Just wondering which engine would have more an advantage of a turbo. Now we all know the 2.4L will produce more, but which is more turbo friendly? I can not think of the term right now...I mean the part...but responds better? I believes its the throws...or the throttle body....

Oh anyone know if SEMA (by Philly) this April will have turbos for the Cobalt? Thanks!

Depends on the compression ratios. I'm not sure of the math, I'm far from being an engineer. l

we dont know yet to be honest, some people think the vvt will work to the 2.4 advantage (me) and some think it will be a disadvantage but only time will tell

alright, yea cuz im lookin into the mazda3 and the 2.0L engine has better ratios for the turbo than the 2.3L...but of course the 2.3L produces more...got the 2.0L up to 350whp, and 2.3L up to 500whp :) :)

theres no replacement for displacement

theres no replacement for displacement


Engineering

Engineering

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.

Well, the things is with a bigger 4 cylinder engine like the 2.4ss, there might be a possible reliability issue because the 2.4 has a bigger bore than say a 2.2 or 2.0 from the cobalt, so because of this, the cylinder walls are thinner thus not as efficient as taking heat out as a car with a bigger cylinder wall. In a 4 cylinder application, the bigger the displacement usually the harder it is on the rods so if you were boost a 2.4, you'd prolly need to internals to accomidate boost levels higher than say 6-8lbs id say.

2.4's have forged rods. 2.4 is definatly a more advanced engine. With a good tune, the 2.4 can handle 8psi all day long, with higher octane gas, you could see as high as 12-14. Both will need internal work once gone past the 300 mark.

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.


Also s2k is 32-34k.....yea...

i saw somewhere that cylinder walls being big making the engine stronger and less heat was actually proved wrong

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.


Dont mistake that for better enginerring .... just enginered with a different purpose in mind

yeah i think the 2000 has super high compression to make those numbers as well as an abnormal ammount of hp loss to the wheels

The 2.4 will make more power if the compression ratio is low enough to allow high boost levels and the rods and crank and pistons are all forged pieces. However it would be interesting to spend time on the Dyno at a cam grinding company. the VVT valvetrain could create a situation where you might not make optimal power at all rpm levels. Generally turbos do not like a lot of overlap between the intake and exhaust valves closing. (Flames and Backfiring in the exhaust) a lot of unburned fuel. If I were turboing a VVT ecotec I would be calling some of the big Cam companies to see if they have done any R&D on these motors with a turbo. This is new ground to cover.If Comp Cams, and Crane, and Edelbrock get enough requests they will develop some performance cams for the VVT Ecotec. anyways because it's bigger than the Honda motors it should waste em'.

well there are cams out for the ecotec motor but im not sure if a 2.4 can use them or not due to vvt

I could be wrong but I think that VVT turbo cams could be the answer to getting rid of that little bit of lag that even ball bearing turbos have. they could be designed to bring on the power at a more even rate instead of being kicked in the rear the application of power might come on smoother.This thought also comes to mind, staging a low boost turbo for around town and a high output turbo for the track. It seems to me that VVT could make that work really well. What do Ya'll think about that?

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.

it also has like 130TQ, 11:1 compression and makes its peak power at around 8K rpm, thats not engineering thats reving the piss out of a car to acheive power. :lol:

Obviously from 2.0L to 2.2L to 2.4L is the order of which would be most turbo friendly for compression reasons. Yet because of the increased compression you can make more power on less boost, you just can't run as much boost which may cancel out any advantage on that part. However, as said before there is no replacement for displacement, I'd put my money on the 2.4L. Especially if you bring in built bottom ends to the equation...

yo that SEMA show is gonna be sick man, there will most likely be turbos where in PA are you?

Yeah, there is a post about the SEMA show having a turbo Cobalt. There is also a list for the people from these forums that are going. Including me :D

how would the 2.2... or 2.4 for that matter be the best for turboing?? GM usues a 2.0 to drag race with... and over 1,000hp, tuens it into a 2.2 for a lil more power. Id put my bet on the 2.0 being the best motor to turbo, which is Y i'm buyin the SS S/C, so i can turbo it down the line.:guns:

how would the 2.2... or 2.4 for that matter be the best for turboing?? GM usues a 2.0 to drag race with... and over 1,000hp, tuens it into a 2.2 for a lil more power. Id put my bet on the 2.0 being the best motor to turbo, which is Y i'm buyin the SS S/C, so i can turbo it down the line.:guns:

stock for stock the only reason the 2.0 would be better is because of its bottom end (which is NOT forged btw, just learned that recently) which will allow you to throw more boost at it. My guess is that a stock bottom end 2.2 or 2.4 would make similar numbers to a stock SS/SC but with more TQ. With all having built bottoms ends though I'd put my money on the car with the most displacement.

the 2.2 is very turbo friendly and you can get a lot and a lot of power with turbo on it

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.


