how much psi
#1
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Car: 1990 iroc z
Engine: LSX 376 F1A
Transmission: 4l60e
Axle/Gears: 12 bolt 3.42
how much psi
here are the motor specs
zz 383
Compression Ratio: 9.7:1
Block: Cast Iron, 4-Bolt Main, 1-piece rear main seal
Crankshaft: Forged 4340 Steel, Externally Balanced
Connecting Rod: Powdered Metal
Pistons: Hypereutectic Flat top with offset pins
Camshaft: hydraulic roller, 222°/230° @ .050'', .509''/.528'' lift, 112° centerlobe
Cylinder Heads: Aluminum Fast Burn 62cc chamber, 210cc intake runners, 2.00'' hollow stem intake/1.55'' sodium filled exhaust valves, LT4 Corvette valve springs and lightweight retainers, D-shaped exhaust ports and dual intake manifold bolt pattern and standard & center bolt valve cover paterns
Rockers: 1.5:1 Aluminum full roller, self-aligning
super ram intake and 52 mm throttle body
i am thinking of running 30lb svo injectors.
now i just bought a d-1sc procharger and it came with a 15psi pulley iam kind of worried it is to much boost.
+ transmission is pro built made to handle 600+hp
rearend is stock and has aluminum gridle with 2.73 gears.
i would like to keep the stock rearend for a while. i dont drag race either by the way. thanks,bryan
zz 383
Compression Ratio: 9.7:1
Block: Cast Iron, 4-Bolt Main, 1-piece rear main seal
Crankshaft: Forged 4340 Steel, Externally Balanced
Connecting Rod: Powdered Metal
Pistons: Hypereutectic Flat top with offset pins
Camshaft: hydraulic roller, 222°/230° @ .050'', .509''/.528'' lift, 112° centerlobe
Cylinder Heads: Aluminum Fast Burn 62cc chamber, 210cc intake runners, 2.00'' hollow stem intake/1.55'' sodium filled exhaust valves, LT4 Corvette valve springs and lightweight retainers, D-shaped exhaust ports and dual intake manifold bolt pattern and standard & center bolt valve cover paterns
Rockers: 1.5:1 Aluminum full roller, self-aligning
super ram intake and 52 mm throttle body
i am thinking of running 30lb svo injectors.
now i just bought a d-1sc procharger and it came with a 15psi pulley iam kind of worried it is to much boost.
+ transmission is pro built made to handle 600+hp
rearend is stock and has aluminum gridle with 2.73 gears.
i would like to keep the stock rearend for a while. i dont drag race either by the way. thanks,bryan
#3
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Car: 1989 IROC-Z
Engine: 5.7L EFI LTR setup
Transmission: T-5 World Class
Re: how much psi
I suggest lowering the compression ratio . 9.7:1 may be a bit high for 15 psi . I am doing a turbo as we speak , I am only startign out at 4 psi . I also have 9.7:1 C/R I figure with an intercooler I can possibly run 6-7 psi without any detonation problems. Possibly you can get away with a thiner headgasket ( depending on what you have right now)
#4
I agree w/ D's89IROCZ
That sounds like alot of boost for 9.7:1. I think 30's are out of the question unless you're running an FMU.
From what I've read, most blown engines are around .55 BSFC, which means it takes .55lbs/hr of fuel for every HP. Divide your 240 lbs/hr of fuel (MAX) by .55, and you're only supporting 436 HP. And you don't even run injectors at 100%, most recommend 85-90%. That puts you well below 400 hp. That engine sounds like it would outrun those injectors at 1/2 that boost, or less.
From what I've read, most blown engines are around .55 BSFC, which means it takes .55lbs/hr of fuel for every HP. Divide your 240 lbs/hr of fuel (MAX) by .55, and you're only supporting 436 HP. And you don't even run injectors at 100%, most recommend 85-90%. That puts you well below 400 hp. That engine sounds like it would outrun those injectors at 1/2 that boost, or less.
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Car: '88 G T/A
Engine: L98
Transmission: 700R4
Axle/Gears: 3.27 9 Bolt
Re: I agree w/ D's89IROCZ
Can solve a lot of your problems with Water/Methanol injection.
Will give you knock resistance, added fuel (can run smaller injectors) and it cools the charge.
