Can someone look at my mods in my garage and tell me if it is safe to put a 3.6 pulley on with no further mods? Because now it feels like with the Thrasher CAI and GMPP/Magnaflow cat-back exhaust I have more air out but maybe a 3.6 pulley for a little more boost?????

Lisa

 

Just like in your other thread, the mods don't mean anything, it's the KR values.

I still think you need more exhaust mods, Powerlog and downpipe minimum.

 

This

Seriously, you do not need to run a smaller pulley until you have a tuner/scanner to check how much detonation you're getting.

 

1st off, here are the listed mods (for those who don't feel like clicking on 13 links to find the garage page):

I hate to say it, but the catback probably did virtually nothing for power or KR reduction. You're not getting 'more air out' because you still have the nasty stock downpipe and front manifold. The stock catback is not a restriction on most 3800 vehicles. Same with the TB spacer- great place to tap for nitrous- otherwise virtually useless. The TB will still get heated from engine bay heat, as well as the exhaust crossover running right underneath it. Even if it does stay 20-30* cooler than the SC, air is in there for such a short time that its not going to make a massive difference in inlet air temps at the cylinder (not to mention, it can only really heat the boundary air).

The plugs and CAI probably helped kill a little KR, but what you've got to understand is your car probably had a good deal of KR stock (even running premium fuel)- so chances are you may just be getting close to being knock free on a stock pulley, much less a dropped pulley.

As the others have mentioned though, you need to find someone local who will scan the car at WOT for KR (or buy a gauge or scan tool to do that yourself)- its the only way to know for sure. However, I will say from the L67's I've seen - having a car that has virtually no KR stock, or even with a minor pulley drop with few to no mods is definitely the exception to the rule- most L67's seem to have a good bit of knock, especially as they all get older.

 

You don't need to click on 13 links to get to the garage, just my name to my profile in the dropdown to where the garage is there

 

I'm going to be the different one and say that you will be able to run a 3.6 pulley as it sits now, and that it will be considerbly faster with it.

I ran a 3.5 pulley on my Regal ,GS with zero exhaust mods and was completely KR free. My setup was a 3.5 pulley, drop in K&N, AL104s, a 180* thermostat, and a ZZP 1.0 PCM. Again, I was 100% KR free and trapped 99 in the 1/4 mile like this.

Being that your Monte already has better flowing exhaust than my Regal (Regal's have the most restrictive exhaust of any L67 car- tests have confirmed up to 10% more backpressure), I'd certainly think you'd be fine on a 3.6 pulley. Even ZZP (a vendor who is going to try to talk you into buying more parts...so is obviously going to pitch supporting mods) claims a 3.6 pulley is fine on an otherwise stock L67.

Scanning is wonderful, but for such a basic setup...I wouldn't sweat it. Get yourself a 3.6 MPS, and if you mod more later you'll be able to easily pulley down.

 

My point is, rather than make people hunt for your mod list clicking through other pages- you'll get more help if you just straight post the information up front so they don't have to go hunt for it.

And if the car had considerable knock from the factory- then what? I'm not crazy about just throwing it on and hoping it'll be faster; especially since its so easy to get a hold of a scan tool. Only way I could see not having anyone local (even a small mechanic shop or something) is if you really live out in BFE. Even then, used Aeroforce gauges only seem to run $150 or less; which is a great investment for someone who wants to continue modding their L67 and has absolutely zero people nearby with a scan tool.

You've got to admit that's not the norm for L67's though. Your car was definitely on the knock friendly end of the spectrum.

Heck, even on my 99 gtp- I had like 3-5* KR with a 3.4" pulley, and that was running 1.9 modded stock rockers, a PLOG, 3" catless DP, res delete, etc etc (before I tuned it of course).

It will be fine as in it won't chip a piston (at least I've never seen anyone chip a piston on anything bigger than a 3.4")- but if you have a lot of KR, and add this- then you'll have a lot more KR- and be slower. A lot of places also used to say the 3.4" was fine for a stock L67- and I've personally seen 3.4" setups with very few minor mods (CAI, plugs) get beaten by a stock pulley car.

I could see if getting it scanned was some massive headache, but it really takes less than 5 minutes once you find somebody local with a scan tool- and they only need to monitor 1 parameter, KR, so they don't need to be some kind of super pro at using their scan tool.

My thing is, if you're going to keep modding the car, it will be useful information regardless. It will also instantly tell you if you're going to be faster or slower with the new pulley. My other thing is- how far do you plan on going with the engine? As mentioned, a 3.6" isn't really a huge jump from stock- you could always save a little more money, do a few more mods, and go straight to a 3.4" instead of spending money on an in-between pulley size.

 

Yeah, there's a reason why you don't see a lot of L67 guys go to a 3.6" pulley. That's because you won't gain much if any hp. People often make the mistake of pulleying down when they really should have gottn more supporting mods to take care of KR. If I wer you, I would wait until you had it scanned and then if you can, go to a 3.4" pulley. The 3.6" is just barely better then stock.

Also I was unaware of the Buick L67's having such a restricted exhaust system. Could someone post a link to those tests that prove that?

 

Get a downpipe, port your SC and lim (guys on GP forums always do it cheap) and then run a 3.4, after scanning.

 

Not true- plenty of dudes have run high 13s on a 3.6 pulley with a few bolt-ons. Most folks don't run the 3.6 because until recently in 3800 world it was common practice to slap on a 3.4 and be done with it...unless you got a few more mods and used a 3.25. The 3.5-3.6 pulleys are a relatively recently phenonemon.

I really, really, really, really, really, really, really, really, REALLY doubt that anyone has ever "chipped a piston" on a 3.6 pulley. It's a great option for someone looking to casually modify their car a bit and doesn't want to invest any serious time or effort into their grocery getter. Not everyone wants to port their blower, fight rusty exhaust bolts, and learn how to tune.