New member from NC

Hi, my name is Mark and I am from western NC. I own a 1995 SC Riviera which I drive daily 150 miles round trip to and from work. While I am interested in modifying my car, I am not looking for more power or anything that would cause me to have to use premium gas, since I already spend about $125/wk on gas.
I drive on curvy, mountainous roads and am focusing on braking and suspension ugrades, along with interior comfort for obvious reasons. I have had my car about a year. It had about 60,000 miles on it at that time. It now has about 88,000. I am hoping to drive it to at least 200,000. that should only take a few years.
To date, I have done the following upgrades/mods:
*Infinity component door speakers
*Infinity 6x9 rear speakers (should I install 6 ohm resisters in line to them???)
*Gutted airbox with K&N filter, sealed off so that only outside air can be drawn in
*EBC sport (slotted & dimpled) brake rotors and Ultramax pads on all corners (I will be doing a write up on this soon since I just installed them this weekend)
Planned mods:
*Stiffer springs (Olds Aurora?)
*KYB shocks and struts
*Performance exhaust (3" down pipe, remove cat and resonator, large single oval outlet in center a'la Porsche Boxter)
By the way, I am an engineer for Borg Warner Turbocharger Systems, and no, I don't plan to trade the SC for a turbo.

Welcome to the site!

You should be using 93 anyway with the SC. Unless you never get on it hard but even then I'd still go with the 93 it calls for.

Hi, Mark. Welcome to the forums. Please post some images of your car in our showroom when you can. I'm interested in knowing more about your intake system, as I've been trying to improve my own recently. A write-up on your brakes would also be much appreciated!

No need to put resistors on the rear speakers, just fade the volume to the front if the rears get too loud or distort.

As an engineer for a turbo manufacturer, I'm sure you're well aware of the benefit of using premium fuel in forced induction applications. You drive a car with a supercharged engine pushing boost, plus you've opened the intake to help deliver even more air. One of the first performance mods I'd recommend is to switch to higher octane fuel. Our engines were designed to use it exclusively. If you want the most out of your car, use the recommended fuel!

I do understand money concerns, but premium is only a little more if you shop around. The performance benefit is well worth the money, imo, and could save you costly repairs down the road.

Hi, thanks for the advice on the fuel, and yes, I do know how and why I should use it, but after doing many tests on 87 vs 89 vs 93 octane Shell gasoline, I have found no difference in the way the car performs or the gas mileage I get. The car runs great and never seems to lack power, even when pulling long steep grades. I have never driven another 3800 SC series 1 to compare my car against, so maybe I am missing something??? I used to have a much modified Mazda B2600 4x4 which required premium fuel and there was a noticeable difference in performance, not to mention pinging, with that vehicle. Over the years I have found that it was very important to find good quality gas from a reputible station.
Concerning the stereo, at upper volume levels my rear speakers start to fade on the bass, like when listening to Godsmack. This is at about 75% volume level with the fade set to about 70/30 front/rear. Before finding this site I assumed my stock head unit was on its way out. Maybe I should just install a 4 channel aftermarket amp?
I will do a write up on my air intake set-up. It was pretty easy to do and cost almost nothing, other than a can of spray foam and a K&N filter. i will post some pics of the car when I get it painted. It is faded badly on all horizontal surfaces.

Don't expect much power output from the stock head unit. It has good sound quality, but I estimate 8 watts per channel max. If you want to enjoy truly dynamic music, an external amplifier is a good idea.

About fuel...

The 3800 SC V6 may come from old roots, but it's been refined into a pretty advanced system. The PCM does some pretty amazing stuff to protect the engine from damage, and it does so in such a way that you're not much aware of anything. You may not think your engine performs any differently when you use premium, but it probably does. The PCM learns how you drive, and it knows what gas you put in, and it takes action to make the best of things. Sometimes it acts so quickly that you won't even feel it, sometimes it makes changes over several days, but it does learn to cope. Usually this results in an engine that runs at less efficiency or with decreased power output.

Bottom line is, premium is not an option in our engines, it is required to achieve the performance the engine was designed for. The owner's manual, the dashboard, and the fuel door are all telling you this. On your everyday commute, you might not notice much difference, but it's during those times when you really need the car to perform... that's when using the right fuel makes a difference.

Welcome to the board! There is a nice ROA chapter in NC. You ought to check it out sometime. Post some pics in the showroom when you get a chance.

WELCOME!
have you heard about the STB for our cars? it really helps with body roll.

i am not going to preach on which fuel you should use, but i encourage you to do some reading and research on KR in our engines. the price difference between 87/93 gas is not that much for the added safety and longevity of the engine.

i'm glad you were able to find us. welcome! I spend about $100 a week on 93 gas myself but it doesn't bother me much. If I have to drive a lot, I'd rather spend the money to make it a more pleasurable experience. ~by driving a riviera that is~

I see you already have the rotors and pads handled. Only other brake modification I would vouch for is upgrading the front calipers to the LS1 dual piston. Not too expensive of a mod at all.

