Author Topic: Controlling TDI pump (Read 10525 times)

dalek · « **on:** May 14, 2007, 04:07:47 am »

Has anyone found out how to control the TDI pump, as in writing your own code? One of the reasons I am here is that I have a Mercedes diesel I want to go from IDI to TDI. Yeah, I am rather tired of the precombustion chamber dance and I despise the inline pump those cars have. I also feel what I want to do is a pretty tall order (will even have to modify my pistons to create that little volume to compensate for the lack of the said chamber). but I am like that. Anyone?

vwmike · « **Reply #1 on:** May 14, 2007, 10:20:54 am »

Why not just swap the engine for a TDI? Maybe import a 5 or 6 cylinder TDI (depending on what country you're in)? For that matter doesn't Mercedes have a more modern DI engine available? I, along with many others can modify the code in the TDI ecu's but that's a lot different than writing completely new code.

dalek · « **Reply #2 on:** May 14, 2007, 06:45:06 pm »

Well, I kinda like that iron head/iron block engine. There is something to it I can't put my hand on. In Europe they have made that engine deliver more than 400HP. But, they have better pumps that we do here in the US. So, I have been thinking on swapping the pump altogether and go direct injection. yeah, I will have to machine the pistons to compensate for the volume lost when the precombustion chamber goes bye-bye, but who cares? It is fun.

About the coding, well, do you know the protocol to talk to the pump?

jtanguay · « **Reply #3 on:** May 14, 2007, 06:56:39 pm »

hmmm will this even work???

DI's are direct for a reason... the pre-chamber won't be needed, as the combustion process is much quicker. pre chambers on di's might actually screw things up.

iron heads are definitely the way to go for heavy power though..

dalek · « **Reply #4 on:** May 14, 2007, 08:05:59 pm »

Well, that is the idea: I would take the precombustion chamber and machine it to hold a TDI injector the same way it expects to be. So, the chamber itself is no longer as a chamber. I asked in VW vortex for cutouts of the heads for a IDI and TDI VW; I believe they are very similar with the main difference is the precombustion chamber was modified to hold the injector right up to the combustion chamber. Am I correct? I saw some pictures of the pistons, both IDI and TDI, that made me believe that VW did something as I mentioned, machined a hole in the pistons so to keep the combustion chamber volume about the same of the IDI.

But then again, this is just guesstimation.

About working, well, there is this company I met at sun-n-fun that made a turbodiesel engine off a 1.5L Honda block to use in airplanes, replacing rotax engines.

jtanguay · « **Reply #5 on:** May 15, 2007, 12:44:46 pm »

the compression ratio of a TDI is much lower than that of an IDI. the cutouts in the pistons are actually like post combustion chambers. lowers the CR, and gives a better combustion the way it 'swirls'

vwmike · « **Reply #6 on:** May 18, 2007, 02:14:04 am »

Those cut outs in the pistons are the combustion chambers. An IDI engine uses the prechamber as a combustion chamber but since the TDI doesn't have a prechamber the combustion has to happen somewhere. The combustion chamber is also designed to swirl the intake air and fuel to fully atomize and burn the fuel. I think you're setting yourself up for disaster by trying to do this. That's not to say it can't be done but a fair bit of R&D goes into designing an engine and what you're proposing is nothing short of a complete redesign. There are some aftermarket injector seals out there that are too large so they place the injector up probably half a millimeter or so. This is enough to cause increased smoke and reduced mileage. If you're machining this whole thing yourself then what are the chances that you're going to be able to get the injector in there just right? For that matter, are you sure that you're going to be able to have the same nozzle spray angle? If not then you're going to have to source other nozzles. It's a cool idea but I think it is impractical, expensive, and unless you've got a year or so to devote to a lot of trial and error, unrealistic.

dalek · « **Reply #7 on:** May 30, 2007, 05:33:25 am »

Two reasons I got interested in doing this. First, Mercedes only fitted the ghey Bosch MW pump in their 5 cylinders cars for the US Market, as opposite to the M pump they use probably anywhere but not here (insert ***ing about how every foreign performance car is defanged when brought to the US). So, I would like to use something better.

Second, there is this group of people who build a common rail turbodiesel for aircraft use (replaces a rotax) based on a Honda 1.5L engine. And, they wrote the entire code. So, I thought why not? It is not like that car is my only car/daily driver.

Also, did VW change the angle (forget about precombustion chambers or lack of thereof) of the injectors when they went to TDI? Because of the off-center location of the hole in the piston, I can't help but guess they kept it.

But, yes, I do not plan on getting this done in a year but I think it would be fun.

