These were done on the old RegalGS.org site (now in shambles)- I believe by Dave Wild. They actually did extensive comparison testing between the stock GTP cat-back and the stock Regal GS catback and found not only a significant difference in back pressure, but a significant gain to be had by swapping the GS cat-back for stock GTP cat-back.

 

No one is saying that she will chip a piston on the 3.6, but if she's running with KR and the 3.6 just adds to the KR, then the PCM will pull timing and the HP will go down and not up with the smaller pulley. Therefore negating the effect of putting it on and spending money on it.

 

Provided the car is in a decent state of mechanical tune (spark plugs, fuel filter, wires, O2 sensor, etc) I really don't see that happening either.

 

Im running a 3.2 pulley. Yea, it knocks a little.

 

And IMO is better suited to the top swapped guys. A 3.8" to 3.4" pulley really isn't that massive of a step in terms of blower efficiency, and basic bolt ons can make a car run knock free on a 3.4". They're nice for the top swap people who want more power than a 3.8" pulley, but who don't want to do all the mods necessary for a 3.4" (which is much more than with a L67 bottom end).

Really really really really who said someone is going to chip a piston with a 3.6? really? really? really?

Here's the quote from my post:

Ported blower is not necessary for a knock free 3.4" setup; learning how to tune is not necessary for a 3.4" setup (I've seen relatively knock free 3.4 setups on a canned tune). You're trying to make it seem like the mods to run a 3.4 are super expensive or super difficult to install- modded stock 1.9's go for like $200- and only take a couple hours to put in; headers are only like $300 and take longer to put in, but still really aren't that bad (if you're capable of changing the SC pulley, you're capable of doing headers)- or even just a PLOG and downpipe- you could easily do both in 2 hours or less.

Honestly, the basic bolt ons are so cheap and make so big of power gains, that I don't see why you'd bother just doing a little baby step and a few of them- IMO, keep doing the basic bolt ons until you get them all (total for all the stuff should be easily under $1k, especially if you buy used)- and then stick a 3.4" on there, and have way more power.

Its not like the supporting mods are useless without the pulley either- I'd bet a 1.9 rocker car (or headers only car) running no knock on a stock pulley would give a lightly knocking CAI / 3.6" pulley car a run for its money, if not beat it. Then you add the pulley drop at the end, and see even more power from the setup.

Ok, lets give you a common scenario- a person has a 100k mile GTP that has about 4-6* KR bone stock on premium fuel in this hot summer weather (very common)- they install the mods like the OP has, copper plugs, a 180* tstat, a regular box CAI, and swap out the mufflers- do you really think those few mods are gonna kill all that KR? I'd bet there is still an easy 3-4* left. Now stick on your 3.6" pulley, and you add more boost, more heat, and more KR- which means more boost, but less timing (probably would at least put you back to the original 4-6* I'd imagine), meaning you could easily be just as slow as the same setup with the stock pulley.


Honestly, if its really too much of a bother to try and find someone local on the forums, in a local car club, or at the local drag strip who will scan your car for 2 minutes, then you probably aren't up to spending an hour or so changing SC pullies either.

 

Not always. I know this.

 

Not everyone is a gearhead- installing rockers is well above the skillset of 99.99% of the population out there, and most don't want to learn. Let's not even talk about headers. Face it- most people don't care enough to fight rusty exhaust bolts to install a downpipe, or rock there engine back and forth to clearance a valve spring compression tool, or to fight with getting a rear header past their firewall.

Some of these same people may want to wake their cars up a bit. Not because they care about hardcore performance...they just want a little more get up and go. The 3.6 is a great choice for them. Telling someone who asks about installing a little 3.6 pulley to get rockers/headers/a tune and a 3.4 is kind of silly.

...and if they've got a high mileage, poor condition L67 that's got 4* of knock on stock boost, they probably should address mechanical tune issues before throwing mods at it period (or find something else to play with). Maintenance should always been addressed before mods.

 

I live in NJ. This is my daily driver AND it has to pass inspection including emissions so I don't want to go too crazy. I had a 3.4 on here briefly last month and the car FLEW and took off like a rocket, I really felt how much faster it was, but took it off when people were saying that I still needed downpipe, u-bend delete, headers, hi flo cat, etc...... or I will chip/burn pistons, that freaked me out. When I ran her in April bone stock before anything she gave me 14.95 in the 1/4. I thought that was pretty good, so I was excited to mod her a little to see the difference, still haven't gone yet. And no, it's not easy to find that used scan gauge anywhere and I do live out in the boonies and there is a guy here that soops up Corvettes and such for BIG money and he wanted like $200 just to scan it through a complete drive cycle, just telling me my kr was not an option, so yeah, money is an issue too. I do wish I knew someone that could scan it for me so I know my kr. And it's funny, the guy I talked to at 3800 performance said that it was fine to run the 3.4 without all that extra stuff. I get all these conflicting opinions on it's ok, it's not ok, I need the extras, I don't need the extras. The 3.4 is damaged now anyway along with the puller, wasted $$$$. I was PLANNING on just buying the puller(which was an awful aluminum block design, tore up cone too), bought a 3.4, change it once , be done with it and sell the puller, but it didn't happen that way and from all these switching pulleys over and over, looks like I need a spare cone to put a smaller pulley on when I am ready and just swap them, don't think this one will survive another go at it. I didn't get modular because this was supposed to be a one time thing.

 

Oh yeah, and my car has approx. 53,000 on it and was owned by an older lady who always took it to be serviced at the dealer, you should see, I have like 4 or 5 pages on the carfax of just her servicing everything. I ONLY run super, add octane booster here and there and fuel injector etc. cleaner, change oil faithfully, check fluids all the time, did a trans service, and more, she has been/still is well taken care of. I just hate these damn swirl marks! Grrrrrrr!

 

9 times out of 10 a 3.4 on a stock L67 in good running condition WILL make it faster- it will have plenty of KR, though, and it will stress your bottom end and potentially frag a piston down the road.

Slap a 3.6 on your car, change your fuel filter yearly, and be done with it.