FAQ: Modding 101 - How to Increase Acceleration Performance

Abaddon wrote:

AutoLite 104's, a 160* T-stat and a good CAI/FWI (at minimum) can handle a 3.4" pulley. Yes, a "mail order" tune will help, but I (we) recommend an actual WOT scan in order to tune out the KR. You will still get decent amounts of KR with a 3.4" and the above mods, but it won't blow anything up IMO. Again I'd (we'd) have it scanned and tuned accordingly to get the KR down as much as possible, especially if you're planning on beating it up at the track.

Another note.....92 octane fuel may not be enough on really hot days if you're planning on tracking it. You may need to add some Lucas or similar booster to keep the KR at a "tolerable" level when racing it.

And yeah.....where did you find a mail order tune for a Riv???? A GP PCM won't work......

We generally don't recommend using a 160 T-stat unless you have modified the KR activation temp in your PCM. In fact, I recommend modifying it regardless of your t-stat opening temp. A 180 deg t-stat should be cold enough if you live in a temperate climate. It's marginal in extremely cold temperatures. A 160 would be terrible. If you live in the southern US, or will be using the car primarily at the track, go nuts with the 160.

Intense does sell tunes for the Riviera. You can use a PCM from a Grand Prix (or regal, park ave, monte carlo etc) as a core provided it is tuned for your riv.

LT1Squirrel, create a sig and profile with your location and car info. Mail order tunes for the 3800 are like the ones for the LT1: they still leave a lot on the table.

LT1Squirrel wrote:

albertj wrote:

1. Not really but you would not be the first to try.

2. There is a huge resonator just aft of the cat.

3. don't bother, the factory cat is low restriction anyways.

1. Even though its only 10% overdrive, a mail order tune wouldnt suffice despite these engines began production over a decade ago?

2. Is the resonator a bigger restriction than the cat?, I just want a little more throatyness to the exhaust without buying a catback and regretting it since these motors sound like ass

The only way to make the car sound 'throatyer' is to mess with the mufflers. The 3800 is a buzzy engine, sounds like a hornets nest on a good day when you rev it. That said - try a pair of hooker MaximumFlow mufflers in place of the stockers. And please don't confuse noisier with throatier

Albertj

I would add that the right cam can give the exhaust a throaty sound. To date, I've never heard a 3800 V-6 that sounded good (to me) by replacing the mufflers alone. But I have heard a cammed GTP that sounded awesome with straight pipes.

Hey, i was just wondering if i would be able to take the airbox out of my riviera and just hook up a air filter on the end of the intake (keep stock intake). If i do so ill completely remove the airbox, this would leave me with the IAT sensor left over. Any suggestions of what I could do with this sensor or even if I really need it or not?

you can put a cone filter onto the factory intake tube however you will loose performance because your engine will be ingesting the hot air from the engine bay, as far as the IAT goes, you can drill a small hole into the intake hose and us a little silicon to seal the sensor into the tube. but again, you will LOOSE performance. if your not going to make a fender well intake, a simple drop in is a good start.

YoungIke8732 wrote:

Hey, i was just wondering if i would be able to take the airbox out of my riviera and just hook up a air filter on the end of the intake (keep stock intake). If i do so ill completely remove the airbox, this would leave me with the IAT sensor left over. Any suggestions of what I could do with this sensor or even if I really need it or not?

Short answer: No.

Better more descriptive answer: The IAT gives the PCM critical information for setting injector pulsewidth and what-not. You need it whether you modify the intake or not. Further, the stock airbox as it is is not all that restrictive; you will get more grins per mile by getting a larger downpipe and installing it. The airbox is a tempting modification and a lot of people write about it. a number of people on this site have done it too. Mostly the popular mod is to leave the airbox in but remove the muffler from it, you'll find a post using the SEARCH function on this site that tells about that.

