Turbo Optra - Now on tuned Haltech @ 225whp

Post by **PrecisionBoost** » Wed Jun 14, 2006 3:06 am

exist3nce wrote:Yes I know I don't have a C20LET, but it would seem the theory would follow over in general to any engine.

Rule#1.... what works for one engine may not work for another... unless you have identical part numbers and identical power bands.

The LET rods/bolts were designed for a factory turbocharged engine that made way more power than our U20SED.

Long story short.... the C20LET bolts are probably of a higher quality and cost than the U20SED bolts... even if it only saves GM $2 per bolt.... that's $8 per vehicle.... and when your banging out 100,000 vehicles a year that means the manufacturer saved nearly a million dollars by going with a cheaper set of rod bolts.

Rule#2.... manufacturers are cheap bastards that invest the least amount of money possible... if they can save a dollar they will... even if it means that they are just barely inside of their safety factors.

We have absolutely no idea of how much power U20SED bolts are capable of withstanding... there are only a handfull of turbo U20SED/X20XEV engines out there..... if you want to take the chance all the more power to you.... just let me know the power levels when your engine blows so we can warn everyone in the future.

They might take 500hp before shearing (500% safety factor).... or.... their shear point might be as little as 200hp (200% safety factor).... there is no way to know unless you take a factory bolt to a University and have their engineering department conduct some tests.

Of course this will cost you ten times more than buying a set of aftermarket bolts but if your willing to let your engine blow over a set of bolts then you must have money to burn.

exist3nce · Post by **exist3nce** » Wed Jun 14, 2006 3:46 am

Fair enough. I still plan to get them.

But what about other pieces of the engine internals? If I should replace the bolts for 200hp, then why not the rods, pistons and fasteners that connect them? I guess what I'm saying is that if the manufacturers only build in a small safety margin, then how can I expect all the other internals to hold up?

exist3nce · Post by **exist3nce** » Thu Jun 15, 2006 4:24 am

Can anyone answer the above ^^^ ? I'm quite curious as to why only those bolts would need replacement.

Nubira2.2 · Post by **Nubira2.2** » Thu Jun 15, 2006 5:01 am

stock internals will hold 200-250 hp

above of that u need forged internals

the bolts ares just for safety that the engine wont break being near 200hp

what u do with the internals of your car depends con your goals

kinkyllama · Post by **kinkyllama** » Thu Jun 15, 2006 6:02 am

Nubira2.2 wrote:stock internals will hold 200-250 hp

above of that u need forged internals

the bolts ares just for safety that the engine wont break being near 200hp

what u do with the internals of your car depends con your goals

It's been awhile since I've looked into it but I think I remembering the internals being able to hold more power than that.

Nubira2.2 · Post by **Nubira2.2** » Thu Jun 15, 2006 12:20 pm

well always have in mind that it also depends on tuning

good tuning: timming control, no detonation, low charge temperatures, right turbo, fuel management and other factors

have to do with the power the engine can hold

I would say that if u r going to use stock internals for over 200hp

use APR head studs, refresh the engine with new gasket set and replace crank shaft bearings

aveosam · Post by **aveosam** » Thu Jun 15, 2006 5:29 pm

id say if you just adding a turbo to put some more kick into your car then I say stay stock with the internals because 200-250hp is enough kick to enjoy in a fwd car...but if you are serious and it isn't jsut for kicks, then I would upgrade everything you possibly can just for safety reasons and so that the engine will last longer so all the money to turbo it wasnt wasted when you blow your stock internals

ubuyau · Post by **ubuyau** » Thu Jun 15, 2006 9:32 pm

Nubira2.2 wrote:well always have in mind that it also depends on tuning

good tuning: timming control, no detonation, low charge temperatures, right turbo, fuel management and other factors have to do with the power the engine can hold

+1. All the beefy internals in the world arent going to help you out if the tune is bad or non-existant!

