Cruising the Riviera- 1998 Buick Riviera Challenge Build

After lots of false starts and CL sellers being, well, CL sellers I finally have what is likely to be my $2017 Challenge car- a white 1998 Buick Riviera. Seller was asking $1000, ended up getting it for $850. Here it is in all its, well, lack of glory...

And of course, the main reason for having bought the thing:

It is, of course, not without its issues. First off, being a white GM car from the late 90s and as the pictures show, the paint definitely has some issues. Which doesn't concern my TOO much- I don't like the white paint anyway. As eastsidemav put it, with that paint a few minutes with a pressure washer will get me a nice gray car.

Mechanically, it's actually in pretty good shape- the engine runs well and other than the rear shocks being very soft the only real issue was that there appears to be a pinhole leak in one of the radiator hoses. There's also a broken wheel stud on the back, which should be pretty easy to replace.

The interior is far from anything to write home about. Besides being a not particularly attractive maroon color, it's rather beat up. The rear view mirror popped off when I went to adjust it when I took it out for a test drive. That's OK though, since I'm more likely to strip as much of it as possible out.

So, the good:

-Its L67 supercharged 3800 engine in stock form puts out 240hp, and it doesn't take too much in the way of mods to push it over 300hp. In stock form the car should do 15.5 in the 1/4 mile, so with more power, some weight reduction, and stickier tires it should do decently well on the drag strip

-Getting it to drivable should cost less then $30, so I'll have over $1100 for actual improvements

And, the bad...

-The thing is a BOAT. For some bizarre reason, the Riviera (coupe) is .2 inches LONGER than the same-era Park Avenue (sedan). It's going to be pretty laughable on the autox course to say the least.

Current plans for improvements:

1. Upping the power: Smaller supercharger pulley, probably some porting on the LIM/SC, adding an intercooler and/or methanol/water injection and retuning the computer. This will be where the bulk of my money goes.

2. Handling: anything I can do to make it turn better. Obviously as much weight reduction as possible, but let's face it- this car is always going to languish on the autox course.

3. Appearance: Haven't totally decided what route I want to go, but it will hopefully look quite different.

Have you done a burn out yet? At least on the test drive before you bought it?

Late 80's Rivieras had plastic windshields. Not sure if these do too or not, but find out before you try gluing the mirror back on. Make sure that your glue is compatible and won't dissolve the windshield. And scrape carefully.

Stampie wrote: Have you done a burn out yet? At least on the test drive before you bought it?

There was at least one person there advocating smokey burnouts.

Don't these have rear air springs instead of actual springs? Seems like a good way to reduce weight, complexity, and improve handling to do a spring swap all around. Then figure out a way to add a pile of anti-roll into the rear and probably a bit more into the front if possible for cheap.

Simplify and add lightness.

I like it.

Woody wrote: Late 80's Rivieras had plastic windshields. Not sure if these do too or not, but find out before you try gluing the mirror back on. Make sure that your glue is compatible and won't dissolve the windshield. And scrape carefully.

I'm about 98% sure the windshield is glass, but I'll be sure and check before I try anything on it (not going to with it so cold out anyway, so I have plenty of time).

wae wrote:

Stampie wrote: Have you done a burn out yet? At least on the test drive before you bought it?

There was at least one person there advocating smokey burnouts.

Unfortunately there wasn't anyplace that lent itself to trying to do a burnout on the short test-drive, so not yet. And I want to fix the coolant hose before trying anything else like that. Definitely confirmed that the blower was working as intended though- it certainly pulls HARD.

pres589 wrote: Don't these have rear air springs instead of actual springs? Seems like a good way to reduce weight, complexity, and improve handling to do a spring swap all around. Then figure out a way to add a pile of anti-roll into the rear and probably a bit more into the front if possible for cheap.

I believe they have auto-leveling air shocks and not springs- it is a fairly common thing when the air shock system fails to just replace it with conventional shocks, which is what I imagine I'll be doing. A beefier rear sway bar is definitely in the cards- apparently there's one off a Caddy that is a lot stiffer and works very well.

