325 Tds tune'ability?

[Midnightclub]

Anyone got an idea of how tuneable the 325 Tds's are? From what i can see you can 'chip' them but haven't really seen much else in terms of big turbo's, injectors etc. and how reliable they are or what sort of power can be made, anyone here have any experience with them?

Thanks

[THE_Liam]

From what I know from Gen's stepdad and his Rangie with that engine, a chip gives you about 170 bhp. You can then uprate the intercooler and fit bigger turbos like any TD, but there's a couple of problems. Firstly, the ECU is read-only, so you can't map it to suit the new parts, and secondly the engine has a history of cooling problems, and the cylinder heads are weak...

Not a great one for tuning, and actually pretty poor on diesel. My mate has an E36 TDS and he only gets 28-29 round town and high 30's on a run, the 328i he had before that was 24 round town and mid 30's on a run, so he's looking for another 328i

[Dum-Dum]

Very tunable from what I hear. Id of had one if they did a 3 doof

[Midnightclub]

Hmmm.. Seems to be mixed views on these, read a thread on TDOCUK and they reckon with fairly heavy mods they'll see over 200bhp but also saw about the cylinder head issues..

I'd love a beamer but i don't think i can afford the fuelling of a petrol and E46 330D's hold there price well! I'd love a 6 pot diesel not too sure on how decent the 4 pot 16v's are?

[Ruan]

They have a weak cylinder head. APPARENTLY. I bet it's like the XUDs reputation for blowing HGs - it's just dicks who don't have a clue who couldn't bleed them properly after a coolant change.

Just need to rip off the VP37 pump and replace with a 6cyl VE pump (6BT pump anyone?) But being a 6 cyl it'll NEVER be a revver, you're talking 4000rpm max really, you have half the cylinders again on the injection pump, and we struggle to get past about 5200rpm in our 4cyls without massive fuelling drops.. Then whack on a big turbo, and off you go... I've seen a few tuned up, 200hp should be fairly easy on a stock mechanical injection pump and a bigger turbo.

But they are indirect injection with Ricardo Comet V Precups... So they're almost identical to the XUD in injection system, just they have a VP37 electromechanical pump, but all you have to do is rip out the stuff inside and replace it with mechanical parts. Levers etc from an XUD pump would probably work pretty well and just keep the camplate and injection head from the VP37.

[4WayDiablo]

Go browse the 3 series forums :-P

[Ruan]

Being BMW forums, it's just always a case of, ugh diesel is shit go get an M3 lump.

[Midnightclub]

Hmm.. Saying that though i was reading over a thread on TDOC on the OM606 engines, Apparently the bottom and valves etc. are all good for up to about 6,000 rpm's before they start to throw rods? But I'm guessing the engine design is completely different to the BMW tds engine.

I've been spending a lot of time looking at the 330D's and 525D's and it seems they can get decent gains without a massive amount of work BUT they are £££ to buy in the first place if you want a decent one.

I'd like something RWD and Turbo'd but without the massive fuel costs


Yeah Ruan, That does seem to be the general consensus with most forums unfortunetly.. Except for the finnish/swedish etc.. who seem to love the big boost, big power dervs!


EDIT: From a bit of reading i think those tds's have a 10mm pump and people usually upgrade them to a 12mm but not too sure what the '12mm' is from, however from the ones i've seen so far they keep them semi-electronic, haven't found one so far which has gone mechanical injection

[Ruan]

The OM606 is a completely different beast.

It's not the engine that has a problem with 6000rpms, it's the injection pumps, they just won't deliver the fuel up there... The inline pump on the OM606 is what makes them able to rev... But they're a frikkin' nightmare to setup and very finnicky...

The 25tds is a GOOD engine I'd say, it's prime for mucho boost... Bet you the bottom end will take some serious abuse, not as much as a 603 or a 606, but they're something else!

The 330D engine isn't that good to begin with, it's riddled with faults like the swirl flaps, the turbo is nigh on it's limit, you'll sturggle with nozzles and HP pumps, and then you've got to pay for remapping... Which no one really does that well tbh, it's pretty much a 6cyl HDi tbh, has all the same problems of lack of parts and knowledge equalling muchous £££ to find the people who do it properly and are usually up tight and dont let any info out about them.

[Ruan]

http://www.youtube.com/watch?v=TO8KJeWWKNI

Ayyyyye!

Mech VE6, 12mm, GT32.

Win.

10 mins of research will reveal where the 12mm 6cyl head comes from, it's an obvious one...

[Midnightclub]

Hmm.. I wonder what sort of power that one in the video is making?

When converting from electronic to mechanical is it a case of literally just swapping the pumps and binning the ECU? It's not really something i've looked into much as i've mainly read up on the electronic tuning side of things

[Ruan]

Pretty much, yep!

IIRC that one is about 240hp...

EDIT: It's 202KW - 271hp and 470nm Torque - 350lb.ft.

[Midnightclub]

Just checked the blokes other videos and with a boost leak (it only running at 23 psi) it made 275BHP @ 4160RPM and 489NM @ 3840RPM..

That's pretty impressive! I'd like to ask him a few questions but the video's were posted over 2 years ago and i don't think there's been any recent replies..

This could prove to be quite an interesting project, I've been thinking about the mechanical side of things lately and was thinking Dt, this could well possibly be my answer, turbo seems to be in an easily accessible location too which could mean swapping the turbo not too difficult

[Dum-Dum]

Ruan want!

I thought the bmw diesel were quite revvy though

[hbomb1905]

I'm thinking of looking into one of these when I can afford the insurance - thinking mans Beemer!

Tourer for me though!!

[Ruan]

Ruan want!

I thought the bmw diesel were quite revvy though

The *ENGINE* is revvy - sure.

