[Rik]

This is part one in a four part article. Even though this motor is using a supercharger the basic motor mods will translate over to a turbo motor.


click here for the PDF file with part one of the article

 

[achieftain]

Good pictures and a lot of info for any rebuild project. Can't wait to see the rest of the articles,esp. the S/C install.

 

[Lost Sol]

:cheers: Thanks for the article :cheers:

 

[kingarthur]

I just realized that the engine being modified is the 2.0 ecotec
found as turbocharged in the Redline, Cobalt SS. I don't know whether the
crankshaft is the same as the 2.4, or the bore (pistons) or even the
connecting rods. I also don't know if the block has been modified, etc.
Does anyone know the differences between the 2.0 SC ecotec
and the 2.4 ecotec?
If the Supercharged 2.0 described in the article is to be offered in the Saturn Sky Redline (currently an unknown), then this article is very relevant
to a build up - assuming the supercharger is the same (which I think is true, since the article didn't mention that a larger one was required).

 

[LS2 MN6]

I just realized that the engine being modified is the 2.0 ecotec
found as turbocharged in the Redline, Cobalt SS. I don't know whether the
crankshaft is the same as the 2.4, or the bore (pistons) or even the
connecting rods. I also don't know if the block has been modified, etc.
Does anyone know the differences between the 2.0 SC ecotec
and the 2.4 ecotec?
If the Supercharged 2.0 described in the article is to be offered in the Saturn Sky Redline (currently an unknown), then this article is very relevant
to a build up - assuming the supercharger is the same (which I think is true, since the article didn't mention that a larger one was required).

Check out http://media.gm.com/us/powertrain/en/product_services/r_cars/car eng trans.html for information on the engines. This covers all GM engines and Transmissions, including pictures, and stats.

 

[brentil]

The entire full length GM Performance Build Book has been available for a while.

Covers the 2.0L and 2.2L engines.

http://www.gm.com/company/gmtunersource/html/race_shop_build_book.htm

 

[kingarthur]

Many thanks to both DuSpinnst and brentil for the GM web citations for the performance info re Ecotec. I'm rather amazed that GM is so involved in providing supercharged kits for the Ecotec. The idea of a GM warranty makes their kits "factory" as far as I'm concerned, a BIG plus.
In comparing the engines' dimensions, I find that the 2.0L (supercharged) Ecotec is a de-stroked (but builtup) version of the 2.2L (86X94.6 vs a totally square 86X86). It is more or less bulletproof with forged rods and
crankshaft (however, even the cast crank of the 2.2 is good for over 400 HP).
The Solstice Ecotec is both stroked and bored w/respect to the other versions (88X98). It is similar to the 2.2 in that crank, rods and pistons are cast.
Since the 2.2 can be supercharged to 250HP with a GM supercharger kit, the 2.4 can also easily obtain that power level (and more) with a totally stock engine.
In addition to the supercharger itself, the kit requires installing a new belt idler pulley and generator bracket and intake manifold bracket and throttle body-to-supercharger adaptor plate (all included) and a new set of larger fuel injectors. The electronic engine management needs to be reprogrammed by a GM dealer. Installing the hardware shouldn't take more than half a day's work, if that. Note that no modified intake, cat or exhaust is involved.
So the question is whether the 2.4L in the Solstice can be supercharged with the existing GM 2.2L supercharging kit. Someone said that the intake side of the engine in the Solstice/Sky is too crowded to fit the supercharger over there. Except for that issue, everthing is pretty straightforward, and simple. I wonder what the kit lists for? I have a source in a GM parts department who can get me anything with a GM part number for about
20% off. It still might be cheaper to buy the from-the-factory version, since you have to replace the injectors and that money is thereby wasted. Injectors used to cost over a $100 apiece, although that was many years ago, and they may be cheaper now.

 

[brentil]

The 2.2L Supercharger kit isn't actually out yet unfortunately. There's been no official release date or more information about it yet. Rumored price was ~$2500 for the kit.

There are two main problems that will greatly hinder this kit making it on our cars though.

1. Engine orientation/compartment space. I'll try to dig up my close up pics of the Cobalt SS and some Solstice engine compartment pics to compare how much space is used/needed. It might require moving some things around in there to actually make it fit if at all.
2. Our engine runs a CR of 10.4:1 compared to 10:1 like the 2.2L ECOTEC. So without lowering the boost level or adding an intercooler the chance of knock occuring will be much higher.

 

[Rik]

The fwd and rwd Ecotecs are different. The info I was given is that the hardmounting points are configured disimiliar. And the 2.4 and 2.0 are different in bore and stroke as well as cylinder head configuration. I posted the article not because it shows how to build a 300HP Ecotec, but because in my opinion GM is showing us how to build a 300 HP "street" Ecotec. Everything GM has released so far has been race related. I just thought it was cool to see GM start hinting at the Ecotec's streetable potential. Ultimately, the 2.4 is cable of making a lot more streetable horsepower than the 2.0 not because of it's size advantage, but due to the variable cams.

 

[brentil]

GM is releasing a Stage I and Stage II upgrade for the LSJ engine after SEMA this year supposedly. They're supposed to provide larger fuel injectors, a smaller Supercharger pulley, and an ECU reflash. The Stage II will produce 275HP supposedly. In their stock forms the LSJ will always outperform the LE5 due to the components they've upgraded. However an LE5 with the LSJ's forged components would be an awesome engine.

