Champagne performance on a beer budget

Folks,

All I can say is that Evry needs to take a place with all the rest of the TDI Gods here on the forum.

I performed the "Evry fuel mod" on my stock TDI and gained an immediate "feels like" power increase of around 15 hp.

The generalities have been posted before, here are the details..

Cost: Around $5

How-to:

1) Bridge pins 2 & 3 on the 10-pin fuel harness with a 1.5K pot. Set pot to max resistance.

2) Start car

3) SLOWLY decrease resistance from 1.5K

4) When the engine shivers (you will know, its very obious) the mod is starting to work.

5) When at around 1.2K, drive around.. you will be impressed

6) Go down to 1K ohms, drive around.. you will be MORE impressed

I've had it down to around 700 Ohms, and the idle was marginal (terrible!) but the power was un-friggin-real. Evry says he is down to around 850 Ohms and is happy there. At this setting it takes the engine a second to straighten out the idle, but its still acceptable. I'm going to replace the pot with a striaght 900 Ohm or 1K resistor and have done with it.

Most beautiful part about the mod: As good as the price is, if you use stick pins into the harness itself (at the rubber surrounding the wires), you can pull the mod out in a minute and leave no trace.

This should be mandatory for all stock or chipped TDI's sans tuning-box (who needs a TB with this mod?).

Power is very impressive.. if you dial it to the point where idle is marginal, smoke is impressive too. Otherwise, smoke is slightly more than stock. Evry has also done the equivalent of an "electric bleed" using a similar method on the MAP sensor, and as soon as I can get a boost guage, I'm doing the same.

Thanks Evry.. super cheap, simple, and effective.



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

Hey, I missed the posts on this, and I can't find it doing a search. Can you cross-post a reference?

Re: Chapagne performance on a beer budget

Great mod suggestion for Ric or anyone on a 20 year old tractor fuel budget!

Re: Chapagne performance on a beer budget

Steve,

I wouldn't be so quick to dismiss this mod.

Some test results you might find interesting...

When I first installed this, I hadn't gotten a good crimp on one of the connectors, so the connection between pins 2 & 3 was intermittent.

Under that condition, I got the dreaded "Warp field collapse".

HOWEVER..

I can dial up more power and NOT get the warp field collapse if the resistance is dialed in from before startup (good connection at all times).

What might this mean?

How about the computer checking the difference in the sensor and causing a CEL and blinking glow plug if the signal changes radically very quickly (on/off nature). However this doesn't seem to happen at much higher power levels when the signal is modified all the time.

The power is VERY smooth, no surging or problems under light throttle or cruise.

What happens with a TB when someone has it constantly powered I wonder? Can you dial up more power?

Skypup, you gotta try this and let us know your results..

Ric, you're welcome to come over and I'll install it for free for you.



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

ANTARTI or SkyPup:

I suspect that this mod simply magnifies the existing ECU signal to the injection pump like a Tuning Box (TB) and probably advances the timing and adds more coal to the fire.

I personally wouldn't want to be the guinea pig in trying it out on my ride with an Upsolute Chip and Tuning Box. My clutch and tranny won't even handle the amount of torque the engine produces with the Chip and magic Box.

Question: Do you also believe that this mod should not be attempted in chipped TDI's with an adjustable Tuning Box?

Seems that it's a nice upgrade for stock or possibly chipped engines, but perhaps not wise to use with both a Chip and TB.

Re: Chapagne performance on a beer budget

Steve,

NO WAY would I do this on a TDI with a Tuning Box already!

For those with chips only, or stock setups, this should be cool.

My car is 100% stock (even "snow screen" still in place) and the improvement is huge. Can't wait till I clear the screens out and add a K&N and boost guage, and wick up the boost too.



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SkyPup:
even Ric could emulate a real TDI God at that price, if the power didn't scare him so badly ).

<HR></BLOCKQUOTE>

The ONLY power that would scare me is the power Gore would have if he somehow weasels his way into the Whitehouse!!!



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Ric Woodruff

I'm not cheap... I just
know a good bargain
when I see one!


1998 Jetta TDI Custom Sport

Re: Chapagne performance on a beer budget

I'm confused...
and I want to try this, so someone better explain it!

(I have a tuning box, but i might want to try this as an alternative)

Re: Chapagne performance on a beer budget

What it is doing is altering the fuel temperature signal I surmise as I do not have the Bently on the 10 pin A4, the modulating piston is a waveform, controled by dutycycle.

