CAI or SRI for Better Mpg and Efficiency? - Chevy Cobalt Forum / Cobalt Reviews / Cobalt SS / Cobalt Parts
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post #1 of 31 (permalink) Old 05-05-2013, 11:54 AM Thread Starter
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CAI or SRI for Better Mpg and Efficiency?

Title says it all lol. I don't drive hard (most of the time) and I'm more concerned about more mpg and efficiency than power. I've heard a lot of mixed things about which one actually DOES increase mileage. So I'd kinda like to settle it now since payday is coming up soon;) I'd like facts, instead of "what you heard or think you know" thanks guys!!
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post #2 of 31 (permalink) Old 05-05-2013, 12:03 PM
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Just buy a k&n drop in filter. Does the same as am sri technically. You will not see an increase in power wi th just an intake

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post #3 of 31 (permalink) Old 05-05-2013, 12:05 PM Thread Starter
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Well I don't care about the power. I just want the mpg lol
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post #4 of 31 (permalink) Old 05-05-2013, 12:31 PM
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Drop in filter is what you want

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post #5 of 31 (permalink) Old 05-06-2013, 10:59 AM
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Drop in filter would be your best bet in MPG increase. Lots of people think that a CAI would do it, but you have to consider that your airbox is basically a CAI, it pulls airflow into your engine. Lots of people will argue that its restrictive, but you have to ask yourself, "Did I increase the size of my intake valves or are they stock?". Engine design engineers design todays cars perfectly for MPG. Just the right amount of air, fuel, and exhaust for best volumetric efficiency. Manufacturers will argue against K&N cause of 3rd party reasons.

2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille
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post #6 of 31 (permalink) Old 05-07-2013, 12:24 AM Thread Starter
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Sounds pretty reasonable. Will a drop in effect the sound at all?
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post #7 of 31 (permalink) Old 05-07-2013, 12:34 AM
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gives it a little more throat when you step on it but not to loud
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post #8 of 31 (permalink) Old 05-07-2013, 09:33 AM
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Quote:
Originally Posted by 5t3alth View Post
Drop in filter would be your best bet in MPG increase. Lots of people think that a CAI would do it, but you have to consider that your airbox is basically a CAI, it pulls airflow into your engine. Lots of people will argue that its restrictive, but you have to ask yourself, "Did I increase the size of my intake valves or are they stock?". Engine design engineers design todays cars perfectly for MPG. Just the right amount of air, fuel, and exhaust for best volumetric efficiency. Manufacturers will argue against K&N cause of 3rd party reasons.
This is wrong. That has absolutely nothing to do with the intake being restrictive. You have to think, your air is restriced by the smallest pipe you have in your intake system. If your intake can only take in so much air, not any more, then the valves can only flow that much air. Valves in modern engines are actually designed big from the factory for a reason of knowing people will probably be doing things to their cars to make them less restrictive and run more efficiently. In my Evo, it is actually useless to get 5mm oversize valves, even if done right, because even after being fully built, it will only net me about 3hp. So valves don't have anything to do really in restrictiveness as they are designed to flow more than the actual head will allow anyways.

Another way you could look at this is just like a turbo. (Most people say you can't compare a NA car to a FI car but just hear me out). If a turbo'd car wants more power what do they do? They do 2 things, 1) raise the boost level, or 2) go bigger weather the whole turbo is changed for something bigger, or they start porting housings and getting bigger wheels. Bigger turbos will ALWAYS have a bigger inducer for the intake. The turbo housing output is generally the same size, but think of it like this. With a 2in opening, it can only flow x amount of air, and that air is put into a 2" pipe that goes to the turbo. Now a bigger turbo has a 4in inducer, so it is drawing x*2 (as it is double the size (yes i know there is more to this but I'm not going to deep into details) and cramming double the air into the same 2" pipe. Now when that happens, this is why guys with big turbos can achieve the same power with less boost, is because they are flowing a lot more air. Same goes with a NA car. Once you have everything flowing the same (intake, engine and exhaust), then you will be at maximum efficiency. That there will allow the best amount of power and the best MPG as there is nothing restricting the engine, so it runs much smoother with less feed back and doesn't have to work as hard to achieve what it's trying to do. Does that make sense?

'09 SS/TC - Stolen
Mods - Injen CAI, CIA MAF Relocate CP's, Dejon FMIC,
Custom 3" DP, 3" Exhaust, GT3076R, Pioneer AVH-4100DVD, Hurst STS, ZZP triple pod, Autometer Cobalt boost/DPIC/WB gauges, Nitto NT05 245/40/18's, H&R Springs, 80:20 Meth Spray
Future - KSport Kontrol Pro Coilovers, 10% Tint, FMIC spray
538whp/501wtq @38 psi on meth and 93 oct on stock ish motor


