Wifes NEW SC3800 Park AveUltra mods?

  • Thread starter Thread starter 90rocz
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What's up guys?
Well, some of you know me, but this is our first SC3800 car and the wife wants more power. She likes the Z's punch, and wanted a fast classy car. We really nailed that one! Turn off the trc/control and it'll squall'em good!!!I'm thinkin "total sleeper"! Still only weighed in at 3640lbs...
Now, I know about some of the mods like; CAI and Pulley, cat-back...
BUT who makes 'em? How much? Where can I order them?Any drivability trouble? And can I do all of them, or are they GSRegal specific?

Also what's "Dynaride"?

Thanx in advance!...
I took a good look at a Park while my '99 GS was having some warranty work done. It's the same motor and all, so what works on the Regal will work on the Park. The following website has all the stuff you'll need:


For a Park I would go with:

(1) A K&N drop in panel air filter in the stock airbox. If you want to go with a CAI, I'd recommend checking with Terry Reals first at the website above to make sure the airbox portion of the CAI will fit (or at least be adaptable to) the Park. It looked to me like there was enough room behind the Park's DS headlight to mount one.

(2) I wouldn't go much smaller than a 3.4" pulley and the requisite alightly shorter Goodyear belt to go with it.

(3) 160 t-stat

(4) A set of TR55 spark plugs at .055" gap

(5) Take the Park to your muffler buddy and have him put it on a rack. Cut everything off behnd the cat all the way flush to the factory muffler. Once done, replace the u-bend portion with straight 3" tubing which will require that you remount & reclock the O2 sensor (you'll need a new bung to do this") to clear the floorpan. Continue with the 3" tubing to about the rear axle. Swedge down to 2.5" and duplicate the same bends as the OEM pipe, and weld to the factory muffler. The factory muffler is a fairly good flowing unit, plus it's quiet and looks stealthy. When I did this mod (cost: about $90) the top end opened way up. Our Regal GS is my wife's car, and she didn't notice the exhaust mods I'd done for over a month until one day she was standing behind the car and noticed the slightly louder burble at idle.

Have fun!


'87 Buick GN (11.1s @ 120)
'99 Buick Regal GS (14.22 @ 98.1 w/ a few mods)
'67 Buick GS California (beautiful original; one of 544 made)
'96 Buick Roadmaster Limited LT-1 w/a few mods (aka a stealth Impala SS)
Now what's the factory boost, or where can I find out?

How much more boost will I get with the 3.4" pulley?

Any one want to unload a used 3.4" pulley for a reasonable $$$?

Also I was looking at the muffler config, and I think a good "cross-flow" will fit easily, giving a more desirable "dual outlet" look.
( Not a "jack-leg"job, but a first class exhaust fab w/stainless or chrome 45* turn downs. Not unlike the Caddy ..)
The most boost I saw on a stock pulley (which is 3.8") was on a cold night-- 8.0 psi, most of the time it was 7.5. With the 3.4 the most I saw was 10.6 psi.

Really, a new press-on pulley is not that expensive (about $80). Also, keep in mind that when you remove pullies they can distort (or, as in the case of the last swap I did on my wife's car) shatter altogether. The last swap I performed required an air grinder to get the remnants of the ASP 3.4 off. You're better off going new. The trick is to use the proper tool to remove the old one and press on the new one; I like Thrasher's.

OK, I just measured the pulley diameter on the Park and I got 3.100" from outside edge to outside edge with my calipers.

Now what????

Where is the "U-bend" on the exhaust, over the transmission???
The maifold to cat pipe is 3" but after the cat drops off to 2.25" even smaller at the bends, I can see why the "cat-back" needs help...
The 2001 Park I saw at Tustin Buick/Pontiac/GMC here in Oange County had the same stock-size pulley as my '99 did. What year is your Park? 3.1 seems really small....
It's a '95 "Ultra", I double checked it with a friend it's 3.100" in diameter. And I had a fuel smell that turned out to be a loose hose on the purge canister.
I know almost nothing about the SC3800's on these cars. I know most people opt for the 3.4" on the GS and the GTP's, maybe they can get different size pulleys from the dealer or parts stores if they know what different sizes came on what models.

I hope I can improve performance w/o swapping SC's then down sizing the pulley...Maybe mine has a weaker compressor or cam or b/c it's heavier and needs the smaller pulley for decent power & improved drivability???

Where is a good source of Buick SC3800 information??
Hp/boost per models??
Differences/models eng set-ups??
Final drive ratios/tire sizes??
Series I & II SC's??
OK, you have a series 1 car. The Regal GSs and GTPs are series II, along with all the 96 and up cars. You do have the most powerful of the series I motors though(225hp). Unforunately almost all the mods popular to the GTPs won't work. You can however put a pulley on from and older car, 91-93, since it is smaller. And you can always open up the exhaust, only the GTPs and GS have the U-bend, your car does not.