Daewoo of Death - Trackday/Autocross Build of Doom!

[garridob]

This is my 1998 Nubira 1.5 Sport.

Engine:
- 2.0 16v DOHC (U20SED) swap
- Internally stock
- Custom built CAI
- Exhaust pipe of infinite fury coming soon.
- Custom built aluminum intake manifold coming soon. Just need to weld it up.
- Custom catalytic converter specially modified to fill the cabin with noxious acids and trip the check engine light.
- Oil cooler, oil temp sensor, oil pressure sensor and voltage meter all ordered and on the way.

Transmision:
- Whatever came on a Nubira Sport 1.5. It's really short and I redline in fifth at 215 km/h.
- Stock clutch, 2.0L Magnus flywheel.

Wheels/Tyres/Brakes:
- Hardrun sport pads off of a Magnus.
- 15" ASA chromepocalypse blingtastifiers. Looking for a cheap alternative as we speak.
- 205/50/15 Hankook V12 Ventus.
- Custom slotted stock rotors in front.

Suspension:
- Swaybar delete front and rear, yes I do have a reason for this.
- Poly bushings in the rear, fresh stock fronts cause I kept breaking the poly front stuff.
- Custom built Tech Pro coilovers with non-adjustable Bilstein cores and 9kg/mm (488lb/inch) springs on all four corners. .75 inch drop front, .75 inch drop rear.
- Caster/camber plates coming soon.

Other:
- Custom built air extractor hood for cooling and aero-lift purposes.
- Gutted trunk
- Sound deadening pulled out from beneath the carpet
- Miscelanious weight reduction
- Leganza seats

Performance: 0-60 in about 7.8 seconds. 1/4 mile in about 15.5 I'd guess. A full lap of Taebaek racing park, before the engine swap, in 1:17.3. Top speed redline limited to 215 km/hr.

Below, I shall provide you with the build, but for now you must content yourself with these few pictures ...





http://www.youtube.com/watch?v=vLzX7_ntl-4

[benzino]

Do you know the current weight of the car after you've stripped it?

Also, you think that gearbox is short... mine maxes out at 170km/h in 5th

[garridob]

I'd guess about 2400 lbs but I haven't weighed it. As for your gearbox, damn. First gear is almost useless for me as is, I'd probably be launching in third gear with your tranny!

[benzino]

Wow, 2400lb would be excellent in a nubira! Mine weighs 2470lb without any major weight reduction (only A/C removed), but it is a lanos...

2nd gear starting for everyday driving is pretty normal...

1st goes to about 40km/h
2nd to 80km/h
3rd to 120km/h
4th not tried
5th to 170km/h @ 5500rpm... it stops there

I have the 2.0l gearbox in my garage, I might swap it over if I ever get sick of the shortness.


Soooo, what's your reason for no swaybars?

[garridob]

The weight is a guess. My Nubi was listed at 2600 ish lbs. I pulled about 200lbs out and then added a little back with thee motorswap.

I think we have the same tranny, or at least close. The highest Ive been was 200kmh but it was still pulling. Mathematically it will hit the fuel cut at 215.

No swaybars ...

Little reasons:
Theyre heavy. They tie the wheels together and negate much of the benefit of having independent suspension. They are inconsistent. The amount of anti roll you get changes at different rates than does a spring. This makes bars and consistency unlikely bedfellows. The rear bar design on my Nubi was comprehensibly retarded (falling rate?!?!) and I didnt want to fabricate an alternative.

Big reason: A swaybar converts roll into weight transfer. This means that a swaybar fights roll (generally desirable) but increases the amount of weight on the outside tire while decreasing the amount of weight on the inside tire. Take into consideration the fact that a tire's coefficient of friction decreases with load and you see that swaybars lessen the amount of mechanical grip available to the system. The bigger the bar in relation to the spring, the more pronounced the effect.

[garridob]

Build - as promised.

Here is the beginning stage of the project. I have done nothing except for taking out the window tinting that made it impossible to see out. Some may see a frumpy Daewoo with questionable accessories and poorly chosen factory options, I see potential.

Interior pictures.






