Exhaust Manifold.

[darrenjlobb]

Im not digging at you at all, as someone who also tunes other peoples cars, i can totally understand your frustration, most of what im saying is aimed purely at tuning your OWN car point of view...

But then 500 quid for set of injectors? How would it cost that much...Im willing to bet i could build a set of mental 16v hdi injectors (only cos im clued up on angles etc with them) for a hdi injector for under 250 quid INCLUDING having them professionally lift set and tested... if i wanted to be cheap, i could do it for even less

I guess the long and short of it is people dont want to put money into it, which is fair enough, but i still maintain that big injectors + big vnt will result in GOOD results, im yet to see a hdi that makes me think "fook me, thats impressive" not meant offensively to anyone on here, because there are alot of well tuned cars etc...but in terms of raw power builds, im yet to see one...

[Mr Whippy]

I agree.

I bet we could see a 300bhp HDi if someone just spent the time.

Since it's not something I want to start with, for oodles of reasons, that is why I haven't hehe.


As per injectors, really that cheap?

I think Pete found some good tips, off an Alfa iirc, probably something around 2.0 4 pot, and similar cylinder aspect, with 200bhp output standard I guess

Can't remember which car it was.

I do remember Pete saying another issue was injector bodies impacting calibration.

If you could specify the exact body and tip, and make sure people DID use those parts to make the injectors then it'd make the remappers life a lot easier if they could just drop in the calibrations and KNOW they would work... and also know the injectors are guaranteed right!


I guess for 300bhp you'd want to see what CR engine in 2.0 4 pot guise or 3.0 6 pot guise, made about 75bhp per cylinder when remapped... possibly only the x35D BMW injectors get close?


Dave

[Just Sean]

Darren! Ill have a set of those injectors of you when i get back from afghan!

lol

[Poodle]

I agree.

I bet we could see a 300bhp HDi if someone just spent the time.

Since it's not something I want to start with, for oodles of reasons, that is why I haven't hehe.


As per injectors, really that cheap?

I think Pete found some good tips, off an Alfa iirc, probably something around 2.0 4 pot, and similar cylinder aspect, with 200bhp output standard I guess

Can't remember which car it was.

It's a 1.9 fiat jtd engine i think, got the part number kicking about somewhere...

Darren if you can do it for that price, i can find £250. Maybe not before christmas lol, but i WOULD find the money. Even a set of standard refurbed injectors go for at least £350, pumps for £150 upwards, it's expensive shit lol.

I think there's a damn sight more people willing to go the distance in this community than there were previously, even as little as a year ago. We only need a few people to experiment and share their findings and the whole thing progresses. The HDi scene has lagged behind for quite some time, i think it has reached the point where the fuel system is the next big obstacle. Besides, it's got to be tackled some time if we're ever to advance.

I'm up for sharing info to get a 300bhp HDi, it's got to be achievable.

[darrenjlobb]

When i say i could do it for that, i mean for myself, not for other people, ive not got time for sorting injectors much, the nozzles that i use generally come from the states, as the uk sucks / are incapable with edm / understanding tuners needs! The only thing that makes it as expensive as 250 is the fact you have to pay import tax, and then pay the test man, as altho i have pop tester for mech injectors, i dont have anything to energise the injector solenoids to measure lift with, let alone flow test them, albeit flow testing only if you want to be rally anal, as given they lift right thre all near as damn, no worse than mech ones anyways!

[Jonny81191]

I really can't see any reason why 300 bhp is not doable, it's just a case of putting in the time, effort, and money.

The thing is, people usually don't have all of the above 3 things!

Poodle, Ruan, Darren, at some point in the new year, can we have a chat about injectors and the HP system in general, I'm getting mixed ideas and views from all different angles, I think it'd be a great idea to consolidate what's KNOWN, and go from there.

[darrenjlobb]

Remember, not all information is information people are willing to share....you would be suprised how much time it can take a man researching / buying injectors / nozzles to find out different engines angles and planes....

[Jonny81191]

No darren, I wouldn't be surprised. I'm painfully aware of the research that is done by people, myself included (although I'll freely admit I'm still in the early stages of understanding what I want to know). I'm not suggesting it gets posted all over the internet, and I'm definitely not asking for answers/all you know on a plate. But it does help to chat things through with other like minded people who know what they're on about.

Not having a dig, just sayin'

[Poodle]

Damn, thought that sounded too good to be true, more's the pity Darren.

PM me your number Jonny, i'll be happy to go over what little info i've got, these guys are in another league though.

[Dum-Dum]

300bhp is entirely possible on the HDi. Its all about injectors though.

Personally I dont entirely think finding injectors to suit the HDi is the way forward. For 300bhp youll need rods and pistons so why not get a different combustion chamber machined in the new pistons and use something cheap and easy to get hold of (like uprated VAG injectors)



Also what Dave said about 20 posts back about you not knowing if its port size thats holding it back and maybe making it undrivable is silly. You cant run double the stock airflow through stock ports without it being a slight restriction unless peugeot made them ridiculously over sized to start with which would of made the car undriveable at very low revs.



As the only person here to of had a professionally ported head and manifolds on a HDi i can tell you that it dosent affect low down drivability in any particularly noticeable way.

