186 replies to this topic

[chris_uk]

i had the same idea about these vents.. i was going to look at using 2 rads for the charge cooling then i could get rid of the larger one under the front rad.

[cs_]

Got all of them. The PA Pre-Rad plus additional 3 rads left, right and in the middle. I am pretty sure the IAT-temperatures will be no issue anymore, even at full throttle for a longer time. Main goal is to achieve better times on quartermile in summer. Recently times at subsequent runs were lower than on the very first. The water inside the secondary cooling system kept too warm. Also while driving high speeds on the Autobahn got significant IAT and power drops. Think they will be gone now.

 

I'm not sure though what will be the impact on the (engine) cooling. Maybe the temps will rise too high now. Will know it some weeks from know.

 

Btw. the rads have a well thought sequence. Warm water starts in the big PA rad beneath the primary engine cooler, then goes through both outer ones and at last passes the middle one returning to the (7-core-) charge cooler in the back of the car. Water always flows from bottom of the rads up so that bubbles have no way of remaining in the rads, they will be blown out very soon.

Edited by cs_, 02 April 2014 - 05:38 PM.

[cs_]

Almost done now...

 

 

[KurtVerbose]

Cool - litterally!

[siztenboots]

sub-zero

[leevx2.2]

Top job have fitted the small oil coolers myself, just need to duct them the same as you I am venting the hot air that comes out of mine up through my wing vents .

[Cookies220]

Top job have fitted the small oil coolers myself, just need to duct them the same as you I am venting the hot air that comes out of mine up through my wing vents .

Have you managed to fit your coolers and wheels at the same time Lee   

[chris_uk]

Top job have fitted the small oil coolers myself, just need to duct them the same as you I am venting the hot air that comes out of mine up through my wing vents .

 

duct it to 1/2 of the vents and use the other 1/2 for the high pressure release in the wheel arches.

[cs_]

First launch was two weeks ago, everything works as supposed.

 

 

Here's a diagram of an acceleration from 0 to 200 kph at 18 degs celsius, it shows the IAT:

 

 

Some remarkable facts:

 

- the instant temperature rise at full throttle has dropped from around 25 degs to ~15 degs, the PA 7-core charge cooler is a large improvement over the old 5-core.

- after releasing the throttle temperature drops back down within seconds.

- what you can see is, that the water in the systems needs about 41 seconds to circulate which means there is some 7 litres inside that has to move around. after 41 seconds you can see the former 33 degs warm water that now only has 23 degs. that makes the four front coolers a good way to keep IAT at a low level constantly.

- the critical temperature for engine protections is 55 degs celsius. that is far away now, even if you think about ambient summer temperatures of 35 degs.

 

I am very happy about the outcome of all of this. was a long way to go this winter, but everything worked well right from the start. a stint on a local racetrack will follow some time this year topush the system to it's limits.

[Ormes]

Car looks mint... and glad the hard work paid off

[Nev]

Good work Carsten, glad to see your car going from strength to strength.

[cs_]

The joy of power passed away soon, OBD fuel trim values danced to some weird tune, everything OK at full throttle, but much too lean at very low power or idling. Sherlocked some time and finally found the reason: the K16NG2 Turbocharger had two of the four screws connecting the turbine housing with the centre casing gone loose somehow and exhaust gases passed out between. And in case of low power fresh air got in that way.

 

Did not want to fiddle by myself with the charger. So I drove the car on a trailer down to Giessen to Regelin-Performance. Dismounting the charger, the problem got to the point I hoped could be avoided: at least one of the screws was loose because it has been broken inside the turbine housing. Part of the thread remained inside the cast. So a revision of the charger had to be done.

 

Interesting: the screw hat a marking "8.8" which may be a problem if it is a "normal" 8.8 steel screw. At the hot end of the Turbo you need heat resistant screws of a special alloy.

 

I had to drive home with an empty trailer. Now waiting for a sign from the Manufacturer of the charger which is no official one, the Next Gen chargers are done off the line of the official production processes.

 

I am *a bit* angry about that. The charger is some 30 months old. But it has only seen some 5.800 kms over this time. The manifold is as good as new, no heat signs, no distortion. Never seen too high AGT, alsways had an eye on the Lambda.

 

Hopefully this will be fixed permanently. Heard about some more NG2s failing in the same manner. No good perspective...

[Nev]

Hmmm, maybe they unwound themselves due to vibration (very high freq). I guess you will threadlock and double chek them on the next turbo.

 

Good luck.

[Baron Von Scubadaddy]

Today everything worked out fine:

 

Can you please go back to that location with your vx and do a nice tracking shot from up High 

that zooms in to just about windscreen hight and fly past the vx over the grass to the side

then pan round and let the vx go off into the distance!!

 

car looks very nice I love the front 

you should make a mold.

[cs_]

Hmmm, maybe they unwound themselves due to vibration (very high freq). I guess you will threadlock and double chek them on the next turbo.

 

Good luck.

 

No, they did not unscrew. And you cannot threadlock where the turbo gets red-hot.

Got the information yesterday that the screws were not the proper ones. Turbo will be rebuilt with heat-resistant screws and modifications for better screwfitting in a way that they do not press on only one side again.

 

Will last until the end of august until I get the car back because of summer holiday. All that is a shame, the summer passes and I cannot drive.

 

 

@Baron

 

Had the same idea months ago but as you can see got other priorities these days.

Edited by cs_, 20 July 2014 - 05:53 AM.

[Nev]

That is a shame that you will miss the summer, you are one of the people who really impress me on this website - always innovating I used K-nuts on my turbo flange for this same reason of unwinding but if the turbo was supplied with unsuitable bolts are they paying for the replacement? The k-nuts on my car have thankfully stayed put on my car (except for 1 that unwound once). I heard about stories of the high freq vibrations unwinding everything on some cars.

[Nev]

If you really want to see a RC helicopter flown properly check this guy out....for those of you like me who've had a go themselves you will appreciate it even more.  

OMG, that's hard to understand how that works, quite incredible.

[cs_]

Too old for rock'n'roll, too young to die?

 

Sold my beloved VX yesterday. So I am saying farewell, setting sails, aiming for new shores.

Got 50 by the end of last year, feeling there has to be a new fun car. Did not feel the need for driving the VX for some years now and this told me there has to be a change somehow. And some months ago I saw the new Audi TT RS rising. That triggered some thoughts in my head that grew bigger and bigger. And right before xmas last year I made the decision, the VX will go to someone else. It took just about three weeks to sell the car. Did not think it will go that fast. Perhaps the price was too low. Now the contract is signed, car will be transferred around midth of february. And then, there will be a big hole in the garage. And in the heart. But selling my baby is also a relief. I am really looking forward for my new fun car. And beside of that I will keep my Golf R as the daily driver.

 

Thank you all for the years of participation, for all the informations I could gather here.

 

I will still manage the german forum in the future, but only as a passive member of the community. Forum and Blog will stay online. I am just going to drive an Audi from now on.

 

Bye bye!

[rob999]

Thanks for all the posts Carsten, sorry to hear the VX has been sold. What did it sell for? Was a lovely car. Stay on the forum and let's hear your thoughts on the TT....

[Nev]

oooh