Massive Power from Turbo 2.0L Daewoo Engine

debo890 · Post by **debo890** » Tue May 04, 2004 3:09 pm

something fishy. i have the 99 nubira hatchback and i am about to do a turbo myself. the engine has a 9.5:1 comp. guys. 9.5:1 comp. is standard compression ratio. boosting to 15 lbs is going to get you an effective compression ratio of "19.19..." wow. thats too high. our cars are not nascar race build. a 7 pound boost would give you "14.02" effective comp. 14.02 is good. 15.00 effective comp. is also ok but you can run into timming issues, detonation. you would also need to run a higher octaine or race gas to run 15 psi. if you dont believe me, go on google and search " effective compression VS static compression. p.s. the more you compress a gas the hotter it gets. example: a turbo compressor shell. ring a bell. 15psi is not imposible, but you would need to build the engine to handle it. or lower compression.

Post by **Efratech** » Tue May 04, 2004 3:45 pm

UPDATE:

His headgasket blew in the dyno...

so the car now sits in his garage... it seems his gonna rebuild the engine...

debo890 · Post by **debo890** » Tue May 04, 2004 4:08 pm

at what psi did it go? do you know? so i can stay away from that psi when tunning mines. also i need real answers no fake ones. can the forged pistons in the 88 pontiac sunbird gt fit in the 2.0l nubira engine? need to know.

Tim04 · Post by **Tim04** » Tue May 04, 2004 8:50 pm

That's friggin' cool!!

Stefan · Post by **Stefan** » Tue May 04, 2004 10:04 pm

debo890 wrote: can the forged pistons in the 88 pontiac sunbird gt fit in the 2.0l nubira engine? need to know.

No. The 8v engine uses a press fit pin and the 16v's use a floating pin. Then there's also the 4 valve reliefs to consider. You can use the C20LET or Z20LET pistons (9.2:1). JE and Accralite have supplied forged low compression pistons for this engine at around 8.5:1.

Stef

Post by **PrecisionBoost** » Wed May 05, 2004 5:19 am

debo890 wrote:15psi is not imposible, but you would need to build the engine to handle it. or lower compression.

You have to admit however that depending on intercooler and turbo efficencies you can have a very large difference in the intake charge temp.

There are quite a few guys running 8:1 compression C20GET's in the 15psi to 17psi range so I think that 15psi is achievable as high as 8.5:1 with pump fuel and a good intercooler/turbo setup.

When I first posted this link to PontiacJeff's car I was thinking it was going to see detonation right off the start...and I was wondering how long that engine would last.

I'm also working on a new solution for all us poor C20/T20/U20 series guys..... I did some measuring and it would appear that the US ECOTEC piston top to connecting rod center is very close to that of the C20GET.

Between the two engines the rod lengths are different but so is the height from the piston top to the pin so they equal out.

The numbers I calculated a while back were..... 6.818" (5.765" con rod + 1.053" comp height) for the ECOTEC and 6.835" (5.650" con rod + 1.185" comp height) for the C20GET.....which means that if you put in the ECOTEC rod/piston you would end up loosing a little compression due to the difference of 0.017" in height.

Several companies make low compression pistons for the ECOTEC and if my memory serves me correct I used the 8.5:1 Ecotec pistons in a compression ratio calculator and came up with a ratio in the range of 7.9:1 (don't quote me on this.... I can't remember the exact number... I was thinking it was just under 8:1 but I could be wrong....I forgot to write it down)

I was also thinking you could shave the head if you wanted to raise it back up closer to 8.5:1

The only issue is on the thickness of the lower section of the rod... but I'm working on a solution for that.

It sure would be nice to be able to purchase forged rods and pistons from the US ECOTEC and use them in our engine.....then the only weak link would be the crankshaft.

