MrBrownPants

So I have a few questions. I have looked around and I just can't seem to find the answers I am looking for. This mainly goes out to Lew as well.

I have a stock 08 Impala SS. Approaching 110K miles. I have had the car less than a year and a half and put 40K miles on it already. Only modification I have done (lack of funds) is a QTP cutout right after the cat. Sounds awesome, loud, and gets better gas mileage too! I am thinking about going on to the next step for mods.
I am wanting to get a CAI cai, the ZZP 3" DP, and a Lew tune (need the trinity or whatever Lew would recommend.)
Concerns: I mostly run on 87 so I don't want to be forced to buy 93. And I also have to keep by DoD.

Will the mods support my daily driving habits or does all that turn the car into a street car?
Thanks everyone.

Sint3k

Pointless imo, turbo and tep trans is the only way to go, 10 gs later

Koren

Turn that dod off it'll save you oil and a head ache and your losing mpg by using cheap gas plus engine knock, use 91 it's a difference of 2-3 dollars more and saves you a engine in the long run. If you mainly drive highway I would say get it tuned for dod to kick on at about 70 so you still have cruising but the car drives much better without at the mpg is only 1-2 lost. Just my opinion

spawne32

iTrader: (2)

I wouldnt say its pointless, it's just if you dont have any intention of going all in, then don't waste the money. Modding a car and then running 87 octane is really what is pointless. The car probably knocks all the time and probably is severely down on power because of it, its just the way it is with these cars. Cold air intake won't do anything for you, the ZZP 3" DP might free up a few ponies, but in reality, why even bother if you don't want to free up horsepower just by changing fuel.

Red_Zone

I think if your funds are going to be limited then you should just stick with exhaust cutout... and skip all that other stuff.

Instead put a ground effects package on, lower than car, stiffen the suspension, and put on reasonably good tread along with plastidipping ALL chrome around the windows etc... oh and slotted rotors too why not...

If you can't afford the 10K+ turbo route the car still fun to drive because it will look cool.

Anything other than those two options is pointless imo... or stay completely stock and buy an 80" TV I dunno

BTW to put it into perspective a basic LS4 Turbo Impala should allow you to keep pace with a base C7 vette on a highway race from 60mph to 125mph and even should due well 0-60 too

You decide if you want your Impala that fast on the street.

spawne32

iTrader: (2)

The NA mods are still perfectly acceptable, so far anyone on this forum who has gone turbo has gone through transmissions like toilet paper unless they are running very very low boost.

rottonj

iTrader: (4)

You should be using 93 already as been stated, the mods you are considering will gain you some for sure and it can probably be tuned to run 91 I would think . Leave the DOD alone, you said nothing of future mods so it sounds like you are looking for just a little more . If you have the cutout already then the downpipe might not be the best mod. If you like the car, do a shift kit and transmission cooler and maybe stereo or appearance mods. If you plan on keeping it budget for a transmission. Good luck.

MrBrownPants

Thanks for everyone opinions.

You are absolutely right, I do not want to turbo or SC the car and make it a vette killer. I don’t want to have to put a trans in it every time I get my oil changed. If the trans does go, because you never know about them, I might send it to TEP but I really can’t say. And as far as DoD, I would like it to be removed below 50. I drive a lot of 55 and at that speed with DoD, running with 87 and C/O open I pick up about 32mpg.

I am just looking for a little more. And I do put 93 in it from time to time, just not when it is 1$ higher than 87. And the stereo / exterior stuff is in the works. Speaking of which, does anybody have any experience with LED headlights in the stock assembly? Does the light scatter really bad and blind people on low beam?

I was just curious if the cai, DP, and tune would force the car to 93 and remove DoD.