Those are kilometers, btw ^



The only thing better than fake wood and velour is fake wood and velour that's falling apart.



Mmm, more fake wood.



This sticker means "good mind, good neighborhood, good community." I think it will go well with the flat black and skulls.






Suspension/Exterior/Engine Bay Pictures



This is the rear strut setup. Actually looks pretty good to me.



Not excited about the strut mounted swaybar links.


Try to contain your jealousy.


1.5 liters of pure Korean fury!


Supposedly this is a variable geometry intake manifold. Kinda cool, I guess.


Why yes it does have ABS, and 4 wheel disk brakes too.


I think this is the opposite of badge snobbery.



In her full glory!

[garridob]

Later.







So day one was supposed to last one hour. We where going to pull out the ugly wood trim and paint in black. But, evidently tearing my car apart was way more fun that computer games so instead we spent 4 hours taking the entire interior apart and (amazingly for kids) putting it back together. Got out all the sound deadening, got rid of some plastic in the engine bay, and painted the trim. The day's only major whoopsy berkeley came when one of the students accidentally spray painted my glove box door.





So with the benefit of a couple more weeks my crew of midgets was able to complete several tasks of vital importance - painting the valve covers red, installing "racing" pedals, painting the fake wood black, gutting the trunk, building a new mount for the broken horn, and installing some bling-bling wheels.

Engine before:

Engine after:


Interior before:





Interior after:




Bling before:



Bling after:



Now, onto the tech stuff. A Nubira stock weighs about 2700 lbs. Daewoos use a full size spare and a surprisingly thorough tool kit in the trunk, axing it and all the trunk trim probably dropped 50 pounds. We also pulled all the sound deadening out from under the carpet, the various carpet covers etc call it 30 pounds. The extraneous under hood bits, things like insulation and engine covers probably weighed 10 lbs. The stock wheels were really heavy, I'd guess in the neighborhood of 40 lbs for one with the tire mounted. The new blingsters are noticeably lighter. Call it 5 pounds per wheel/tire, 20 pounds total. That puts the Nubira at 2590 lbs. Gonna have to get creative if I want to keep a full interior and AC while getting it closer to 2400.

Ah yes, the wheels. It turns out that Daewoos are weird. Instead of using wheel studs they take the road less traveled and rock some amazing wheel bolts. But if you're going to make a 2700 lb car the size of an EG Civic with super heavy wheels, it's important to shave each possible milligram from the rotating mass. Daewoos engineers did this by making the wheels mounting surface very thin and coupling this with the shortest possible wheel bolts.

Alas, ASA (the makers of my bling) did not see the wisdom of using the smallest possible wheel bolts and, perhaps worrying about trivialities like wheel rigidity, made the mounting surface thick. As such mounting the new wheels got about two and a half threads into the hubs. Definitely not safe.

But I am not easily deterred and thus spent the next two days amazing local tire shops with my poetically perfect Korean ("I receive new beetle." "What?" "I need new beetle." "I don't understand." Idiot foreigner points at hubs. "Oh, ok. I'll give you a 'beetle.' ") and searching for another car that uses longer, compatible bolts. Eventually I found them in a vehicle so similar I wonder if Daewoo didn't simply steal the design.


Thankfully the Ssangyong Rodius is a 5000 lb vehicle, so the bolts are probably pretty tough. Certainly they look beefier. Further, after consulting with many of the world's foremost experts, I have concluded that ugliness is not a contagion among automobiles and therefore do not need to worry about Ssangyong styling spreading onto my Nubira.

Further notes:

With the red valve cover, my motor kind of looks like a 4g63. I'm sure this means it's safe at 20 psi of boost.

Daewoos have adjustable trunk lid springs. Who knew?

I would normally dismiss pedal covers as pure rice. But damn, it's way easier to heel and toe now.

The intake tube has a corrugated exterior and a smooth inside. That's a more expensive arrangement than on my Mom's Mercedes.

I think I figured out why the handling balance is thus 1. quick, flat sports car like turn in 2. understeer on the scale of a 1993 Buick Century. Turns out the front stabilizer is 1 7/8 inch and the rear "sway stick" is smaller around than my pinky. Normally I would worry that when the time comes to install a bigger rear bar, it would rip out. But fear not, Daewoo knew that a majority of their Nubiras were headed into motorsport and thus built the sway bar mounts from reinforced anti-ballistic tank armor.

