The U20SED track-reliable power limit.

[garridob]

I've always thought that if I ever need more than 170/180 hp, I would just make the Nubira into a pure track car, shit can the GM drivetrain stuff and cut up the engine bay stuffing in a K20 and six speed. Are there reasonably affordable, more easily swappable substitutes? I would want to stay NA because, no offense to anybody, the turbo builds on this forum seem pretty fragile and I've never tracked a car that couldn't use cooling help.

[benzino]

why go to honda?
my opinion has always been, if you want a honda engine, just go honda

http://www.migweb.co.uk/forums/engines- ... 00bhp.html
http://www.migweb.co.uk/forums/engines- ... -tips.html
http://www.migweb.co.uk/forums/engines- ... ughts.html
http://www.astraownersclub.com/vb/showt ... al+edition

some inspiration. the xev engine has 1 point higher CR and bigger injectors as well as bosch management to begin with.
note that when the brits use BHP it's almost always at the flywheel (even though it was measured at the wheels )

[garridob]

Why not go Honda?

1. I like my sleeper effect.
2. My car handles better than any Honda I've driven.
3. Massive import taxes in Korea.

It looks like I'd need an intake manifold (which I've already built, just need to weld and install), rods ($$$) and a better cylinder head ($$$ ?). Then I'd end up with an engine that needs 1500 rpm over factory to make 200 hp. And cams. Hmm.

"Engine:
- X20XEV, 2.0 16v Ecotec
- Alpha throttle bodies
- Alpha management
- 45mm trumpets
- Jr air filters
- FSE fuel pressure regulator with gauge set to 40 PSI
- Pico injecters
- Reprofiled camshafts
- Lightened pot type flywheel
- Cylinder head ported,polished,egr ports weled up exhaust ports reshaped
- Lexmaul 4-2-1 manifold
- Pre-Coated Graphite Black exhaust heat wrap
- Decat silencer
- Scorpion group A 2.5" cat back system with monza back box
- ARP rod bolts
- New sash clutch
- K1 Racing 10mm, Quad Spiral Core blue HT leads
- Denso Iridium Plugs
- Mobil 1 0W-40 Fully Synthetic Engine Oil
- Vauxhall oil filter
- Full engine rebuild
- Water wetter
got a 183.5bhp@6355rpm 154.9lb ft@5479rpm"

[benzino]

I still think that it would be much easier than shoehorning a k20 and gearbox into a nubira.
Surely you can find all the parts you need to build up your motor in Korea?
Are you saying that it costs less to supply a k20 with gearbox and wiring, then fabrication cost to get it sitting right than it does to rebuild your own engine?

[garridob]

I still think that it would be much easier than shoehorning a k20 and gearbox into a nubira.
Surely you can find all the parts you need to build up your motor in Korea?
Are you saying that it costs less to supply a k20 with gearbox and wiring, then fabrication cost to get it sitting right than it does to rebuild your own engine?

The Daewoos are not real popular for hot rodding in Korea. Let's put it this way, I had to get my coilovers custom made. I had to make my own slotted rotors. The swaybars I was looking into getting - custom. My intake - handbuilt. My exhaust will be custom.

It's not because I'm a master fabricator, which I'm not, it's because nobody makes anything for Daewoos. You've probably got better aftermarket in Australia and the Euro guys certainly do with their Vauxhall/Opel stuff.

Up front, no, it wouldn't be cheaper. But if it's going to be frequent rebuilds, it seems like an engine that was designed to do 8500 rpm and 200 hp with a factory warranty would be better over the long term. I'd also get an aluminum block out of the deal. That built engine looks like it could give a K series a run for the money cost wise as well. I don't know, I can get another U20SED for 400 bucks. Maybe I'm wrong, but I've always preferred stock OEM stuff to aftermarket when shooting for a specific power goal ...

It would be pure racecar at that point. Meaning screw the ECU and Daewoo/Honda loom splicing, I'll just use a megasquirt. I can build mounts on my own. On the other hand, the US style Ecotech (ie the 2.2/2.0L engines that came in everything from the Leganza 2.2 to the Solstice ) is another option. I've heard it isn't any easier to install, though.