 

[kingarthur]

"The Stage II will produce 275HP supposedly. In their stock forms the LSJ will always outperform the LE5 due to the components they've upgraded. However an LE5 with the LSJ's forged components would be an awesome engine."
The GM Ecotec buildup book detailed the 250HP SC buildup for the 2.2
(no internal changes) and noted that anything up to but less than 300HP
wouldn't need anthing stronger than the stock crank and rods. They listed 400 HP as a power level the cast crank can reliably handle. The 300 HP
2.0 buildup did require forged alum pistons. All this tells me that, in
terms of reliability for a 250 HP level engine, the 2.4 is OK as it now stands.
Possibly the high CR you noted will have to be dealt with by lower
CR pistons. That would be a much more involved modification, although not
difficult enough that I wouldn't feel confident in tackling. I noticed that the 2.0 CR is 9.5:1, apparently in anticipation of the forced induction.

 

[LS2 MN6]

The 2.4L Ecotec is interchangable from FWD to RWD, somehow GM made the mounting points the same, or made the block versitile enough so that it works in both cars. The Solstice, along with the SKY have an extra belt and a Power Steering pump on the back of the block since they do not use EPS like the G6 and Cobalt.

Currently the 2.2 and the 2.0 are NOT interghangable from FWD to RWD, they are FWD only. This is the main reasoning behind a modified 2.4L as opposed to a 2.0L for the Turbo. Any technology developed on the SKY and Solstice Turbo models could be moved into the FWD Cobalt SS. Personally I think the 2.0L's days are numbered.

It's safe to assume that next year's SEMA will yeild upgrade kits for the Sol/SKY Turbo's.

 

[kingarthur]

"" Ultimately, the 2.4 is cable of making a lot more streetable horsepower
than the 2.0 not because of it's size advantage, but due to the variable cams."
In terms of stock horsepower gains via VVT for the 2.4 vs no VVT to
be in the range of 10-12 HP (by comparisons with the 2.2, which has no VVT
- corrected for the effect of displacement differences), or 6-7%.
The 2.4 is .4L larger than the 2.0, so that the increased displacement
would account for approx 28 HP increase, since the engines create approx 70
HP/liter. Therefore, unless I've made some gross error, the increase in
displacement of the 2.4 over the 2.0 acounts for more than twice the HP
increase that can be attributed to the VVT camming.

 

[LS2 MN6]

But depending on the internals you can have a more agressive cam, and with VVT I'd expect more HP than normal.

 

[kingarthur]

I just visited www.hahnracecraft.com and picked up some details of
their intercooled turbo system for the Ecotec 2.2L. Their system apparently allows up to 375HP for the engine using pump gas (CR 10:1). They also
mention that the weak point of that engine are its powdered metal con
rods (same as 2.4L) , which they claim are OK up to 300HP, but not significantly above that power level (assuming turbo rather than nitrous - nitrous is much harder on an engine that forced induction). So there you have it - a 300 HP 2.2 w/o any internal mods required. The GM performance
book mentions Hahn as a source of turbos for those who want to go in that direction rather than a GM supercharger, so they have a sort of official recommendation from GM. I'm contacting them to find out about possible
future 2.4 turbo kit. Personally, I prefer a supercharger.

 

[LatinVenom]

They told it would be available spring of 2006. There is going to be some announcement at SEMA.

 

[kingarthur]

I received the following email from HahnRacecraft.com :
"Yes, we are buiding a turbosystem for the sky /Solstice platform. I do not have pricing or specs as of yet. Please stay tuned to the website, as we will have these updates and pricing shortly.
Thanks
Brad @ sales"

 

[Rik]

"" Ultimately, the 2.4 is cable of making a lot more streetable horsepower
than the 2.0 not because of it's size advantage, but due to the variable cams."
In terms of stock horsepower gains via VVT for the 2.4 vs no VVT to
be in the range of 10-12 HP (by comparisons with the 2.2, which has no VVT
- corrected for the effect of displacement differences), or 6-7%.
The 2.4 is .4L larger than the 2.0, so that the increased displacement
would account for approx 28 HP increase, since the engines create approx 70
HP/liter. Therefore, unless I've made some gross error, the increase in
displacement of the 2.4 over the 2.0 acounts for more than twice the HP
increase that can be attributed to the VVT camming.

kingarthur, you mistake my meaning. The VVT allows any engine with a given displacement with a given horsepower to be more streetable than it's counterpart that is with out VVT. Also even though peak power may not change greatly, power under the curve is also substantially inproved by VVT.

 

[brentil]

Well technicly the type of VVT on the ECOTEC is mainly for emmissions purposes. This isn't the type you find on VTEC engines like the Civic and RSX where you get a power boost from it. Using VVT on an engine like this though permits you to better control emmissions so that you can get higher performance levels out of an engine and still stay 50 state legal.

 

[Rik]

Although VVT can't change cam duration or lift like Vtec, the abilty to change intake and exhaust lobe seperation and valve opening as related to crank postion can have a positve effect on power as well as emisions.