2004 Turbo Regal intro - Dave


2004 Turbo Regal
Hello gang. Saw this site after a fellow member posted on our RegalGS 3800 forum about GS Nationals. Since that got delayed, I figured my introduction can start by posting here, instead.

My current car is a 2004 Buick Regal GS (GSX grille).
CAR PROFILE LINK - Best 1/4mi: 11.46 @ 122, 1.87 60ft - YouTube Video (with 1998 Regal commercial theme music)
I originally built the turbo setup for a friend in Upstate NY, who was the previous owner. Started with a 2006 14k-mile junkyard 3800 Series III (L32) GTP engine, and built the attached 4T65e-HD transmission with every available upgrade to take the beating (hardened shafts, GM Racing 1" chain/sprockets and Torsen differential, Raybestos blue plates, etc.). The ZZP Z7 turbo kit we installed was upgraded to a T66 T3/4 turbo with Air-Air I/C that worked great.

Just pulled the engine last month to upgrade the cam to a Stattama/ZZP ST5, after enjoying the INTENSE Stage 3 turbo cam for 10yrs. Also, I was about to put my MP112 supercharged L26 engine in it, but after learning about GS Nationals, I figured I needed to bring my A-Game sticking with a turbo 3800 setup, so I've got a T-67 ball bearing water-cooled T4 turbo and FrozenBoost Air-Water I/C setup ready to drop in as I re-assemble it.

Hopefully the picture collection from the 2009 build loads correctly, or I'll work on hosting it elsewhere to show more details. Pictures and videos of the 2020 setup will be loaded up as I finish it up during the quarantine.

- Dave

Buick 2009 build collage.png

Jon Early

Active Member
Alright! Welcome to turbobuick.com! Your car looks awesome. Sadly, this forum got pretty jacked up a couple months ago and hasn't quite been the same since. Hopefully it starts to bounce back a little. Speaking of which, I better go update my build thread as well. I look forward to updates!


2004 Turbo Regal
For the last month, I've chipped away slowly at getting the engine out, in-between other busy work (some actual work duties, online engineering school, 3D printing random stuff, lawnmower leaf mulching, chainsaw'ing fallen trees at g/f's)...

Some shots as I have been prepping this sideways-mounted beast for more fun:

2020-03-16 - Regal L32 ready to pull.jpg

2020-03-16 - L32 in the air.jpg

Decisions... Decisions... upgrading turbo L32 setup for GS Nationals won over putting in the MP112 L26, for now...
2020-03-16 - L26 MP112 and T66 L32.jpg

As it sits now, bigger cam in and timing chain refreshed.
Cam/Crank bolts arrived w/ cover gasket, so time to clean and start integrating some new toys.
2020-04 engine w-ST5 new chain.jpg

- Dave

P.S. - preview of the turbo and A2W I/C core that arrived last week



2004 Turbo Regal
Thanks. Just ordered Morel 6504 lifters and a pushrod checker tool that should arrive tomorrow (most likely need new PR's, then engine can go back together).

All sorts of parts have arrived, and the valvetrain parts will be what initiates the ball rolling the other way.
- '99+ style OEM fans (swapped '98 GTP fans for T67 header setup that almost got installed in 2010, so the better fan setup is going back in)
- Buick Rendezvous/Pontiac Aztek aluminum front bumper support (close to a direct swap, like the Chevy AL engine cradle, and weighs a lot less)
- '08 L26 GP lower intake (some of the less-supported bolts holding the plenum under the MAP cracked on mine)
- GM strut tower braces (from classifieds)
- Dorman square tube trailing arms (bought new for my '98 GTP 6yrs ago (RIP), never installed)
- external trans cooler and -AN fittings (should've done a while back, doing now)
- 85mm LQ4 MAF/IAT (was running LS1, just trying this slightly bigger one with internal temp sensor)


T66 and T67 comparison pics...
2 turbos.PNG

(easy-out action pending for the little guy)

fast NY Six

Active Member
Awesome! Who built your trans? I'd like to rebuild mine but can't justify 4k on a built one. If you're still in the area, Empire isn't that far from me. Do you have any more 1" chains :)


2004 Turbo Regal
My dad in Rome is a transmission builder (drag setups down to 7's, dirt/asphalt circle track cars, 4x4 mud trucks, daily drivers)... so after I collected every upgrade part possible, he made sure those went in with all the 4t65e rebuild fixes also common. It was probably $3-4k back in 2009, when some of rarer things were still available (GM Racing chain set & Torsen, Raybestos blue plates). You can still get their performance red clutch packs, though. I have them in my old 12-sec '98 GTP transmission, and they did fine.

