Newbie with a wildly modified 2001 needing help

OtherCarsnAlfa said:

I think I agree with him, if I won't be dumping in as much fuel, using smaller nozzles should allow for better "resolution" when tuning. I think smaller nozzles also allow for a cleaner burn to from what I read online?

That being said, I may just elect to keep the nozzles to save some of my budget for other things the car needs.

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That is very wrong information, basically completely opposite. Get the car to someone who knows modded tdi's or this is going to turn into a disaster for you.

Pick a tuner, find out what turbo is in the car along with other mods (MAF housing size, intake manifold, whether or not the head is ported, cam, etc.) and work with the tuner to get the correct hardware and tune to meet your goals. Otherwise you're forcing the tuner to figure out how to make what you have work.

OK thanks for the input. I trust he can do the engine mounts for me just fine but I'll hold off on the nozzles until I understand what's going on a bit better. I can say that for a gas engine larger injectors volumes do reduce resolution but I am new to diesels..

BTW from other posts Howard put up it looks like this engine has:

VNT20/15 hybrid with clipped turbine
ported head, big cam, pd150 intake
ALR block (pd150?) with ALH head, lift pump and 11mm pump. Some of this info is news to me.

Thanks again guys.

I'll try to take a look closely under the hood this weekend to identify what I have.

I wonder what, if any changes have been made to the tune since Howard had it?

I don't know, but the PO seems to have tweaked with the injection timing on the physical pump. I don't know if this could cause this much of a change in smoke. The car drives well otherwise.

Not sure what that turbo is, but it sounds like it might be VNT-20 internals in a VNT-15 (stock turbo) housing. If that's the case, with Race 520s and an 11mm pump the turbo is going to run hot and smoke like crazy. It simply won't move enough air to clean up the smoke. You need a bigger turbo, less fuel, or both.

i'd like to see some pics of this car and it's engine bay

There's a couple of photos on the first page and the engine bay is a mess! I'll probably take some photos this weekend regardless.

Indigo,

I'll know more when I get a chance to look under the hood this weekend. There's not much going on until 3K and it pulls to redline. Does that sound like a stock housing with VNT20 internals? The head is ported and cam'd if that matters...


So the more I have been reading, the more I'd like to go in and start editing the actual maps myself. I'm thinking if I can just turn down the pulse width at the high-load areas and not mess with the injection timing (kinda like adjusting fuel but not the ignition timing on a gas car) I think I can figure it out. I have an EGT gauge on the car as well.

Are there any solutions out there to do my own mapping? I've sent an email to RC in the meantime but I'm wondering how much back and forth I will need to do to get the map right where as doing it myself I might get to learn something and have fun doing it.

Rc, Malone and others generally lock their tunes so they cannot be accessed. Others here have given you excellent advice. I know Chaz, I met him a few months ago at a training seminar. He does his own thing with tuning. He seemed to be quite knowledgeable but I have never seen his work in person. You may want to stick with RC for now.

That sounds like the turbo would need some mechanical adjustments. VNT20 is slow spooling ancient turbo compared to more modern turbos that can produce the same power, but it should light up before 3000rpm.

If you want to do your own mapping just go ahead. Changing basic fueling maps isn't that hard to do if you study the principles and logic the ECU uses. Install an EMP gauge, Adjust the stop screw on the turbo to get it spooled. That EMP gauge is the most important gauge as far as tuning goes. EGT is pretty useless.

Thanks for the info on the VNT. I'm aware how much of a difference a nice ball bearing turbo can be...on some SR20's I used to tune a T28 ball bearing would hit full boost so early...

What do I use to access or edit the tables? I know for ECU's like Motronic people use .XDF look ups and edit the raw tables. Ideally I could just use a normal graphical interface..one can dream right?

But if RC gets back to me and sounds like they can help me out I might want to leave the advanced tinkering for later and just get the car drivable

Currently, if I punch it at 2000 there pretty good torque off bost I'd say but the boost arrives very slowly....until about 2800 rpm and it immediately swings to 30, which is pretty typical of a big turbo application.

OtherCarsnAlfa said:

pretty typical of a big turbo application.

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VNT 20 not really a big turbo...

Like Hannu said, it's an ancient VNT.

Might be a good idea to get something more up-to-date for quicker spool, more flow

For daily driver a GTB1756vk or maybe better yet a GTD series if you can get one for good price

IIRC Howard had a nitrous intercooler spray kit on there too at one point

Sorry I meant to say the car is driving like it has a big turbo. If the VNT20 doesn't normally respond like this I was wondering what kind of adjustments I need to make?

I am open to a nice new BB turbo but I have more pressing issues with the car...too much smoke!

Update: I acquired a 20th GTI steering wheel and removed the TDI badge from the interior. The car has blacked out badges front and rear, I'll be replacing them with chrome OEM units and putting a new OEM TDI and GOLF badge back on!