06 EVO IX MR/SE - Sold
Mods - *Updated 10/6/13* AEM TRUboost EBC, 4in custom TBE, SD dual 93/e85 tune, ETS 4in Race Core FMIC, Dual Aeromotive 400lph Fuel Pumps, T4 Tubular Manifold w/ dual WG's, FP Super99HTZ DBB Turbo, GSC 274 mivec cams, ARP headstuds/rod studs, FIC 2150cc Injectors, Aeromotive FPR, Aeromotive Fuel Rail, catch can, Mini Battery Kit, Slim Coolant Fan, Kiggly Racing high pressure valve Springs/Titanium Retainers, Supertech Stainless Steel Valves, Dual VTA Tial 44mm WG's, 4g64 Stroker Manley Pistons, 155mm 2.4 LR Manley Turbo Plus I Beam Rods with ARP 625 Studs, 100mm forged non-billet Manley Crankshaft, Full H/E PNP with Port Matching, Kiggly Racing Girdle, Dual Tial 50mm BOV's, Excedy Triple Disc Carbon HD Clutch, AEM EMS

'95 Ram 2500 Diesel
Mods - 5in TBE, Boost Elbow set to 28psi, Adjusted fuel pump, Open Turbo.

Future Mods- Super Street Clutch (rated @1400ftlbs tq), 67mm turbo, 160lb valve springs, added timing, tubular exhaust manifold, larger injectors, possible 6 spd swap.


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post #9 of 31 (permalink) Old 05-07-2013, 02:57 PM
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Look at my little diagram and this should explain it much better of what I am referring to.

and your SRI setup, you can clearly see where its lacking.

In order for the intake to actually do what is designed for, you will need a larger intake runner, plenum, intake valve, exhaust valve, exhaust header, camshaft, and a re-tune in order to achieve maximum 0% STFT/0% LTFT volumetric efficiency.

This may be a bit more advance to some, my apologies, but Leevi will understand what I am talking about.

2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille

Last edited by 5t3alth; 05-07-2013 at 03:02 PM.
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post #10 of 31 (permalink) Old 05-07-2013, 03:10 PM
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Quote:
Originally Posted by 5t3alth View Post
Look at my little diagram and this should explain it much better of what I am referring to.

and your SRI setup, you can clearly see where its lacking.
oh I understood what you were saying. I'm saying, look at the size of the "snorkel" for the stock air box. It's maybe 1 inch in diameter that brings in outside engine compartment air. that's VERY small. Another thing to think of is that there is 2 valves per cylinder (each valve is 1.38 inches in diameter so basically it flows 2.76in air per time the valves open) which is bigger than the snorkel, so it flows better for sure. You'd be suprised at how much those small valves will flow tho.

I'm not saying by any means that you're wrong, please don't mis read that. I'm saying tho, that the biggest restriction is at the very front of the air system which isn't good. Opening that up will help the cylinders breathe better. Think of trying to vacuum a golf ball through a garden hose. The ball is the air trying to get through that small opening, and the engine is straining to pull that thru, by opening that up is less strain on the engine.

'09 SS/TC - Stolen
Mods - Injen CAI, CIA MAF Relocate CP's, Dejon FMIC,
Custom 3" DP, 3" Exhaust, GT3076R, Pioneer AVH-4100DVD, Hurst STS, ZZP triple pod, Autometer Cobalt boost/DPIC/WB gauges, Nitto NT05 245/40/18's, H&R Springs, 80:20 Meth Spray
Future - KSport Kontrol Pro Coilovers, 10% Tint, FMIC spray
538whp/501wtq @38 psi on meth and 93 oct on stock ish motor


06 EVO IX MR/SE - Sold
Mods - *Updated 10/6/13* AEM TRUboost EBC, 4in custom TBE, SD dual 93/e85 tune, ETS 4in Race Core FMIC, Dual Aeromotive 400lph Fuel Pumps, T4 Tubular Manifold w/ dual WG's, FP Super99HTZ DBB Turbo, GSC 274 mivec cams, ARP headstuds/rod studs, FIC 2150cc Injectors, Aeromotive FPR, Aeromotive Fuel Rail, catch can, Mini Battery Kit, Slim Coolant Fan, Kiggly Racing high pressure valve Springs/Titanium Retainers, Supertech Stainless Steel Valves, Dual VTA Tial 44mm WG's, 4g64 Stroker Manley Pistons, 155mm 2.4 LR Manley Turbo Plus I Beam Rods with ARP 625 Studs, 100mm forged non-billet Manley Crankshaft, Full H/E PNP with Port Matching, Kiggly Racing Girdle, Dual Tial 50mm BOV's, Excedy Triple Disc Carbon HD Clutch, AEM EMS

'95 Ram 2500 Diesel
Mods - 5in TBE, Boost Elbow set to 28psi, Adjusted fuel pump, Open Turbo.

Future Mods- Super Street Clutch (rated @1400ftlbs tq), 67mm turbo, 160lb valve springs, added timing, tubular exhaust manifold, larger injectors, possible 6 spd swap.


Master ASE Certified Gasoline/Diesel Technician since 2004

Speed Junkies Social Group

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Syndicate of Tuners Official Page! Up and going again as of 1/11/13

Click here to PM me if you have questions or issues!
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