FAQ: Smaller SC pulley? What Size?

The Torque app for Driod is only $5, but you need to purchase an interface cable or module. I think that's around $100.

A used LSM1 scanner can probably be found for about the same price, maybe less.

Get the Kiwi bluetooth adapter if you go the Torque route. I've had awful luck with the cheap eBay one's.

Well I just picked up a scangauge2 at AutoZone, its about 3 degrees outside so I can't really set it up, I did plug it in and the display looks nice, I wasn't about to spend 70 more on an interceptor just for looks

http://www.scangauge.com/support/x-gauge/gm-specific/

Those are the programming codes so that you can read knock. Let met know how it works, I wanted to get one of those. I just like how they look over the aeroforce. Wrong thread I know, sorry AA.

Yea I don't wanna get off track of the subject but all I will say is I definitely recommend it, I'm curious to see if its safe to drop down to a 3.4

Nice job getting the scanner. You're protecting your investment in doing so. Pulley size is never a set value, because depending on what your car is doing, the situation is always changing. Mods are a part it, but it's also about your maintenance level, and how you intend to drive your car.

As an extreme example, you can run any size pulley at idle with no harm. You can run a 3.4" pulley on a totally stock Riv and drive it to the grocery store - if you drive it the way the average shopper does when they go shopping. You'll never see full boost, so no harm done.

But who wants to do that? (believe it or not, I've seen a few custom hot rod builds that rarely do much more than idle and roll a few feet.) Most of us want to drive our cars. Add a few supporting mods, tune the PCM and you'll be able to add some WOT to the routine with a 3.4". Not constant WOT, but some. Depending on level of mods, you might be able to do a few 1/4 mile runs if you scan.

Then there's motorsport. By this I mean whenever the engine is running, the throttle will be at WOT for extended periods of time. Competitive drag racing, autocross, and road course racing are some examples. A long distance high speed trip might fall close to being in this category. When you push the car to this level, an entirely different set of rules that come into play. Maintenance also becomes a critical issue. A small issue could result in catastrophic failure if not addressed.

Where do you fit? Most Riv drivers will say they drive easy most of the time with some WOT now and then. Fair enough. You need to be honest with yourself and tune the car to run optimally in the worst case scenario. If you don't do this, when you push the engine into uncharted waters, trouble will come a knocking (pun, oh yeah!). I used to run as low as a 3.1" pulley with my current mods. If I drove easy, a little WOT now and then, there would be no problem. But I needed to be careful to avoid KR. I was fooling myself saying I could support the 3.1". Even a 3.2" or 3.3" resulted in some compromise. As I tested these pulleys, I was beginning to drive the car more aggressively, finding KR in places I hadn't before. When I started running autocross and road course laps, I found a 3.4" was the only pulley that I could run safely - but only with a perfectly maintained engine.

The best thing was knowing this: if I could support a 3.4" on the track, I would never need to worry about KR in the street, no matter how hard I pushed the car. This is known as being "bulletproof". It's a really good feeling, btw.

At the end of the day I realized that a small pulley size doesn't mean a thing. A car with a 3.2" isn't necessarily faster than one with a 3.4". The pulley is just a tuning variable. It's the mix of pulley + everything else that makes the end result. For perspective, there are 3800-powered cars turning 13s in the 1/4 with a 3.8" pulley! If you think of your build less in terms of how much boost you can make and more in terms of how much air you can move through the engine, you'll see better results in the end.

I totally agree, I also place myself in the category of everyday driving occasional wot, 3.4 personally will be my limit for this car if I can determine its safe to run it since its going into storage in April. I'd like to install a plog and have the throttle body ported eventually but Im gonna start working on the exterior since its a little rough. Things like cleaning my corner lights, painting my rims, and tinting the taillight are in the very near future. If I lived in a house and not a condo id be able to drive both my cars year round but my family has already reached the car limit.

