HiSpdPursuit

I've decided that im going to probably keep my 2.4 as N/A. The most i think i would use is a Supercharger...turbo is too complicated and $$$ right now

anyway i wanted to get some opinions on how much HP and torque you can really squeeze out of the 2.4L VVT. I know the basic bolt ons like CAI, cat-back, and header.

what i am really interested in is really digging into the motor itself. Ie. Full port and polish of the head, camshafts, and is it possible to bore over and possibly stroke the 2.4L without having to re-engineer the computer?

can you change the camshaft's lobes and the crankshaft stroke without messing up the VVT and the PCM? Frankly this new technology is complicated...im used to my old 5.0L and bored and stroked pushrod engines.

joeworkstoohard

Well, strictly speaking... you really shouldn't do more than external bolt ons without making changes to the ECU. However, i don't see why this would be an issue.

06G5GT

The engine is too new for anyone to have done this. I would guesstimate that 220hp is probably the max without forced induction.

Brandon97Z

iTrader: (1)

Boring the 2.4 is out of the qestion, to thin of cylinder walls since it is already a bored 2.2. Cams and what not will be a little futher in the future since we don't yet have any turbo kits out. Also most internal mods are gong to most likely be geared more towards forced induction ie. forged lower compression pistons, forged rods, etc. But banks supposedly is donig alot of research with the 2.4's as they bought about 10-15 of them so hopefully they will be able to come out with something.

But if your looking for the most NA definatly look into the ecu tune and like you said intake full header back exhaust then take a look into nitrous if your looking for cheap power.

avro206

I would think the untapped power lies in the cams and head work. Maybe getting that compression ratio up to 11:1--might need custom pistons. Stroking would be prohibatively exspensive......a custom crank and rods.

GM did not go aggresive at all with this engine.

savior

cams are coming, i talked to a representative at turbotech

for now, do basic bolt ons and start spraying.. then you could throw in a s.c later and still remain in a reasonable price range - of course, this will take time

HiSpdPursuit

This is what i figure ill try to squeeze the most out of an NA 2.4L and stay in budget.

- obviously the regular bolt ons
- full head port and polish as well 3 angle valve job and polishing of the combustion chamber
- more aggressive cams
- possibly a custom intake manifold (havnt heard of any intake manifolds in the works yet)
- and an ECM tune to top it all off....

i wonder if 240+hp at the crank would be possible with all of this??

Gory

Man I think that is totaly possible in fact I bet you sould make it put out 300 but there is no whay it would pass smog.
You would have to use some big cams and they would raise the power band up quite abit like in the 8000rpms range then you need new internals pistons ect.. but talk to some of the larger cam manufatures Like COMP or BULLET see if they have made them for it yet.

Brandon97Z

iTrader: (1)

I believe Hahn is working on an intake manifold. And if our head is anything like the S/C's it flows good enough for 400hp.

savior- Did turbotech say who was making the cams?

mike25

well as far as the intake mani. goes...there is a company gm used to make one for their i think it was time attach car..maybe..not sure it was on one of them...and ne ways it was a custom intake mani. specifically made for the cobalt and was ranked high-very high performance range...very high i mean like drag strip ...so if your interested i can get you the company name and number+part number so let me know

savior

savior- Did turbotech say who was making the cams?


**** i am sorry, i meant to say j-body is making our cams *****
- here is a quote from the email he sent me
"We have no cams for the 2.4L yet, but are close to releasing them."
-Information Repsonse <info@jbodyperformance.com>

HOLLA!

Tomtwtwtw

Will you be upping the rev-limiter? Does it have the same redline as the SS/SC normally? I can't remember...

avro206

You have to up the rev limiter, some where north of 8K I think to get 240hp.....6750 is the noraml redline for the 2.4L---mines at 7200

Tomtwtwtw

That's about what I thought...at 8k rpm, to make 240 hp you need to be producing about 158tq, which isn't impossibly by any means with a 2.4l engine. I would expect a max torque number similar to what it is now, perhaps a little higher, but with it peaking much higher in the rpm band.

ChevyTuner

I think the heads are the same as the 2.2L, and just so you know almost all the parts available for the 2.2 fit the 2.4 as it is the same block with identical accessory placement...the only mechanical differences lie in the additional displacement and vvt.

NJHK

Turbos are only complicated if you don't know how they opporate. Just take the chance to learn it.

How much power can you gain? There is no set amount or limited amount you can make so that's kind of an impossible question to answer.

Before you do any camshaft work, find out how much that will effect your VVT...basically how your VVT operates. Next, find a company that will make a camshaft that will work properly on your cylinder head because you basically have 2 sets of lobes and they would have to design the camshaft to work properly as far as duration and lift goes. From what I've read, it switches lobes due to oil pressure which is controlled by your computer.

A bigger bore won't gain you that much in displacement, more stroke...I don't know if that's even possible at this moment being that your motor is a years or so old, there is no stroker kits available. Plus, a 2.4 liter 4 cylinder is a pretty big displaced 4 cylinder.

Do you need tuning from this? Depends on what you decide to do and how extreme you go. If you change the stroke, you're more than likely are going to have to change the ignition timing, if you change your camshafts to a bigger profile and get a ported head, you're going to need to monitor how much fuel you'll need cause you may run rich from your computer naturally running rich or slightly leaner, no one knows.

In this stage of the game with a new motor, alot of stuff hasn't been done yet.

When I get home, I'll add more input to this thread.

avro206

thats simplfing things a bit. The block is different (stronger and heavier, deeper water jacket for better cooling, block mounted oil cooler, different balance shafts), as are the heads (larger cc)--nothing radical--just an evolutionary update

NJHK

You can get Pistons forged whatever height (compression ratio) or width (bore) you want. Contact Karo @ Car Customs and he can get them made for you by Wiseco.

You can get pistons that are 11:1 or 14:1, it all depends on what you want.

mike25

with 14:1 pistons...what kind of power gains could we expect to see?....and also wouldnt pistons with that high of compression a ratio greatly decrease the engines life?...cuz if im correct isnt that a shitload of compression?

NJHK

I was just giving an example...I honestly don't know anyone who is willing to do something like that. Power gains, no one can honestly give you an answer on that. Yes, that's a high compression but that's more so for an non-street vehicle.

Gory

hey compression isnt that important ther is a ratio its about 3-4% increase for evry point up or down but it depends there are so many other factors i personaly wouldnt go over 11.5:1

jaslowyota

damn, 14:1 is what my bike has, if it were me i would go with 12:1 if its an daily driver you wouldnt have any problems.

HiSpdPursuit

does anyone know where i can get some detailed technical info on the workings of the 2.4eco especially the VVT workings of it.

also, is the 2.4 VVT head different from the 2.0 and 2.2 heads?...it looks different to me but that may be because the 2.0 and the 2.2 have spark plugs and the metal cover on the valve cover while the 2.4 VVT has coil packs which are exposed with no cover.

joeworkstoohard

it's hard to come by but here's a few "what it looks like to me"

the VVT system looks alarmingly like the VVTi system used by toyota, wouldn't surprise me based on thier close dealings

the 2,4 seems to be a bored over version of the 2.2 block wise. since it' snot a HUGE increase in displacment, i'd guess that it was done to match up with the much wider valve spacing that the VVT's SEEM to have on toyotas

the head is way different. the cams have larger lobes on similar engines and the timing changes a lot. if you look at a lot of dyno sheets the 2,4 seems to make less power than the 2.2 at low RPM. i assume this is to smooth out the idle.

Gory

Interesting considering that lotus was one of the co designers of the ecotec and they use almost exclusivly toyota stuff hmmm.