I have recently bought my 2006 Monte Carlo SS with the LS4. I was curious what is the best tune and gear ratio to go with for a daily driver? I dont “race” by any means but I want the most pep I can get out of the car without hurting IT or the trans. I’ve heard of people using the diablo predator? Any reviews/experiences. I only plan do to a Tune, CAI and exhaust since it’s my daily like I said. I’ve never tuned before and I can’t seem to find enough info anywhere about the 7th Gens and tunes. I’d like to tune of the DOD so it runs on 8CYL the whole time and then to run 93 octane? Or I heard of the “diablo tune”? It’s hard to find info on this unfortunately..:/. ANY help would greatly appreciated.

 

I wouldn't touch the gear ratio. That's a really expensive / difficult mod on this car for not a ton of actual benefit.

As for the best tune - get a custom tune done by a local LS shop. No plug in tuner is going to come anywhere near a one off tune for your specific car. Tuning for octane and disabling DOD (electronically only - you'll still have the mechanical weakness of the actual hard parts) are standard fare for a tuner.

Keep in mind the trans is already doomed, even bone stock. Plenty of these transmissions have failed on regular stock daily drivers behind the LS4, so dont let anyone fool you into thinking this things gonna last forever just because you kept the mods basic.

 

Hard parts I’m guessing you
mean the cam and lifters or whatever for the DOD inside the engine? I’ve heard that if you delete DOD You should do a Cam swap? Should I? I’d be doing it so labor isn’t an issue just haven’t been able to find out enough but if you know any more man lmk thank you for the other info above as well it’s highly noted!

 

It's really just the lifters that fail. For some reason the DOD lifters are much more prone to failure than standard lifters.

But certainly if you're going in there to install normal lifters and a normal cam to delete DOD, I'd really think about putting some kind of aftermarket cam. Of course being a daily, you're not going to want to go crazy or you risk running into reliability issues again, but even something mild would be nice especially if you're looking for more power anyways.

Theres the other option which many do as a cam swap is such a pain on these cars - do the electronic delete now and wait to see if / when it has a mechanical failure. Some seem to last a really long time, so you may never have to deal with it going this route. A lifter failure generally isnt catastrophic (of course any major failure has some small potential for greater damage).

 

Okay awesome I see what your saying man thanks! My other questions are about the suspension/fuel..I want to replace all struts all the way around. Should I just OE replace? Does running 91 oct. on the car really all that better? Owner before me ran normal gas and I’ve read a lot about using 91 because that’s what the owners manual recommends. Obviously I can see the car runs fine using 87 But if 91 is what it Recommends I feel I should run that.

 

Cant be of much help on suspension as my monte is a 96 and the front is pretty different. I replaced everything on my monte though and TBH handling is still mediocre - would certainly struggle against any new stock Miata, s2k, etc on a tight autocross track. Just saying I'd be careful dumping too much money into suspension mods as itll never be really competitive at handling events.

I did have a LS4 GP GXP as a daily driver for years, but just ran the stock Bilsteins its whole life as they were perfect for what I wanted.


As far as fuel goes, it would be helpful if you had or could borrow a scan gauge to read KR / knock. If you put 87 in it and its showing KR, that means its sensing knock and pulling timing - hence making less power. The LS4 isnt nearly as high compression as some of the other LS engines, but it's still possible that itll have KR, especially in the summer. If it's not picking up any knock, then you won't see any gains from the higher octane (in those weather conditions). You'll just need to pick which you prefer prior to the tune so its optimized for that.

 

Okay I’m at E rn on gas and I want to run 91 from here on out so i should be good then? And i’ve been doing research all day and I agree the Holsteins are really great I’m going to go with those!

 

Yeah, you can certainly run 91 now for as long as you want. Only downside is the cost. The way I've always thought about it though- if I was that worried about spending a couple extra bucks a tank, I wouldn't have bought the trim level with the highest performance engine.

The engine has knock sensors that are constantly listening, so itll adjust if you get a bad tank of gas or have to put in 87 again at some point.