JimS

I drive my truck around town to have fun.. i.e. do burnouts starting at 15 to 30 mph, make noise, impress the youngsters (I'm 69.. almost). I don't drive long distance's on the highway. I don't wind it up very high or very often. I don't even drive it very often... it's more a show queen and weekend cruiser than anything. I just get on it hard for 5 seconds or so, on Main St.

So, all that said, what's the opinion's about having a 2.5" pulley machined? I'm thinking that should get me in the 15 to 20 lbs of boost area, make more power and enable even more impressive burnouts at 20 mph.

I remember a story in Hot Rod, I think it was, where they turned up the boost until the 5.3 was making about 1200 hp at over 23 pds of boost and even though it had a stock bottom end, it still held up.

I know that it'll shorten the life of the Radix but hell I'll bet it'll last me for the rest of my life, given that I only drive it maybe 50 days a year for less than a 3 thousand miles a year.

Before I do it I want some opinions from you guys. So, whaddayathink???

Oh.... I'm figuring on a 100 shot of nitrous as well.

Atomic

iTrader: (42)

Haha, I like your style. However I dont think a 2.5 will even fit given how the pulley is attached to the front of the blower. And belt slip is going to become a larger problem because of less area on the pulley for the belt to grab, and more resistance from the blower. I would look at a bigger blower like a used 122 that would be an easy swap to what you have now instead of a nickle sized front pulley.

RibeiroBJJ

iTrader: (17)

Sounds like you enjoy your truck! I hope I am doing that at your age

As far as the Hot rod mag, that was a 4.8 with a turbo..You will NEVER see that much HP/psi out of a radix..I would say to get a larger crank pulley, or get some 4.56 gears..Or just slap a tvs1900/2300 on it and you will see your 20psi

Good luck

AKlowriderZ71

iTrader: (22)

Texas Speed has a larger crank pulley with the correct offset for these trucks. It's not very expensive.

Is your crank pulley pinned? You'll need to pin the new pulley if you go that route. Of course you'll need a retune as well.

JimS

My crank pulley is pinned and I hate to spin the ac, water pump and alt faster but I would if I have to. Maybe I should just go with 150 hp of nitrous? I already have 4:56 gears

When the fun is over they can call the coroner... or I guess you could say, when they call the coroner the fun is over and NOT until!

I thought about going with a bigger blower but now we're getting into much bigger money and if I'm going to do that then it's time for many more cubes etc, and the bill really grows big. I'm on SS and work part time so money is somewhat of an issue. I can't afford more cubes or a bigger blower and certainly not both... and that's what I really want. Hell... what I want is 1000 hp/torgue at the wheels.

03regcab sierra

iTrader: (7)

U will need to machine the blower to fit the pulley and deffinitly get a bigger heat exchanger and coolant reservoir (icebox) and also if u dont already have get some oversized idler pullies. my brothers truck sees intake temps of close to 200° if he doesnt cool it down real well after making a short wide open throttle run.

AKlowriderZ71

iTrader: (22)

Jim, here's another thought since it seems like you're trying to maximize your setup. Let more air into that blower. You've got a 90mm throttle body on it, but you're negating those gains with your MAF sensor and stock Radix tubing. The I.D. of those is 3 3/8". If you switch to a speed density tune with a 2 bar MAP sensor, you will see some large gains. You'll probably see more boost also if you build a 4" intake. You can keep the airbox you already have.

I have a thread somewhere from when I did mine.

Blowndenalixl

Just curious about the 20 psi reference - is this just with a tvs1900/2300 on a 5.3, or can get there with it on a 6.2 as well. If so I may be looking to pulley down a bit as only running 5 lbs right now.

Thanks

D

Atomic

iTrader: (42)

a 2.8 pulley with a 1900 on a 5.3 will get you about 13psi
a 2.8 pulley with a 1900 on a 6.2 will get you about 9psi

Keep in mind this is moving the exact same amount of air, so with less boost it will run cooler and better overall.

You can get 20psi out of a roots if you spin the **** out of it, but I would not recommend that. It would require the jackshaft version anyway.

caddy03pimpin

iTrader: (18)

I got a 2.45 pulley laying around I can tell you what you have to do to make it fit its very minor .