I even checked the bore spacing to see if a steel/forged ECOTEC crank would fit...... but unfortunatly the spacing isn't the same

The bore spacing for the C20GET was 93mm while the ECOTEC is 96mm

Oh well it was worth a try..... I suppose I could allways get one custom made but I'm sure it would cost a pile even if I purchase a half dozen.

daewooluvr · Post by **daewooluvr** » Wed May 05, 2004 12:36 pm

Erfinder wrote:
debo890 wrote:15psi is not imposible, but you would need to build the engine to handle it. or lower compression.
You have to admit however that depending on intercooler and turbo efficencies you can have a very large difference in the intake charge temp.

There are quite a few guys running 8:1 compression C20GET's in the 15psi to 17psi range so I think that 15psi is achievable as high as 8.5:1 with pump fuel and a good intercooler/turbo setup.

When I first posted this link to PontiacJeff's car I was thinking it was going to see detonation right off the start...and I was wondering how long that engine would last.

I'm also working on a new solution for all us poor C20/T20/U20 series guys..... I did some measuring and it would appear that the US ECOTEC piston top to connecting rod center is very close to that of the C20GET.

Between the two engines the rod lengths are different but so is the height from the piston top to the pin so they equal out.

The numbers I calculated a while back were..... 6.818" (5.765" con rod + 1.053" comp height) for the ECOTEC and 6.835" (5.650" con rod + 1.185" comp height) for the C20GET.....which means that if you put in the ECOTEC rod/piston you would end up loosing a little compression due to the difference of 0.017" in height.

Several companies make low compression pistons for the ECOTEC and if my memory serves me correct I used the 8.5:1 Ecotec pistons in a compression ratio calculator and came up with a ratio in the range of 7.9:1 (don't quote me on this.... I can't remember the exact number... I was thinking it was just under 8:1 but I could be wrong....I forgot to write it down)

I was also thinking you could shave the head if you wanted to raise it back up closer to 8.5:1

The only issue is on the thickness of the lower section of the rod... but I'm working on a solution for that.

It sure would be nice to be able to purchase forged rods and pistons from the US ECOTEC and use them in our engine.....then the only weak link would be the crankshaft.

I even checked the bore spacing to see if a steel/forged ECOTEC crank would fit...... but unfortunatly the spacing isn't the same

The bore spacing for the C20GET was 93mm while the ECOTEC is 96mm

Oh well it was worth a try..... I suppose I could allways get one custom made but I'm sure it would cost a pile even if I purchase a half dozen.

What is this ECOTEC engine that you're talking about?

subachad · Post by **subachad** » Thu May 06, 2004 4:32 am

He's lucky to have only blown a headgasket, especially with that high of a compression. For about $150, www.headgasket.com will make him a thicker headgasket which would be a simple way of lowering the compression to a much safer level.

Chad
www.uniquemotorsports.com

Post by **PrecisionBoost** » Thu May 06, 2004 2:33 pm

daewooluvr wrote:What is this ECOTEC engine that you're talking about?

It's the 2.2L ECOTEC in the sunfire,cavalier......... same engine GM pushed to over 1000 horsepower for drag racing.

There are a fair number of companies making aftermarket rods and pistons and it just so happens that the rod/piston combination from the 2.2L ECOTEC (which has the same bore as our C20GET,U20SED) is just a fraction smaller than our 2.0L Daewoo/Pontiac engines.

I don't have time to calculate the difference in compression..... it's only 0.017" shorter so it doesn't change it dramaticly.

The only issue is the thickness of the bottom end of the connecting rod as this is the only difference.

Stupid thing is I can't find out what the ECOTEC con rod thickness is.... doesn't seem to be posted anywhere..... have every other specification but that.

I have a fellow in BC who is supposedly going to send me a couple of rod/piston combinations out of a damaged engine (two have broken rods and pistons....the engine got a pile of water in it..... he bought it for parts really cheap)

If the lower part of the connecting rod on the ECOTEC is larger than the thickness of the C20GET rods then we can have them machined down to fit our engines.

The more likely story is that the ECOTEC rods will be smaller...... which might require some interesting modifications to make it work.

I can't really say if it's even possible until I see the Connecting rod.

I will keep everyone updated as things go along.

If anyone else can find the thickness of the ECOTEC connecting rod around the crankshaft journal hole that would be very helpfull.