Will give you knock resistance, added fuel (can run smaller injectors) and it cools the charge.
#6
Re: I agree w/ D's89IROCZ
That would be a great way to stop detonation with his high boost, I didn't think of that. The Buick guys run the hell out of methanol injection. I don't think I'd use it to replace adequate injectors, but you're right you are adding fuel.
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Car: 1986 Camaro SC
Engine: 305 TPI Procharged D1SC
Transmission: Tremec TKO-600
Axle/Gears: Moser 12 Bolt 3.73 posi
Re: how much psi
when you say 15# pulley you mean 3.4" pulley right? also a 3.4" pulley is equal to about 15#'s on a "stock" 350 at 5500 rpm, you probably wont see 15#'s from it maybe 12-13#'s and 30lb injectors are way too small i'm running 42lb/hr on my 305 without an FMU, methanol injection would be great, i have the snow stage 2 kit and just by adding it i feel a seat of the pants difference.
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#9
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Car: 1990 iroc z
Engine: LSX 376 F1A
Transmission: 4l60e
Axle/Gears: 12 bolt 3.42
Re: how much psi
well i don't have the measurement of the pulley but ya the pulley says it is a 15psi pulley. i really would rather run less boost for getting used to.
So u guys feel if i run 42lb injectors with the fmu i will be ok?
So u guys feel if i run 42lb injectors with the fmu i will be ok?
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Car: 92rs
Engine: 350
Transmission: 700r4
Re: how much psi
even 12-13# on hyper pistons with 9.7:1cr is really pusing it. With forged pistons and quality rods I'd say go for it, but one lean spell and crackety-crack go the pistons. With efi you're not going to get the cooling effect of a carb so the max boost will be reduced a bit more. If you're going to run more than 8-9# you will definitely need either an intercooler and/or methanol/water injection.
Is E85 available anywhere nearby? That would help things a bit but you'd need even more injector 60lb or so. You could look into dropping the CR a bit with a thicker head gasket and give it a bit more boost and keep the pistons around a bit longer.
Is E85 available anywhere nearby? That would help things a bit but you'd need even more injector 60lb or so. You could look into dropping the CR a bit with a thicker head gasket and give it a bit more boost and keep the pistons around a bit longer.
#11
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Car: 1990 iroc z
Engine: LSX 376 F1A
Transmission: 4l60e
Axle/Gears: 12 bolt 3.42
Re: how much psi
well the ati d-1sc comes with a 3 core intercooler so i will be running that.
i guess i will look into getting a 12psi pulley that way i will be only running 9-10psi max.
i guess i will look into getting a 12psi pulley that way i will be only running 9-10psi max.
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Car: 92rs
Engine: 350
Transmission: 700r4
Re: how much psi
Good luck with the buildup. Hope you've budgeted for new tires because that blower/383 setup will annihilate your radials pretty well. I've got a 9.1:1 350ho witha p1sc @ 8 lbs and traction is a major issue below 60mph even with full bolt on suspension and 275 series BFG kdw radials. With your setup you should see 500+ rwhp pretty easily.
As stated before, back down your timing a bunch and listen very closely for any detonation, that's going to be the key to not cracking any ring lands
As stated before, back down your timing a bunch and listen very closely for any detonation, that's going to be the key to not cracking any ring lands
#13
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Car: 1990 iroc z
Engine: LSX 376 F1A
Transmission: 4l60e
Axle/Gears: 12 bolt 3.42
Re: how much psi
whiteghost what gears are u running in your car?
i am going to have a dyno shop tune the car before i put the belt blower on.
i am going to have a dyno shop tune the car before i put the belt blower on.
#14
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Car: 92rs
Engine: 350
Transmission: 700r4
Re: how much psi
I have a 3.23 eaton posi in a stock 10 bolt and a t-56 so its geared pretty high. Max theorhetical speed in 6th is like 250mph but i cruise on the highway under 1500rpms. Any reason why you're getting it tuned before the blower is working? This will just necessitate more tuning and $$$$ later. What fuel pump are you using? You will need to flow a lot of fuel to keep the engine from starving itself on boost at high rpms. I went with the racetronix forced induction kit for efi even though I'm carbed and it has been fine. You will be on the edge of what the stock fuel lines can flow
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