Floor Pan Swap - haldex to come...

[145117]

Re: Floor Pan Swap - haldex to come...

how is this awesome build progressing?

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Installed and wired up my new precharge pump the other day... rather than order parts and repair the old pump, I just ordered a new one for about $30 extra from a seller named haldexpart on ebay. Same guy I bought the Sport Insert from - fellow enthusiast, quick shipping and no funny surprises when the parts arrived.

Re-soldered and shrink-wrapped the wires...




Little wire protection...




Originally I had planned to try full time AWD with pure Haldex fluid (just to see how bad the binding would be) and then to swap in a little LSD friction modifier at a time until the binding went away. Since I was draining fluid to replace the pump, I just exchanged 50ml of the Haldex fluid with the Red Line friction modifier that I have and called it a day. Next time I'll try 30-40 ml instead just to see if a little less will work.


As it is now though, all four wheels are active and I'm getting no binding whatsoever. I've uploaded a jack-stand vid of the new pre-charge pump in action...

[All_Euro]

Re: Floor Pan Swap - haldex to come...

no updates?!?!

I know, it's been a while... been busy chasing a vac leak and tidying up odds and ends.

Had a coolant leak from a pinched o-ring, where the hard coolant pipe attaches to the block under the thermostat, so I replaced that - other fluids are sealed nicely. Want to tidy up the catch can lines... did work on the boost pipes - extended the hard pipe above the exhaust mani as much as space allowed. Fixed turbo to mani bolts that I overtightened. Noticed some cracking on the fuel injector wires so I stripped those back and replaced them with the TT clips and protective boots...

[All_Euro]

Re: Floor Pan Swap - haldex to come...

After daily driving duties for a week or two I did hook up the precharge pump to give it a go... there are only two wires controlling it - a black ground wire and a yellow positive. I tied into a common ground location on the inside of the drivers side rear fender and then went up to the fuse box with the positive. Since I don't have a rear wiper, fuse #27 was available and retained for service.

Unfortunately, the pump was weak right from the start... both wheels were rotating at first, then just the passenger and the next day it was toast - didn't even get to drive it. I haven't pulled it out yet so I don't know if there is fluid on the wrong size of the seals or if it's a brush wear problem but a new pump will be here early next week and I'll have a look after it's replaced.


Squeaky wheel vid...

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Driveshaft is just a little too long to bolt up in one piece so you'll need to find enough play on the engine/rear diff ends or install it in two pieces and then attach... kind of messy but not too bad if you're careful - good time to swipe in fresh grease...



With these centre brackets I just bolted them up in the middle of the adjustment range and then you'll want the driveshaft to be in the middle of the trans to diff range of play. I'll get in touch with Standens to get their thoughts on driveshaft alignment and take it in if recommended - will let you guys know how I make out with that...



This picture is a little deceiving but the downpipe is only a few mill's away from the driveshaft flange - not sure what stock clearances are but thankfully it's not rubbing...

[onceover]

Re: Floor Pan Swap - haldex to come...

Maybe it lit on fire from that oil return line?

[145117]

Re: Floor Pan Swap - haldex to come...

no updates?!?!

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Finally made time to install the new transmission - thanks for the clutch disc Natty.

I was expecting a struggle but it popped right into place thankfully. I just pulled the transfer case off and balanced the transmission on a jack - the tranny is tilted away from the firewall so it clears the subframe. Raised the jack until the spline notches into the clutch disc and then rolled the trans forward while pushing in...



In but filthy - cleaning session is in order...




I had to redo the oil drain from the turbo as it wasn't clearing the axle very well - the K03 line is a bit too short and the K04 line also has a bracket that bolts to the block so it stays out of the way of the axle. K04 top connected to the K03 bottom...

[martin13]

Re: Floor Pan Swap - haldex to come...

Hopefully the strength of the welds you made trying to get that bolt out aren't indicative of the ones holding your floor and rear suspension in

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Haha - so those Talon guys were doing it before Corky Bell wrote about it... I wonder if that's where he got the idea

The primary purpose of the external spring and its other benefits are addressed in the thread I linked above. I was seriously considering an awd Talon before I bought my last Jetta though - still working on the awd part.

[bobkatkat]

Re: Floor Pan Swap - haldex to come...

Ya the spring mod was some thing that used to be popular in the 80s and 90s on talons etc. I know that a lot of others have done a tone of testing on the KO4 framed turbos, Mantis on here seemed to find the sweet spot for actuator crack pressure and high boost for a KO4. Also there have been dyno testing. One comes to mind.

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Unless you are going to remove the n75 and run a MBC or aftermarket EBC and boosting over 30lbs (poor little KO4)then you are over thinking this a bit too much. If not, as Pat said just let the N75 control the boost to what ever level you want. I looks like you have a lot of room for adjustment of your actuator arm. Just preset the tension with a Mighty Vac to 12-14lbs cracking pressure. In any even you should be using a Mighty vac to set test the actual cracking pressure with or without a spring.

Hey Bob, no danger of overthinking this simple little mod - I've been doing this with success for a little over three years now.

If I remember right, VW recommends adding 2 or 3 psi of preload on the wastegate and the last thing I'd want to do is add a bunch more than than. Cranking the wastegate reduces the amount of travel on the rod and therefore the ability of your wastegate to open fully... which leads to overheating.

Here's where I first learned of this wastegate actuator spring mod but Corky Bell also makes reference to it in his book "Maximum Boost".

As mentioned, this spring mod is simply an inexpensive way of preventing your wastegate from opening prematurely in higher boost applications... the wastegate still opens fully to expel exhaust gases as soon as my target boost has been met. Check the link...

[bobkatkat]

Re: Floor Pan Swap - haldex to come...

Unless you are going to remove the n75 and run a MBC or aftermarket EBC and boosting over 30lbs (poor little KO4)then you are over thinking this a bit too much. If not, as Pat said just let the N75 control the boost to what ever level you want. I looks like you have a lot of room for adjustment of your actuator arm. Just preset the tension with a Mighty Vac to 12-14lbs cracking pressure. In any even you should be using a Mighty vac to set test the actual cracking pressure with or without a spring.

[All_Euro]

Re: Floor Pan Swap - haldex to come...

Or you can allow the ECU to control it with the N75 valve as it was intended. Not sure what the benefit of doing it this way is?

Yep, and that's fine at lower boost levels. At higher boost the wastegate ends up cracking open early because of inadequate spring pressure. Then the turbo has to spin harder and harder to try and meet boost demands - overworking turbo in the process. This is why the EFR lineup, for example, offers different wastgate canisters.

[onceover]

Re: Floor Pan Swap - haldex to come...

Or you can allow the ECU to control it with the N75 valve as it was intended. Not sure what the benefit of doing it this way is?