Some who modify the air intake as you are saying put a bung onto the air snorkel (they use PVC pipe or stainless) and reinstall the IAT there.

This site has a lot of info on modifying the Riviera. Granted there is not all that much to do because the cars were kind of set up for performance in the first place. But after the downpipe, removing muffler from airbox, lower temp thermostat and smaller SC pulley, the mods get more difficult -- taking on the level of difficulty requiring experience or an auto tech class at the level of certification -- you'll be upgrading the transmission, the cam, porting the supercharger, and other things. Thing of it is, no matter what you do the speed limit's still 55/65/75 depending on where you live...

When you think Riviera, you kind of need to think "Monte Carlo SS in a Tux" to give yourself some perspective. (but you already knew that...) The best first thing to do, if you have not already, is fix any problems you may have (is your Service Engine light on?) and get a scanner (Not a Code Reader) to see what the PCM and its inputs are doing. There is info on the site about all that too. Hope you get good use out of the info, and happy reading.

One thing I love about my Riviera: A/C, Power everything, heated seats, and not many other cars can keep up when getting on the interstate

Quote :

Hey, i was just wondering if i would be able to take the airbox out of my riviera and just hook up a air filter on the end of the intake (keep stock intake). If i do so ill completely remove the airbox, this would leave me with the IAT sensor left over. Any suggestions of what I could do with this sensor or even if I really need it or not?

Not saying at all you should do this (Albertj's comments explain why), but if you did decide to run a "short ram" or "warm air" intake as you describe, you could simply mount the IAT sensor anywhere close to the air filter, including on the outside of the filter. The sensor doesn't need to be inside the intake, just needs to read the temps of the intake air. Again, I think it's a really bad idea.

In addition to what Albertj explained, the IAT sensor allows the engine PCM to set correct spark timing. If the air in the engine bay gets too hot, the PCM will cut timing a few degrees, protecting the engine from knocking. The result is the car will become slower, echoing GreenMonster's comments.

Lastly, know that if you simply leave the IAT sensor disconnected, the engine will run, but not optimally, and there will be no knock protection when the air gets hot (it will). You will throw a code, causing the SES lamp to illuminate, and the AC compressor clutch will not engage, so your AC won't work.

I have installed the short ram air type intake with a basic radiant air divider and haven't had any issues. As we saw from a previous post, the Riv pcm will not gain any timing from the air being "colder". We did see that timing starts to be retarted at 122 degrees. The only time I am close to that so far is starting the car after sitting for a while (when the engine air is hot). This is remediated right after moving, and the air recirculates the IAT drops to anywhere from 80 degrees to 110.

Northeast, using current marketing jargon, you could call your intake a "short ram", but I would classify your intake set-up as a Cold Air Intake (CAI) for a few reasons: 1) the length of your intake tube is long enough that it locates the air filter away from the engine, near the fender, 2) it sources fresh air from the fender well through the stock intake location, and 3) you've made an effort to create a shielded section, blocking at least some heated air.

The type of intake I believe YoungIke8732 was asking about, the type which we here call "short ram" or "warm air", looks more like this one:



Note the close proximity of the exhaust manifold crossover pipe to the air filter. This is one of the hottest parts of the engine!

This type of set-up is incredibly common in the modding world, especially with NA engines. But for us, IAT needs to stay low, as there are other functions in the PCM that benefit besides spark timing. Most importantly, an intake pulling in cooler air fights knock and develops more power, regardless of timing.

Fair enough, and I completely agree!

Yes, AA, that intake is NOT good....I like how its directly above the exhaust...

And again, I'd like to stress that high intake air temps are bad for a whole list of reasons when it comes to forced induction engines. Timing retard is not a good thing, but that should be the least of your worries.The fact is that hot air raises blower and cylinder temps, it's much more concerning, imo. Here's what Kenne Bell, maker of aftermarket superchargers, has to say on the subject. They will VOID your warranty if it's suspected a customer is using any type of intake other than a FWI or properly constructed CAI:

Download PDF: http://www.kennebell.net/techinfo/general-info/HotAirWARNING.pdf

If you monitor IAT and KR levels with a scan tool, it's okay to experiment with different intake set-ups, but blindly installing the air filter where it looks good in the engine bay is when you start to get into trouble.