Well then if you had a 2. and a 2.2 you could do they same things and the 2.2 would make more power...so it is displacement.

Well then if you had a 2. and a 2.2 you could do they same things and the 2.2 would make more power...so it is displacement.

True but it also means more rotating mass, thus slower revs. Won't hurt HP but will hurt track times.

hate to break it to everyone but the vvt used on the 2.4 does NOT increase power, it is responsible for the improved fuel economy. a version of vvt like the one used on hondas and ferraris would provide more power. the reason for the extra power in the 2.4 versus the 2.2 is displacement and not vvt.

due to the higher compression ratio on the 2.4l, a turbocharger providing the same boost would offer a greater % increase in power. if adjusted to the same compression and displacement, the 2.2 would be fairly equivelant to the 2.4 in power, but would offer fuel economy benefits.

Bingo, hence why honda's s2000's 2.0L makes 240hp and my 2.2 only makes 145.

Engineering, yes but well balanced powerband, no. Hondas are notorious for making high horsepower due to:

1. High Revving
2. Variable Valve Timing
3. Higher CFM flowing cylinder heads

but because of these things, their power is only made in higher RPMs and have terrible amounts of torque. The only reason the S2000 is fast is because it's a light vehicle and it's a little more well balanced power wise, closer ratio'd gearing and higher powered as far as power goes than their other motors (168 lbs of torque).

stock for stock the only reason the 2.0 would be better is because of its bottom end (which is NOT forged btw, just learned that recently) which will allow you to throw more boost at it. My guess is that a stock bottom end 2.2 or 2.4 would make similar numbers to a stock SS/SC but with more TQ. With all having built bottoms ends though I'd put my money on the car with the most displacement.

When you say forged, you have to realize that there are different degrees and levels. People see forged and associate it with HIGH quality forged products like Wiseco Pistons make or Eagle Rods. If you want to get technical, every piston and rod is forged because it's the process to strengthen them...but of course...to a degree.

how would the 2.2... or 2.4 for that matter be the best for turboing?? GM usues a 2.0 to drag race with... and over 1,000hp, tuens it into a 2.2 for a lil more power. Id put my bet on the 2.0 being the best motor to turbo, which is Y i'm buyin the SS S/C, so i can turbo it down the line.

You know why GM makes over 1,000 HP with the 2.0 motor rather than the 2.2? Less stroke = More reliable higher revving. You think they rev up to 6,000 RPMs like us? No way...

Also, GM puts out the 2.0 ECOTEC to be boosted because more so the compression issue and fuel octane, they don't want detonation to be an issue. I'm not 100% sure but I believe you can run 89 octane on the 2.0 S/C ECOTECs which might sound reasonable for the average person who doesn't want to spend high amounts of money on fuel everytime they have to filler-up.

I could be wrong but I think that VVT turbo cams could be the answer to getting rid of that little bit of lag that even ball bearing turbos have. they could be designed to bring on the power at a more even rate instead of being kicked in the rear the application of power might come on smoother.This thought also comes to mind, staging a low boost turbo for around town and a high output turbo for the track. It seems to me that VVT could make that work really well. What do Ya'll think about that?

Umm what?

Sorry, I'm not trying to flame you but you need to read up more on turbos and turbo lag. Have you ever personally been in a vehicle with ball bearing turbo? Those suckers are like instant FULL boost because they spin so fast and easily. People associate turbo lag with every turbo'd vehicle, which is not the case most of the time. If you match a turbo properly to a motor, you will not have turbo lag. Also, turbo lag is something that is more so split second if it happends.

By the way guys, did you know there is a such thing as supercharger lag? yes...it happends.