[benzino]

the USDM ecotec is completely different... all aluminium and reversed intake and exhaust

so will you be getting custom driveshafts or custom hubs? how about shift linkage?

anyway, I'm sure Chris/precisionboost will chime in soon about high revving natmo builds, if he doesn't it might be an idea to PM him. He is infinitely more knowledgeable on the subject than I am.

Is turbo another option?
K20 power would not be impossible, I just think it would involve a lot of stuffing around and there is the possibility that you get stuck at some point and you will have to throw a lot of money at it...

[gse_turbo]

I'm a huge advocate for remaining all GM when doing builds like this. The axle shafts for sure will be a huge problem for a swap like this.

The list of the engine build above is pretty good it using standard pistons and cam followers is the worst part of that build. For a powerful NA build, higher compression pistons and solid cam followers would potentially achieve the same results as that whole build list.
I'm big on suggesting good "machining" operations to get more efficiency (power) from the motor using the standard part. Spend more on the required parts like the couple I mentioned but here is my list of operations that should be done. Some can be done by hand depending on skill level, however each item will require a final survive by an actual machinist.
- de-cast rods and balance
- floating wrist pin mod in piston and rods
- knife-edging and polishing crank
- lighten crank and balance
- lightened or flat flywheel, balanced
- proper cylinder head port matching
- BALANCE, BALANCE , BALANCE. If it spins in the engine it needs to be balanced.
- shim the valve spring (not a machining operation but cheap and worth while)

One last budget minded suggestion is to use a main support girdle and a crank scraper. Two of the biggest reasons for a loss of efficiency in a motor are harmonic vibrations and oil "roping" or "windaging". Using a scraper and girdle helps and many of the GM Iron ECOTEC engines come with one or both of them. Make sure both are present if they aren't there standard.

[PrecisionBoost]

Well, the K20 is a decent engine with good potential, not sure how well the engine/gearbox would line up, but if it's race only then there is probably room for flexibility in cutting out some metal and repositioning certain items ( exhaust and intake are reverse of U20SED )

I guess it comes down to your budget.

The 2.0L GM engine is capable of going toe to toe with the K20 for power in naturally aspirated situations, but most of the NA applications come from the UK so there is more cost.

SBD has successfully pushed the C20XE engine ( cousin of U20SED ) up over 290BHP naturally aspirated, which correct me if I'm wrong, puts that engine on top of the best K20 tuners out there.

Keep in mind that Cosworth had a large role to play in the development of this engine, there are Naturally aspirated C20XE engines out there running 10,000 to 12,000 RPM redlines

Here is the basic kit for the 290bhp C20XE...

http://www.sbdev.co.uk/Taper%20Kits/New ... pgrade.htm

For 250bhp your looking at about 6500 GBP and it goes up from there.

http://www.sbdev.co.uk/Price_List/Price%20list.pdf

There are other tuners in Germany selling C20LET turbo engines set for 750bhp for about the same price as the 290bhp SBD setup.


In conclusion, tuning the C20 series engines is expensive compared to the K20, but the question is whether you will end up spending more time ( and money ) trying to drop in a K20 than it's worth.

[PrecisionBoost]

I would want to stay NA because, no offense to anybody, the turbo builds on this forum seem pretty fragile and I've never tracked a car that couldn't use cooling help.

No offense taken, this site has very few serious builders, most people are on a fairly tight budget.

My project car has the potential for 600whp but I lack the time to complete any of my projects and there are practically zero people in North America I would trust to play with my engine/chassis.

The only way I would let someone touch my project would be if I flew in a few guys from the UK or Germany for a few weeks to push the project to completion.


So, I'm not that different than you, just like in Korea there is nearly zero help in tuning a U20SED.


However, I will say that a high performance U20SED would be very unique, which is one of the main reasons I keep going piece by piece.

Dropping a K20 into a Daewoo is interesting, but it's probably not as interesting as a built U20SED.

[Efratech]

You can find lots of guys doing trackdays on C20LETs in the UK.

I've been told like 1000 times to put a B Series engine in my Kadett, but just the fact of adapting it and runing some odd axles doesnt ring a bell for me.

The K engines are awesome, they can make big power on a stock block. Is a tottally different game and more parts avaliable in the US market.

Is up to you really but I would prefer to keep it GM.