[garridob]

Let's start off here with some background. I recently made friends with some missionaries (Korean missionaries love me, which is weird, but anyway) who know a guy who owns a repair shop. Nothing special, but he does get a good deal on junkyard parts. With the help of my students, I turned that connection into a cheap spare hood and trunk (we haven't cut up the trunk ... yet). Badabing badabang.

So the next thing was to sit down and teach a little about aerodynamics. Areas of high and low pressure, the function of gurney flaps, down force/lift etc. That was interesting, considering I was trying to do it while speaking Korean. When we finished talking and looking at aftermarket hoods on the internet, I turned the kids loose with masking tape, measuring tools and a mandate to design a lift reducing, airflow and cooling enhancing hood that would also feed the custom cold air kit we're building right now. I've never owned a track/autocross car that didn't have cooling problems, so I emphasized requirement number three most. They needed about three hours to get both vents straight and symmetrical, but I think they did a good job.

During the design phase I noticed several recycling centers in the neighborhood, snooped a little bit and found huge piles of scrap metal. About fifteen minutes of begging and petting junkyard cats later, the owners donated 10 pounds of steel in various random shapes. Some stainless steel designed for roofing became our gurney flaps and the skin to a small filing cabinet gave birth to the scoop. I did the cutting and grinding out of concerns for safety, but all the design, drilling, installation, riveting, shaping, hammering etc came from the students.

About the scoop. One of the students spent several hours (somewhat effectively) hammering the tabs flat and true. Probably because he'd designed it in the first place, this kid decided the scoop should be riveted on in five separate locations. I'm relatively certain this part approaches the engine block's levels of rigidity.

Other stuff. The grey lining you see on the vents is a safety feature designed to keep kids from cutting their fingers on sharp metal edges. I couldn't find any purpose made liners, so we built our own by stripping the insulation off of large gauge electrical wire, wrapping it over the edges and then supergluing it on. Not sure how it's going to work, but worth a try. The stock grill was ugly so we ditched it, but the mounting tabs for the stock grill were even uglier. The kids decided they should join the grill in car parts heaven. We also cut all the sound deadening baffles out of the stock airbox. We'll be painting the whole thing flat black Monday, but I wanted to get the pictures now so you all could see the fabrication process.

Next week we'll make that custom cold air kit (fed from both above and below) and take out a big chunk of exhaust. After that, we'll be doing a brake job (might modify the rotors to a slotted design) and hopefully dropping in some coilovers.

Please let me know if you guys have any budget friendly, not-that-skilled-of-a-mechanic friendly ideas. Thanks.






The kids and I finished the custom hood and got started on the rear spoiler.

Here's the hood painted and installed:




This came out way better than I expected. The hood is noticeably lighter, the scoop is dead center over the air filter and the engine bay is much cooler. I used to get some heat soak into the clutch when stuck in traffic on really hot days. No longer an issue. I haven't built my pressure tester yet, or gotten above about 50 mph, so I don't know if the aero effect will be what we expected.

Here's the spoiler we're making:







This is the almost final mockup with all the tabs ready and just the drilling and riveting left over. We picked this design because I've read it's almost impossible to f-up a spoiler of this type.

And to keep up the dumpster diving theme, this is where the steel came from.



They're doing some remodeling at my school and this used to be a ventilation duct. Stainless, free, big and if we cut it correctly, reinforced.





Brakes, intake and coilovers coming soon. Then it's time to hit the track.

[Rodd1s]

Haha! Loving this project!

Kind of a similar direction my next Daewoo will go

Keep it up man!

[garridob]

Thank you, sir.

[garridob]

Update. We finished the spoiler and are now waiting on a 70 mm airfilter, brake pads and the coilovers.

Pics.







We ran out of summer, so I did some of the assembly on this. The students did all the fabrication and design, except for the middle support which I added later for strength.

[garridob]

Here are the new coilovers and home brew slotted rotors. Oh, and I painted the grill white and reinstalled it.

