Air intake muffler delete on a Pontiac Sunfire

[Andyb04]

No one is out to get you! Although some of these posts may not be polite or sympathetic...

Reducing the airflow restriction will increase your performance at wide open throttle, but just cruising it seems like the same amount of air would be going into the engine. It may be possible that you are entering a different BSFC region of your engine with this new configuration, or some other phenomena, although it's unlikely.

If you really want to, you may consider getting more data, including putting it back on and trying it again. My variation from tank to tank is about 5mpg even without changing anything on the car - driving mode, wind speed, temperature.. they all have a big impact.

[mcrews]

it's hard to hate stupid........

Stupid like saying one tankful of gas is driven the exact same way of 300 miles as the last tank..........

stupid like ignoring a simple A-B-A test over a flat 10-15 mile stretch using the cruise control to duplicate the drive with the mod and the drive without the mod.

stupid like not reading other posts that discuss the placibo effect (look it up)

stupid like even being so clueless to post the in-your face nanny nanny pooh pooh .......

[Andyb04]

Alright, he is out to get you

[moorecomp]

A similar intake mod, called the Keman mod on the ZX2, gained me ~2 mpgs. Is it possible the modification helps due to warmer intake air, instead of air drawn from outside the engine compartment? Maybe, but whatever the reason, I am keeping my intake mod. I have no problem with people saying it will not work, I just take my results and keep plugging away.

[euromodder]

Originally Posted by moorecomp

Maybe, but whatever the reason, I am keeping my intake mod. I have no problem with people saying it will not work, I just take my results and keep plugging away.

If it can net some results - for whatever real reason - grab it.
One mpg here, another one there ... that's how we get there after all.


Just make sure the air intake path isn't so easy that it can scoop up water.

[graydonengineering]

Originally Posted by Phantom

Before anyone says anything here is the reason that it can save gas. Having better throttle response means there will be less delay in the engines ability to rev. If the engine can rev easier and faster changes in TPS are easier to detect allowing for more fine tuning of speed when cruising, and less time spent accelerating. In the end the change might not do anything for MPG but it will give a better seat of the pants feel and can allow the driver to better adjust the throttle for more efficient driving.

I agree! I have found faster acceleration improves my mpg. That said, obviously flooring it and reving up to redline is not the right idea but accelerating "briskly" so you can settle into a high gear and a stable speed is beneficail. Keeping up with the average driver after a light seems to be about right for me. I also catch less flack from the passangers for driving "slow" that way as it seems to them like I am driving just like everyone else but getting great mileage. I find that small engines like mine have a hard time keeping up without flooring it (not good for mpg at all) so performace mods might net a gain even if they shouldn't in theory. If your engine is already quite powerfull, letting more ponies out of the barn will probably keep milage the same or even make it worse.

[Silvey01]

Originally Posted by Daox

However, the fact of the matter really is that we have some great knowledgable users here that really do know a lot about engines and how they work, especially when related to efficiency.

That being said, this modification is not responsible for getting you your extra 1 mpg. I would highly recommend looking over the 65+ mods list for staring out ecomodding. Its a very good list. The mods listed are proven modifications that do work.

Yes, there are some knowledgable people out there who know a lot about engines including my best friend who's an engine builder (not engine assembler), machinist, fabricator and GM tech.

While my engine is very underpowered the air intake muffler delete has in fact improved HP at WOT it has also stopped the hesitation and sputtering when I'm going up hill in a higher gear at partial open throttle as I said in my original write up.

Also, why I only got 1 mpg and not 2 or more is probably because I've been driving with Max A/C on because for the last 3 weeks the heat index has been between 105 and 115 degrees in Missouri. It's not a dry heat either.

I've looked at the modifications on the 65+ mods list and while I agree with most of the mods on there there is no mention on advancing the cam timing (not ignition timing). COMP Cams® - COMP Cams® Valve Timing Tutorial

There's a brief write up on it... If this is confusing basically advancing the cam timing brings the peak power (both Torque and HP) down in the RPM range.

A stock cam usually has peak power in the 4000-6000 rpm range... I know of no one who drives on the highway at this speed. Bringing the peak power down moves the vehicle without the engine "breaking a sweat" like on the hotter cam engines that make all either power up in the upper rpm range. This advance in cam timing coupled with the a economy or "RV" cam would optimize the engine for economy.

[Silvey01]

Originally Posted by Andyb04

Alright, he is out to get you

Yes, he is.

Considering he has a pompous car and a pompous attitude and only gets 23MPG I don't think I'll take his advise for ecomodding.

Also, my car is a base vehicle... no cruise control and if I could find a "flat" stretch of land that is 10-15 miles in length in Missouri, I'd let him know.

[Silvey01]

Originally Posted by Andyb04

No one is out to get you! Although some of these posts may not be polite or sympathetic...

Reducing the airflow restriction will increase your performance at wide open throttle, but just cruising it seems like the same amount of air would be going into the engine. It may be possible that you are entering a different BSFC region of your engine with this new configuration, or some other phenomena, although it's unlikely.

If you really want to, you may consider getting more data, including putting it back on and trying it again. My variation from tank to tank is about 5mpg even without changing anything on the car - driving mode, wind speed, temperature.. they all have a big impact.

I always check my tanks' mileage even when I don't do a mod. It's just about the same considering I got this car to go back and forth to work only, but I do go on errands for my wife here and there in the "city" and that drops the mileage unforchantly. What can you do?

[moorecomp]

Autospeed has a great 5 part article on this. It shows that reducing the differential between atmospheric and intake (not manifold) pressure does have an effect on performance at less than WOT.

Eliminating Negative Boost