daNpy - Golf MKII Group H

Discussion in 'Say 'hello' in here.' started by daNpy, Apr 4, 2022.

  1. Adamss24 Forum Member

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    Nice of you to Keep on top of maintenance! Pity that oil cooler split, it should withstand 5 bar of pressure without much bother !
    What brakes are these on the front ? They look nice !
     
  2. daNpy Forum Member

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    They are G60 brakes with Hawk pads on Brembo slotted discs.
    Thanks for the compliments. On the track you don't really want to take risks :)
     
  3. daNpy Forum Member

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    Brake ducting is going quite well, made a hole in the dust cover to get access to the disc. Also made additional holes in the lower front plate to allow the intakes to fit.

    The only minor issue is, how to get the hose to stay connected with the inlet. The inlet has a short extension for the hose fit. Using clamps specifically for these duct-hoses but after some fiddling they some loose.
    Just add some good old tape I guess?

    IMG20220716111824.jpg IMG20220715205327.jpg
     
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  4. daNpy Forum Member

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    It fits
     

    Attached Files:

  5. daNpy Forum Member

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    Yesterday I went to Zolder again. It was getting a bit close, as on Tuesday the hose decided to part from the connection on the oil cooler.
    I had no spare oil anymore and had to switch brands, but in the end I managed to remove the oil cooler, hoses and adapter plate and fitted a new filter and new oil. I was also not quite happy with the brakes, they are different as normal. A MK2 pedal is always deep, but this time it was even deeper. I re-bled the brake fluid once more but it didn't help.
    I also spent many hours on cleaning the oil but today it is still dripping. It was really everywhere in the front left, also over and in the front member, gearbox etc.

    Yesterday was really warm which brought some more challenges. I can't really say if the brake cooling worked, as I didn't trust the brakes for 100%. The brake power was there, but the pedal remained deep. I noticed I was braking with my toe... The brakes did feel the same over the whole afternoon.
    Also the engine itself was getting warm, I saw over 140 °C of oil and 120 °C of water temperatures. I had to take cooling laps every few laps and sometimes managed to keep the oil just below the 140 °C on the laps. This did mean I 'play' with the others who were just a bit faster or slower, that was too bad.

    And then there was the not-starting issue with hot engine. The starter turns, but the engine won't go. According a friend of mine it could be vapor lock in/after the injector. When cooled down a bit, the engine starts and runs normally.
    The gearbox mechanism also showed a lot of play, I have to see if I can fix it for the rest of the year, the plan is to build in a 020 in the winter anyway.

    So, things to do
    - check/replace/overhaul master brake cylinder (Meyle, € 50,-, Ate 250,- [:[])
    - check/overhaul/replace front calipers
    - buy decent stuff for the oil cooler and fit it once again...
    - find a way to cool the engine better, would a Davies Craig electrical waterpump help?
     
  6. daNpy Forum Member

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  7. daNpy Forum Member

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    [youtube]
     
  8. daNpy Forum Member

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    Unfortunately the E46 coupé went into the pits. Without the high engine temps I could have overtaken him earlier :)
     
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  9. daNpy Forum Member

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    Piece of the third session:

     
  10. Tristan

    Tristan Paid Member Paid Member

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    I don't know if an electric pump would be better, they seem to be fitted more for space purposes than anything. Even newer VAG Tdi Stuff with the "electronic" water pump only uses electrics to disconnect the pump.
    Can you go bigger /thicker with the radiator? Open any more of the opening?
    Is it all sealed around the sides?


    Re the fuel, higher temperature can cause funny problems. We had it on one of the Rally cars, on hotter European events ot would start boiling the fuel, and vapour lock. Only when on the walking pace, lining up to the start.
    We created a few extra bonnet vents. And got the exhaust manifold thermally coated by Zircotec, that made a big difference.

    I've heard of people putting fuel coolers on the return line.

    Does your return go to the tank or to the swirl pot?
     
  11. daNpy Forum Member

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    Hello Tristan,
    thanks for your reply.
    I've mounted an Opel radiator, as it is wide, but not as high as the VW variants. Initially I wanted to be able to direct cool air over the radiator into the motor, but as I have fitted an airbox due to noise restrictions, that's not directly necessary anymore. The radiator is also mounted a bit to the front of the original one, as the airbox is quite big. Actually I think it's due to the "long" manifolds before the ITBs. Still there is a bit of touching condition between radiator and airbox unfortunately.
    I was thinking of putting the biggest VW variant back, but I haven't quite come to that. The main problem is that the entry of the radiator is on the RHS top and that's where the airbox is. Routing the hoses will be a big pain.
    It's also possible that there will be a fitting issue with the oil cooler, when I'm going to put that one back.

    The radiator is not sealed around the sides, the only thing I did is make a "scoop" on the lower end to avoid the air into the bumper going under the car. It's now forced into the radiator. I've already made some samples with cardboard to seal of the top as well, but didn't come to it to make them of alu.

    What if I remove the thermostat? It's not really needed, just takes some more time to heat up the engine, but it does not restrict the flow anymore.

    My fuel returns to the tank, I don't have a swirl pot yet. I think that the temperature problem would only be increased if I had one fitted.

    Some additional bonnet vents would be good, but how to make them without having to respray the bonnet? One of the previous owners had the car painted in some kind of "metallic Porsche green", and that means $$$. The color is hard to come close to, I already bought some paint to have the interior painted.
    Worst thing is, the paintjob is very badly done.
    A carbon bonnet would be nice, but also quite expensive ofcourse.

    Fuel cooling might not even be necessary, as long as fresh fuel is coming by the injectors, whilst the car is running, there is no problem. When the engine is turned off, starting again is an issue.
     
