.:Shaved Bay Information Resource Thread:.

[need_a_VR6]

You will get false knock detects and the crank sensor might lose sync at odd times. It's more likely to be noticeable with the crank sensor during fast accelerations where decoding is more critical.

The foil shield should be tied to the drain conductor (braided wire). Odd yours were not grounded, it could just have been age taking its toll. I have a few harnesses here that I can check and see if they are the same way.

[rollinslow95]

You will need some form of overflow if it is a daily.

Just wondering as to why you would need an overflow?

[harlequin80]

just in case, or you leave it overflow onto the ground, whatever you want. it shouldn't really be getting to the point that its always doing it though but it can happen

[Lamy207]

I thought this conversation was familiar; we discussed this over PMs back in 6/2010. The shielding in my car was not tied to ground, the ground twisted with the O2/crank/knock sensors is not a shield. I have run my motor since then, it seemed to run fine from idle through redline but not under load (just running, not driving). If there was a signal noise issue, wouldn't it stall or stumble at some point through the rev range even free-revving?

No, your ecu calculates load by the tps and crank sensor, without the system properly grounded it will send an inaccurate signal to the pcm, causing a dead petal or a miss. You have live data on your scan tool afaz?

[Afazz]

My sensors are all grounded, just not shielded. I'm a mechanical guy so really I just reverse-engineered the OEM wiring, I saw that the "shield" in my car was not grounded on either side. Because the OEM "shield" wasn't actually a shield, I didn't shield my knock and crank sensors. I don't have a scan tool at all right now, can I view live data with a VAGCOM? It's an early OBD1 car without the true OBD plug.

Worst case scenario, I will build a knock sensor/crank position sensor harness. I can use one plug for all 6 wires + 2 shields through the bottom of the firewall near the shift linkage. I have the harness drawn up, I just would rather not spend the $200 if the car runs without the true shields. This is the conclusion need_a_vr6 and I came to when we talked over PM; try it as-is and build a new harness if I need to.

[Lamy207]

My sensors are all grounded, just not shielded. I'm a mechanical guy so really I just reverse-engineered the OEM wiring, I saw that the "shield" in my car was not grounded on either side. Because the OEM "shield" wasn't actually a shield, I didn't shield my knock and crank sensors. I don't have a scan tool at all right now, can I view live data with a VAGCOM? It's an early OBD1 car without the true OBD plug.

Worst case scenario, I will build a knock sensor/crank position sensor harness. I can use one plug for all 6 wires + 2 shields through the bottom of the firewall near the shift linkage. I have the harness drawn up, I just would rather not spend the $200 if the car runs without the true shields. This is the conclusion need_a_vr6 and I came to when we talked over PM; try it as-is and build a new harness if I need to.

You and I should converse via text message... I feel like you would be a very ample fountain of knowledge as i'm planning this... where is it your located again? Pm Me.

[Lamy207]

You and I should converse via text message... I feel like you would be a very ample fountain of knowledge as i'm planning this... where is it your located again? Pm Me.

As in what part of Pittsburgh

[need_a_VR6]

Yeah I remeber us talkinh about it now. One of those things where its a fine line between totally fine and potential problems, especially intermittent ones.

[JohnStamos]

You will get false knock detects and the crank sensor might lose sync at odd times. It's more likely to be noticeable with the crank sensor during fast accelerations where decoding is more critical.

The foil shield should be tied to the drain conductor (braided wire). Odd yours were not grounded, it could just have been age taking its toll. I have a few harnesses here that I can check and see if they are the same way.

Remember me asking about anyone getting false knock, and experimenting with knock spacers?

Then about the car shutting off randomly at WOT for a split second.





Yeah, it was from the harness I made. Added the shielding from a stock harness, and its gone.

Also, the way I had the rear knock sensor wiring hidden, it was very close to the plugwires. After the wiring, it all but went away. New plug wires, and its now all gone.

[JohnStamos]

Just wondering as to why you would need an overflow?

Water/coolant expands when hot. If the system is a closed system, you will blow the weakest joint, when the pressure gets high enough, hence the need for a pressure relief (AKA: Rad cap.)