Stock interals should be fine handling alot of power with a good tune! Its when you start increasing rev limits that rods start snapping and bad tune that detonation occurs and hurts pistons....

If your engine needs a rebuild and you're boosting - then do it once and do it right for what you want to achieve...

--Tim

Post by **PrecisionBoost** » Fri Jun 16, 2006 12:31 am

exist3nce wrote:Fair enough. I still plan to get them.

But what about other pieces of the engine internals? If I should replace the bolts for 200hp, then why not the rods, pistons and fasteners that connect them? I guess what I'm saying is that if the manufacturers only build in a small safety margin, then how can I expect all the other internals to hold up?

How can you expect the tiny factory connecting rods and cast pistons handle lots of power.........Ummm.... well... that's why both Tom and I have C20LET rods.... there are hundreds or even thousands of C20LET engines out there with stock rods.... I don't plan to push the car into the 300hp to 350hp range where they are said to break.

Both Tom and I debeamed and polished the rods..... he had his balanced with his pistons (made all the weights identical ).... I will probably do that when my Forged pistons arrive.

Tom is using C20LET forged pistons and I'm using some aftermarket forged pistons designed for the X20XEV.

How much power can the engine handle with stock internals??? absolutely no idea... sorry... should be 250whp or perhaps more.... hard to say.... I think they should be fine for 200whp

I think Intimidator had their 2.0L (or was it 2.2L ) running up in the mid 200hp range.... 235whp comes to mind... not sure.

Now.... the manufacturer designed the engine to only run 100whp..... they build all components to that number.... if you modify it to make more power.... they won't warranty the engine in any ways shape or form.

Like I said..... Rule #2.... if they made the engine good enough to handle 300whp it would cost a pile more than what they have into it right now.... which in the end means a higher sticker price or loss of profit.

debo890 · Post by **debo890** » Fri Jun 16, 2006 12:46 pm

where to find the rods?
here you go

http://cgi.ebay.co.uk/STEEL-RODS-VAUXHA ... dZViewItem
http://cgi.ebay.co.uk/Opel-Vauxhall-C20 ... dZViewItem

if thats too much, thne here you go

http://cgi.ebay.co.uk/VAUXHALL-CALIBRE- ... dZViewItem
you can try asking for shipping

or just keep searching here
http://motors.search.ebay.co.uk/c20let_ ... eNameZWLRS

exist3nce · Post by **exist3nce** » Fri Jun 16, 2006 5:51 pm

Wow thanks to everyone for the informative replies!

exist3nce · Post by **exist3nce** » Mon Jun 19, 2006 8:26 pm

ok some more updates, just got off the phone with the shop. They are considering using the stock manifold and just creating an adaptor (there is still enough room to run the oil drain properly) as it would be a fair bit cheaper. They say the stock manifold flows reasonably well. I'm gonna try to get over there today to have a look and decide what I want to do.

ubuyau · Post by **ubuyau** » Mon Jun 19, 2006 10:16 pm

exist3nce wrote:ok some more updates, just got off the phone with the shop. They are considering using the stock manifold and just creating an adaptor (there is still enough room to run the oil drain properly) as it would be a fair bit cheaper. They say the stock manifold flows reasonably well. I'm gonna try to get over there today to have a look and decide what I want to do.

Join us

Using an adaptor to the stock exhaust manifold seems to be the way to go for turbo Daewoos

Dont even worry too much about the oil drain - you could run an external bilge pump if its too low (im considering running one) - just make sure you have enough ground clearance

--Tim

exist3nce · Post by **exist3nce** » Tue Jun 20, 2006 10:06 pm

Some of these pics might be redundant, but I thought I'd post anyways, gotta start the pics somewhere. The exhaust pics are of my current exhaust.

kroz123 · Post by **kroz123** » Tue Jun 20, 2006 10:24 pm

nice, wow your mani is red hot and what did you do with your HD did you paint them black?