How much difference does a smaller pulley make?
03-20-2006, 06:21 AM
#1
How much difference does a smaller pulley make?
Yeah, i know...you guys warned me it would be addictive. I guess there is nothing i can do now but 
. So here is my next question(S). How much difference does 1psi make? How many psi would i need to jump to notice a decent performance gain over what i have now (i want to get into the 13's)? Lastly, how many psi can i get away with before have to intall some sort of injection or an IC? I live at sea level (give or take a hundred feet) and the winters are cold and dry and the summers are hot and moist.
. So here is my next question(S). How much difference does 1psi make? How many psi would i need to jump to notice a decent performance gain over what i have now (i want to get into the 13's)? Lastly, how many psi can i get away with before have to intall some sort of injection or an IC? I live at sea level (give or take a hundred feet) and the winters are cold and dry and the summers are hot and moist.
03-20-2006, 08:32 AM
#3
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I know with my Radix, stock 4.8, and stock tune I went from 7.5lbs boost to 11.5lbs and it was the single best mod I ever made! Holly ****! I can't even explain the difference it made. Well with that particualar set up I ran an 03 Cobra from a 50 roll and he got me by about 1 car length to 100. Then with the tune he would have been beat by 2. A tune is a must with boost increase if you want to survive it of course. I was just lucky because Magnacharger has really conservative tunes.
03-20-2006, 08:55 AM
#4
Tuning is not an issue, i am about 10 minutes from the dyno and tuner. Has it been established yet that a DMax intercooler will work on these trucks and that it will provide sufficient cooling (i would imagine it can considering Dmax's run 25+ psi)? I know there was some "back and forth" about it because it was a taller core, but i figured since i have the HD truck already, it may be a pretty easy MOD. I figure it will bolt right in, just a matter of some plumbing, manifold inlet, and compressor outlet to make it work. Am i wrong? Anyone have any PICs of a stock DMax engine bay so i can take a look at the plumbing?
Last edited by Linda; 03-20-2006 at 09:09 AM.
03-20-2006, 02:42 PM
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Originally Posted by mjhoward
I know with my Radix, stock 4.8, and stock tune I went from 7.5lbs boost to 11.5lbs and it was the single best mod I ever made! Holly ****! I can't even explain the difference it made. Well with that particualar set up I ran an 03 Cobra from a 50 roll and he got me by about 1 car length to 100. Then with the tune he would have been beat by 2. A tune is a must with boost increase if you want to survive it of course. I was just lucky because Magnacharger has really conservative tunes.
I did not go quite as far, up to 9.5 - 10 psi, depending on which gauge I use 
. The power increase was amazing, about half again as much as the original install gave me. I didn't have to tune, because the PCM was able to adapt to the new conditions, but if you have a GOOD tuner, then I would recommend it. Unfortunately, I have now maxed out my injectors at 86% duty cycle, so I can't go any smaller. 
As they say "Git 'er done!", believe me, you won't regret it. 
03-20-2006, 03:02 PM
#6
Originally Posted by GMC_DUDE
I did not go quite as far, up to 9.5 - 10 psi, depending on which gauge I use . The power increase was amazing, about half again as much as the original install gave me. I didn't have to tune, because the PCM was able to adapt to the new conditions, but if you have a GOOD tuner, then I would recommend it. Unfortunately, I have now maxed out my injectors at 86% duty cycle, so I can't go any smaller. As they say "Git 'er done!", believe me, you won't regret it. Are you running an intercooler? The only thing im worried about is going to be the summer heat. Not sure how much of an impact its going to have.
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03-22-2006, 03:12 AM
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Originally Posted by Linda
Are you running an intercooler? The only thing im worried about is going to be the summer heat. Not sure how much of an impact its going to have.
]Yeah, the radix has a built-in intercooler. If you don't have one, then I think you are probably at your limit at 5 psi. It really would be best to add an intercooler before any more boost.
A few thoughts on intercoolers:1: If you are going air-to-air, try to keep the pipe length and overall volume as low as reasonable. Otherwise the blower has to pressurize all that plumbing, which can cause lag.
2; If you have e-fans, be sure they are wired such that they are running any time you are in boost
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