This happens all the time while driving. On a show car, trailer queen, its not that big of a deal.

But on a daily, everytime the system gets hot enough, and pressure builds, coolant has to be displaced from the system, so it leaves through the over flow spout on the radcap adapter.

If there is no overflow, it will just leave coolant all over your bay.


A GOOD overflow setup, will recirculate the coolant. It will have the coolant source connected to the bottom, so that if the cooling system is low, the rad cap is open, and there is enough coolant in the overflow to provide enough force, gravity/weight of the coolant in the overflow will push coolant back into the system, self burping it of air.


With out a overflow, you need to constantly check/worry about where your coolant level is/how much you have lost, and you have no good way to check.

[mushroom_curry]

Are the systems with pressure correct caps on built in end-tanks (ie, Scirocco rads) insufficient for using as an overflow/pressure release system then?

[JohnStamos]

Are the systems with pressure correct caps on built in end-tanks (ie, Scirocco rads) insufficient for using as an overflow/pressure release system then?

I have never seen one.

But if it is like most VW cooling systems, it isn't an overflow. Most VW's use an expansion tank from the factory. Much better setup then a overflow, but ALOT harder to hide/plumb in a shaved bay then a simple overflow.



Also, not saying you HAVE to have an overflow on a daily, but I like to do everything right the first time, and not have to mess with it later. If constantly checking/hoping/cleaning is your thing, go ahead and don't run one. On a car I put 30k on a year, and rely on to get me to work everyday, that is not possible.


And if you EVER plan on going to the track, you better have one.

[need_a_VR6]

You can run a 'cap only' system (like the stock early mk1) as long as it's the high point.

[rollinslow95]

Water/coolant expands when hot. If the system is a closed system, you will blow the weakest joint, when the pressure gets high enough, hence the need for a pressure relief (AKA: Rad cap.)

This happens all the time while driving. On a show car, trailer queen, its not that big of a deal.

But on a daily, everytime the system gets hot enough, and pressure builds, coolant has to be displaced from the system, so it leaves through the over flow spout on the radcap adapter.

If there is no overflow, it will just leave coolant all over your bay.


A GOOD overflow setup, will recirculate the coolant. It will have the coolant source connected to the bottom, so that if the cooling system is low, the rad cap is open, and there is enough coolant in the overflow to provide enough force, gravity/weight of the coolant in the overflow will push coolant back into the system, self burping it of air.


With out a overflow, you need to constantly check/worry about where your coolant level is/how much you have lost, and you have no good way to check.

Great info, I do realize that it expands as it heats and understand the point of releasing pressure in the system, but looking into older systems that do not use an overflow or expansion tank, and thus just using a pressure cap, is there any way to incorporate that type of system into our cars? like need_a_vr6 stated, being that it would be made the highest point(aka:fitting a different style upper rad hose to make the inline cap sit above the radiator line)

On a side note, i want to talk more about hiding, moving, and modifying charchol canisters. Where do most people move them to? Maybe give an option for emissions required and non emission required area. Ive always wandered about this modification.

[Miggie89]

What gauge wire should be used in the bay?

[pubahs]

You can run a 'cap only' system (like the stock early mk1) as long as it's the high point.

This... the highest point is the main focus of any coolant system. Reason why I am just going back tot he stock coolant bottle (brand new it will look clean) shaved? no. But clean and functions properly, yes.

There are some good examples out there of custom coolant overflow tanks though, I snapped a few pics at waterfest this year. I could post them if anyone is interested.

Also can someone show me exactly this 'shielding' you speak of? I am wondering if I have this issue as well.

[Afazz]

Here is a picture of shielded wire. The wires carrying the signal are wrapped in a conductive sleeve, either foil as shown here or a woven braid. The shield is grounded, which reduces electrical noise and makes for a cleaner signal. Other things in the bay create "noise," like ignition coils and plug wires.

[Afazz]

On a side note, i want to talk more about hiding, moving, and modifying charchol canisters. Where do most people move them to? Maybe give an option for emissions required and non emission required area. Ive always wandered about this modification.