[This message has been edited by valois (edited November 13, 2000).]

Re: Chapagne performance on a beer budget

Steve:

In very simple, basic, easy to understand terms, what is happening is that the 10-pin connector (joining the main wire from the ECU to the Injection Pump) is being hot-wired into producing a different voltage, which alters or magnifies the ECU's signal in a similar manner that a Tuning Box does.

This increases the amount of fuel the injection pump pushes and advances the timing, for more efficency and etc....

Re: Chapagne performance on a beer budget

I just boosted the thread, http://forums.tdiclub.com/NonCGI/Forum4/HTML/001475.html

Re: Chapagne performance on a beer budget

Are you sure those pins don't go to the quantity feedback sensor? That would make more sense to me. I can't see how advancing the injection timing would make more than a few percent of difference at most, but more fuel would obviously make a big difference!

Could someone with an A4 Bentley manual cross-check what pins 2 and 3 go to inside the injector pump, so that us A3/B4 folks can find out what pins we're supposed to fiddle with??

I like mod suggestions like this but if it results in overly advanced injection timing rather than increased quantity, expect trouble ... nothing blows peak cylinder pressure and temperature higher than excessively advanced injection timing.

Brian P.
'96 Passat TDI

Re: Chapagne performance on a beer budget

This will have a direct bearing on the quantity of fuel delivered, it does not affect timing. It will affect duration. The warp field collapse you encountered is due to limitations of the smoke map. Get more air in and you will be able to take it further. To alter timing you have to play with the coolant temp sender, as GoFaster pointed out, it's risky business. This mod will gain you some extra power, I do not recommend it if you have a tuning box. The modulating quantity adjuster is a pulsed signal being adjusted continously by the ECU, a parallel resistor across the fuel temp sender will trick the ECU into throwing more fuel to the injector, this of course will increase duration.

Re: Chapagne performance on a beer budget

Folks,

From what I understand:

pin 3: Ground terminal
pin 2: Secondary transformer coil, on the pump plunger
pin 1: AC going to primary coil of the transformer in the pump housing.

------
In Evry's words:

The signal at terminal 1
induces the signal in terminal 2. Now, when the plunger moves w.r.t. the fixed coil, the amplitude (voltage) of the secondary coil
changes. It is the amplitude of the secondary coil which tells the ECU what the current status of the plunger is. When this signal is
reduced by an external resistor, the ECU allows the plunger to travel a bit further - and YES, more power!
--------

Timing should not be affected by this mod.

------------------
ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

[This message has been edited by ANTARTI (edited November 14, 2000).]

Re: Chapagne performance on a beer budget

So which is a better option? The tuning box, or this mod and the electric bleed?

It would seem that the tuning box has a limit, whereas this is limited only by how much air you can force into the engine, and the capacity of the pump. Increasing boost increases the amount of air injected, correct? So either this electric bleed, or a chip that increases sustained boost substantially (like the experimental upsolute chip, i believe) would work to this effect. The two would compliment eachother better than a tuning box and chip, it would seem.

Re: Chapagne performance on a beer budget

Ah ha, this is my kind of mod, the parts at Radio Shack might set you back $0.59 cents or so, so I might have to do without an Almond Joy, but hey if it makes the TDI go like stink for that measly price, it can't be wrong (even Ric could emulate a real TDI God at that price, if the power didn't scare him so badly ).

Thanks alot for this excellent information!

Re: Chapagne performance on a beer budget

The tuning box is more than a resistor shunted across wiring to the pump, the upsolute box is controlling signals by modulation, that is why it's operation is smoother than most of the alternatives out there. If this is affecting the modulating piston I would recommend against it, the pump is pretty expensive, and I don't think they sell the parts for it off the shelf. Altering the fuel temperature sender would accomplish the same thing and run much less risk of damage, since it's just a variable resistor in the first place, done properly the response would be linear as it would still be able to vary total resistance of the circuit.

Re: Chapagne performance on a beer budget

Valois,

Altering the fuel temp signal to get more fuel would mean very retarded timing, and an upper limit of probably 10% more fuel. That is NOT a combination for keeping EGT's low, actually that's worse than 15% more fuel and standard or slightly advanced timing.

My playing around with the fuel temp sensor (as part of ANOTHER mod, not this one) is leading me to create a system where fuel temp is offset by a variable amount, so as to slightly advance timing under all conditions, EXCEPT when the cold start solenoid is operating. The fuel temp mod I'm working on has been temporarily removed whilst I finish up with this mod. The two will eventually be running in concert.

