FAQ: Smaller SC pulley? What Size?

How would I tell if I have press on pulley or mps?

Never mind rookie mistake don't read all post found it thanks

crstump, the custom heat shield was a good idea. 180 t-stat also a good idea. I would recommend AutoLite AL104 spark plugs to support the 3.5" pulley.

As for the FWI, this is a great mod, but it possibly might increase KR due to the added air entering the engine (the PCM will need to try harder to keep fueling in check). Or, maybe you'll be fine, but you won't know without a scanner. My advice is to install the plugs, t-stat, shield, and the 3.5" pulley - but wait on the FWI until you have a scan tool, or can use one to verify you are knock free.

Once you know you can run the 3.5" safely, you can then add the FWI and rescan. If you're good, you're good. If you're not, you can back off to a 3.6", or do the 3" down pipe mod.

Another plan that could work is to install the 3.5" + supporting mods, and the FWI, and the down pipe. I'd guess there would be very low risk for KR with that set-up.

thanks for the info AA, but what brand of down pipe do you suggest for the money? or does it matter. and im still new at modding, so you will probably be hearing more questions in future, just a heads up

I've never purchased a downpipe, but have heard good things about these guys:

http://stores.ebay.com/Hogan-Performance

More info: https://rivperformance.editboard.com/t1142-hogan-downpipe

well bought some things from zzp's black friday sale a 3in cat dp, a 3.6 pully and a zzp pcm 1.0 just wondering if im good. Ive been doing some resurch and looks like i will. would just like to be sure. If posible maybe go to a 3.5 pully i know i won't have enough done for a 3.4. thank you

I am going to win the lottery tonight but I wish I would have had the money last weekend. I would have went on a ZZP shopping spree.

gtsr100 what year is your car? Did you get a press on pulley or an MPS? In theory you should be okay with a 3.6 but some cars have KR even with the factory pulley. Have you ever scanned your car?

Its a 97 haven't really scanned it yet it's the modler pull system

Anyone know why ZZP only offers PCM upgrades for 97 Rivs? What about 98s and 99s?

Not a clue but it works for me

charlieRobinson wrote:

Anyone know why ZZP only offers PCM upgrades for 97 Rivs? What about 98s and 99s?

I got my first PCM from Intense for my '98, back before I had a tuner.

gtsr100 wrote:

.... just wondering if im good. Ive been doing some resurch and looks like i will. would just like to be sure. If posible maybe go to a 3.5 pully i know i won't have enough done for a 3.4. thank you

The ONLY way to know if you are ok with any mods like that is to scan for KR first. No one can state for a fact that you are ok. I had KR with my oem pulley and didn't know it until I scanned.

Has anyone, of is anyone running a 3.5 pulley on their riviera, if so, what supporting mods do you have? Do you HAVe to upgrade the PCM?

Supercharger belt broke last week due to a pulley that failed and shattered. I was able to limp home and decided to replace both the sc belt and the accessory belt along with all pulleys. Went down to a 3.4" sc pulley and put on Gatorback belts.

The car is sooo much more responsive in the mid-range. I can only explain it as being "alarmingly fast".

I like it...

"alarming" is a good way to describe your set-up. Daily driving you'll be fine, but be careful getting on heavy throttle. If it knocks, the PCM will cut timing, but only so much. If you cross that line, it's engine rebuild time. Or, if you drive easy, the engine could last forever. Question is, why run a 3.4" pulley if only to drive easy?

After a 180 T stat, a scanner is the next best investment, I think. What's the point in modding if you can't see if you're hurting your car or not? You need eyes on Knock at all times when dropping pulleys. Welcome to modding 101.

AA wrote:

"alarming" is a good way to describe your set-up. Daily driving you'll be fine, but be careful getting on heavy throttle. If it knocks, the PCM will cut timing, but only so much. If you cross that line, it's engine rebuild time. Or, if you drive easy, the engine could last forever. Question is, why run a 3.4" pulley if only to drive easy?

Hi AA,

I thought I was in good shape for the 3.4" pulley since I did some supporting mods prior (K&N open air intake, 180 t-stat, AL 104 plugs, low restriction exhaust). I haven't purchased a scanner yet as I am not sure what will work with the 1996... I am open to suggestions on this.

I don't drive her hard all that much, but when I do put my right foot down, I want to take off like a shot! I am actually worried about the non-heavy duty transmission in the car as I start to make more power... Ugh! The old saying "How fast can you afford to go?" is starting to bounce around my head again...

Thanks for the direction and the word of caution! Point taken, my friend!

