few questions on my little project

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Mr_Efficiency
Posts: 33
Joined: Sun Dec 18, 2005 3:53 am
Location: Peterborough, Ontario, Canada

few questions on my little project

Post by Mr_Efficiency »

I have a 89 sunbird and I'm building up a 90 C20GET with stock crank, C20LET rods and pistons, and a dohc 16v daewoo head from a leganza and I'm gunna run a intercooled t-3 turbo on it, and i have a few questions.
1: What kind of reline am I looking at with this combo, I know the bottom end is good for 7250, but i dont know what the top end would be like for valve float and such.
2:About my crank, its the stock C20GET, will it be able to hold up to this kind of abuse, and i heard a lot about teh newer cranks being heavyer and everyone wanting the older lighter cranks, my crank being a 90 its teh lighter one right?, or does teh C20GET use a completly diffrent crank.
3: Anyone know the stock gasket thickness for a C20LET, the cc's of the head, the cc's of the piston dish and teh deck height? or even one of those would help.
4:What kinda boost can i saftley run on this engine combo before it starts to get dangerous, I know this could be a pretty wide area but just a rough estimate would be nice.
5:Whats teh wak link withe this combo or these motors? waht am I most likley to break?
thanks in advance for anything u can come up with.
Mr. Efficiency

-91 Pontiac Grand Am SE (stock car) - 2.3 Quad 4 HO
-90 Pontiac Grand Prix GTP clone in progress - 3.1MPFI / Future holds: 3100 turbo, 5 speed
-And a pile of parts in the corner that will someday become a 2.0 DOHC turbo GASE
Mr_Efficiency
Posts: 33
Joined: Sun Dec 18, 2005 3:53 am
Location: Peterborough, Ontario, Canada

Post by Mr_Efficiency »

forgot one:
6: What are my options for cams with the C20SED (lagenza dohc 16v) head?
thanks
Mr. Efficiency

-91 Pontiac Grand Am SE (stock car) - 2.3 Quad 4 HO
-90 Pontiac Grand Prix GTP clone in progress - 3.1MPFI / Future holds: 3100 turbo, 5 speed
-And a pile of parts in the corner that will someday become a 2.0 DOHC turbo GASE
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PrecisionBoost
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Re: few questions on my little project

Post by PrecisionBoost »

Mr_Efficiency wrote:I have a 89 sunbird and I'm building up a 90 C20GET with stock crank, C20LET rods and pistons, and a dohc 16v daewoo head from a leganza and I'm gunna run a intercooled t-3 turbo on it, and i have a few questions.
1: What kind of reline am I looking at with this combo, I know the bottom end is good for 7250, but i dont know what the top end would be like for valve float and such.
2:About my crank, its the stock C20GET, will it be able to hold up to this kind of abuse, and i heard a lot about teh newer cranks being heavyer and everyone wanting the older lighter cranks, my crank being a 90 its teh lighter one right?, or does teh C20GET use a completly diffrent crank.
3: Anyone know the stock gasket thickness for a C20LET, the cc's of the head, the cc's of the piston dish and teh deck height? or even one of those would help.
4:What kinda boost can i saftley run on this engine combo before it starts to get dangerous, I know this could be a pretty wide area but just a rough estimate would be nice.
5:Whats teh wak link withe this combo or these motors? waht am I most likley to break?
thanks in advance for anything u can come up with.
1) Not sure.... the stock head will run to 6500rpm... I wouldn't push past that unless you upgrade the valve springs
2) I doubt you will break the C20GET crank as long as you keep the power output under 300WHP
3) I have one in my garage, if I find my calipers I will measure it for you.... not sure about the factory piston dish volume, I think I wrote down the deck height info when I diassabled my first C20GET.... will look around for it.
4) 12 psi if your using the stock ECU... it will cut out above that....many are running way higher.... 20psi + boost but they have various ways of increasing the fuel (larger injectors for some..... extra injectors for others)
5) The first weak link is the connecting rod bolts..... they will snap fairly quickly and end your engines life.
6) Options are not great as the only replacements come from the UK and they would probably run $1000+ USD

Personally.... I think you will be very happy with the stock 6500RPM redline and 12psi.... it should net you around 235 horsepower at the wheels.... which is a very significant jump from the stock engine.