If car smoking, can be problem with too much fuel and low of air. If you want, send me log from diagnostic, full throttle on 4th gear, from 1400 to 4000rpm and i will compare MAF sensor, if is good values calculated by actual turbocharger or something is wrong.

OtherCarsnAlfa said:

Currently, if I punch it at 2000 there pretty good torque off bost I'd say but the boost arrives very slowly....until about 2800 rpm and it immediately swings to 30, which is pretty typical of a big turbo application.

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Make sure the N75 Vacuum line is connected....different car and engine but that sounds a lot like mine before plugging the line back in.

PeeWee, what does the vacuum line do? What is it used for?

I emailed and called RocketChip....no reply so far. I have an appointment to drop the car off with Shaz to at least get the engine mounts replaced with OEM.

I've been driving the car at very light loads and have been getting between 41 and 45mpg, mixed driving.

A couple people I met in person seem to recommend KermaTDI for a tune that delivers good economy and low smoke. Can anyone else vouch for them? I still haven't given up on the idea of editing the maps myself but I might need to play with that kind of project later on once I learn more and have more time.

Grant

Cool car, Cool thread - great TDI history! Awesome reading the other post about the car running 14.7's when it was just 2 years old!

Deff have to get the car to someone who knows modified TDI's, Jeff @ Rocketchip has tuned countless cars for me. Once you know what hardware the car has send the ECU to him. 3,000 rpm is late for power to come on, Jeff's tunes had my last ALH making peak boost at like 2K-2,200 RPM and it would just light the tires up (super fun to drive - had 17/22 Turbo's).

Good luck in what ever path you choose with that car, thanks for the read. Without cars like this, I would NEVER have had it so easy to tune my TDI's. Someone had already been there, broke that!

OtherCarsnAlfa said:

PeeWee, what does the vacuum line do? What is it used for?

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I know you didn't direct the question to me but I'll chime in anyway.

On most waste-gated turbocharged cars pressure from the turbo is used to open the waste gate. When intake manifold pressure rises to a set point the PSI overcomes a spring thereby forcing the waste gate open allowing exhaust gasses to bypass the turbo. However, on our cars that use VNT vanes instead of a waste gate the movement is controlled by vacuum. Vacuum is piped from the cam driven vacuum pump through a valve (the N75) and then down to the VNT actuator. If the vacuum line is leaking or otherwise disconnected the VNT vanes will not respond properly (or at all). Without sufficient vacuum the vanes will remain in a position that causes the turbo to spin up slowly. Since you aren't getting full boost until 3000RPM PeeWee thought it would be a good idea for you to verify that the vacuum circuit is as it should be.

Search the forum here for posts describing how to properly test the system. In particular you'll be checking that the VNT vanes are able to move without restriction, the actuator is working and adjusted properly, the hoses aren't leaking, and the N75 valve is in good working order. The topic has been discussed more times than you can imagine and there are good how-to's over on My Turbo Diesel; like - This one

Good luck!!!

Wow thanks so much for the kind comments!

Thanks for writing up what VNT is all about. I wasn't aware the turbo worked on an a-typical design. I'll have to look in that this weekend

Hi guys,
Several members have asked me to upload log files...
Both files were taken today, with close to full throttle. Please let me know what information I should be capturing to help figure out why my car is a chimney!

http://s000.tinyupload.com/index.php?file_id=09952490895711548521

http://s000.tinyupload.com/index.php?file_id=22702680028279824040

I tested these uploaded files, nothing but a .CSV gets downloaded, they're safe

I also replaced this god awful momo wheel with a 20th AE GTI wheel.





PD150 intake:



cone filter I'd like to replace with a VR6 airbox:



rat's nest actuator plumbing:



Hotside plumbing I'd like to replace with somethign more OEM looking...any suggestions?



Engine bay is a mess, I'd like to slowly start adding the factory bits back on to make it look like a real car.

OtherCarsnAlfa said:

Hotside plumbing I'd like to replace with somethign more OEM looking...any suggestions?

http://s84.photobucket.com/user/stupidbuthey/media/image5_zps50d1ee81.jpeg.html

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Um, so that 1" heater hose is between the turbo and ic?

Houston, we've found the problem.

I'm sort of curious, in Cali, the car has to pass smog including a visual, before changing ownership. How did it pass smog with the smoke and engine compartment "challenges" it current has?

I picked up a base model tan interior for the Golf. I was going to get GTI recaro front and rear but for $80, it was too cheap to pass up and in nice shape too.

The bad news: the PO REMOVED the rear seat anchors to save weight! I'm going to have to weld in new anchors *SMH*.

As for the logs I posted, what do I typically need to log to get help diagnosing the setup? Do the logs in the post right above look ok?

Add nitrous oxide.

I see now, the thin hose is from the crankcase vent, not the hot side turbo plumbing.

ETA: That isn't tied in anywhere, right? Because if it is tied into the hot side like you mention, then it will be pressurizing the crank case (and being a massive metered air leak and boost leak). Should just dump out onto the ground, or into a tin can to catch the drips.