  12. Tristan

    Tristan Paid Member Paid Member

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    Last point first, that sounds like heat soak alright.

    I was always told an engine needs a 'stat, it's not just to help it heat up, but it helps the engine cool properly too. By creating a bit of backpressure, it makes coolant circulate more effectively in all the nooks and crannies of the castings, and stops "dead" areas remaining hot.
    Like the way in a fast running stream of water, the area behind a large rock could remain still and calm.
    The only instance you'd definitely remove it, is if you had an electric pump.

    I usually fit either a lower temperature one, or drill a 3mm hole in the stock one myself.

    I think it was actually here, years ago, but I distinctly remember someone who used to work on cooling packs for OEMs saying you need to close in the 4 sides of the rad so all air in front of it has to go through the fins, otherwise it will "spill" past it either side, or top and bottom.

    And if you have a fan, it's not really effective, without a full shroud.
    Also, giving the hot air from the rad fan somewhere to escape can be a big help.
    If not cutting a vent, raising the bonnet up on the hinges even.

    What coolant are you using? I'm switching to a very low amount of antifreeze, and adding RedLine "Water Wetter", myself.

    Is your exhaust manifold thermally insulated?
     
  13. daNpy Forum Member

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    Thanks for the theory! That 3 mm hole is done easily when the stat is out :)

    Yes that is logical, the thing is it is not really easy to make it completely closed, but I will try and start closing the sides too. Some rubbery flaps like the OEMs would be good, but where to buy it?

    I understood that's true for when the fan is blowing when standing still. The fan wil make a vacuum in the shroud and sucks the air through.
    When driving you have the wind and above certain speeds the fan won't even help.

    Yes, that tip has been given on another forum as well and I am looking into it. Making a hole in the first half of the bonnet should suck air out due to the vacuum that is there. It could help a lot if I would make a vent (like these guys) where the airbox isn't, so on the gearbox side. Above the ITB's I could make some triangles too.

    The thing is, the car has been re-painted in an expensive Porsche metallic green. I've already tried to get this color for the interior but the closest we could get wasn't quite the same color... for the interior it doesn't really matter, but I have no interest in re-painting the bonnet in a color that's not the same.
    So either I have to do a real clean cutting job (and no welding), get a custom carbon bonnet, or buy a second bonnet to try out first (and that's what I am looking into now).

    Normal coolant. How can I find which coolant/ water additives have better cooling capacities?

    Yes!
     
  14. Tristan

    Tristan Paid Member Paid Member

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    Pure distilled water, ideally that has been through reverse osmosis is the best fluid for cooling.
    Water Wetter is a help.
    If you need antifreeze for low temperature, the absolute least amount possible.
    https://www.redlineoil.com/waterwetter

    There are other similar additives available, i haven't used any others personally


    Re sealing off the rad, I used rally Mudflap material.
     
  15. daNpy Forum Member

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    So distilled water + water wetter is recommended? I can change to that, the car is "never" at freezing temperatures.

    How about Motul Mocool? Seems to be the same application as the water wetter :)
     
    Last edited: Aug 8, 2022
  16. Tristan

    Tristan Paid Member Paid Member

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    Not familiar with it, but looks like a similar product.
     
  17. daNpy Forum Member

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    I'll try to add it to the order of oil that hopefully has not been sent then:)
    Again, many thanks for the help!!

    I also ordered revision kits for the front brakes and the gearbox selector mechanics, which will arrive end of the week :)
     
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  18. daNpy Forum Member

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    Been busy on several things lately, but unfortunately time is short when the holidays are planned almost full [xx(]

    I've been working on following;
    - new plates for the brake cooling, I am looking for someone who can weld alu so I can add some pipes for the hose connection;
    - gearbox bushings have been replaced
    - front brake calipers are finally painted black (today)
    - bought new hoses and connectors and a new sandwichplate for hte oil cooler, to be fitted still (but I am kind of anxious)
    - bought a second hand bonnet, placed it on the car today to locate the pins of the aerocatch, so it will fit like the current one obviously. The bonnet is going to get some nice holes in them to get rid of the hot air, as tipped over here:thumbup:

    My current plan:
    Motorkap_aampassingen.jpg

    I found a video on-line where they have a similar temperature issue and just cut a nice U shape out of the hood, press the front down and weld the side shuts again. That's what I've drawn on the right of the image. The green line in between show the gitter is under an angle (see the side view in the top).
    As the airbox fills the front quite tight I thought about making air outlets above the ITBs. Hot air is still passing the ITBs, but it doesn't stay "hanging".
    Also on the left in the picture I've added some rectangular outlets. I don't want to cut of the reinforcement completely, so their exact location is to be defined. There is no direct relation to the radiator, but it's still meant to take out hot air.

    What do you think of the setup above? Pro's, cons?
     
  19. daNpy Forum Member

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    Unfortunately no replies on the proposition for the cooling. Maybe I can try a drive with some wool strings taped to the bonnet to verify where the air pressure/vacuum is. That would give a nice insight.

    Yesterday I finally got to mounting the front bakes back and bled them. The pedal is now much harder and half way, so that appears to be good!
    I really thought it would be in the master cylinder, that would make more sense. Let's see in the test drive next weekend.
     
    Last edited: Sep 29, 2022
  20. dodgy

    dodgy Paid Member Paid Member

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    There is quite a good thing about mgf/tf vented bonnets and the vortex caused by doing so, where the airflow is and relation to slots screen etc.
    But it was about 4 or 5 years since found it, quick search hasn't found it, but will delve when get chance.
     

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