Quick question, with my setup now I'm seeing 0 Kr at all times, is this possible or do I have a bad knock sensor

Possible, but very unlikely. I've never seen or heard of one of them going bad. Yet another question for Abaddon to answer   

Not impossible. Just make sure "at all times" means your scan session represents the hardest and longest you will drive the car. Do a scan on your next long trip. Near the end when the engine is good and warm do a WOT run. Scan in summer on a hot day. Then you'll know for sure.

Ok now that I think about it this scan session was in 15 degree weather, I basically drove until it was at operating temp then went wot and no Kr at all I guess these engines love the cold

h20man wrote:

I guess these engines love the cold

ANY engine loves cold air. Forced Induction engines especially benefit from it. It's like a free Intercooler   

Yea I know they like cold but this is on a different level lol constant 20 degrees

Abaddon wrote:

h20man wrote:

I guess these engines love the cold

ANY engine loves cold air. Forced Induction engines especially benefit from it. It's like a free Intercooler   

Yup, cold air is denser with more oxygen per volume. Any engine will make more power on a day that is cool with a high barometer reading. The engine breathes better, and makes more power.

Well in that case I guess I really am getting o Kr, I'm not complaining!

h20man wrote:

Well in that case I guess I really am getting o Kr, I'm not complaining!

Keep in mind that when it warms up, even with a stock pulley, you ARE going to see some KR. DO NOT FREAK OUT. All Rivs get spikes of KR, and is usually momentary. It's constant KR that you need to be concerned about.

Yea this is my winter/fall vehicle so it won't be out when its hot what temp would I usually see these spikes?

wanted some educated opinions on if I should run a 3.4" SC pulley on my 97? my front many cracked so I ordered a PLOG and I thought I could drop down a size.

supporting mods are
PLOG
180*
104 autolites
Hogan DP
2.5" cat back with res and mufflers
FWI

I don't have a tuner so im worried about KR. you guys think it will do more harm than good at this point? I know maybe rockers would be better but I want to do that once I rebuild my engine (192K currently) so for now I just want to do the easier items with out going overboard.

You should be fine with a 3.4, but i wouldn't go below a 3.5 without a tuner/scanner.

Depends on what you plan to do with the car. If you drive it daily and punch it once in a while, you'll be okay. If you are doing repeated, sustained WOT runs for 10-15 secs each time, that rebuild will come sooner than later.

And, with the extracurricular activity comes added strain on the transmission. It's the weak link in our powertrain. You can never predict when it will go, but it tends to happen when you are stressing, heating, spinning wheels. Trans cooler and good fluid maintenance helps, but start saving. Again, if you are just driving daily in the normal routine, it will probably last longer than if you hit the track on weekends.

Bros, first mod should be a scanner. Torque on the droid with bluetooth is perfect.

Then do plugs and tstat and whatever you want from there.

You want to see see exactly what each additional mod does and they only way to do that is by scanning.

I regret not getting a scanner first. I did plugs tstat and 3.6" first instead then torque.

I really wish I couldve seen stock KR and other stats before i did any modding.

We all regret not scanning first, but for the price of scanning software, we can have 20 HP. Most of us take the HP.

Eh, $20 for bluetooth and 5-$6 for torque app?

Cheap investment.

matt270avian wrote:

You should be fine with a 3.4, but i wouldn't go below a 3.5 without a tuner/scanner.

I agree with Matt, I installed a 3.4 pulley a while back and neglected to scan. I was fine for a while but on a hot day last year I abused the rivi racing a ricer on i55. I mean pedal to the metal like 3-4 miles. Well ended up spinning a bearing. Make sure your oil is nice and fresh, premium gas, and I'd say make sure your intake gasket is in good shape. I suspect mine failed. I had been having fun for a while with my car tho. 10 years of abuse . I won the race , but coasted off the expressway with the warning lights on and the chime going off

Thanks everyone, guess ill hold back on the pulley for now. I always wanted a tuner but cost was always a big factor, and i was worried about messing something up. Seems like though that should be something i do once the rebuild is needed.

For now i have to figure out why my car feels like its being held back, ever since i installed the brakes (recently put cross drilled and sloted rotors + ceramic hawk pads)