I would argue that this mod may be just as smooth (if not smoother) than a TBox, especially considering some peoples posts about the TBox's "kicking in" intermittently under cruise control or other circumstances. This mod is there right off idle, and it really comes on strong on the high rpms. As I posted above, depending on the setting, idle quality could be diminished. So far, this is the only discernable caveat.

Before the mod (stock), 4th gear was a lot of fun, but now all gears make the speedo climb smoothly and quickly. I can now understand the "it pulls like a (train/jet)" posts that people write right after a TBox or chip upgrade.

As for being bad for the pump... who knows. I think the TB is just doing the same thing but dialing down the resistance in a quick-but-controlled fashion when activated. Most likely a Tbox generates more power, and then again (re-read my experience with the CEL) maybe not.

If someone is uncomfortable with trying it, they shouldn't. I'm of a mind that someone with chip+Tbox+propane is in no position to tell me about how I'm risking my ride... as compared to what? theirs?

Bottom line: I need to get to a dyno or borrow a Gtech.



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

If someone is uncomfortable with trying it, they shouldn't. I'm of a
mind that someone with chip+Tbox+propane is in no position to tell
me about how I'm risking my ride... as compared to what? theirs?

I would not dream of telling you what to do with your car. You are not the only member on this forum. Have you scoped out the pump signals? I have. Reducing the fuel temp signal will not affect timing. The ECU uses this signal as a measurement of fuel density and adjusts quantity accordingly, I was trying to relay information to you and to also convey not to do this with a tuning box to others. If you want to affect timing you have to play with the coolant temp sender.





[This message has been edited by valois (edited November 14, 2000).]

Re: Chapagne performance on a beer budget

Valois,

Fuel temp signal: Raising the perceived fuel temp will add more fuel, lowering it will result in less fuel. Your argument is sound.

To qualify that, you aren't going to add significant amounts of fuel doing this unless its 50*F outside (meaning that the fuel filter is recycling warm fuel right at the minumum 75*F IIRC) and you've tricked the ECU into thinking the real fuel temp is 212*F.
THEN what happens when the fuel heats up after a long drive to 140+*F, you get less power from this mod? No thanks... Power increase depends on fuel temp? If fuel mass increased 1% for every 10*F, then you would get a max of 7% more fuel at normal operating temps (in Florida anyway, or with a near empty tank elsewhere). Is that a realistic description?

I gave your post a quick read and thought honestly, vs. chips and TBox, there's no way I'm generating that kind of fueling (or power) from this mod.

However the ECU deception is accomplished, the injection pump is still the one place delivering it, and the boosted signal I'm pushing can't nearly be that high. Was what I meant unfair, no, was the way I put it unfair, yes. I misread some preaching; I was wrong, I apologize.

Yeah, I've seen the graphs in the TDI-technik doc. The VP44 doc that was translated and it are at odds in places though (VP 44 doc gives more detail). I've tried (and you could argue I'm a dolt who didn't get it right too) manipulating other sensors that should have triggered more fuel/timing/blah,blah with and and without success while re-reading these docs over and over.

Bottom line for me? NO CEL, no foul... Caveat Emptor.. Newbie beware (I am a newbie too)..

You'll notice I went way overboard with this (just like people with the TBox do) and then backed off (just like people with the Tbox do) to a more reasonable setting (for me anyway). I am just as susceptible to the "more is better" thing as everyone else.

I didn't originate this mod, and should probably have dug out Evry's emails at home where he scoped these signals and describes them in detail, along with the mod's effect. I am only the duplicator and reporter, but I am a happy one.



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

Well, I thnk this is excellent work no matter how you look at it and would appreciate some more technical detail of the descriptions if that is possible. Everyone starts off from scratch here at some point and advances over time to a higher plane. There have been some terrific advances in modifications here on this Performance Forums these last three years. Most often they start off with alot of hemming and hawing from the disbelievers who have never tried it out to begine with. Time evens the playing fields however and this looks like it needs close attention. I would appreciate the background experimental discussion that led up to this. Thanks!

Re: Chapagne performance on a beer budget

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ANTARTI:
Folks,

From what I understand:

pin 3: Ground terminal
pin 2: Secondary transformer coil, on the pump plunger
pin 1: AC going to primary coil of the transformer in the pump housing.

