Mods for efficiency

[HotBoxer]

This thread is for simple mod ideas that can improve engine efficiency and aerodynamics.

Intake: CAI or short ram. Probably won't have much of an effect on performance, but they look and sound cool.

Belly pan: I'm going to look for the belly pan that was discontinued after 2012. I've heard it helps aerodynamics, stability and protects from the elements. Many GM parts dealers say it is not available anymore but I'm sure I can find it with some searching.

Other undercarriage pans: I've read some other pans from the Cruze Eco may fit the Sonic and aid aerodynamics, does anyone know what those might be?

Exhaust: Catback could probably see some decent gains, turboback even more (illegal though).

Grille Block: One that opens and closes like the Cruze, if you want to be really fancy. Or maybe an aftermarket grille that is more restrictive than stock, but still lets a bit of air through for cooling.

 

[Kcmo83]

If you are worried about your warenty , then buying any mods without a tune is basically pointless . Now you can get a tune with your mods and from what I've read Trifecta has a ghost mode to hide from the dealer. Bottom line mods without tune from what I've researched on here is useless .

 

[HotBoxer]

Really? I'll have to rethink my plans then. Thanks for letting me know

 

[perrymk]

Not specific to Sonics but as a fuel saving measure in general I've read people remove the rear seats and spare tires and whatever else is there to reduce weight. One can also replace the heavy lead-acid battery with a lighter lithium ion battery. I've not done any of these but to each their own.


I have two primary fuel saving measures.

1. I purchased a Black and Decker inflator and regularly check/maintain my tire pressure. It's quick and easy to use and there's no tank to fill (filling a compressor tank takes time and I prefer not to wait)

2. I drive for gas mileage whenever safe to do so. Slow starts, coast to stops, etc. I intentionally try not to go over 2000RPM even when shifting gears, unless the speed warrants it. I believe 70mph is about 2150RPM or something like that.

 

[ScarabEpic22]

1. Tune
2. Warm air intake, not sure what good that's going to do you on a turbo car that will put the charge air through the intercooler anyway. Hard pipe the stock air box or do a CAI.
3. Most restrictive part of the exhaust IMO is the downpipe. Chokes the turbo from spooling and has a massive cat there so you need a tune to disable the codes and retune accordingly.
4. Belly pan is a good idea, I've toyed with getting one for myself just dont think I'll get $90 worth of mpg out of it anytime soon. But heard high-speed stability improves, so there's that...
5. Keep your foot out of it

 

[HotBoxer]

2. Warm air intake, not sure what good that's going to do you on a turbo car that will put the charge air through the intercooler anyway. Hard pipe the stock air box or do a CAI.

I thought about this recently, and you are right. On a turbo car with an intercooler, a WAI is pointless. If anything all it would do is make the intercooler work harder. Plus, WAIs in general are stupid because you will end up using more throttle to achieve the same results, negating any MPG benefits they might provide.

I'll update my original post

 

[mja]

I thought about this recently, and you are right. On a turbo car with an intercooler, a WAI is pointless. If anything all it would do is make the intercooler work harder. Plus, WAIs in general are stupid because you will end up using more throttle to achieve the same results, negating any MPG benefits they might provide.

I'll update my original post

Neither aftermarket CAI or warm air box.

Keep the stock air box, at part throttle it will be the most efficient in terms of reading fuel trims off MAF sensor.

 

[mja]

Other undercarriage pans: I've read some other pans from the Cruze Eco may fit the Sonic and aid aerodynamics, does anyone know what those might be?

Check my build thread, I've installed one so far... they're not a direct fit by any means.

Grille Block: One that opens and closes like the Cruze, if you want to be really fancy. Or maybe an aftermarket grille that is more restrictive than stock, but still lets a bit of air through for cooling.

Upper grill block, someone on the forum has this on his car, can't find pictures of it. The same guy has a simple aluminum rear pan / diffuser that helps air flow under the rear.