As far as "low boost around town and a high output turbo for the track", once again, you should read how turbocharged systems work. If someone wants to run low amounts of boost, they should get a wastegate spring that is more limited (for example, I have a 68 MM wastegate that has a 5 PSI wastegate spring). If I say want to run over 5 PSI for track reasons or racing reasons, that's what a boost controller is for. The boost controller will not (and can not) decrease your max psi lower than your wastegate.

hate to break it to everyone but the vvt used on the 2.4 does NOT increase power, it is responsible for the improved fuel economy. a version of vvt like the one used on hondas and ferraris would provide more power. the reason for the extra power in the 2.4 versus the 2.2 is displacement and not vvt.


I wouldn't say that 100% will not increase power. I've always said that Variable Valve Timing is only as good as you can manipulate it. Look at guys with V-tec, they have V-tec controllers to change the lift and all that good stuff to make great power gains from that. Just something to think about...

i saw somewhere that cylinder walls being big making the engine stronger and less heat was actually proved wrong

You mean thicker cylinder walls, not "bigger".

Well, the things is with a bigger 4 cylinder engine like the 2.4ss, there might be a possible reliability issue because the 2.4 has a bigger bore than say a 2.2 or 2.0 from the cobalt, so because of this, the cylinder walls are thinner thus not as efficient as taking heat out as a car with a bigger cylinder wall. In a 4 cylinder application, the bigger the displacement usually the harder it is on the rods so if you were boost a 2.4, you'd prolly need to internals to accomidate boost levels higher than say 6-8lbs id say.

There should enough "meat" on the 2.4 cylinder walls to handle boost.

In conclusion, I will say this...

You CAN boost a 2.4 motor. The issues are not compression but detonation. If you can find a way to retard timing, that will lead to a better running turbocharged vehicle, even on 10.5:1 compression. If you don't change the timing, you'll be pushing the limits while boosted and depending on what PSI you choose to run, fuel octane will be an issue. Remember, higher octane and retarding timing is for reducing detonation....compression doesn't matter (well in our cases, it wouldn't matter).

I've talked enough.

I wouldn't say that 100% will not increase power. I've always said that Variable Valve Timing is only as good as you can manipulate it. Look at guys with V-tec, they have V-tec controllers to change the lift and all that good stuff to make great power gains from that. Just something to think about...


ok i dont mean to be rude, but i think you had better read up on gm's vvt. its sole purpose is to optimize fuel economy. it allows advancement and retarding camshaft timing and the algorithm in the E67 was programmed solely around increasing fuel economy using closed loop feedback. tuning for power is independant from the vvt system. if anything, it is more of a burden than a gain for power.

the honda vtec incorporates a second lobe at a specified rpm, which is why it can provide more power.

even better, the 'vvt' used on some european cars has a better system. again more power because of adjusting the effective part of the cam.

dodge/chrysler vvt is one that i have yet to read up on, but i am sure that it is a varation on one of the above.

ok i dont mean to be rude, but i think you had better read up on gm's vvt. its sole purpose is to optimize fuel economy. it allows advancement and retarding camshaft timing and the algorithm in the E67 was programmed solely around increasing fuel economy using closed loop feedback. tuning for power is independant from the vvt system. if anything, it is more of a burden than a gain for power.

the honda vtec incorporates a second lobe at a specified rpm, which is why it can provide more power.

even better, the 'vvt' used on some european cars has a better system. again more power because of adjusting the effective part of the cam.

dodge/chrysler vvt is one that i have yet to read up on, but i am sure that it is a varation on one of the above.

Isn't the VVT in the 2.4 motor based off of Toyotas VVT-i technology?

Isn't the VVT in the 2.4 motor based off of Toyotas VVT-i technology?
i dunno about that, but its the same principle. are you confused with toyota's VVTL-i technology?

i dunno about that, but its the same principle. are you confused with toyota's VVTL-i technology?

Possibly. You probably know more about it than I do though. I'm kind of limited in information when it comes to VVT.

I was under the impression that the vvt in the 2.4 also helps keep the tq from droping off in the middle to upper rpms. On stock dyno's you can see the little hump where they start changing.

http://cobaltss.net/gallery/files/4/1/CobaltSSDyno.JPG

Look there about 3800 or so on the stock tq graph

and tuning the 2.4 is no problem. Companies have already broken the ecu and already have turbo tuned calibrations.