Ron's Rocket Riv wrote:

I thought I was in good shape for the 3.4" pulley since I did some supporting mods prior (K&N open air intake, 180 t-stat, AL 104 plugs, low restriction exhaust). I haven't purchased a scanner yet as I am not sure what will work with the 1996... I am open to suggestions on this.

I don't drive her hard all that much,

You'll be fine with a 3.4" pulley and those mods. You're not driving around WOT in 3rd gear on the freeway (which is where you'd get the most KR). The only thing I suggest to you is that you get somebody with a tuner to tune your PCM for you. Add a little more fuel in the higher RPM's, and your car will run great....you'll love it.

Not that it's ok, but your PCM will retard as much as 15* of timing. That's a lot. No, it isn't good, but that's how GM designed it....to save the engine. A 3.4" pulley shouldn't ever reach that much KR with your mods. You MUST run premium fuel, ALWAYS. You will have noticeable KR on extremely hot and humid days, but a tune would cure most of that. Yes, absolutely, 0* KR, and even timing advance is most desirable and optimal, but if you just have a daily driver that you want to up the HP a bit, a little KR isn't going to hurt anything.
If you were building your car to beat up at the track, then yes, you would want to mod more to reach the all mighty 0* KR mark. 5* of KR in short spurts (WOT in 3rd on the freeway) won't damage a thing, you'll just get reduced HP because the PCM saw fit to retard the timing....which again, is what the system is designed to do. You will only start causing damage (like AA pointed out) if the KR reaches beyond what the PCM can handle.

Thanks for the input on this, guys!

Yeah, that's when I feel a little engine lug... crusing at 50 - 60mph and giving it enough gas to increase RPM but not enough to induce a downshift. What I've learned is that I either want to really GO, and give it the gas to induce the downshift, or I will slip the gear shift down a click to avoid the lugging.

I was considering a 3" downpipe and high-perf cat as the next mod. But if you guys think I would be better off w/ a tuner or a modded PCM, I will go in that direction.

Trying to find a tuner that works with a 1996 or a company that offers modified PCMs for a 1996 is proving to be a challenge for me (I've casually looked in the past).

Ron's Rocket Riv wrote:

Thanks for the input on this, guys!

Yeah, that's when I feel a little engine lug... crusing at 50 - 60mph and giving it enough gas to increase RPM but not enough to induce a downshift. What I've learned is that I either want to really GO, and give it the gas to induce the downshift, or I will slip the gear shift down a click to avoid the lugging.

I was considering a 3" downpipe and high-perf cat as the next mod. But if you guys think I would be better off w/ a tuner or a modded PCM, I will go in that direction.

Trying to find a tuner that works with a 1996 or a company that offers modified PCMs for a 1996 is proving to be a challenge for me (I've casually looked in the past).

Thing about that is, at 50-60mph, the transmission is in converter "lockup". It's at it tallest gear ratio. Even a bone stock Riviera "lugs" from that point.

Please don't buy a pre-tuned PCM for the Riv. All of the tuned PCM's you find from places are mostly tuned for the Grand Prix and it's counterparts. The Riv is different. Same engine, same transmission, but it's still different. You will need to find someone with a tuner, and more importantly, someone who knows what the hell their doing with it.

P.S. ANY mod helps

Another vote for 3" DP. Also, a big concern that many overlook is KR from very heavy load at low RPM. This can and does happen in everyday driving, especially when climbing hills in OD. When the TC Is locked, and the lugging begins, this is where you can see sustained KR - you may even hear it. I'd argue 3rd gear would actually be safer at freeway speed, with regard to KR.

I agree, you'll probably be fine, but still wouldn't recommend this plan to anyone, especially if you live near hills or mountains. Best of luck!

Thanks again for the input. I live in a very flat area, only about 30 feet above sea level. 95% of my driving is done here.

AA, what would you recommend, in additon to the 3" DP, to make this a plan that you would deem as stable? PCM tuning? Cam and rockers?

Just looking to see where I should be heading next.

Thanks again for the input and advice!

You can do a cam or high lift rockers. Both are great KR fighters. Read this thread to decide which is best for you:

https://rivperformance.editboard.com/t857-cams-rockers

i dont know where this topic would go but i notced that when i put on my 3.5 pulley, autolite 104s with my fwi and down pipe that the car runs alittle bit rougher than normal.. im wondering what that could be? no CEL, no hesitation in any throttle position... its not terribly noticeable but sometimes itll miss alittle.. strange.

Dude, you changed the car. It's running on a stock tune. The MAF is probably reading more air coming in than what the PCM is programmed for.
Did you gap the plugs properly? Too much oil on the air filter?