Now, the final and biggest question I have is if I should try TDI first or skip it altogether and go for common rail.

gigaz2 · « **Reply #8 on:** June 12, 2007, 07:03:56 am »

why write code? import a common-rail system (CDI for mercs) and then tweak it as necessary.

if you are going for a VP37 system, you can use the ECU and loom for a regular TDI, then tweak

VP44 is a more complex system but you can still pull it off if you transplant the entire system from a running car

but why not just buy an M pump form ebay.de ? I buy all my stuff there.

dalek · « **Reply #9 on:** June 13, 2007, 05:52:38 am »

Tweaking would make me feel I am no better than a bloke with stock system dropping a chip. I would like to know more, like you are able to with, say, megasquirt in a gasoline engine. I thought that the TDI was a bit simpler so it would be a good starting point. However, if commonrail/CDI is better deal in the end of the day, I would be willing to jump all the way to it. Getting the right injectors is the problem here; I do not even know where to begin besides trying to find a car with a similar displacement per cylinder and go from there.

About the M pump, yes there are people in Norway (?) doing 400HP with them, but then it has a few issues:

1- People have done it already.
2- You still need to send it to a shop and have it magically tweaked. i.e. it becomes a black box.
3- Soot. I think with electronic control I can do a better job of not wasting good fuel.

OM617 · « **Reply #10 on:** June 17, 2007, 12:28:49 am »

Going from an IDI system to DI system is not possible. Just get a 2.7L CDI engine out of sprinter and swap it into your car.

gigaz2 · « **Reply #11 on:** June 24, 2007, 01:21:02 pm »

Quote

="dalek"]Tweaking would make me feel I am no better than a bloke with stock system dropping a chip. I would like to know more, like you are able to with, say, megasquirt in a gasoline engine. I thought that the TDI was a bit simpler so it would be a good starting point. However, if commonrail/CDI is better deal in the end of the day, I would be willing to jump all the way to it. Getting the right injectors is the problem here; I do not even know where to begin besides trying to find a car with a similar displacement per cylinder and go from there.

About the M pump, yes there are people in Norway (?) doing 400HP with them, but then it has a few issues:

1- People have done it already.
2- You still need to send it to a shop and have it magically tweaked. i.e. it becomes a black box.
3- Soot. I think with electronic control I can do a better job of not wasting good fuel.

no offense mate, but I have converted one of my cars to megasquirt and that is pure tweaking, you dont write a single line of code.

I believe you should go for mechanical injection in the begging anyway, you will encounter hundreds of problems just to make it run, let alone make it run efficiently.

a hint: any VE pump can be later converted to VP and vice-versa :wink:

Guy_H · « **Reply #12 on:** September 20, 2007, 02:24:17 pm »

Hi All,

New in here, and just reviving this thread a little

I am currently researching the possibility of driving a VP37 with a megasquirt and any info anyone has on the VP37 would be very much appreciated. Any Bosch literature (esp. Diesel Engine Management) would be useful still waiting for my copy

I've got a VP37 in my 300tdi Discovery and unfortunately the ECU in it is not as open as some are to hacking so really it's got to be done from scratch.

I particularly need info on the workings of the HDK sensor inside the pump any specs or waveforms or anything would be great.

Anyone else interested?

Cheers
Guy

Holeshot · « **Reply #13 on:** October 04, 2007, 01:59:46 pm »

I'm quite interested...and at wit's end with the blasted computer controlling my VP37.

It's to the point where I'm investigating making it an M-TDI. I've made settings in VAG-COM only to have them either not help at all or have the values change back to OEM after a while...my old '98 NB TDI did the same thing as my current '98 NB TDI.

Too bad the ECM isn't as open as a GM ECM - I think the engineers left MANY doors open on them. EFI-Live is pretty slick...but it only works on the GM's - we need something like that for the VW/Bosch ECMs.

Heck, even the Chrysler/Cummins/Bosch ECM on the Dodge/Cummins vehicles has been hacked - thanks to Marko in Italy with the 'Smarty' products.

Beers,

Matt

hillfolk'r · « **Reply #14 on:** October 16, 2007, 04:26:08 pm »

i thought there was some kind of "stand alone engine management system" that would work on electronic pump equipped diesel vehicles,or one was being developed or something like that or its here already,please excuse the bad memory
i feel like lil richard in that geico commercial:"sumbuda heelp meee"
oh if it helps im pretty sure this was taking place in europe
:oops:
thats what we need
then id try goin electronic myself possibly :shock:

Author Topic: Controlling TDI pump (Read 10525 times)

OM617