Why is my GTD running so well?

[MontanaGTD]

Ok! I was running a little late for work one day on forgot to fill up the tank - I was already on the red. Got to work fine (42 miles), but on leaving work I had other stuff on my mind and didnt fill up on the way home. This time I wasnt so lucky! I got to the motorway offramp and ran out of fuel just at the top of the ramp. Lucky there was a fuel station not more than 300 yards away. So getting fuel was no problem!

Now 4 things have happened and I cant explain any of them!

Rev counter has stopped working - its not the clocks - if you waggle the wire that goes into the alternator then it jumps to life. cant keep it working without keeping the wire moving - any ideas?

Its harder to start in the morning from stone-cold. have to heat the plugs twice and then it fires.

MPG is up by an average of 5mpg and i havent changed my driving style.

The acceleration and top speed are up by a huge chunk! 60 comes up in about 11 seconds or so - speeds in each gear are different before running out of poke, but i have a weird flat spot in 3rd - 10mph or so in 1st, 25 in 2nd, 60mph in 3rd, 90 in 4th and over 120 in 5th (ran out of road!)

acceleration from 60-90 is quick enough to keep up with a motorbike on my twisty road home!

What the hell is going on with this thing???

[Black Smokin' Diesel]

Rev counter has stopped working - its not the clocks - if you waggle the wire that goes into the alternator then it jumps to life. cant keep it working without keeping the wire moving - any ideas?

Replace the wire. It's probably broken somewhere and you can't see it.

Its harder to start in the morning from stone-cold. have to heat the plugs twice and then it fires.

One or two of your glow plugs could be burned and need to be replaced. Test them to see what's up.

MPG is up by an average of 5mpg and i havent changed my driving style.

The acceleration and top speed are up by a huge chunk!

Better fuel? Maybe they switched to summer fuel. It could explain the cold start problems too.

[jtanguay]

it almost sounds like you need to clean some wire contacts... if your alternator has bad contacts, it won't need to produce much electricity because of the smaller path.

(alternator robs quite a bit of power... dont believe me just take off your belt and drive around  :wink: )

that is my best guess.  when my alternator wire corroded off, it was like the best 5-10hp i've ever had!!!  :lol: but i had to use jumper cables to start the car...

[burn_your_money]

that is my best guess.  when my alternator wire corroded off, it was like the best 5-10hp i've ever had!!!  :lol: but i had to use jumper cables to start the car...

Just carry a spare battery in the trunk and a set of booster cables. I did this for a few months with a rabbit

[jtanguay]

that is my best guess.  when my alternator wire corroded off, it was like the best 5-10hp i've ever had!!!  :lol: but i had to use jumper cables to start the car...

Just carry a spare battery in the trunk and a set of booster cables. I did this for a few months with a rabbit

i would honestly like to have a clutched alternator like the compressor... but yea yea clutch robs power still! hehe...

would be nice though for that extra kick

[745 turbogreasel]

OK So we need a relay that kills AC, cooling fan, and alternator current at WOT?  Sweet, Why didn't VW think of that?

[jtanguay]

OK So we need a relay that kills AC, cooling fan, and alternator current at WOT?  Sweet, Why didn't VW think of that?

That is a very good idea.  Put those stupid upshift light switches to some good use although I wouldn't kill the cooling fan.

Andrew

hmmm kill the cooling fan at WOT? i'm with Andrew on that one...  :lol:

just out of curiosity does anyone know how much electricity the a/c clutch draws???

[Black Smokin' Diesel]

OK So we need a relay that kills AC, cooling fan, and alternator current at WOT?  Sweet, Why didn't VW think of that?

That is a very good idea.  Put those stupid upshift light switches to some good use although I wouldn't kill the cooling fan.

Andrew

The cooling fan is there to help only when the car isn't moving or very slowly (below 20km/h). The cooling fan on my NA golf didn't work. In stop and go traffic temps would go very high but as soon as I'd pick up the pace and reach 40mk/h and more it would cool down fast. When the car is rolling, the cooling fan is useless and is probably not even on. Anyway as soon as the alt is killed, there's no need to kill anything else because it'll run on the battery. Unless you want to reduce the load being put on the battery to make sure it's not being drained but I doubt a short acceleration would do much to it. I ran my NA for 2 or 3 days on battery power because of a dead alternator.

How would one kill the alternator when rolling? As soon as the exciter wires "turns on" the alt it can't kill it. Unless you mean simply cutting all load being put on the alternator. You'd need one big ass relay. I'd put a switch on the alt kill setup just to have the ability to turn it on or off. A small delay on the system would ensure it doesn't "revive" the alt when shifting, something like a 2 second delay. I can't see killing and reviving the alt that often being good for it. A light indicator when the alt is killed would be nice incase something goes wrong and the system fails to revive the alt.

Wow I've never written the word "kill" so many times in one shot.

[dieselpower]

i did that exact thing when i was drag racing my car....i installed 5 relays inline with the alternator in the normally closed state then i installed a switch to open the circuits when i wanted to...it gave me a few horsepower...actually noticeable to my suprise...i was just bored when i did it and didnt expect much but it wwas pretty good

[Slave2School]

Usually when my cars start running really well it is a sign.  Increase the insurance to full coverage because you are going to lose the beloved soon.

[Black Smokin' Diesel]

i did that exact thing when i was drag racing my car....i installed 5 relays inline with the alternator in the normally closed state then i installed a switch to open the circuits when i wanted to...it gave me a few horsepower...actually noticeable to my suprise...i was just bored when i did it and didnt expect much but it wwas pretty good

Why did you use five relays?

Does anyone know if the load reduction relay used on our cars is a normaly closed relay? My guess would be yes but I'm not sure. It's a 4 pin relay so it could be a good cheap OEM alternative to aftermarket relays.

[jtanguay]

this is some pretty awesome discussion we have going... the rotating mass of the alternator could rob upwards of 5 hp IMO.  and exponentially as the revs increase.

i'm actually considering that, and the power steering pump as the culprits to my low mileage as compared to my older '86 TD with the 50 amp alt & no ps and no a/c!

[MontanaGTD]

All the wiring to the alternator has been replaced as some one had hacked it to fit one of them stupid security screws into the battery line to stop the car starting. I'm on my 2nd tank full since my run out and i've done 311 miles on half a tank!

[745 turbogreasel]

MontanaGTD, you didn't change tire size did you?

I don't think the AC clutch draws much compared to the compressor.  It does have kind of a beefy relay though...
Unless you have 4x4 low, you realy sholdn't need the cooling fan at full throttle, some EFI cars have WOT fan kill from the factory.

[jtanguay]

MontanaGTD, you didn't change tire size did you?

I don't think the AC clutch draws much compared to the compressor.  It does have kind of a beefy relay though...
Unless you have 4x4 low, you realy sholdn't need the cooling fan at full throttle, some EFI cars have WOT fan kill from the factory.

makes sense about EFI cars having WOT fan kill... they need the extra juice  :lol: