2005 Pontiac Grand Prix Build Progress

Before I begin, I wanted to keep a log of everything that I was going to do to this car as I did them. I figured what better way to do that than to share it with other people. I’ve dabbled doing videos with some buddies as we work on it as well, so if that is something that some of you would like to see, then definitely let me know.

Introduction

This is a base model 2005 Pontiac Grand Prix with 220,000 miles on the odometer when it was given to me by my parents. This is the first car that I ever drove as well as the first car that I have really worked on. With that being said, it is fairly special to me.

It was nothing but a solid daily driver during their ownership, despite their lack of maintenance to it. Only thing they ever really did to it was replace the brakes…once. I do believe they also changed the air filter a couple of times and the serpentine belt. They also bought an aftermarket head unit (I installed it). Other than that, almost everything else was from the factory. Factory plugs, struts, fluids (with the exception of oil), and pretty much anything else you could think of.

During the tail end of it being theirs, I personally replaced a stuck thermostat, all 4 brakes (pads and rotors), adjusted the e-brake, replaced both front wheel bearings, put in 2 new 6x9 rear deck speakers, and put in two JL Audio 10” subs that I pulled from our Sierra before we sold it.

Long-term Plan as of 3/8/2016

I’m beginning with new suspension. It may not be a super fast car, but its quick enough, and better handling would really make this thing come to life.

Cosmetically, I would like to tint the windows, tail lights, and replace the hazy headlights. These in addition to the ~1.5 inch drop I’m getting with new struts and springs, I think I’ll be very happy with how it looks. I’m really not trying to spend a ton of money on the outward appearance. That money could be better spent elsewhere on this car.

A concern with putting in any real power gainers as of right now is that the motor and trans have over 220k on them. Not to mention the transmission already acts up from time to time.

With that being said, I am planning on swapping the transmission with one that is built for up to 360whp and replacing the N/A 3800 Series III that is in it right now with a S/C 3800 Series III. This would cost me around $5-6k in parts, but I would also gain some very good experience. With the new motor and transmission, in addition the the Supercharger, I can really start to put some power gaining mods on without risking blowing up my car, considering this is still a daily driver as of right now.

I’m sure I’ve left some details out of this, but as I think of them I will try to add them in. Please leave some feedback!

March 8, 2016

I cleaned up the outside and detailed the inside. I have also sprayed the rims black with Plastidip and made a new intake with a universal fit filter and some tubing. PCM is zip-tied in for now, but I will be using a more elegant mounting solution soon.

New struts are ordered and waiting to get paid to buy springs and strut tower brace.

March 9, 2016

Put in a magnetic phone mount to go along with the new Bluetooth OBDII adapter. New struts came in the mail too. Now I am just waiting to pull the trigger on some new springs (and maybe mounts) and suspension is good to go. We chopped off the muffler today as well. While it actually sounds pretty good, I think I will be throwing on an aftermarket muffler soon.

March 13, 2016

The new springs were ordered the other night.

We played around with the exhaust too. Just for grins, we took off all of the exhaust after the cat. We ended up putting it back in (with the exception of the muffler of course) because it was just too loud. I’m not trying to get pulled over. It sounded better than I thought it would with no exhaust though (it definitely sounded better in person). It backfires all day too with no exhaust. It had a little bit more pickup too, so I’ll be playing with it a little bit more to see what kind of gains I can get out of the exhaust.

On another note, just with less restrictive exhaust and intake (just piping and cone filter), it was able to shave ~1-1.5 second(s) off of it’s 0-60 time. The lowest I was able to get was 7.3 seconds. When it was completely factory, I was getting 8.8 seconds on a good day.

March 19, 2016

We went to go put on the new struts and springs just to find that I was shipped the wrong front struts and the new springs don’t seem to sit correctly on the factory struts. The retailer has already emailed me a return label and has the correct struts on the way. They also assured me that the springs should fit on the new struts. While it was kind of disappointing, its not the end of the world.

April 10, 2016

Finally got my replacement front struts in the mail two days ago and put them in the car with the new springs. Ride is definitely better and less rattle with the new strut mounts. I’m still waiting on the new springs to settle a bit more, but you can already notice a bit of a difference in ride height.