Ahhh yes....'ye olde hot air intake!!!! LOL!!!! That's the dumbest possible thing to do to your engine. Suck all that hot ass air off the crossover.......

Agreed. To be fair, I misinterpreted what YoungIke8732 was originally asking. Reading it again, he wasn't suggesting to go straight off the TB, he was thinking about putting the filter at the end of the stock intake tube, which is a somewhat better idea than the picture I posted above. I was just showing how bad things can get!

I own a 98 riv and i have had the car for about a year now i picked it up from an old couple i am the second pwner.A lot of people tell me i am dumb for wanting to do this but i want to deck the engine in this out with as many performance parts as i can without blowing the engine up, anyways im jus wanting a list of what u guys think i should do first and so on, or a great website to get the parts from.

Welcome aboard. There's tons of modding info in the Series II engine tech section. Spend some time reading there and heed the warnings it contains.

Welcome. Since you asked I'll give you some free advice!

If you are really serious about building a performance motor, start with research. There are a lot of bolt-ons available (headers, rocker arms, pullies, etc) but before you do any of that -

I would recommend going straight for a cam. Too many 3800 builds have people maxing out what can be done without a cam, then ending up with a cam and starting the mod series over again. The bolt-ons add up, in general, to more than a cam would have cost in the first place. All of these bolt-ons apply to a cammed engine as well, only the potential is so much greater once the cam is in.

All this said - just about everyone with a cammed motor ends up needing a transmission. They just weren't made to handle much more than stock HP levels. So save your money and build up a trans before getting too deep into the motor.

What is your budget?

zzperformance.com and intense-racing.com are two of the better places to deal with for 3800 parts. Even easier might be to watch a site like clubgp.com classifieds for a complete engine already built.

After doing bolt-ons to my car for a few years I ended up pulling a rebuilt, modified engine with a VS cam and GenV blower from a rolled over car for $1000. I sold my old engine for $400. The blower and cam projects were worth almost $1000 alone. That engine is still running strong in my car even though I don't have it anymore. My old engine is still running strong in a local grand prix, after many lectures about being careful with tuning the current owner is happily modding away on it.

And as Dave mentioned - our Series II engine tech section right here has a LOT of the information you need.

I have a 97 SC Riv and was wondering what some cheap mods are that can be performed? Also does anyone know a parts dealer? Thanks

ZZ Performance, get a different size SC pulley is your best bang for your buck.

I was wondering the same thing for mine.

If you can afford to splurge best gains/$ would probably be seen in an exhaust system upgrade for your 89.

Im attempting to look around at what there is. There really is not a whole heck of a lot for an '89 Riviera. Exhaust and a cold air intake are what I would like to do for sure. Cold air is cheap, more or less $200 for something really dece. But exhaust, I want the most bang for my buck. Any suggestions?
Also, I found a cold air on carid? i think... anyway, 144 without shipping, and the reviews are all good, but it says its for '92-'02 Rivieras. Should it not be able to fit my '89 since the 7th gen was '86-'93?

Thanks man i'll look into a pulley.Do you recomend a size?

Hey guys,
I want to upgrade my engine. What is the peak potential of this engine? I am sure someone here has to of maxed out the performance on their 3800.
Can someone point me to their thread? I searched and searched and found nothing of engine upgrades like im looking for.

it seems like the end all - be all power mods for our engines are:
Intense racings level 3 performance package combined with level 4 cam and heads package.
~$5k
Am I wrong to assume this?
How much power can I get for ~$3k-$4k?
Is it possible to get a Riviera to 350-400hp with only engine modifications?