Strut tower braces are also likely going to be in the cards to stiffen it up.

There's an 03 Deville in a yard up here, if parts can be salveage from it...

The air shock may act as a helper spring, if you will, to the real spring in that case. I'm betting GM didn't throw a lot of spring at these things. What could work are those load assist shocks that are basically a coil-over spring and shock combo that don't cost too much. Maybe get another 50 ft/lb's of spring out of them and if you're already swapping shocks anyway...

Good call on Caddy parts. It's GM stuff, there's usually something else that shares some DNA that you can cross together.

I find it interesting on these that the headlights are really more on the side of the car than they are on the front of the car.

Diggin' it!

Ashyukun wrote:

wae wrote:

Ashyukun wrote:

Oh, believe me- I noticed that similarity as well... that was one theme consideration.

Another was that the thing looks a lot like a spaceship, with the grille looking a good bit like the deflector dish on Federation starships.

pres589 wrote: The air shock may act as a helper spring, if you will, to the real spring in that case. I'm betting GM didn't throw a lot of spring at these things. What *could* work are those load assist shocks that are basically a coil-over spring and shock combo that don't cost too much. Maybe get another 50 ft/lb's of spring out of them and if you're already swapping shocks anyway... Good call on Caddy parts. It's GM stuff, there's usually something else that shares some DNA that you can cross together.

Monroe apparently makes a conversion kit that takes car of everything:

Just have to find it for the best price. Or, try and adapt the 2 leftover coilovers I have from the Fiero to do the same thing, whichever is cheaper.

If you haven't taken a look at the exhaust on the car yet, the front manifold is a crappy cast manifold whereas the rear is welded tube. ZZP came out with a tubular front manifold called the Power Log that replaces the cast manifold. See details here. Anyway, I have a first generation steel version of this that you can have for the cost of shipping. The steel was prone to cracking, so this one has been repaired already. Let me know if you want it.

For the rear manifold, the tubes are welded on the ID to the flange. If you weld them on the OD, you can then open up the ID quite a bit with a die grinder.

I don't know if the H-bodies got the infamous U bend in the cat back that the W-bodies got, but you'll definitely want to check. GM opted to crush the main exhaust pipe into a U shape so that the rear O2 sensor could be mounted vertically. This major restriction should be removed before any pulley changes.

Speaking of pulley changes, I have the ZZP tool for pulley removal and installation. You can't use a three jaw puller as the pulleys are aluminum and you'll destroy things. If you want to borrow the tool, let me know!

eastsidemav wrote: There's an 03 Deville in a yard up here, if parts can be salveage from it...

I think the STS/Seville is the one that the sway bards work off of- both the front and rear apparently are improvements.

One annoying thing I'm finding is that there are apparently not poly bushings available for the car that I can find. I suppose it shouldn't be THAT surprising given it's far from a car you'd expect to be doing performance things with...

FooBag wrote: If you haven't taken a look at the exhaust on the car yet, the front manifold is a crappy cast manifold whereas the rear is welded tube. ZZP came out with a tubular front manifold called the Power Log that replaces the cast manifold. See details here. Anyway, I have a first generation steel version of this that you can have for the cost of shipping. The steel was prone to cracking, so this one has been repaired already. Let me know if you want it. For the rear manifold, the tubes are welded on the ID to the flange. If you weld them on the OD, you can then open up the ID quite a bit with a die grinder. I don't know if the H-bodies got the infamous U bend in the cat back that the W-bodies got, but you'll definitely want to check. GM opted to crush the main exhaust pipe into a U shape so that the rear O2 sensor could be mounted vertically. This major restriction should be removed before any pulley changes. Speaking of pulley changes, I have the ZZP tool for pulley removal and installation. You can't use a three jaw puller as the pulleys are aluminum and you'll destroy things. If you want to borrow the tool, let me know!

I'll certainly take you up on the front manifold- the exhaust system was something that I was not sure how I was going to tackle within a Challenge budget, so that would help a good bit! Good to know on the rear manifold too- that should help there too.