[garridob]

The new coilovers are all 9kg/mm units from TechPro, a Korean company I know almost nothing about. They look like quality pieces but there's a sticker on the side commanding that I should never disassemble them.

The set, custom made, was about 600 bucks.

Now I'm just waiting on the cold air kit (internet score, 50 bucks brand new) and the aggressive street brake pads, then it's off to Taebaek Racing Park to blow all those BMWs and Genesis Coupes into the weeds!

BTW, 9kg/mm is a little less than 500 lb/in.

After many moons and the end of summer vacation, the Daewoo has once more risen from the ashes of anonymity, financial prudence and good taste.

I'm trying to get everything in order to make the car, decent reliable and safe for the first track day on (fingers crossed) October 2nd. This consisted of a) brakes b) suspension install c) juggling parts to try and compensate for Daewoo weirdness.

So brakes: Took off the heavily grooved and professionally cracked front rotors and replaced them with our homebrew slotted rotors. For the front pad I'm rocking Hard Run sport compound pads and some stock replacement pads out back. I had had no idea that Hard Run existed before I came to Korea, but everyone assures me they are the most aggressive pads available for stock caliper Nubiras. I also put in fresh fluid and replaced the brake line I so expertly sliced open.
Let me explain the logic of running different pads front and rear. The Nubira, for reasons I did not formerly understand, seemed to have a ton of rear brake bias. Trail braking into a corner would often set off the ABS and even a mild amount of turn in would have the inside rear tire squealing. This sounds like aggressive, race friendly stuff, but in actuality it was just spooky as the car transitioned from ABS juttering oversteer on entry to heavy mid corner understeer.

Flash forward to me slicing the brake line open. With the fluid safely spilled out on the ground, I decided to drive the car to a shop very near the school, not more than 100 feet. I had planned to use the emergency brake and the clutch (engine off, me coasting downhill) to get there. However, making an unplanned stop from 1.5mph I instinctively went for the brake pedal. To my non surprise the pedal was dead off the top. To my complete surprise, pushing it almost to the floor triggered the front front brakes completely normally and did not fade as the fluid leaked out. My theory is that the dual circuit on my master cylinder triggers the rear brakes first and then the front brakes later. This would seem to explain the rear bias and the fact that my car goes through rear pads unusually quickly for a nose heavy econo crap can.

So, I'm thinking about this and decided to run a sport pad in front, where it will hopefully bite harder, and a stock pad in the back. Don't know if this will work, but in any case it's worth a shot. The pedal feel is already better.

As for the suspension, damn, our car might actually end up looking good! The ride (parking lot and surface streets putzing so far) is really bad at low speed but seems to be tolerable at anything over about 15 mph. The response is infinitely better and we haven't lost any wheel travel. The drop is about an inch and a half. I also slotted the front strut mounts and pushed the struts as far negative as they'd go. Purely by eyeball, I'd put it at about -1.5. Because the car was such an understeering pig before, and because 9kg/mm is a pretty serious spring, I've pulled the front sway bar. Actually, right now it's running without a front or rear bar. Got to do some hooning to see if the rear bar should go back on. Those friggin swaybar links, grrr. A combination of rust, stupid design and my incompetence meant I had to pop all four out of their sockets to get them off the car.
Now we're just waiting on the cold air kit to show up. Past that its time to start playing with air pressures and contemplating the necessity of rear swaybars.

Did a little more research and it looks like Tech Pros might be relabeled Bilsteins! Whoot whoot!

[garridob]

The new coilovers are all 9kg/mm units from TechPro, a Korean company I know almost nothing about. They look like quality pieces but there's a sticker on the side commanding that I should never disassemble them.

The set, custom made, was about 600 bucks.

Now I'm just waiting on the cold air kit (internet score, 50 bucks brand new) and the aggressive street brake pads, then it's off to Taebaek Racing Park to blow all those BMWs and Genesis Coupes into the weeds! <img src="/media/img/icons/smilies/wink-18.png" alt="" />

edit, 9kg/mm is a little less than 500 lb/in.