I don't have any extra parts, but sometimes they pop up on various Grand Prix/3800 forums or FB?


2004 Turbo Regal
Got bored and made a short walk-around video, and some gee-whiz assembly work. I'll get better at making them more exciting to watch.



2004 Turbo Regal
It's been almost 2 months since an update, but I was waiting for my new turbo pipes to be fabricated during the shutdown. They finally arrived ~75 days after ordering, and I put them on today...

Time to start piecing together these and the (too many?) new parts I've collected the past few months.

2020-07-02 (1)-a.jpg

2020-07-02 (2)-a.jpg

2020-07-02 (0)-a.jpg

- Dave
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2004 Turbo Regal
Also got an Australian Holden Commodore 3800 N/A (L36) intake manifold on the way from an eBay purchase. That might take about a month to arrive, so I'll run the L26 setup until all the conversion parts for that swap are ready.

Example images from around the internet:

...installed in another turbo 3800 Regal (courtesy PRJ Performance)
PRJ 20080825IMGP2001.JPG

...plenum lid removed w/ lower plenum loose
VX & VY intake plenum 002.jpg

...lower manifold
Generic AUS LIM s-l1600.jpg

There's also a shop in AUS (ProFlowFab) making a wild custom adaptation of the Holley LS-based Hi-Ram plenum, but they want $1,650 AUD (~$1,150 USD)... Looks great, but that price is not worth a mild appearance, and possible minor performance gain.

Jon Early

Active Member
That Holly deal looks really neat, but how does it bolt on? The original has is a two piece plenum, but that only looks like 1 piece.


2004 Turbo Regal
They appear to have welded it all together (not a fan). If I get frisky, I may go for the Holley upper from Summit, and get an adapter to customize for the Holden lower. Total would be ~$500, but maybe that's what next winter is for?

Holley top for Hi-Ram use with carbs/blowers/etc. https://www.summitracing.com/parts/hly-300-217
(or could cut up a Holden plenum and try to add a flange)

Holley plenum lid for 95mm TB https://www.summitracing.com/parts/hly-300-245


2004 Turbo Regal
It's been a few weeks, but I've popped into the garage a few times while waiting for the Holden intake to make its way thru Customs, etc.


Was able to accomplish the following while waiting:
- new oil pan gasket
- new valve cover gaskets (probable source of leaks causing mess; these ZZP aluminum VC's may be less forgiving to non-OEM gaskets )
- degreased engine bay (mess from above-mentioned leaks)
- hi-temp Krylon sprayed new turbo downpipe and crossover
- started DEI heat wrapping those pipes, and coating (for temps, survival, and performance... any will be worth it)

DEI heat wrap.png

Finally, I was prepping the exhaust manifolds (ZZP power logs) for the Krylon as well, when I discovered this crack, so they're headed to my uncle's machine shop where he'll work his TIG magic to seal it and add 2 support tabs across all 6 primary connections...

2020-07-28 rear manifold crack - a.jpg

2020-07-28 front manifold coated - a.jpg

...was planning on them both looking like this, but they'll wire wheel this one to add the supports. You can also see we added exterior welds to the flange on this one, but the other didn't get it, yet (this was ran for a bit on the supercharged engine in '08-09, and already had cracks). That'll also happen for the other side.
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2004 Turbo Regal
Forgot to mention I'm also building the PCV vacuum system that some boosted LS folks use, with the AIR injection pump from early 2000's GM's on a Hobbs pressure switch trigger. Coupling that with a catch can, and we'll see how it does as I monitor vacuum on the lines.

Also, got a nice 2.5 gallon reservoir for $23 on Amazon (fuel cell, just had a foam chunk and level sender inside). Should give me the volume in my Air-Water Intercooler system as I run it to/from the trunk and standard VW Scirocco radiator with 3/4" reinforced hoses.