For suspension, I'd probably suggest the strut brace, like Matthew said, and the beefier sway bars for the front and rear. Those should really help on those mountainous roads without sacrificing any comfort. With harder springs and struts, you start to trade the comfort factor for handling. If you're someone that really likes to drive, it's worth it

Thanks for the info. I am trying 93 octane gas again to see if I notice a difference in mileage or driveablility over the next few months. I was really surprised in my earlier tests that I didn't get better mileage with Premium. I averaged about 20.5 mpg (combined city/hiway) with 93 octane and about 21 mpg with 87. The routes driven were identical and the fuel was from the same busy Shell station. Both tests were for 2 week durations and were repeated twice. I use about 40-45 gallons of gas per week, depending on my weekend driving. Anyway, I used premium fuel until I started driving 150 miles/day to and from work about 8 months ago. I am going to try another station this time.
I am leaning (pardon the pun) towards upgrading the front and rear sway bars as a starting point and installing a STB too. Lowering the car isn't an option as I live on a dirt road were ground clearance is already an issue.
I guess the bottom line is that I love my Riviera and I get an opportunity to drive it through the eastern edge of the Smokey Mountains on twisty roads everyday.
How lucky can a guy get?

I love that part of the country. Last year I drove down through Deals Gap, through the portion known as "Tail of the Dragon". Very exciting trip! I had noticeably less sidewall tread upon arriving home.

Agreed, I've preached too much about using correct fuel already. My apologies if it came off as a not-so-warm welcome. Your test with premium vs. regular doesn't surprise me, however. There really shouldn't be too much difference in gas mileage between the two. The biggest reason premium is better is so that your engine doesn't knock as much when you get on the throttle... efficiency is not a concern when you have the pedal to the floor. It's about getting the most out of the engine without it blowing up!

I was looking through my PCM code last night (using my tuner) and noticed there are two sets of timing tables. One is set more advanced for optimum performance, called "Good_Fuel_Spark". To use this advanced timing, the PCM must decide that there is not enough KR to be of concern (means you are using premium gas). As a stopgap, the PCM also has a table called "Bad_Fuel_Spark", which has less advanced timing values. This means less power is made using this table, so the car can safely run on regular fuel if it has to. Fuel economy at cruise probably wouldn't be effected much, imo.

Perhaps the reason you aren't noticing a change is that your engine has "learned" to use the bad spark table. If this is the case, premium fuel won't make any difference with the less advanced timing in effect. You may need to reset the PCM immediately after filling up with premium to get it to go back to the good gas table. This can be accomplished by pulling the PCM fuse or disconnecting neg terminal of the battery for an hour.

Best of luck!

I'll try resetting the PCM after lunch today. I didn't know that there were two spark advance settings...I just assumed that the PCM would retard the timing based on signals it received from the knock sensor as needed. I had no idea that the OBD1 system (as my '95 is) was so sophisticated (sp?). I am more familiar with OBD2 systems.
No offense taken regarding fuel type use. I appreciate everyone's opinion, and, the best part is that I can do some minor mods such as running a smaller pulley should I stick with premium gas. I am usually not so sensative to fuel costs, even considering my daily drive, but I have two houses to pay for right now...until the one sells were I used to live and work.

Mark, I'm not certain that your OBD1 system has the dual spark tables, but if I had to guess, I'd say there'd have to be some way for the PCM to cope with KR in the long-term. Otherwise, you'd hear it knock for sure. My spark tables are even more advanced than OEM. Once I tried some 89 octane during a cruise through TN. Was in OD, and this big mountain came up... then I heard the "Pin-pin-ping" sound. Scary, because it didn't take much throttle or RPM to make this happen.

blackbart95 wrote:

Lowering the car isn't an option as I live on a dirt road were ground clearance is already an issue.

I hear that! In order to do springs I might have to have the road graded and at least $500 of gravel put down each year (or thousands for chip and seal).

I shoulda got a truck! At least they look good with mud on 'em.

jax95riv wrote:

Welcome to the board! There is a nice ROA chapter in NC. You ought to check it out sometime. Post some pics in the showroom when you get a chance.

Thanks Jack!
I was in Maggie Valley last weekend for the Rally in the Valley with the Harley, but I didn't try the Tail of the dragon
318 curves in 11 miles, saw a picture of a dresser doing the dragon a couple of weeks ago...a little too much into a curve and luckily he fell off before it went over the edge!

Here is the next ROA thing in NC:


This is a postcard I sent out to NC ROA members.

I tamed the dragon at night, here's a clip:

http://videos.streetfire.net/video/b76001ae-fbec-448c-8f8e-989d00c4b3a8.htm