cam choice
#1
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Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
cam choice
These are my can choice's.... What do you guys think...
LUNATI
490/490 lift
224@.50
112 lobe sep
106 @ cent
Comp Cams
224/231
.520/.515 lift
113 lob sep
109 center
Which would perform and sound better.
LUNATI
490/490 lift
224@.50
112 lobe sep
106 @ cent
Comp Cams
224/231
.520/.515 lift
113 lob sep
109 center
Which would perform and sound better.
#2
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Car: 86 IROC
Engine: 5.0 TPI
Transmission: 700-R-4
Axle/Gears: 2.73 open
Re: cam choice
in what engine? what, if any, other mods have you done to the engine you have? flat top or dished pistons?
#3
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Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Re: cam choice
Stock internals.. 86 trans am 305 tpi... 9.5/1 compression... Headers/3" borla/ no cat/ tune,25lb inj. CAI, edlebrock runners and base. 1.6 rockers
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Car: 86 IROC
Engine: 5.0 TPI
Transmission: 700-R-4
Axle/Gears: 2.73 open
Re: cam choice
I would go with the lunati. but im not sure if it is computer friendly. you can go to their website and check. there may be better choices. IMHO comp cams have better selections for TPI cars
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Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Re: cam choice
What makes the LUNATI better? I'm learning as well..
#6
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Car: 86 IROC
Engine: 5.0 TPI
Transmission: 700-R-4
Axle/Gears: 2.73 open
Re: cam choice
a TPI engine ,even pro built, is all in by 5000 rpm. so its a torque monster. by design. you cant really have much of a rump ,rump lumpy idle cam in these. the ECM don't like that. not that it cant be done ,but I would go to the comp cams website and use their cam selection software to select a cam that will give you the power output youre looking for
#7
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Re: cam choice
Keep in mind that those cams have lift numbers assuming that you're running 1.5 rockers. (check to be sure). ...so If you've got 1.6 rockers, you're lift is gonna be higher, and frankly I think you're already a little high for a 305.
...not a 305 guy here, but I'm pretty sure the stock valvetrain can't handle that lift either.
I think that you'll get a decent lopey chop with either of those cams. I'd say on a 350 you might be a tad high on your duration, but for a 305 which needs less air, and a high flow (although still long tube) intake, I'd say your duration looks about right. ....you'll definitely need a tune! Definitely!
....as a rule, the TPI has a LOW overall flow, but a high velocity at lower RPMs. Hence the high torque, low peak HP numbers. Think thumb over the garden hose, restrict the flow, increase the speed. ....the higher the amount of duration, (and valve overlap) the more choppy idle (cool sound) and the more overall flow at higher RPMs, but all the chop gets in the way of smooth high velocity (TPI) lower RPM air flow.
...not a 305 guy here, but I'm pretty sure the stock valvetrain can't handle that lift either.
I think that you'll get a decent lopey chop with either of those cams. I'd say on a 350 you might be a tad high on your duration, but for a 305 which needs less air, and a high flow (although still long tube) intake, I'd say your duration looks about right. ....you'll definitely need a tune! Definitely!
....as a rule, the TPI has a LOW overall flow, but a high velocity at lower RPMs. Hence the high torque, low peak HP numbers. Think thumb over the garden hose, restrict the flow, increase the speed. ....the higher the amount of duration, (and valve overlap) the more choppy idle (cool sound) and the more overall flow at higher RPMs, but all the chop gets in the way of smooth high velocity (TPI) lower RPM air flow.
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#8
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iTrader: (3)
Re: cam choice
....also keep in mind that since you already have the exhaust done (which helps!!!) ...and since you have stock heads....I'm not sure how much I'd expect from a cam. More power, sure, but not sure that'd be my next step after doing exhaust and other basic boltons. I'd look into optimizing your rear gear ratio, and if you have an automatic, I'd def look into a torque converter. Single biggest seat in the pants mod I've done was a 2400 stall torque converter. (now I've got a manual though). .....next was probably the rear gear. Cam helped, and sounds better, but wasn't as much as I though it would be. In hindsight, I wouldn't have done the cam unless I could've done heads too.
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