Just bought a 2006 MC LT with the LZ9 3.9 engine. So far, it rides like a mix between a caddy and a rocket! It's pretty quick, but I feel a little disconnected when taking it around turns. I tried looking up some strut tower braces or sway bars, but to no avail. In fact the only suspension product I can find is the generic Eibach Lowering springs.... And on another related note, Why is there nothing out for this engine?! I'm planning on doing the magnaflow catback and maybe a pcm reprog(SuperChips?), because I honestly don't know where I would go to get it proffesionally tuned. Anyways, if you've got any advice, I'd love to hear it. Thanks.

 

The previouse owner of my Montelowered it by 1.3 in the front and 1.5 in the rear. He said it use to handle like a caddy and now it's more like a go kart. He passed the original springs on to me but I'm leaveing her lowered.

 

Ok, as far as getting it tuned, no local shop I've tried has any idea of what the 3900 engine IS, much less how to tune it. I pretty much gave up on that route, and have been looking into aftermarket tuners like the HPTUNERS unit. This link http://www.hptuners.com/products/vcmsuite_vehicles.php
if you look at the 7th grouping down, you'll see that it supports 06/07 3.5 3.9 and 5.3 Monte's. It's 500$ for the standard, which has 8 credits, enough for4 individual late-model V6 montes. Or, you can use 6 credits and purchase one year model unlimited. (example all 2006 LTZs, or all 2007 2LTs, etc)
I really like the idea, but hate spending 500$ on something that I can get done ONCE for around 375.
I'd like to find someone in Iowa that would split the cost, and then we could just trade back and forth until one of us bought out the others part. It wouldn't be that hard to pay for the unit after tuning a couple friends cars for them.

The PRO unit is 650$, but allows you continuous feed for a larger number of sensors, if you want to get really specific in the tuning.



My feelings so far are as such:

First, I'm probably staying with stock programming until I get past my 100k powertrain warranty. Being a brand new engine, this extra warranty gives me more confidence. Drive it like you stole it and let the dealer fix it when u get home, right?

Once that's gone, then the sky's the limit. Magnaflow has a cat back, but I'm worried about this for two reasons. First, the 3900 engine has such a beautiful torque curve (twin peaked curve) because of it's Variable intake system, and the Variable Valve Timing to take advantage of it. Reducing the backpressure in the exhaust not only will modify that curve, it could completely offset the advantage of the variable intake. And unless you're able to modify the point where the V.I. and VVT activate with a tuner, you could end up losing torque. Mods for right now will probably be an aftermarket cat, and mufflers for sound. Keeping the stock resonator should keep to basically stock backpressure levels. After that, I won't be doing any serious exhaust changes until I'm sure I can come up with a tuner, and effectively leave the activation of the VI at halfway throughout the RPM range, without losing the broad ends of the torque curves.

Now, you said LT, so being a 2006 I can only assume you mean 3LT package, not the LTZ. Did your car get the brushed aluminium trim like mine? I love that stuff, very technical without being too gaudy, like carbon fiber can be.


Oh, and for the engine they have a drop in K&N. Noone serious has made a factory quality intake, much less cold air intake, but there is a cone intake system that will replace your stock one on ebay, with a K&N, or a generic brand aftermarket high flow reusable air filter.

After that and the cat back from magnaflow I haven't found much. A high-flow catalytic converter will be a trip in itself, but I believe Magnaflow has a universal unit that's OBD2 certified