Serpentine Conversion.. now having issues!

[R.O.R-2.0]

So, i did a serpentine conversion to my non-ac/ps GTI yesterday. i know, its just a dumb gasser, but ive got a fetish with OVERKILL charging/cooling systems!  

can pretty much jump start a dead dump truck now, with all the power my car has. brand new over size battery, and a nice big alt!

i used the VR water pump pulley, because the power steering pulley was already gone, damn it! it would have worked OK with no spacer behind the pulley, but i wanted the belt to ride in the middle of the pulley, instead of on the edge, so i built an aluminum spacer for it, then everything lined up PERFECT! belt rides directly in the middle of the pump pulley. belt does not flutter at all.. not at idle, not at WOT.. no belt flutter. its friggen sweet!

i also used the VR6 120a BOSCH alternator.. its the same 120a that the TDI uses. its physically HUGE compared to the 90a alt i took off the car.. has the same W-term/D+ plug as the TDI alt, but with a regular rectangle injector connector, rather than the D shaped connector.. and it bolts right up to the ABA serpentine bracket perfectly.. all i had to do, to be able to use it, was swap the ABA pulley onto the VR6 alternator..

and, according to my butt-dyno, the car is just a little bit QUICKER now.. im absolutely amazed actually. i thought i would LOSE power from the huge alternator, but i swear it added some bottom end torque, just from the bigger spinning armature..

also, since i installed the ABA bracket on an 86 GX engine, i didnt get to install the top right (looking at the bracket) stand off bracket for the alt bracket.. so its bolted to the water pump with the 2 long, bottom bolts, and then it has only ONE bolt holding the top of the bracket to the block.. there was no provision for the top right stand-off bolt, that the bracket bolts to.. i looked the alt bracket over good and well, and i saw no reason that i couldnt safely run the bracket with only 3 of the 4 bolts holding it to the block.. it doesnt flex at all, and really doesnt have to do anything more than hold an alternator.. i should be ok with only 3 bolts right? or should i build up a bracket so i can use the 4th stand off bolt? i also had to make a little aluminum spacer to go behind the timing cover.

oh, and i forgot to mention the best part of the swap:

you know how most every old mk1 or mk2 VW has the "blip throttle to excite alternator" syndrome? well, my charge light now goes out before the OXS light, or oil pressure light!!!

its soo nice not having to manually make the alternator charge, now it just does it without any human input! could also have something to do with the fact that i cleaned every grounding point on the alternator/water pump/bracket, and die-electric greased every metal to metal connection between the engine block, and actual alternator..

anyways, this is DEFINITELY a worth while upgrade, even on a diesel, being that you have to get the crank broached, and use a TDI sprocket..

[Toby]

"Serpentine" refers to belt routing, not type. The type of belt is a "Poly V"; its only "serpentine" if it wraps back on itself and drives something from the back of the belt.

The reason the Butt-O-Meter registers more bottom end is more likely that the poly V belt uses less energy to spin the accessories. That is the major reason the use then. I have heard 5 hp in some applications.  Driving everything with one belt is just gravy.

[R.O.R-2.0]

so, maybe the serp setup isnt soo sweet..

it squeeks when its cold.

it vibrates at 3000 revs.

what gives?

[srgtlord]

If it squeeks when its cold, you need new bushings in your tensioner arm, and probably a new tensioner too. That squeeking noise is the tensioner arm machining itself on the bushing. I just finished refurbishing my serpentine tensioner setup.The bushings are a pain in the arse to get out but its doable. You will need the 2 steel tensioner bushings, 2 rubber seals , a new tensioner arm, and a new tensioner. All for about $70, cheeper than purchasing a new alternator bracket when your old one cracks in half.


You can purchase everything you need from IDParts.com, all the physical hardware in the tensioning bracket is the same for gas and diesel. To get rid of the weird vibrations you need the updated free-wheeling pulley which is about $90

[R.O.R-2.0]

screw it, im putting my V-belt setup back on the car if thats the case.

the tensioner pulley is brand new, and the tensioner arm doesnt move when its squeaking.. it sounds like the belt is squeaking, not the tensioner arm. besides, there is no detectable play in the tensioner setup.

i swear its the belt squeaking, and not the tensioner. because it wont squeak unless its raining, or very humid outside..

i did purchase a belt that was a TINY bit too long for the setup, think that could be causing issues?

[theman53]

On the 3/4 of the bolts holding it in you can weld a tab onto the IP lower bracket with an elongated hole in it. That is what I did and I stole that from libby. I did mine out of car, but you maybe able to get to it in car.

[R.O.R-2.0]

On the 3/4 of the bolts holding it in you can weld a tab onto the IP lower bracket with an elongated hole in it. That is what I did and I stole that from libby. I did mine out of car, but you maybe able to get to it in car.

im on a gasser car tho buddy.. no injection pump bracket..

didnt want to install this onto the diesel until i had a TDI crank sprocket, and mod..

does anyone have any idea as to why it vibrates @ 3000 revs tho? is the harmonic balancer shot? just wrong for a 1.8L engine? or do i have something else wrong?

[theman53]

Me getting caught up on all theads not reading...No idea on the 3000 revs? What kind of viberate? Is it the belt or is it felt in the car? Just wondering.

[srgtlord]

You probably need the harmonic balancer too....

[R.O.R-2.0]

You probably need the harmonic balancer too....

weird thing is, the balancer runs perfectly straight and true, not a bit of axial, or radial wobble.. the belt doesnt bounce at 3000 revs, but the engine gets a strange vibration that you can feel in the whole car..

[CRSMP5]

missing 4th bolt will let it vibrate dude... ive seen too many broken ac brackets on gas bunnies when 1 of those bolts break... and on a diesel.. hell the bracket would already be broken.. need to build a 4th bolt mount...

[R.O.R-2.0]

missing 4th bolt will let it vibrate dude... ive seen too many broken ac brackets on gas bunnies when 1 of those bolts break... and on a diesel.. hell the bracket would already be broken.. need to build a 4th bolt mount...

was wondering if that was the key ingredient to making it not vibrate..

swear ive seen people install it with 3/4 bolts...

can i just build an aluminum bracket that goes from a bolt hole a little farther north, to the location where the 4th bolt on the bracket is?

or should i build something out of steel, to avoid vibration fatigue?

i couldnt install all of the ABA stand off bolts, being that the boss for the 4th stand off bolt is non-existent on the old 1.8L engines..

[srgtlord]

Granted Ive had my setup for roughly 20,000 miles but I only installed 3/4 bolts.

[R.O.R-2.0]

im gonna do some work on it today. swap parts out, and see if i cant get rid of the vibrations..

if i need a harmonic balancer, im gonna re-install the V-belt stuff till i can afford new parts..

[Toby]

Is it a new belt? Is it a quality belt or chinese crap? Did you try taking the belt off and see if the vibration goes away? Have you tried another belt? I would take the alternator down and have it spin tested and see if IT vibrates. Before I did that I would probably pull the leads off of the alternator and see if the vibration goes away. Some times an electrical fault in the an alternator will cause the load to vary and vibrate the case.