I have read some posts here and gained alot of knowledge. My car has 170,000 miles on it. It seems REALLY slow. There is barely any exhaust coming out the rear tips(I suspect clogged cat). After warmed up, it clatters slightly under hard accelleration and does not pull very hard at all. It has a mild tune up - plugs,wires,cleaned TB, I gutted the stock airbox and installed a Fram Air Hog(this helped alot). The trans is new and shifts very firm. I have a boost guage in my attic somewhere to put in it - how many pounds of boost should I get? I was wondering if maybe the coilpacks might be weak also? they look original. I read an old post where someone used a newer model pack that is hotter and better, so what year model and application do I use. I don't want to step on any Bonneville owners toes here with a Riviera question but I did not find any sites for Rivieras. I also measured my SC pulley and end to end it measured 3 inchs. I am assuming that is a 3.85? Where do I get a 3.5 for cheap? Can I get it at GM dealership? Or is this mod even recommended for my car?Any mod ideas will be GREATLY appreciated. Robert

OOPS I put 3.85 and I meant 2.85 ,so I want a 2.5 right?

well it should not be slow. 7-8 seconds or so till 60. It should be real quick off the line so if thats not going on your probably have a major restriction somewhere a cat would do that. could be a fuel related issue as well, I'd make sure fuel pressure is what it should be.

any check engine light?

No check engine light, I will check fuel press. in morning. What PSI at idle? WOT?

you should be looking for mid 40'*

Hi..Welcome.

Sounds like you are on the right track for getting it running right. You might want to contact OLDsman105, he has a 95 SC Riv as well and is aiming for ported manifolds and other goodies.

Can you put "95 Riviera" in your signature? We're no strangers to them. My boss at work has one as well, and there are a few here.

You can go to a stock 92/93 pulley size or a 2.5" from www.pulleyboys.com but you need to fix your issues first, then open up your intake and install a 180° thermostat first. You should also check your fuel pressure before the pulley change, and be prepared to scan afterwards.

Where are you located?

First welcome to the club Hafrod. As you can see in my sig my car is similar to yours. . I would say a get a scantool . You want to know your car is in tip-top shape before doing a pulley drop. I would recommend a 2.55 pulley from a 92/93 supercharger just to be safe.

And add a boost gauge.

here is a suggestion. On where to place it.