Koren

My tune is 91 and above and my engine no longer knocks, I get decent mpg but then again my suspension is old so I'm in the process of replacing parts. These cars were built to run 91 and up, but if you get a Cai get cold inductions or make a fender wall intake, the k&n is basically just a hot filter. I still have my stock box for that reason lol..the right tuner will wake it up for sure. But yeah when you change your exhaust your dos sound will change too and it might be annoying.

spawne32

iTrader: (2)

No, they won't force you to remove the DoD or run 93, but the power gains you will see with them are minimal at best because you are not even trying to optimize the car's power even as stock. The downpipe would probably be more helpful to you because at the very least, letting the car breath out a little better helps reduce the chance of KR, and the stock downpipe and cat are very very restrictive on these cars. At the very least, opening that part up gives you a little more of a v8 note.

rottonj

iTrader: (4)

I am all about gas mileage, when mine was a DD it was my main concern. That being said be careful of running 87 octane, getting 32 MPG is great but you are running super lean if you get that(hole in a piston lean). I am close to stock, and have seen 32 MPG on a trip but mine was a solid 24 commuting. Not sure what your day to day drive is but be careful. Do the factory air box mod, I did and it helped some I think with a K+N drop in it probably flows a little better.

rottonj

iTrader: (4)

He has a dump, his exhaust is already flowing better than stock.

MrBrownPants

I was thinking that with the 3”DP that I would essentially have a 3” all the way out after the manifolds because I have a 3” cutout. Considering how many are swearing by 91+ I will start using that now. Honestly thought that 87 wasn’t causing that much of an issue other than a little less power and mpg, but I didn’t think damage.

In my thinking, I figured that if I was going to make this much change that it would be stupid to run the stock tune.

Anyone on the LED headlights? 

spawne32

iTrader: (2)

I havent used the LED bulbs before, It is something I am considering however I would just like to see more examples of them being used.

Koren

I gained mpg by swapping to 91+ tbh. I use 1 led in my license plate light and so far so good

rottonj

iTrader: (4)

Its your car and your money, once you get the downpipe now the manifolds are the restriction. The trend will continue with each mod,(ask Spawne ) The rear looks worse then the front I think.

MrBrownPants

I know all about mod fever! Catching it slightly. I would probably end up doing headers if it wasn't so difficult and expensive on these cars. Thank everyone for you input. I'll message Lew and see about some pricing.
And I was talking about replacing the halogen headlights with LED. Just wondering if anyone seeing this has any experience with it. I am definitely get LED reverse lights. 5% tint makes it hard to see at night.

06MonteSS

First off.. You do NOT want to be using 87/89 octane.. LS4s HATE that low octane crap!! A TON of knock retard on only 87/89 octane.

I will not tune these cars for 87/89 octane.

You need to use at LEAST 91 OCTANE in that car!! I can definitely get you hooked up with a tune, and it would be for 91 octane or 93 octane.. NOT 87/89 garbage..

You will HAVE TO run at least 91 octane gas in that car..

I had an LS4 myself for 8 years, 145,000 miles (Monte Carlo SS), I know these LS4 cars...

And Yes, I always disable the AFM/DOD in my custom tuning. it helps with better throttle response... disabling it also stops an oil burning issue that it causes every time it switches modes, which was even acknowledged by GM in a technical service bulletin... as well as failed lifters due to the afm/dod operation.. plus, a lot of people actually end up getting a little better mileage with it off, once the tune is done and things are dialed in... Disabling it also eliminates a surge you would feel between shifts due to torque and torque management with having DOD disabled.

You can email me at: diablo DOT help AT gmail DOT com - with your vehicle info/mods and I can send you a looong email with all the info about the programmers and the custom Tuning, the process for what you need to do, etc.

Thanks!
-Lew

06MonteSS

And Make sure you are using GOOD 91/93 octane gas, it makes a difference... mobil, exxon, sunoco, amoco, bp, chevron are best brands to use, with mobil and exxon being the best..

NEVER use Shell, costco/bj's, mom-n-pop, or no-name brands, as it's crap gas that tends to cause a lot of knock retard and less performance/mpg...

Sint3k

Lol.... fyi shell and costco are part of top tier standardization, your claim that they are any worse or better is pretty silly, lets stick with facts please