5.3L V8 Mods

Hello again everyone.

I have a 2003 TrailBlazer EXT with the 5.3 V8.



To get a little more power out of my lead sled, I have added a Granatelli
Power Programmer. Supposedly will add 20-30 HP.


You can adjust your shift points & firmness. I only lowered the shifting RPM to 5400rpm's. Peak HP is at 5200rpm, so no sense to go much further than that. HP just drops off from there.

By using the programmer to just add performance was easy to do. It was done with in about 3 minutes & I noticed the results. My brother has a new full size Chevy Conversion Van with the 5.3 as well. We raced 2x's & it was dead even between us. After installing just the programmer, I walked him at a noticeable pace. Nothing major, but definately noticeable!
It does a bunch of other things as well, but I really didn't have to use everything it did, but I do rec. it to anyone with the V8.


Second thing that I added was the TrueFlow air intake kit. Again, another relatively easy installation, for me about 40 minutes. It is designed to be used with your stock air house, but some of the insides were removed as well as some of the outside stock stuff. Decent quality for the TrueFlow. It looks kinda cheap when you get it out of the box, but if it works & holds up well, that's all that matters.
What the intake did for me in addition to the Programmer was really noticeable again. Deaper tone & it seemed to be a little quicker as well. Really noticed an improvement in the throttle response as well. During normal driving, you really won't notice you have it on there...noise wise. But if your getting silly with the gas pedal....come on, you know you will :iceslolan , you will start to hear it around 2500rpm until around 4500rpm to where the sound tapers off. Really sounds great IMHO!
Their tech guy said it would add 16HP to the mix.....one of there dyno sheets for a 2001 5.3V8 in the trucks added an additional 11.6HP, so maybe his claim wasn't too far off.

I still have coming a Granatelli Mass Flow Air sensor. That is supposed to give you 18-20 rear wheel horsepower :iceslolan .


Adding all of those figures up between the 3, I had "figured" it "should" give me an added 55hp & somewhere in the area of about 60+ or - torque.

So I could be pushing 345hp & close to the 400lbs of torque mark.
If that is true, then GREAT! I just wish that someone would come out with an exhaust system for the V8. I find all kinds of items for the inline 6, but NOTHING for the 5.3 :mad:

If anyone knows off hand if there is something for the V8 in the exhaust systems, please e-mail me with any information P-L-E-A-S-E! If I can do something for it, then my TrailBlazer will be complete!

[email protected]

Thank you all for reading this. I know it will never be a Corvette for speed, but having an edge over standard TrailBlazers is always nice. Especially the smaller & lighter inline 6's!




Once I get the Air Sensor...hopefully next week.....I will post the response on here & how I liked it.

O.K, my bad....you CAN bump up your top speed rating to 125mph.

Not that I would or even have enough room to get her up that high, but nice to know it "could".

Jeez.....I could just imagine the smell of the poor brakes trying to slow/stop you from that high of speed......wouldn't be pretty :nono:

STILL waiting for the Mass Flow Air Sensor to arrive.....stupid backorders! I am told that I "should" have it next week.....yeah...heard that before....Will report back then.



Here is something that you guys might like. Before I did any mods to my 5.3V8, I raced my buddy at my work. He drives a new Dodge 1500 quad cab 4X4 with the Hemi. His stock against my stock surprised me!
Both of us going around 50mph, we both puched it & believe it or not, neither of us pulled or lost any space between us....it was dead even!
I laughed at him for it....... :lol:
After installing my 2 things, I raced him again today & doing the same mph start, I passed him up! Slowly, but again, noticeably!!!!! :rofl:
I raced at a lower mph at 30 & on & he had a little bit of a jump on me & only s-l-o-w-l-y pulled away, but that was until I hit around 55mph where he pulled away no more. I actually started to real him back in. But the cars ahead were coming up quickly & we both had to shut down.

Not bad for a big tub huh?! I still want the Air Sensor & whenever an exhaust comes out, I "should" be done. It'll never be a race car, but it is sure fun to surprise those who aren't expecting my ride to be faster than it is. Have you beaten a Hemi lately?!!! :iceslolan

Perhaps I will try out the Throttle Body Spacer. Maybe a new throttle body as well......ah yes, the possibilities! Must get MORE low end power to move the lead sled! Anyone got a supercharger?!!! :bananasmi



ENJOY!

O.K about flippin time!!!! The Granatelli Mass Flow Air Sensor arrived yesterday & I installed her today.


I don't know if your supposed to hear anything differant or not, but I didn't hear anything........

Installation was easy...about 20 minutes at the most for me.


Supposedly it is going to give you about 12-15 extra Pony's. Torque is going up to 15-20 extra. These figures are for a bone stock vehicle mind you ......by having a few other add on's....your going to get even more power!!!!!! :iceslolan

First test drive proved a little more power. Nothing as noticeable as the programmer or the intake, but still nice. Seemed a little smoother with the power & it moved throught the rev range quicker than before.
Still no race car, but better indeed!


I put in a e-mail to Borla Exhaust & Banks Power packages to see who has what if anything as far as exhaust systems go.

Here's hoping that SOMEONE has something for my vehicle. Then I'll be done.

You figure an exhaust system will give you another 10HP give or take.....if so, I'll be easily at
350+ HP
400+ Torque


Oh Yeah!

Final thing that I have done to my vehicle was a FlowMaster 70 series muffler with a 3.5" polished stainless extention coming out the back.

It really made a difference in the tone of the V8. Deep growl from about 2600 & down. You'll probably hear it a little more than you would like down low....especially in the cabin, but the wife never complained once which is a shocker! Guess it isn't that bad afterall!
From about 2600 & up, the sound level seems to go down becasue you don't hear it as much & it is rather quiet on the highway just cruising.
Punch it though, & you will hear it again.

So far, I am really happy with it. FlowMaster said that this is there largest muffler, though smaller than your stock unit, & it is also there most quiet one. Sure glad I didn't go with the 50 series like I wanted to!
That probably would have been way to loud for me. The 70 series is loud, but nothing overbearing, but your reminded it's there when you blip the throttle.



After having the tune in my Predator redone by Diablo (the maker of the tuner) the TrailBlazer runs really good. I had it out on the expressway the other night & there really wasn't many cars so I punched it hard.
I was at around 5550 RPM & the speedo said 121 MPH!!!! The darn thing was STILL puling hard. I know I didn't have too many more RPM's to go before the fuel cutoff would have interjected, but man, that surprised me! I couldn't maintain the speed becasue of up & coming traffic & the major fact that the tires are NOT speed rated for that kind of speed.
The bottom line is that I now have a TrailBlazer that will go well & sound great & be able to surprise a few people when needed to.
All that is missing is a supercharger or a turbo ;- )

If I do anything else, I will post it here for all to read.

Adam