You might want to think about getting the C20LET rods debeamed, shotpeened, polished and balanced (with pistons )

You might want to think about having the piston crowns ceramic coated.

You might want to have the crankshaft lightened, balanced and nitrated.

I think the C20LET rod/piston combo is slightly shorter than the C20GET setup.....not by much.... you should end up with decent compression levels.

You should check the valve clearance between the LET pistons and 16V Leganza head..... the valves should be very close in position.... but you should check to make sure.

The stock cams are probably just fine for turbo application.... but a set of adjustable cam gears would be nice ( I'm working on that )

Which tranny do you have in your Sunbird??

The automatic 125C can be fixed up to take massive power.... but I'm not to sure what the limit is for the 5spd Getrag trany ( model 282 )
2010 BMW 335D
1994 Opel Calibra 4X4 turbo ( C20LET 2.0L Turbo )
2002 Daewoo lanos
Mr_Efficiency
Posts: 33
Joined: Sun Dec 18, 2005 3:53 am
Location: Peterborough, Ontario, Canada

Post by Mr_Efficiency »

One correction, when i said i needed teh cc's of teh head i meant the daewoo head.
also if the rods are shorter in the C20LET then does anyone know the deck height of the C20LET?
I wont be worrying about upgrading vavlve springs 65000 is fine I wouldnt want to go any higher than that, and I will be running a 3 bar map sensor so i can get over 14 psi and I plan to get bigger injectors and I've also been playing with the idea of propane injection.
As for connecting rod bolts being the weak link I do plan to run ARP rod bolts any ways cause I want to run around 17-20 psi. I do plan to have the crank lightened, kinfe edge the weifghts and balance it, never tjhoiught about doing anythingto the rods before, I'll have to look into that. Adjustable cam gears would be awesome, definatly have to keep an eye out for a set.
And the tranny i will be running is the getrag 282, I'm not sure what to do to it to prep it to take the abuse, but I've heard its good for 300hp, but i want to get a LSD for it and a good clutch, probly have the flywheel lightened to.
Thanks a lot ofr your help so far and i'd really apreciate it if you could get some of those measurements for me.
Mr. Efficiency

-91 Pontiac Grand Am SE (stock car) - 2.3 Quad 4 HO
-90 Pontiac Grand Prix GTP clone in progress - 3.1MPFI / Future holds: 3100 turbo, 5 speed
-And a pile of parts in the corner that will someday become a 2.0 DOHC turbo GASE
debo890
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Location: rhode island

Post by debo890 »

Mr_Efficiency wrote:And the tranny i will be running is the getrag 282, I'm not sure what to do to it to prep it to take the abuse, but I've heard its good for 300hp, but i want to get a LSD for it and a good clutch, probly have the flywheel lightened to.
thats what i heard about the getrag 282 too. it should be fine up to 300hp. i am considering using that in my woo too, but i dont have a pic of it to make visual measurment and identification before going to a junkyard.
got drift?
Mr_Efficiency
Posts: 33
Joined: Sun Dec 18, 2005 3:53 am
Location: Peterborough, Ontario, Canada

Post by Mr_Efficiency »

AFAIK the getrag 282 only cam in turbo sunbirds and only from 88-91 any other manual trans previous to that is a muncie 4 speed and isnt nearly as strong. so as long as you get the trans from a 88-91 turbo sunbird you should have the right one. I wish the getrag 282 was available in more cars than just that one cuase there really hard to comeby :(
Mr. Efficiency

-91 Pontiac Grand Am SE (stock car) - 2.3 Quad 4 HO
-90 Pontiac Grand Prix GTP clone in progress - 3.1MPFI / Future holds: 3100 turbo, 5 speed
-And a pile of parts in the corner that will someday become a 2.0 DOHC turbo GASE
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