performance upgrades

i'm looking into getting a few goodies for the truck. i have a 2003 4.8L 2wd. i'm looking at getting the Diablo preditor programer, a S&B cold air Intake, helix plus TB spacer. flowmaster muffler w/ high flow cats, plug wires w/plugs, 25% underdrive pulley, electric radiator fans.... and i plan on doing most of these all at the same time. i was just going to see if anyone has tried these products and what they think.... thanks for any feedback

All of these mods are good mods for both performance and fuel economy. A better flowing intake system (not just an open element in the engine bay) and exhaust system will definitely make improvements. The pulley and elec fans will reduce parasitic drag on the motor, freeing up hp and torque while gaining MPG. Just keep in mind that the smaller crank pulley will also slow down the accessories driven by it, i.e. alternator. This means your alternator will be spinning slower, and at idle, the current output will be lower and you may even lose a volt or so while at idle. But if you do not have a lot of high powered aftermarket accessories, you should be ok.

Depending on how loud you want it to be the flowmaster mufflers are great! I went with a Magnaflow becuase the flowmasters were a little too loud and gained 10hp and about 2 mpg better. Good luck! :Chevy:

thanks both of ya'll for the input! on the pulleys i'm getting a 32% overdriven alt. pulley with the others being 25% underdriven. on the intake, i'm looking at the S&B. from looking at your pix JK it looks like you've got one. how do you like it? i considered the volant but i am able to get a package deal on the spacer, intake, and diablo programer for 500. seems like a good deal to me so i'm pretty sure i'm gonna get it. pulleys are about 250, exaust 350ish, plugs and wires 200ish. i think that these mods are good for the prices and will end up paying for themselves in the long run. i'm also about to be driving from oklahoma to alaska pulling a trailer, so i'm looking to up power and mpg. i'm also lowering and doing brake upgrades. i'm going to be running a 6.5" double DIN touchscreen up front w/ a 20" flip down in the back along with 2-12s in the back. do you think that the 32% overdrive pulley will be up to the task? or will i need to get a high output alt? well, thanks for the help!!!

Where are you getting a package deal on the spacer, intake, and diablo?? That sounds like one helluva a deal!! :Chevy:

STREETutilityVEHICLE said:

...looking at your pix JK it looks like you've got one. how do you like it?... i'm going to be running a 6.5" double DIN touchscreen up front w/ a 20" flip down in the back along with 2-12s in the back. do you think that the 32% overdrive pulley will be up to the task? or will i need to get a high output alt? well, thanks for the help!!!

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I actually really like the intake. The intake tube is composite, which is better than the other kits that are metal, as it does not soak up nearly as much heat. The air box comes with a pre-cut/drilled, clear acrylic lid so you can check the filter w/out removing anything. The airbox itself is also an advantage to keep the system from sucking in the hot air from the engine bay. And I got mine with a free cleaning and re-oiling kit that comes with a precise metered oiling tube so you lessen the chance of over-oiling the filter and contaminating the MAF.

As for the alternator, it will be better to use the larger pulley to keep the alt output at maximum levels while at idle, especially if you're adding more high current equipment. If the alt isn't spinning fast enough, it may not be able to charge the battery if you have the a/c, lights, stereo system, etc, on and you are at idle for a while. The underdrive crank pulley is going to slow down the alternator. Even though voltage is regulated, it can still drop below sufficient levels, as well as the current output, if it is turning too slow. The ignition system is also affected with low voltage and current outputs, which in turn, affects power and mileage.

http://www.rpmoutlet.com/newgmcsuv.htm here's the package deal. i'm getting the s&b intake with the helix spacer w/ the diablo. check it out. they also got the k&n intakes, both crome and black composit, and also the AEM brute force intake. then they have the helix spacer along with motorvator and jet power flo spacers available also. but the diablo is included with any combo of the intake and spacer. cool site for our trucks.

also, they have a throttle body by pass kit that is like $10 and they say it gives you like 4 horsepower. anyone ever heard of this part or have it installed? i'm thinking about buying it, but i have a stock throttle body and i'm not sure if it works with stock ones.... let me know if ya'll heard of these and if they work for stock TB's would ya? thanks

http://www.rpmoutlet.com/gmsuvbbktb.htm#1

STREETutilityVEHICLE said:

also, they have a throttle body by pass kit that is like $10 and they say it gives you like 4 horsepower. anyone ever heard of this part or have it installed? i'm thinking about buying it, but i have a stock throttle body and i'm not sure if it works with stock ones.... let me know if ya'll heard of these and if they work for stock TB's would ya? thanks

http://www.rpmoutlet.com/gmsuvbbktb.htm#1

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The stock TB has a coolant line intake to allow the TB to warm up quicker in cold weather and help keep emissions down with warmer incoming air. Bypassing this will help keep the air charge temps down and help some w/ hp. You can perform this mod with your stock or aftermarket TB. But you can get a coupler and a couple hose clamps from your autoparts store cheaper. That's exactly what the bypass kit is.

JKmotorsports said:

As for the alternator, it will be better to use the larger pulley to keep the alt output at maximum levels while at idle, especially if you're adding more high current equipment. If the alt isn't spinning fast enough, it may not be able to charge the battery if you have the a/c, lights, stereo system, etc, on if at idle for a while. The underdrive crank pulley is going to slow down the alternator. Even though voltage is regulated, it can still drop below sufficient levels, as well as the current output, if it is turning too slow. The ignition system is also affected with low voltage and current outputs, which in turn affects power and mileage.

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Re-read the above post concerning the alternator pulley. I had to edit. I posted wrong info the 1st time because I read your original post wrong. My bad.

JK....do you think that throttle body bypass thing could be the reason why my tahoe feels like it has extra balls in the morning in the when its cold and then feel like im hauling a trailer when its warmed up?

sixty9fordkiller said:

JK....do you think that throttle body bypass thing could be the reason why my tahoe feels like it has extra balls in the morning in the when its cold and then feel like im hauling a trailer when its warmed up?

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i agree, really makes me mad