Tuning, CAI, Exhaust, I'm Lost

[Domman56]

OK This is my area of expertise.

Firstly if you're going to claim it helped provide A-B-A testing before and after. Some things work for some on here that don't work as well for others.

My baby right now is a 2004 CLK55 AMG Cabrio that I drag race twice a month, Take on canyon runs, at least once a month if not more. Also I'm a heavy footed person naturally. However I still average 18.5-19 MPG out of it Even while having fun with it. Mods ( K&N filters, Secondary Cats & Resonator Delete, Flowmaster Super 44 Muffler. Transmission internals from European spec CLK along with Tune to delete top speed limiter.)

Firstly Intake and exhaust DOES NOT garuntee mileage on all cars. As you said you're not exactly light footed on it so that is where these mods MIGHT improve your mileage. Then again there's no garuntee.

A CAI pulls in Colder Denser air therefore telling your computer to add fuel to match the A/F ratio. Now here's why it works for heavy footed drivers. 300 HP is going to have a harder time pulling 5000 LBs than 315 HP will.

If you want to upgrade your muffler I'd NEVER tell anyone not to It may help it may not. Just pick something you like the sound of. I see you're from Texas so my suggestion would be LOUD haha. There are different mufflers that flow better than others of course however sometimes it's worth losing 1 MPG for a better sound or better performance.

When you install your intake (I personally prefer the K&N FIPK) Alot of people also like AEM with a Dryflow filter. Make sure to disconnect your Negative battery cable during install and reconnect it after. This way your computer recognizes the new A/F ratio Immediately.

Either way Intake and Exhaust is a nice way to wake up the V8's in the suburban Have fun with it it's your truck however look into Aero Mods also that's where you will usually get the largest increase

[mcrews]

I'm confused.
Hoe modding a mecedes amg even close to to a suburban?
outside of 4 wheels and a v8, they have absolutely nothing in common.
Add what type of advise is.....go for the loud AND loose 1 mpg??????????


and can you document the K&N with your ABA results?
Because all of us have seen the documented report that shows a klogged filter performing the same as a clean filter.

[oil pan 4]

Originally Posted by rogue909

I've done spark plug foulers on the O2 sensors (after cats) to trick engine (laminar air flow, its suppose to help, and it was a cheap mod.)

This is a bad eco mod.
This is a trick used on post converter oxygen sensors to trick them into reading the exhaust as being leaner than it really is after you gut the converter.
If you do this to your primary oxygen sensors then it will cause them to read lean and tell the computer to add more fuel.
*Note: As long as your catalytic converters are fully functional leave them alone.

Originally Posted by rogue909

I've heard the first things to do is a new air intake. I've looked around and I see 4 big categories, standard CAI (like K&N), ram air, super and turbo chargers. I've heard super & turbos actually hurt mileage (they also cost 40% of the value of my car, lol). So what is the break down of ram air vs the standard K&N air intakes? I'm hesitant with the ram air because it will require me to modify the hood of the car, but what are everyones experiences? Is the ram worth it?

Out of your 4 big categories you left out the warm/hot air intake.
People installing CAI, K&N B/S, ram air, super charger or turbo charger on daily driven gasoline powered vehicles are going to part of your immature go fast crowd.
Forget everything they ever said.
I think the ideal intake for a hard working gasoline powered vehicle would be a switchable warm/cold air intake. And no you cant go out and buy one, you will have to build it.

Originally Posted by rogue909

Regarding the exhaust, I've heard that the majority of vehicles (suburbans in particular) have a wide enough exhaust that you should save those for last. So thats what I plan on doing. Although I am curious what people have paid to have their pipes redone.

It cost me about $100 to do the duel 2.5'' pipes back in 2008, then about $50 to put the all stainless steel 3 inch down pipe and 4 inch straight pipe on when I turboed the suburban this summer.
I did all the work my self, and used scrap yard stainless steel this last time.
Install instrumentation and see if you have a back pressure problem. Thats what I did and saved the exhaust mod for last and didn't expect any gains when I did it.
When the turbo went on it had to have a whole new exhaust.

[Domman56]

Originally Posted by mcrews

I'm confused.
Hoe modding a mecedes amg even close to to a suburban?
outside of 4 wheels and a v8, they have absolutely nothing in common.
Add what type of advise is.....go for the loud AND loose 1 mpg??????????


and can you document the K&N with your ABA results?
Because all of us have seen the documented report that shows a klogged filter performing the same as a clean filter.

I meant the fact of using performance upgrades to net F/E Not that the Sub and Mercedes were similar.

And with the exhaust I was saying that not all mufflers are going to flow the same and some mufflers may have better flow or MPG than another. And a loud exhaust may OR may not show better FE. I was simply telling him do the tuning he wanted on his truck. I do my exhaust on my cars for the pleasure of the sound, therefore if he wants an aftermarket exhaust then go for it however It doesn't garuntee better mileage

[Frank Lee]

Loud exhaust pretty much guarantees no mpg improvement. It also guarantees you look like a douche when you're blatting all over the neighborhood.

[Domman56]

That's widely up to your opinion. Besides Just because there is an aftermarket exhaust on a car doesn't mean you're going to ALWAYS run the car full out to the point where Everyone and their mother will hear it. Then again I grew up around muscle cars So most of the "Loud" exhausts nowadays seem very tame

[jakobnev]

Loud exhaust pretty much guarantees no mpg improvement.

That's very true. Since summer my exhaust has gotten a lot louder, while my mileage has dropped dramatically!

(I should get my act together and fix it over the weekend)

[steve05ram360]

Here's a thought that may be worth trying... cool the fuel, heat the air. May keep the timing from getting pulled if there are knock sensors. One of the mods I did to my last gasser ram was to cool the fuel & keep it cool up to the injectors. Overall (all performance mods installed) went from average 12.0 mpg up to 14.5 on the hiway. Mods can work. Cooler fuel gave an extra 12~13% hp/tq in a 1.8t jetta (dyno proven), also did give better mpg based on data I collected on a regular daily commute of 160 mi. Since my home has nothing but diesels, cant try it myself.

Ditch the stock exhaust and get a setup that keeps the OEM diameter without the flat spots. Improve the flow from the airbox to the throttle body (take out any kinks causing turbulance) and keep the low end torque up. Any mod that does not improve torque below 2000 rpm wont help cruising mpg... in my experience. (after doing mods that addressed both go fast performance and being stingy with the fuel when needing it).

edit: forgot to mention that on that Ram I installed a 2.5" dual out cat back exhaust and lost 1.0~1.5 mpg... experimented with a reducer on the output of the muffler which brought the flow to be equal to a single 3.0" output. This brought back the lost mpg for sure but I cannot say (or remember) if it alone helped mpg.

[mcrews]

as I have stated over and over.
Stock exhuast is just fine for eco driving.
Someone PLEASE show me ANY documented test (hp preintout etc) showing improvement at the low end.
ALL the 'hot rodder bolt ons' (cai, k&N, flowmaster....etc......) show improvement ONLY at the top end.
Where (unless you are racing) you spend 1% of your engine's entire life.


note: if you spend more than 1% of your time at wot......your on the wrong forum.

[2000neon]

Originally Posted by mcrews

note: if you spend more than 1% of your time at wot......your on the wrong forum.

I must have took a wrong turn somewhere on the web, one of my cars spends at least 25% of it's time at WOT.

The civic has never seen WOT while I've owned it though.

I fully agree about the exhaust though, going larger than OEM will likely not improve MPG during any sort of normal driving.