I've been figuring on going through and seeing what I can do to open up the exhaust system over all- since this will be a racecar and KY does not have any inspection requirements for emissions I was figuring I'd see about losing the cat, though obviously the computer probably wouldn't like that.

It would be great to borrow the pulley tool as well- I'd have to rent it otherwise and while that wouldn't (at least as I understand it) go into the Challenge budget I'm all for saving money in general. Thanks!

The Riv is not an H-body, I think it's a G-body. In that generation is it is platformed only with the Aurora. I don't think he has to fight with the U-bend either.

The plog is a great option and a really quick install, just be careful it doesn't interfere with the AC-compressor. I had a hell of a time getting one to fit on my series-3 swapped U-van.

Plog on top, factory S2 front manifold on the bottom.

Although a Speed Daddy system can be had for right around $300 new, and half that if you cruise the 3800 swap groups for used ones.

I've got a Strut Tower Bar from a Bonneville GXP that might work on that thing as well as some W-body bars I'd be willing to let go cheap if you need something like that.

And if you really want to have fun, by swapping drive and driven gears in the transmission it is possible to give that car a 3.73 Final drive ratio.

Pre-'96 Grans Prix wheels will direct fit but are wider, 16x8 as opposed to the factory 15x6.5. Might be a cheap way to squeeze some meat under there.

I'd advise against buying from ZZP if you have any other option, unfortunatly you often don't. Intense-racing is much preferred. Thier customer service and product quality are outstanding, but they have fewer products. Sort of a do one thing and do it well company as opposed to ZZP's screw you, we're they only guys who make this mentality.

Good luck, do the 3800's proud.

I love it. I always thought those looked like a fluffy American Jaguar XJ220 or something. Maybe that could be your theme. Put a big plywood wing across the back.

And I bet yours is actually faster than the average Xj220 since it actually moves under its own power currently.

I was THIS close to being given that car only maroon on the outside too.

It was PERFECT save for needing a new fuel tank.

Had no space for it

As a 3800 fan and prior 3800 owner, I approve this build. I also like the looks of the RIV (shark look) and the interiors are comfy.

The supercharger (and 3800 in general) will be happy with more air intake somewhere/somehow.

The 240hp factory rating was underestimated

In reply to AClockworkGarage:

I looked a bit into the Speed Daddy header systems and it looks like it would be a nice budget upgrade to help the engine breathe better- but they don't seem to have any that are specifically stated to work with the Riv. Is it just assumed that a header for any one of the 3800SC's will work for any other one?

I might take you up on the strut bars, at least for the front. For the rear, since it will be out-of-sight and doesn't have to look remotely pretty, I may just use some free scrap metal I got (love when people throw away bed frames ) to fab a brace for back there.

Depending on how difficult it is to swap the gears that might be an interesting mod to make. I'm hoping to avoid having to pull the engine/trans if at all possible, so if it would involve that I might not go that far.

This Riv actually has 16" wheels on it, with (IIRC, I don't have a close-up picture to confirm my memory) 225-65 tires on them. I'm looking at getting bigger wheels if I can get them cheap (there's some decent-looking 18's up in Cinci if they're not gone by the time I'm next up there).

I'll keep that in mind regarding the different companies- but of course whenever possible I'll be trying to find things used/re-sold for cheaper than direct from the companies so hopefully I won't be dealing with either that much.

My son and I were talking about building a challenge car, and this car was my recommendation. Looking forward to results.

TIGMOTORSPORTS wrote: As a 3800 fan and prior 3800 owner, I approve this build. I also like the looks of the RIV (shark look) and the interiors are comfy. The supercharger (and 3800 in general) will be happy with more air intake somewhere/somehow. The 240hp factory rating was underestimated

A more-open intake is definitely going to happen. Haven't decided yet whether I'll go the standard route of a fenderwell CAI or if I'll just say 'berk it' and cut a hole in the hood for one.

I'd certainly believe that they underestimated the power that the engines put out- it honestly shocked me just how much power the Park Avenue Ultra that I had a year ago had. That thing weighed a ridiculous amount and would still accelerate like a bat out of hell when you punched the throttle.