F20/D20/F28 Revisited

gse_turbo · Post by **gse_turbo** » Wed Jan 30, 2008 10:07 pm

so what's your take on the aluminum eco tranny mounted to our motors? the starter would have to clearenced in the tranny from the looks of it but 4 outa 5 bolts are a match.

Post by **PrecisionBoost** » Thu Jan 31, 2008 3:04 am

Well.... I'm not sure.... It does look the same, which would explain why the Saab transmissions (which seem to be coupled to the Saab Aluminum Ecotec ) look like they have the same basic pattern.

Here is the F40.... which mates up to the Aluminium Ecotec as well :

Here is the 4T65-E that mates up to the Aluminum Ecotec.....

gse_turbo · Post by **gse_turbo** » Thu Jan 31, 2008 5:33 pm

+1 that's what I said when he told me about it but I don't know where the drawing he had came from, he said it was an eco. do you know if the first aluminum eco (there are two generations in the States) used a different flange?

that is a pretty good pic, I'll pass that on and see what he says.

Nubaroo · Post by **Nubaroo** » Mon Feb 25, 2008 8:20 pm

Hi there all. Please tell me if this makes any sense???

I have a Daewoo Nubira 1999 model with a T3/T4 turbo making on the motor 335HP and 296ftpd. From what I have read in the forum my car comes with a D20 gearbox good for about 200ftpd?? I have run this car at the above power for the last 2 years running "semi slicks" on race days for better launch and I am really abusing the gearbox on the shifts. I am launching at approx. 4000rpm with minimal wheelspin and doing the 1/4 mile at 14.216sces and 100.66mph.

My question is - why is this gearbox holding up so nicely??? Also I am still running stock machined internals and 13PSI boost. I am planning to upgrade to forged internals and 22PSI boost and I am worried the tranny will die???

I also read in one of the topics that one can have the engine mounts modified for better durabillity - I have broken 3 x mounts already - please axplain how to upgrade them. Pictures will be even better.

The control arm bushed are also too soft - how can I make them last longer than 10 000KM????

Post by **Efratech** » Mon Feb 25, 2008 9:28 pm

the lb.ft rating has been a myth for years

Pir0 · Post by **Pir0** » Mon Feb 25, 2008 9:46 pm

Just because the car is over 200lbft of torque doesnt mean the gearbox will shit itself instantly.

It's not buit to handle over 200, likewise, your engine was built to handle a turbo, but they're both doing a decent job of it at the minute lol. Over 200 is very dodgy when doing launches though, especially on semi slicks/slicks where it bites hard on the ground.

Either that, or your clutch is slipping lol. It has to give somewhere, if not the clutch or the tyres, the most likely next in line would be your gearbox. I guess you've just been lucky lol

exist3nce · Post by **exist3nce** » Tue Feb 26, 2008 12:03 am

Ya that would be my guess as well - lucky. When the gearboxes are mass produced I'm sure some end up being stronger than others, so maybe you lucked out and got a stronger one made perfectly with no flaws. I think the above 200 ft lbs thing is just where MOST people start to see problems with the F20/D20. So you are well over the expected limit, so its really anyone's guess when it would break. You could be right on the edge, and with another 10 ft lbs it will rip itself apart. Or it could take another 50ft lbs before something happens. Mine broke with only 245 ft lbs and never using slicks or doing hard launches.

Nubaroo · Post by **Nubaroo** » Tue Feb 26, 2008 4:55 am

I am running a standard type "MECARM" clutch. One thing I cannot stand is a clutch slipping!!!!! and as a result WILL change it the minute it starts so I can definitally say it is not slipping. I must say I do get wheelspin on the semislicks and I am sure that is my saving grace. This is now where one has to ask, do we do a LSD for a better launch - more strain on the tranny. I might be opening a whole new can of worms once I go that route.....and having to spend a WHOLE lot more money.

Everything is working together sort of nicely at this point. If I get the forged pistons ( already got the conrods and ARP bolts) I can run more boost, but then I thingk I would need the following to keep the car reliable:

1) Opel TS 6 speed gearbox with LSD
2) Button clutch - 3 puck
3) Opel TS side shafts
4) Uprated engine mounts and control arm bushes
5) Uprated brakes
6) ???????