[garridob]

After many moons and the end of summer vacation, the Daewoo has once more risen from the ashes of anonymity, financial prudence and good taste.

I'm trying to get everything in order to make the car, decent reliable and safe for the first track day on (fingers crossed) October 2nd. This consisted of a) brakes b) suspension install c) juggling parts to try and compensate for Daewoo weirdness.

So brakes: Took off the heavily grooved and professionally cracked front rotors and replaced them with our homebrew slotted rotors. For the front pad I'm rocking Hard Run sport compound pads and some stock replacement pads out back. I had had no idea that Hard Run existed before I came to Korea, but everyone assures me they are the most aggressive pads available for stock caliper Nubiras. I also put in fresh fluid and replaced the brake line I so expertly sliced open.
Let me explain the logic of running different pads front and rear. The Nubira, for reasons I did not formerly understand, seemed to have a ton of rear brake bias. Trail braking into a corner would often set off the ABS and even a mild amount of turn in would have the inside rear tire squealing. This sounds like aggressive, race friendly stuff, but in actuality it was just spooky as the car transitioned from ABS juttering oversteer on entry to heavy mid corner understeer.

Flash forward to me slicing the brake line open. With the fluid safely spilled out on the ground, I decided to drive the car to a shop very near the school, not more than 100 feet. I had planned to use the emergency brake and the clutch (engine off, me coasting downhill) to get there. However, making an unplanned stop from 1.5mph I instinctively went for the brake pedal. To my non surprise the pedal was dead off the top. To my complete surprise, pushing it almost to the floor triggered the front front brakes completely normally and did not fade as the fluid leaked out. My theory is that the dual circuit on my master cylinder triggers the rear brakes first and then the front brakes later. This would seem to explain the rear bias and the fact that my car goes through rear pads unusually quickly for a nose heavy econo crap can.

So, I'm thinking about this and decided to run a sport pad in front, where it will hopefully bite harder, and a stock pad in the back. Don't know if this will work, but in any case it's worth a shot. The pedal feel is already better.

As for the suspension, damn, our car might actually end up looking good! The ride (parking lot and surface streets putzing so far) is really bad at low speed but seems to be tolerable at anything over about 15 mph. The response is infinitely better and we haven't lost any wheel travel. The drop is about an inch and a half. I also slotted the front strut mounts and pushed the struts as far negative as they'd go. Purely by eyeball, I'd put it at about -1.5. Because the car was such an understeering pig before, and because 9kg/mm is a pretty serious spring, I've pulled the front sway bar. Actually, right now it's running without a front or rear bar. Got to do some hooning to see if the rear bar should go back on. Those friggin swaybar links, grrr. A combination of rust, stupid design and my incompetence meant I had to pop all four out of their sockets to get them off the car.
Now we're just waiting on the cold air kit to show up. Past that its time to start playing with air pressures and contemplating the necessity of rear swaybars.

***

So I took the car out for some hooning and the news is mostly good. I did all the testing without any swaybars.

In slow corners the response is much better, it still understeers at the limit, but not badly. I get very little body roll and the turn in is almost instant. In transitions the car feels awesome. A touch of roll in the front, the back inside wheel just a little bit off the ground, nice neutral balance. Throwing the car at a transition it feels like the fronts bite and the back tire steps out just a little bit before the whole car hunkers down and shoots out of the corner. Very cool feeling and very fast.

My tires aren't great, but this already handles better than anything else I've driven. (C4 Vette, 3rd Gen MR2, Evo8, Street TouringX prepared Talon AWD, bone stock 914, FC) I can't wait to get some serious rubber on it. Which brings me to an amusing point. I might be able to fit 205/50s, but if I go any bigger I will need to roll/flare the fenders. Flared Daewoo ... hmm.

The only bad news came in longer, faster corners with bumps, which sucks, because a long fast corner with bumps is the most important corner on the track I want to run. On smooth fast corners the car feels great, with mild understeer on the throttle, four wheel drifts with maintainence throttle and oversteer on trail throttle. But when it hit bumps it feels like that back inside wheel touches down, at which point the entire rear end lurches. It hasn't actually done anything when lurching, but it feels really weird.