... the best mod for efficiency is a tune. If you could count changing & gapping plugs, and changing O2 sensors as 'mods', that would help too. I get better mpg when my foot's out of it with trifecta than on the stock tune.

 

[Llia]

The belly pan helps pull air from the engine bay because the speed of the air under the belly pan is much faster. I wonder if that is enough to keep the air pressure on the underside of the hood from pushing up, lifting the car some? At least by venting the high pressure air from under the hood to the low pressure area near the front of the hood it would have a similar effect to keep the car grounded? If anything reduce heat in warmer climates.

I just got completely new CNC manufactured aluminum vents ordered (seven pairs + my pair). Not like my old ones (which were great but frustrating to manufacture with any acceptable success rate) and will be testing them near the end of next week, unless they arrive earlier. I will post MPG and other improvements if any.

 

[mja]

The belly pan helps pull air from the engine bay because the speed of the air under the belly pan is much faster. I wonder if that is enough to keep the air pressure on the underside of the hood from pushing up, lifting the car some? At least by venting the high pressure air from under the hood to the low pressure area near the front of the hood it would have a similar effect to keep the car grounded? If anything reduce heat in warmer climates.

I just got completely new CNC manufactured aluminum vents ordered (seven pairs + my pair). Not like my old ones (which were great but frustrating to manufacture with any acceptable success rate) and will be testing them near the end of next week, unless they arrive earlier. I will post MPG and other improvements if any.

You're right, the underbody trays/pans are for increasing lift more than decreasing drag, but decrease drag slightly:
Underbody panel testing - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

The hood vent + underbody trays may give the best of both - slight decrease in drag with less change in lift. Less like an airplane.

Love the hood vents you're developing btw, aluminum is even better opcorn:

 

[NegasonicWarhead]

I would suggest getting a BNR tune from Jerry that would increase torque levels. Plus the torque kicks in at low end on the rpm scale. I'd talk with Jerry, owner of BNR.

 

[cndctrdj]

Any mod to the engine you do is helping. They are all making the engine more efficient. That's where the power comes from.
The belly pan is great. It changes the way the car feels on the highway. I did notice an increase in fuel mileage when I installed it.
The Cruze underbody trays are very interesting. I'd love to try them but can't find them anywhere.
I've wanted the rear diffuser for a while. But no one makes a good one and the custom ones are tough on the wallet. Haha. I wouldn't mind making one but I need time.
Mja where is your build thread?
Also the grill blocker is a great idea. Just keep an eye on your temps. If you want to, make one that has sections. So if the temps go up you can take off a section to help the engine.
Lowering the car also helps with mileage.

 

[mja]

The belly pan is great. It changes the way the car feels on the highway. I did notice an increase in fuel mileage when I installed it.

likelikelike

The Cruze underbody trays are very interesting. I'd love to try them but can't find them anywhere.
I've wanted the rear diffuser for a while. But no one makes a good one and the custom ones are tough on the wallet. Haha. I wouldn't mind making one but I need time.
Mja where is your build thread?
Also the grill blocker is a great idea. Just keep an eye on your temps. If you want to, make one that has sections. So if the temps go up you can take off a section to help the engine.
Lowering the car also helps with mileage.

http://www.sonicownersforum.com/forum/build-threads/17297-turbo-i-mikes-build-thread.html

See page 4, #36 for part numbers on Cruze Eco (/Verano?) underbody trays.

I also have the Cruze Eco grill block, it looks like it's going to line up with our lower grill very well. It's going to take a while to bolt it in and make it airtight, and get the electronics working well. At some point..

There was a guy at a meet I saw with an aluminum rear valance under his car and an upper grill block. He said it helped with MPG, it was a nice piece, wish I took pics.

 

[dp67]

Does anyone have an update on these mods? How well do you like them?

 

[cndctrdj]

I've got the belly pan and bnr tune. The car runs great. No complaints.