All of the above should set me back no more than ZAR 25 000! a bit steep on my paycheck.
Any suggestions?????

exist3nce · Post by **exist3nce** » Tue Feb 26, 2008 5:24 am

Nubaroo wrote:Everything is working together sort of nicely at this point. If I get the forged pistons ( already got the conrods and ARP bolts) I can run more boost, but then I thingk I would need the following to keep the car reliable:

1) Opel TS 6 speed gearbox with LSD
2) Button clutch - 3 puck
3) Opel TS side shafts
4) Uprated engine mounts and control arm bushes
5) Uprated brakes

If everything is working nicely, then you have to decide how much you really want more power. If by the opel "TS" 6 spd you mean the F28, then yes I think you will need that and all related hardware to go with it (including new clutch). Mounts and brakes would certainly be nice as well.

Nubaroo · Post by **Nubaroo** » Tue Feb 26, 2008 5:32 am

I am pretty happy with what I have at the moment....however the other day at the races I had my BUTT handed to me by a Subaru WRX STI!!! It ran a 13.3 second 1/4 mile and I ran 14.3 sec.....and this after I was ahead on the launch and 1st gear - obviously the WRX was well tweaked!

Times like this I think I should just spend the money on the GOOD STUFF, but where does one draw the line.......?????

Maybe I should concentrate on bigger brakes ( mine are still standard), nicer interior, additional styling and accept the car for what it is - make the most of what I have and live with it??

kinkyllama · Post by **kinkyllama** » Tue Feb 26, 2008 9:53 am

Nubaroo wrote:I am pretty happy with what I have at the moment....however the other day at the races I had my BUTT handed to me by a Subaru WRX STI!!! It ran a 13.3 second 1/4 mile and I ran 14.3 sec.....and this after I was ahead on the launch and 1st gear - obviously the WRX was well tweaked!

Times like this I think I should just spend the money on the GOOD STUFF, but where does one draw the line.......?????

Maybe I should concentrate on bigger brakes ( mine are still standard), nicer interior, additional styling and accept the car for what it is - make the most of what I have and live with it??

There's a chance the stronger F28 6sp won't even handle the power your putting down for long. 280ft.lbs has seamed to be a good point to stay under to keep it reliable and your already over that. Chances of you getting another perfect tranny from the factory is slim. I say save up some money, get an F28, LSD, clutch/flywheel, and strengthen the F28. Especially if you want more power but do the tranny first. You might even want to consider fixing up the tranny you have no to handle the power, I'd guess the price would be close to the same so it'd come down to which gear ratios work better for you.

What width semi slicks are you running?

If your just doing drag racing and not being aggressive on the streets I'd stick with the factory brakes. Otherwise a BBK would be nice, and lighter than the factory brakes unless you go huge with it.

It's up to you rather you want to make more power or put your money into other things. Your making good power and times now so you don't really NEED anymore.

Nubaroo · Post by **Nubaroo** » Tue Feb 26, 2008 7:25 pm

The semislick tyres are Dulop Direzza 195 - 55 - 15 ones and I run them with a tyre pressure of 1 bar at the races.

As you say I think I should first look at the brakes - upgrade to something powerfull, then look out for a F28 box that can handle extra power and then go for stronger internals - it makes sense - that way my car will be safer to drive and I should not land up with something broken...LOL

I do like a bit of "street racing" when I am driving out and about - I have given many hidings to poor unsuspecting suckers ( Subaru WRX STI/M3/Merc C320/Audi S4 etc etc) but mostly just 0 to say 180km/h robot to robot racing. Every now and again on the freeway maybe as well, but not bobbing and weaving through traffic like some of the clips one sees on the forum!!!

The standard (machined) internals are handling the power for now, but everytime I boost up to 13PSI I fear for the worst - broken rod or piston.... The forged stuff ( I already have the forged rods and ARP bolts) should give me peace of mind even though I will only run the car at 13PSI boost till I do the tranny upgrade.

Thanks for ur advice - I now know which road to follow.

