p.1: Exterior pics and history
p.2: Performance Modifications (you are here)
p.3: Other mods
p.4: Pictures with other vehicles

In stock form, the supercharged series II put out 240 hp @ 5200 RPM and 280 lb-ft of torque @ 3600 RPM. Of course, it's no longer stock. It currently has the following mods

Current mods include:
-3.4" supercharger pulley
-VS camshaft
-Home made 4" Cold air intake with 9" k&n filter
-SLP knock-off headers
-Ported gen 3 M90 blower casing
-Addco swaybars
-autolite 104 spark plugs (2 ranges colder)
-Custom 3" exhaust
-180 deg. thermostat
-Auxiliary Trans cooler
-Seville STS strut tower brace
-Larger supercharger tensionner pulley

SUPERCHARGER
3.4" supercharger pulley

I replaced the stock 3.8" pulley with a smaller 3.4" pulley. This is the best bang-for-the buck mod you can do on an L67 powered car.

Ported M90 casing

The supercharger's outlet was reworked and beveled. This is a major contributor to dropping outlet temperatures. As well as modifying the outlet of the supercharger, the inlet was opened up from 72mm to 75.5mm in diameter, polished and blended.

Home made 4" sewer pipe fenderwell intake

The cone filter sits in the fenderwell area, fore of the wheelwell. I used a 9" cone filter with a 4" inlet duct, but it's a very tight fit. It might be adviseable to go with a 7" filter. I already had the 9"x4", so I wasn't about to go spend more of my hard earned money on another damn filter. This setup isn't the most elegant, but it's cheap and it works.

CAMSHAFT:

Comp cams VS Camshaft.
* 206/216 at .050"
* Intake Lift .320" (.512" lift at 1.6:1 rocker ratio)
* Exhaust Lift .317" (.507" lift at 1.6:1 rocker ratio)
* 115 LSA

Taking apart the engine to install the VS camshaft. I keept the stock valvetrain as shift points will remain stockish.

If you aren't privy to it, the 95-99 rivieras featured the stupidest belt routing EVER found on any car. The belts are wound around an engine mount that takes hours to remove. I took advantage of everything being appart to change the s/c belt (which I had nicked while changing the pulley) and accy belt, as well as replacing the lower s/c idler pulley with a metal pulley and changing the 3" s/c tensionner pulley with a larger, metal 3.5" piece. Even though the car only has 37500 mi, I don't really want to fiddle with the lower sc idler pulley ever again if I can avoid it (due to the location of the engine mount).

The camshaft makes a significant increase in power above 2500 RPM. Low-end torque hasn't notably varied, but the difference in power above 2.5k ALL the way to the shift point is considerable. The difference isn't as noticeable as the 3.4" pulley swap (nowhere near the bang-for-the-buck if you tally all the parts!) but I believe that since the power isn't in the lower RPMs, it's just an impression. The new power is most evident from a rolling start.

ZZP claims "gains of 35-50 hp depending on your car's current configuration"

Once I get the car dialed in right and modify the shift points I'm sure those numbers will be accurate, and it will take advantage of all the powerband.

EXHAUST
headers

SLP knock-off headers from ebay. SLPs cost about 790 + shipping + around $50 for the test pipe and are made of 409 Stainless steel. There's no way I'm paying 900+ for headers. The knock-offs that were briefly sold on ebay (before the vendors got their selling privileges revoked for copyright infringement...go figure) were $220 shipped to me (in Canada!) and are made of 321 SS. Yes, you get what you pay for. They are made in China and are a direct copy of the SLP model. To say the welds are sloppy would be an understatement.

After spending 2 hours grinding the slag away from the welds, I think these headers perform just as well as the SLPs they were directly copied from.

The headers feature 1 5/8" primaries, a 3" collector and a 3" downpipe

exhaust

**better photos of exhaust to come**

After the 3" dowpipe, my exhaust consists of a 3" magnaflow round 4" muffler that I use as a resonator. It's 2nd function is to dupe people into thinking the car still has a cat. The exhaust then flows into a 3" aluminized mandrel-bent pipe all the way to a single 2.5" hooker Maximum Flow muffler. It uses a non-assuming slant-cut turndown exhaust tip.