The injection pump isn't for the same reasons our cars won't do over about 5200rpm whilst maintaining full fuelling without going inline, which is not feasible really...

It should be able to rev to about 5k max, but you're gona struggle past there, remember Darren snapped a 4 cylinder 12mm plunger, add 50% to how many times a minute it goes in and out of the plunger being a 6 cylinder... You can guess what's going to happen.

A 4 cylinder pump, at 5000rpm, the plunger is going in and out of the head 10,000 times a minute... That's 166.6 times a second...

Change that to a 6 cylinder. Which makes 15,000 times a minute, that's 250 in and outs a second... With the possibility of starving it of Diesel when putting the IQ through the roof... You can understand why they sieze...

[mark_airey]

The *ENGINE* is revvy - sure.

The injection pump isn't for the same reasons our cars won't do over about 5200rpm whilst maintaining full fuelling without going inline, which is not feasible really...

It is, you just need to weld some injector lines together

[Ruan]

You've not seen how they run without setting them up on a bench - dear god - the timing and lope smoke...

[THE_Liam]

Their very smooth for a derv, but not revvy...

[Ruan]

That's cause they're like that stock..

Give them the fuel up in the RPMs and they'll go mental. They're almost square from what I remember... Very short stroke for a Diesel.

Yeah - 80x82.8mm - The XUD9 is 83x88mm - and the XUD9 is considered "revvy" from a high speed diesel point of view.

[Midnightclub]

[THE_Liam]

One thing I know for definite though is mpg is crap, like I say my mates not really getting better than his old 328i and Gen's stepdad gets even less, although that's in a big Rangie with an autobox...

[Toms306]

Just checked the blokes other videos and with a boost leak (it only running at 23 psi) it made 275BHP @ 4160RPM and 489NM @ 3840RPM..

Peak torque at almost 4k?? That must drive more like a petrol then?? Or is it just really laggy?

(Can't watch the vid btw)

[Midnightclub]

The video is off a different car tom and even more powerful AFAIK

I expect the power delivery to be similar to a petrol straight 6

[Toms306]

The video is off a different car tom and even more powerful AFAIK

I expect the power delivery to be similar to a petrol straight 6

Ah ok......how do they manage to get the petrolly power delivery from a diesel?

[Midnightclub]

6 cyclinders, short stroke and big turbo i'm guessing? 6 cyclinder engines have 3 power strokes per cycle

[Toms306]

6 cyclinders, short stroke and big turbo i'm guessing? 6 cyclinder engines have 3 power strokes per cycle

Ah cool, that makes sense.

[Ruan]

You're looking at ONE component of the torque/power curve...

Darren's engine was exactly the same, just turn down the power a bit to 200 or so, the peak torque would have come at around 4200 and peak power at around 4800rpm... But that's because of the big turbo...

You have to look at the whole graph to get the entire picture...

You could make your PD what you'd call "petrolly" if you wanted... I.e. no torque low down, rising to a big peak in horsepower but giving a low torque figure... All you'd need to do is make the torque limiters pull back all fuel low down, so your torque curve would just go up and up and up until the peak, it'd be a shit engine because you'd have to rev the TITS off it to make it go anywhere, which is kinda pointless, when a Diesel can produce the full 250lb.ft torque from just off idle... That's like saying I want a petrol engine like a Diesel, so I'm going to make the cams so that it can get NO air in up high, but loads of torque down low...

It's just that you're thinking when you see a high torque figure, you assume that's an un revvy, no HP up high... But of course, that's because you had a SPIKE down low... You need to look at the entire graph... Get my drift?

It's all to do with the fact that when torque dies off it feels like it's going slower, even though the HP figure might still be rising, or even staying constant... It's just that Diesels FEEL as if they die, even though often they're increasing in HP.

[Midnightclub]

^^ Much better explanation

[Toms306]

You're looking at ONE component of the torque/power curve...

Darren's engine was exactly the same, just turn down the power a bit to 200 or so, the peak torque would have come at around 4200 and peak power at around 4800rpm... But that's because of the big turbo...

You have to look at the whole graph to get the entire picture...

You could make your PD what you'd call "petrolly" if you wanted... I.e. no torque low down, rising to a big peak in horsepower but giving a low torque figure... All you'd need to do is make the torque limiters pull back all fuel low down, so your torque curve would just go up and up and up until the peak, it'd be a shit engine because you'd have to rev the TITS off it to make it go anywhere, which is kinda pointless, when a Diesel can produce the full 250lb.ft torque from just off idle... That's like saying I want a petrol engine like a Diesel, so I'm going to make the cams so that it can get NO air in up high, but loads of torque down low...

It's just that you're thinking when you see a high torque figure, you assume that's an un revvy, no HP up high... But of course, that's because you had a SPIKE down low... You need to look at the entire graph... Get my drift?

Ahh, yeah I see exactly what you mean!

So theres always gonna be compromises with whatever you try and do to an engine....I want the low down torque of the diesel but then a progressive line right up to the top end, so you're not dropping the toqrue after like 2k rpm, which I think is what makes my car (and diesels in general) feel slow (to me).....cos you can rev it to the red line but its not accelerating any more quickly than when you were at around 2k, whereas the smaller 1.8 which was technically slower pulled hard at 5k+and now driving the diesel seems counterintuitive as you've gotta change gear in the middle of the rev band to get more power. But clearly you can't have a flat constant high torque line, and losing the low down torque which the diesel is so good for would just be completely pointless really.

So basically if I added a larger VNT turbo to mine (from the 150 for example) would that 'keep' the torque for longer or would it 'move' the whole curve further up in the rev range?

I know what I mean.....but that probably makes feckall sense to anyone else as I just can't seem to put it into words! :think: