NOLA Speed and Style

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - vanbcguy

Pages: [1] 2 3 4 5 ... 189
1
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 10, 2018, 10:35:33 pm »
I do recall seeing another TDI boat running in to a similar problem with water jacketing pre turbo. Don't forget, a turbo runs on heat, so if you're cooling the exhaust down significantly before it gets there you're removing its ability to work. On the other hand insulating coatings and the like would certainly help keep the heat where it needs to be.

Oh, also, the Rover pump has a much smaller cam plate than a VW. If you still have stock nozzles it will need a longer injection window to send as much fuel as a stock VW pump would in the same time. See earlier statements about smoke from long injection durations...

Sent from my LG-H873 using Tapatalk


2
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 10, 2018, 02:37:04 pm »
Stock nozzles won't make your HP goals, at least not without a ridiculously long injection window. The longer the injection event the more smoke you're going to have too, as well as higher EGTs.

Larger nozzles have poorer atomization which can lead to soot. They also have a harder time at idle since all of the required fuel gets delivered in such a short time - very large nozzles will give you a rougher noisier idle.

That's at the extreme end though - Race 520s or anything else in the 0.260 or larger sizes. I have 0.275s in my car - I get a large puff at startup and a light haze at full power. The bad spot is low RPM transitions though - give it more than 50% accelerator below 2k RPM and the smoke can be a bit much. Easing in to the accelerator slowly eliminates that for the most part.

I'd work with what you have now till you know everything else is working properly - when you are hitting 20+ PSI and your EGTs are maxing out you should look at changing nozzles. Likely something in the middle of the road would meet your needs, particularly keeping smoke in check.

Sent from my LG-H873 using Tapatalk


3
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 04, 2018, 12:07:11 pm »
Ok, gotcha.

Smoke is wasted fuel, nobody wants that. The engine MAY make a little smoke accelerating - ie if you slam the accelerator to the stop you'll probably have some smoke till the turbo catches up once things are tuned right, however it should be minimal and avoidable by easing in to full power. The LDA will let you control that too - I'm assuming you have it connected?

Definitely turn up the max fuel screw. Levelling off at 2100 / 740F means you are quite short on fuel.

Sent from my LG-H873 using Tapatalk


4
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 04, 2018, 01:47:28 am »
Also, some thoughts...

Are you targeting 2100-2500 RPM? Or is that just the most you can hit with your current setup?

I watched your video above - were the EGTs getting to 740F and stopping there, or did you just abort the test there?

I don't hear any turbo noise really, nor do I see any signs of the silicone couplers taking pressure. At the moment I'd assume you are not making boost.

I too am wondering about the size of your turbo. 2100 RPM is about where a K24 starts to come to life, a GT2052 is about the same size though a bit newer of a design. Can you hit 2800-3000 without changing anything else? Looking back through your posts you were talking about something like 3800 RPM which is quite a lot more air.

Sent from my LG-H873 using Tapatalk

5
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 04, 2018, 01:31:04 am »
It's a bit different in your application than the typical automotive rig. Generally in a car or truck increasing RPMs by down shifting reduces load, and EGTs go down.

Your setup is probably going to be at full power for long periods of time; that's partly why I say 1200F for the EGT limits. If you were in a car you'd never be at peak power for more than a few minutes at most, so you can get away with more - most folks say 1400-1600F for a turbo engine. That's intermittent power rather than sustained though. Different ball game.

EGTs go up with fuel and down with air. Increasing boost lowers EGTs, until your intake air temperatures get too high anyhow. Increase fuel, you'll probably see an increase in boost (considering you have almost nothing now!) - you can turn up the fuel till your EGTs get high, then increase boost to get them back down, repeat until you get the power you're looking for or the boost levels go past what is safe for your engine and turbo.

I can't recall the details of your build now, but 15 PSI intercooled in a steady state with EGTs around 1200F will be safe for anything. You can crank things up from there assuming you have built the engine appropriately.

Sent from my LG-H873 using Tapatalk


6
mTDI Mechanical TDI Conversions / Re: MTDI in a boat
« on: July 03, 2018, 09:36:25 pm »
Sounds like you need more fuel! Steady state EGTs around 1200F at full power would be quite safe. It does take heat to make boost; your EGTs are fairly low if that is loaded up.

Sent from my LG-H873 using Tapatalk


7
IDI Engine / Re: IP Throttle Advance: Mechanical vs. Vacuum Actuated
« on: December 26, 2017, 03:53:39 pm »
No AC on my car, but yes they definitely did hook it in to the AC on some vehicles.

Sent from my LG-H873 using Tapatalk


8
IDI Engine / Re: IP Throttle Advance: Mechanical vs. Vacuum Actuated
« on: December 19, 2017, 12:40:34 pm »
From what I could figure out the vacuum solenoid was simply connected to the glow plug power supply. I know when my GP fuse failed the idle bump didn't engage either.

I had mine set up for about 1150 RPM at fast idle.

Sent from my LG-H873 using Tapatalk


9
IDI Engine / Re: IP Throttle Advance: Mechanical vs. Vacuum Actuated
« on: December 18, 2017, 12:30:21 pm »
My 93 Passat Eco pump had a vacuum idle bump, with a separate cold start handle. It increased the idle speed whenever the glow plugs were active (that is active in afterglow, after startup while cold). Helps reduce vibration at idle till the engine is warmed up a bit.

The other style of pump simply links the high idle to the cold start handle. Pull the handle, get high idle. Push the handle, goes back to normal.

I think the "automatic" system was purely used as the Passat was supposed to be a top of market car for VW. The body vibration at idle when cold exceeded what VW would allow for that market segment. Better to take control away from the operator rather than lose a sale!

The manual setup is clean, simple and works just fine. I liked having that in my Jetta, high idle in 2nd gear was exactly the right speed for playground and school zones. ;-)

Sent from my LG-H873 using Tapatalk

10
I don't believe Passenger is still doing anything for VW unfortunately. He was doing it around 10 years ago.

Sent from my LG-H873 using Tapatalk


11
Franko6 on TDIclub is pretty much the go-to for head work. Let us know if you find anyone else!

Sent from my LG-H873 using Tapatalk


12
Here's the actual numbers - I'm quite actively tuning at the moment but these are getting close... 204 = 80% duty cycle on the N75 valve = vanes fully closed. Any value below 60 is vanes fully open - they don't start to move until about a 20-25% duty cycle.

Sent from my LG-H873 using Tapatalk


13
My current N75 map is below - each band represents 10% more accelerator pedal than the previous one. I have the vanes quite open at zero go pedal or the turbo isn't very happy during shifts at high boost. While it looks fairly flat the vanes open as RPM increases even when all other factors are unchanged.

You can see how much the vanes open around 1600 RPM... They're virtually never fully closed except just off of idle.

Sent from my LG-H873 using Tapatalk


14
They fully close with my setup at low RPM and low accelerator input... I should grab a picture of my current N75 map, it would probably be the easiest... I have a copy of a stock map too, it has a very similar shape to mine though I didn't find it until long after I'd worked mine out through many iterations of testing.

I still am continuing to work on my map; I have the most common driving range (less than 50% accelerator, RPMs between 1600-3200) pretty solid now. I still have some work to do in the upper RPM ranges and at full accelerator pedal, weather has been too crappy to do much of that sort of driving lately.

Sent from my LG-H873 using Tapatalk


15
I have been doing a lot of tuning on my standalone VNT controller lately... Some things I've learned:

- the turbo will often spool much faster with the vanes part way open - fully closed vanes restrict exhaust flow preventing the engine from fully evacuating itself. Less is often more.

- at WOT you really don't need the vanes closed much at all to build lots of boost - I can easily make 30 PSI with the vanes between 50% closed around 2k down to less than 30% closed above 4k

- you virtually never want the vanes fully closed over 1600 RPM, especially not over 60% accelerator

- I personally have the vanes mostly open at idle, I like the way the car sounds better. There might be a slight increase in lag from a full stop but my car will just spin the tires if I try and go full pedal from idle anyhow. I definitely see my EGTs come down faster at idle with the vanes open vs closed.

Sent from my LG-H873 using Tapatalk


Pages: [1] 2 3 4 5 ... 189
Canada Catalys