[garridob]

I'm a huge advocate for remaining all GM when doing builds like this. The axle shafts for sure will be a huge problem for a swap like this.

The list of the engine build above is pretty good it using standard pistons and cam followers is the worst part of that build. For a powerful NA build, higher compression pistons and solid cam followers would potentially achieve the same results as that whole build list.
I'm big on suggesting good "machining" operations to get more efficiency (power) from the motor using the standard part. Spend more on the required parts like the couple I mentioned but here is my list of operations that should be done. Some can be done by hand depending on skill level, however each item will require a final survive by an actual machinist.
- de-cast rods and balance
- floating wrist pin mod in piston and rods
- knife-edging and polishing crank
- lighten crank and balance
- lightened or flat flywheel, balanced
- proper cylinder head port matching
- BALANCE, BALANCE , BALANCE. If it spins in the engine it needs to be balanced.
- shim the valve spring (not a machining operation but cheap and worth while)

One last budget minded suggestion is to use a main support girdle and a crank scraper. Two of the biggest reasons for a loss of efficiency in a motor are harmonic vibrations and oil "roping" or "windaging". Using a scraper and girdle helps and many of the GM Iron ECOTEC engines come with one or both of them. Make sure both are present if they aren't there standard.

This sounds like a high rev way to build an engine. I'm not opposed to that per-se, but is an 8500 rpm us20d a rebuild it every 5,000 miles sort of engine?

I've heard the intakes are really bad, but my students fabricated a new manifold that should support higher revs. Am I barking up the wrong tree here?

[gse_turbo]

If you are looking to get to 8500 you would need more top end parts like stiffer springs and lighter valve train. I just finished working with Supetech not too long ago for a complete valve train so that is an option.

Anyways with a goal closer to 7500-8000 the engine would have a longer life. The life of the engine is also determaned by the budget of initial build and the quality of the assembly. The more serious you get in racing, it's a good idea to tear down and inspect the engine before each season and before a problem accures. A couple hundred in the cost of gaskets and bearings is worth the money saved from finding serious damage.

[garridob]

I would want to stay NA because, no offense to anybody, the turbo builds on this forum seem pretty fragile and I've never tracked a car that couldn't use cooling help.

No offense taken, this site has very few serious builders, most people are on a fairly tight budget.

My project car has the potential for 600whp but I lack the time to complete any of my projects and there are practically zero people in North America I would trust to play with my engine/chassis.

The only way I would let someone touch my project would be if I flew in a few guys from the UK or Germany for a few weeks to push the project to completion.


So, I'm not that different than you, just like in Korea there is nearly zero help in tuning a U20SED.


However, I will say that a high performance U20SED would be very unique, which is one of the main reasons I keep going piece by piece.

Dropping a K20 into a Daewoo is interesting, but it's probably not as interesting as a built U20SED.

I know the feeling. The advice I've gotten from the start here in Korea has been "sell it and buy a Hyundai product." I have some peculiar ideas on chassis tuning and my car has turned into a kind of rolling science project for school kids, so I'm going to keep it, but there just isn't a lot of support.

Kind of a tangent, but you can really make these things handle.

[gse_turbo]

I know what you mean by no support, the US market is very much the same. It's the reason I keep trying to make new and better products. There really isn't anyone developing products in the states or a consumer market for them.

At any rate I'm dedicated to the platform and I'll do what I can to provide support with products to individuals regardless of the location. and as you can tell, the members of the forum will come out of the woodworks to encourage individuals to make performance improvements.

[garridob]

If you are looking to get to 8500 you would need more top end parts like stiffer springs and lighter valve train. I just finished working with Supetech not too long ago for a complete valve train so that is an option.

Anyways with a goal closer to 7500-8000 the engine would have a longer life. The life of the engine is also determaned by the budget of initial build and the quality of the assembly. The more serious you get in racing, it's a good idea to tear down and inspect the engine before each season and before a problem accures. A couple hundred in the cost of gaskets and bearings is worth the money saved from finding serious damage.

Is that 7500 rpm going to require a lot of bottom end work? Am I wrong in thinking the "factory reliable, still cheap" threshold on these engines is about 170 crank horsepower? That's plenty for now, and it would have me very competitive in the local TT classes when I finally get around to making this thing a track only car.

I'll check out your website, btw.