A lot of people just delete them, I built a new one because I didn't want fuel smell and wanted to pass emissions. I kept the OEM OBD1 location under the frame rail, but the stock canister was too long and would have hit the ground. I could have shortened the stock one, but I like making things.











The OBD2 style are a little harder because they're above the tire, they can hit if you're really low. In some ways that helps because they're already hidden, but you have to relocate the plumbing.

[eurovw95]

Anthony great seeing you at h2o.. I can't wait to see this thing in person

[pubahs]

Afazz.. is there some sort of aftermarket shielding we can get for the wires? I guess I am confused if this was something built into the wires themselves or an external shield?

[Afazz]

You can buy shielding braid separately, this can be used if you're building a harness with your own heat shrink.
http://cableorganizer.com/metal-braided-sleeving/

Or you can buy shielded wire, this is much easier.
http://order.waytekwire.com/products...20And%20Cable/

These guys sell milspec stuff
http://www.p-r-s.com/Catalog%202007/PRS%20Wire.pdf

I have not used either of those products specifically, but similar types. The other guys in here might be able to get you a more specific product recommendation for shielded wire.

Coby good seeing you too! Stop out sometime and check it out

[rocklizzard91]

im interested in redoing my whole bays wiring.
its already 90% tucked when i swapped in my 9a 16v and converted to megasquirt

id like to use one of the fancy mil-spec connectors you have afazz
where could i acquire one of those?

ive got a cool idea i would like to try

[need_a_VR6]

I have used braid in the past but unless you need to use it for a specific reason, the shielded, twisted pair cables are better. It can be tough to find in the right temp rating and chem resistance shielded cable. So keep an eye on that when choosing.

[SenorBrandon]

This threads the best. Anyone have some input on using 2.0l wiring? I have almost everything to build a 16v abf clone. It seems most people only talk about shaving the bay on a VR6. Thanks for making this thread, I plan to use it alot this winter!

[gangstagolf]

Very nice I like!
I'm going to be shaving my bay for my 24v swap here soon. Many awful cell pics to come lol

[SooprmanX]

On the VR6, part of the wiring harness is on the firewall at the top. It just goes across the engine bay from right to left. I am thinking of disconnecting that harness and rerouting it into the rain tray. Will I need to wrap all that wiring in additional cover because of the water that gets in the rain tray?

Engine pic that is going to get half-shaved.....

[g-rocco60]

This... the highest point is the main focus of any coolant system. Reason why I am just going back tot he stock coolant bottle (brand new it will look clean) shaved? no. But clean and functions properly, yes.

There are some good examples out there of custom coolant overflow tanks though, I snapped a few pics at waterfest this year. I could post them if anyone is interested.

pics i would like to delete my factory coolant bubble but still wanna have a overflow of some sort

[surge1468]

anybody have a recommendation who can shave a good bay in new england

[Lamy207]

I can help you out. Pm me

[pubahs]

Great example of an overflow IMO.. could be slightly higher up though

[jeuro]

You can remove the FCM, all its wiring, ect, which gets rid of almost 1/4 of the bays wiring.


This is my entire fan wiring setup. It is easily hidden, and uses the stock fan/fanswitch.




He seems to be speaking of the heater core though, which most people with shaved bays don't run anymore. It takes ALOT more work to do it "right" and have full functionality. (Ala Afazz. )

how exactly do you have this rigged up?

[harlequin80]

that looks like an inline filler with an overflow tube running to the ground

all that work and he left the a/c lines sticking out of the firewall??

[RATFINK]

i wish i had someone i could pay to do it on the west coast mine is scaring me.

[SooprmanX]

that looks like an inline filler with an overflow tube running to the ground

all that work and he left the a/c lines sticking out of the firewall??

I saw that too. What I'm thinking is that he normally has AC working on his car but removes it for big car shows or something....

[pubahs]

Esp. since he made a custom cover plate for it as well, with chrome acorn nuts as well. Nice finishing touches.

Those AC lines polish up nicely too!