Post by **PrecisionBoost** » Wed Feb 27, 2008 2:58 am

Nubaroo wrote:I have a Daewoo Nubira 1999 model with a T3/T4 turbo making on the motor 335HP and 296ftpd. From what I have read in the forum my car comes with a D20 gearbox good for about 200ftpd?? I have run this car at the above power for the last 2 years running "semi slicks" on race days for better launch and I am really abusing the gearbox on the shifts. I am launching at approx. 4000rpm with minimal wheelspin and doing the 1/4 mile at 14.216sces and 100.66mph.

Well I'm a bit confused here..... 335hp and 296 ft lb and your only running 14.216 witth "semi slicks" ?????

Something is very wrong here..... are you rating that power at the wheels ( via dyno/rolling road ) or is that a rating at the crankshaft?

So your car has a curb weight of roughly 2566 lbs..... that means your 1/4 mile should be about 11.5s if your making 335hp at the wheels.

Even if it's rated at 335hp at the crank you should still be running about 12.1s 1/4 mile

My stock Mazdaspeed 3 is a fat 3790lbs and is rated for 263hp at the crank.... I found it to be about 233 hp at the wheels ( http://www.daewootech.com/forum/viewtop ... mazdaspeed )

Most Stock Mazdaspeed 3 vehicles are running right around that range of 14.3s / 100MPH

Long story short..... I highly doubt that with that kind of 1/4 mile your managing to put down any more than 180 hp at the wheels..... probably closer to 175whp

I'm not trying to be a jerk or anything.... I'm just saying that there must be some confusion about your power levels.... I don't think your exceeding the power handling of your D20

You also mentioned 13psi of boost as what you currently run.... there is no way on earth that your making 335hp on just 13psi with stock internals.

Here is a dyno of 238whp at 10psi on an engine designed and built to be efficent for a turbo setup.

This particular car did the 1/4 mile in 14.7s with an older weaker engine (194whp) and street radials that spun out for the first few gears.

Nubaroo · Post by **Nubaroo** » Wed Feb 27, 2008 6:38 pm

Hi there.

Nothing wrong with some constructive critisism...LOL

My car standard weighs about 1233KG ( 2718lB ) and if you add the additional weight of the Turbo, branch, wastegate and its relevant accessories, bigger exhaust system, bodykit etc etc I would say the weight at a good guesstimate would be round 1350KG ( 2976lB). The car has not been lightened in any way - I dont want to sacrifice any features on the car and if I start removing seats, window mechanisms, roof liners etc etc the car would fall in a different class on raceday i.e. the guys that run 9,10,11 and 12 second 1/4 miles!!!! I guess the weight on the car could be a BIG issue on the "slow" 1/4 mile time???

If I run the 1/4 mile on standard tyres I get 14.6 secs with LOTS of wheelspin, and with the semislicks I get less wheelspin and the better time of 14.216 sec.

As for the power on the car - If you look at the members section - Daewoo Nubira Turbo from South Africa you will be able to see my latest dyno printout - 195KW/324NM (261hp/239lb-ft) on the wheels.....unfortunately the dyno result does not indicate boost which is set at 0.9bar. I also have an older dyno result before I upgraded to bigger intercooler and injectors showing power on the crank which indicate 228KW/398nm (305hp/293 lb-ft) which brings me back to the question - why is the tranny not giving up on me yet????

The fact that my car runs 14.2 secs @ 261hp on the wheels and yours round 14.3 @233HP taking into consideration weight of the cars, ambient tempereture on the day of the runs, traction on the track, etc, etc makes sense dont you think???

I think to run in the 11 or 12 seconds you need MUCH MORE POWER than what I have at the moment, something like this Opel TS running in South Africa

A lot of people have commented on the amount of power my car make with the low boost (0.9bar) AND STOCK MACHINED INTERNALS I am running. I don`t know why it happens it just does.....if you look at my car (members section) you will see me run the1/4 mile against an Opel Astra Coupe - he is running 1.2 bar boost with watermist injection and I still give him carrots....and both cars are running Ecotec 2.0L engines. I think I am just lucky that everything works so well together.

gse_turbo · Post by **gse_turbo** » Wed Feb 27, 2008 6:50 pm

wow! good on ya mate!