineering and IconAutoSports in the Sponsors specials forum, and got some prices from them for a 347 and a 383 shortblock.
My goals for my car (the one in my sig) is to have a VERY streetable, DAILY DRIVER that can also open up a can of whoop-*** whenever I want it to (450rwhp+ this year, 600rwhp+ after FI). I'd like to try my first drag-strip race maybe this summer, or certainly next year. This will be a street/strip car for sure in the long term.
I've been doing a lot of research on the STS Turbo kits. Sounds like fun, and certainly fits the needs of my car (considering I will be moving to San Diego, CA in the near future and dealing with the smog *****). Realistically a little too expensive for THIS year, but definitely going on at some point.
So I'm trying to decide if I should go with a 347, or a 383. I want to keep gas mileage as high as possible for when I drive "properly" on the street/highways, but I DO realize that the second I stick my foot into it that it's not an economy car.
I'm thinking that the 347 with the turbo is gonna be plenty powerful in the long run, but that the 383 might be a cost & power compromise in the short term till I can afford FI. I just don't want to end up with a car that empties my wallet every 200 miles, won't pass smog, or that doesn't want to play nice on street manners. I am also concerned about how the 383 might perform as a daily driver once I put the turbo on it in a year or two.
Suggestions? Reasons? Experiences?
I'm looking at the sales from AP-Engineering and IconAutoSports in the Sponsors specials forum, and got some prices from them for a 347 and a 383 shortblock.
My goals for my car (the one in my sig) is to have a VERY streetable, DAILY DRIVER that can also open up a can of whoop-*** whenever I want it to (450rwhp+ this year, 600rwhp+ after FI). I'd like to try my first drag-strip race maybe this summer, or certainly next year. This will be a street/strip car for sure in the long term.
I've been doing a lot of research on the STS Turbo kits. Sounds like fun, and certainly fits the needs of my car (considering I will be moving to San Diego, CA in the near future and dealing with the smog *****). Realistically a little too expensive for THIS year, but definitely going on at some point.
So I'm trying to decide if I should go with a 347, or a 383. I want to keep gas mileage as high as possible for when I drive "properly" on the street/highways, but I DO realize that the second I stick my foot into it that it's not an economy car.
I'm thinking that the 347 with the turbo is gonna be plenty powerful in the long run, but that the 383 might be a cost & power compromise in the short term till I can afford FI. I just don't want to end up with a car that empties my wallet every 200 miles, won't pass smog, or that doesn't want to play nice on street manners. I am also concerned about how the 383 might perform as a daily driver once I put the turbo on it in a year or two.
Suggestions? Reasons? Experiences?
Last edited by 89FormulaLS1; Jan 29, 2005 at 06:04 AM.
If your'e buying a new shortblock anyway, going 383 is a no-brainer. As far as later down the road, you are always going to want more. I would at the minimum get 43# injectors and depending on your budget, maybe a high flow fuel pump. Then when your mods get out of hand, "like they always do", you will already have your fuel side up to speed. Otherwise, the mods end up killing your budget, then you burn up the motor trying to make do with an inadequate fuel supply.
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Going with the high flow fuel pump now anyway, my 3rd gen pump would have been inadequate even for a stock LS1. I've already got most of the stuff for the mods I intend to do. Dropping off the car for the swap on February 10th. 
I'll definitely look into the injector situation, though. Thanks.
I'll definitely look into the injector situation, though. Thanks.
i would turbo it unless your running high compression. i dont really see the point of putting a turbo on a car unless your able to run 10+ pounds of boost. but my car would run a 20 second 1/4 if i didnt have a turbo so im kind of partial to them.
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Skip the 383 and go for a 402. It uses the same stroke as the 383, but it's built with an iron block with a 4" bore. Iron 6.0 blocks aren't expensive at all, so it really won't cost much more. A low compression 408 could easily make 450 at the wheels, and a lot more under boost.
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I'll have the shortblock built for 9.5:1 compression, then for now put on my milled & ported heads which will bring CR back up to about 10.2:1 Later on when I go FI, I'll put on some LQ9 ported heads and bring compression back down to 9.5:1
I'm a little skeptical of the 402 and 408 for a daily driver. I know that anytime I get after the throttle it's going to suck up the go-juice with ANY build I make, but with 400+ cubes I'm concerned I'm not going to get ANY decent gas mileage, even on highway trips in 6th gear.
I'm a little skeptical of the 402 and 408 for a daily driver. I know that anytime I get after the throttle it's going to suck up the go-juice with ANY build I make, but with 400+ cubes I'm concerned I'm not going to get ANY decent gas mileage, even on highway trips in 6th gear.
I have seen a lot of guys in south florida that have a hard time with a 383 or around that keeping the heads on he car. By what i have seen most of the gains are just torque. Lots of the cars use 346 or 347s that rev a little higher. I kinda want a 383 to ya know show and tell a little 
but i will end up witha 346 or biggest a iron 370
but i will end up witha 346 or biggest a iron 370 Trending Topics
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Verdad Gallardo well with lower compression youll get alot better milage. the only problem is your motor is weak unless your running a blower. my cars runs 8.5 :1 and i get around 30mpg unless my foots in it then its a whole lot less. so i say lower compression and get good gas milage great drivability and 600 hp under a lot of boost
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You're building a stroker and you think that 20 cubes is gonna make or break your mileage? An iron block 402/408 will be able to handle so much more than you will ever throw at it, i don't see any reason not to do the engine right the first time. When i destroy the 346 in my GTO (and yes, that will happen ) i will go forged 408 and a lot more boost from whatever blower type i decide on.
) i will go forged 408 and a lot more boost from whatever blower type i decide on. Thread Starter
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Well, I'm going aluminum block, not iron. And I've been told - perhaps wrongly so - that there IS a big difference between the 408 and the 383. But the BIGGEST factor against the 408 is that some have claimed that it will never pass emissions in California. Since I'm moving there soon, I MUST know that it will pass emissions for sure before I commit to a 408.
Since I'm moving there soon, I MUST know that it will pass emissions for sure before I commit to a 408. Last edited by 89FormulaLS1; Jan 31, 2005 at 01:49 AM.
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As long as you don't go radical on the cam, and you use shorty headers and two cats for each bank of cylinders the 408 will pass emissions. And if you think all that sounds extreme to get it to pass....you'll have to do the same thing to get a 383 past the smog ****'s.