------
In Evry's words:

The signal at terminal 1
induces the signal in terminal 2. Now, when the plunger moves w.r.t. the fixed coil, the amplitude (voltage) of the secondary coil
changes. It is the amplitude of the secondary coil which tells the ECU what the current status of the plunger is. When this signal is
reduced by an external resistor, the ECU allows the plunger to travel a bit further - and YES, more power!
--------

Timing should not be affected by this mod.
<HR></BLOCKQUOTE>

This makes 100% perfect sense to me.

- Reduce the voltage of the feedback signal, thus the ECU will increase the pump displacement to compensate, thus feeding more fuel than the ECU thinks it's delivering.

- It has nothing to do with the fuel temperature signal and therefore nothing to do with the injection timing.

Now all that's needed is to figure out which pins are the AC source signal and the ground signal on a B4 with 1Z engine...

To quote Rene ... don't try this at home!

Brian P.
'96 Passat TDI

[This message has been edited by GoFaster (edited November 15, 2000).]

Re: Chapagne performance on a beer budget

I did not mean to dispute your results, I believe you when you have stated that you have seen performance gains, and the price is right. I am simply exploring what is happening, I do not have the pin outs on the A4 harness, that would help. I also do not have the document you refer to, please email it to me. If it is indeed the modulating adjuster, than it might be possible to alter timing by shunting capacitance to reduce the duty cycle of the signal being reported back to the ecu. Do you have a vag-com? A scan data on the fuel quantity would be desirale to verify the specified quantity and the actual quantity of fuel. Keep on discovering.

[This message has been edited by valois (edited November 15, 2000).]

Re: Chapagne performance on a beer budget

Everyone,

Please re-read the post above where the pinouts were discussed. I've edited it since it was somewhat inadequate an explanation (and I had a typo on the pin #'s as to which wa ground).

That should help clear things up.

Valois, I wish I had a VAG-COM (not to mention about 100 other things). Every spare penny I have goes towards a new sailboat though.. priorities..



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

Valois,

From looking at the RB book, I would have gotten the pinouts all wrong.

I had to ask (and confuse, and probably test his patience) Evry a couple of times since what he was telling me didn't seem to line up with the diagram I had.

He was right though...



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ANTARTI
99.5 Jetta TDI GL Silver Arrow/Grey Studio

Re: Chapagne performance on a beer budget

I just printed this entire thread out to take home to read tonight, hopefully all the editing of information is complete? This is how it stands now right?

Thanks for the email Emmanuel, I do have a dual trace Techtronix 20MHz oscilloscope at home and a couple of logic probes. If this is a pulsed moducated square wave signal, the pulses stay the same time apart and the amplitude of the wave height is either decreased or increased, correct? Which is what the resistor does to the wave height I assume.

At least we don't have to worry about Ric explaining it for us!! lol

Re: Chapagne performance on a beer budget

I edited my post to include Antarti's updated explanation ...

Brian

Re: Chapagne performance on a beer budget

I have the RB A4 book. Here's how I read it:

The 10-pin fuel harness is the Harness Connector shown as component 19 on Fig. 1 (Diesel injection system), on page 23-2. This connector is for the fuel temperature sensor (G81), cold start injector (N108), fuel shut-off valve (N109), quantity adjuster (N106), and modulating piston displacement sensor (G149).

Wiring diagrams 97-78 (5-speed) and 97-92 (auto) show Wire 1 (lilac/black)--resistor/switch?, Wire 2 (grey/green)--connection, and Wire 3 (white/green)-variable resistor/rheostat--as the wires connecting the ECU to the Modulating Piston Displacement Sensor (G149).


[This message has been edited by rgoetz (edited November 17, 2000).]

[This message has been edited by rgoetz (edited November 17, 2000).]

Re: Chapagne performance on a beer budget

Skypup,

Make sure you connect to terminal 1 (primary to coil) and 2 (secondary) on 2-channel scope. You will see what's happening with the signals when you start playing with the accelerator.

Since this mod, my mpg indicator is in the region of 4 liters/100 km thanks to the modification of the feedback signal.

In addition to this mod, I've installed a bleed resistor on the air pressure sensor. Max. boost now up from 0.8 bar to 1.2 bar.

Evry Schuiling

Re: Chapagne performance on a beer budget

Has anyone tried this who is regularly getting Warp Field Collapse? I am just interested to know if WFC is more or less regular with this mod. Thanks, Des.