[Poodle]

The problem is not finding tips that can flow more, it's getting ones with the right plane angle mate - we all saw how bryns ran on the amg tips. Problem with your ported head is that it was added with several other mods, so it's hard to gauge the benefit. Don't get me wrong, I think head work is necessary too, but to what extent...?

[darrenjlobb]

Changing combustion chambers will hardly help the problem at all...

What dictates the main issue with nozzles is the position the injector sits in the head.. most pots in pistons are all very similer / only require very slight angle adjustments in the nozzle, but this isnt what is so important, you can easily get away with being out with the nozzle angle, I think there's a big misunderstanding amoungst most of the hdi boys on here with regards to nozzles and angles....Its something that the likes of me / other diesel nuts dont talk about much, as it DOES cost money experimenting with nozzles to figure out what is right, but esitronic and the internet can help alot to save buying as many used injectors to look at what nozzles are in them etc...

There are TWO critical things with nozzles.. Angle of cone, and angle of plane....this is what imo no one seems to understand including alot of "specilists" after looking at work they have done...

DI engine, bowl in piston, injector over that bowl, injector sprays a cone spray over the bowl, you want the cone to go in the bowl, not outside / in the middle of it, or you will melt things, but as as i said before, thre is ALOT of give here, its no big deal...espically not with low power levels like 200hp, you could be 15 out and still not melt anything.

So say for example you were running a set of 152 (thats a 152 degree spray cone out the end of the nozzle), for this to work the injector would need to be perpendicular with the piston right....or else 152 angle is just on its side, meaning half is hitting the middle of the piston, and the other half is hitting the cylinder wall..what use is this, none, at all....hence injector PLANE angle, which is the angle the injector sits in the head...this is by far, the most important thing you need to figure out before you start messing with nozzles...and trust me, when you start looking back at some projects, you will now begin to see the scale of fail!

So in the 8v hdi for example, the injector is at x degrees (go figure yourself ) meaning the STOCK 8v hdi nozzles have the cone at x degrees, BUT the cone exits the bottom of the nozzle at an angle, the angle of plane, meaning it still matchs up with the bowl, even though the injector is on the piss..now you begin to see the next probem...you can just start spinning the inector round willy nilly, becauase it also needs to go in EXACTLY the right rotation, or else again, you will just be spraying fuel all over the place...and no, this rotation is NOT the same among all engines, this is why they have a crow foot mount, so they only go in one way...

Its not a problem ,you just have to understand / KNOW about it, so you can A get the right nozzle, B put it in correctly, and C know what the hell is going on, then you WILL make chronic horsepower, end of no questions....but from what ive seen so far, there is very little understanding of this with any of the HDI builds ive seen....

Does that help explain poodle / jonny etc?

Darren

Quick paint lash to explain

[Poodle]

Yeah I understood that much bud, I meant that im lacking info on the injector specs themselves. The spray angle is easy enough as its detailed in the bosch part number, but plane angle is a completely different matter, as you say. So, who's willing to offer a reasonable, professional rebuild/upgrade service for our injectors then....?

[Jonny81191]

Exactly my thoughts mate. That far is the easy bit to get the info on, a quick search on google will tell us that. It's the bit where we want to start uprating them that gets confusing

So, who's willing to offera reasonable, professional rebuild/upgrade service for our injectors then....?

This. As far as I can work out, the US is the place to go but where...?

[darrenjlobb]

Yeah I understood that much bud, I meant that im lacking info on the injector specs themselves. The spray angle is easy enough as its detailed in the bosch part number, but plane angle is a completely different matter, as you say. So, who's willing to offera reasonable, professional rebuild/upgrade service for our injectors then....?

If this is understood, why the hell are hdi owners STILL using bmw nozzles and things....

First step, is finding engines with similer head setups, buying used injectors to see what nozzles are in them, and then looking at head to see what rotation the injectors are at so you can put them right in another head...once you have found a base nozzle, then you go overseas and make them chronic

[Poodle]

Because the ones with money aren't necessarily the ones with brains... And because a long time ago someone said it might be a good idea, so everyone said "baaa" and, well, you know the rest all too well i should think. Tbf i should think most people reading this thread wouldn't have known that previously, so still useful info for the community.

Gotcha, so still a very expensive option if you haven't got free access to a wide variety of old cr engines and injectors then...

[Dum-Dum]

OK one of the other things i was meaning when talking about trying to find he right injectors is why not drill the head to the right angle for the injector then smash a sleeve in that back to the right size of the injector.

[darrenjlobb]

Lol...the injector is in at an angle purely because it has to be because of water valleys / valves / cam gear etc...

[Jonny81191]

Sorry, buy buying injectors "just to see" what the angles and nozzles are seems like a massive waste of money to me!

If they exist, there'll be information about their fitment. But I've heard Bosch don't like telling people anything.. Which leads us back to buying used injectors and .....

Frustrating.

[Dum-Dum]

VAG engine in a 306?

[darrenjlobb]

Sorry, buy buying injectors "just to see" what the angles and nozzles are seems like a massive waste of money to me!

If they exist, there'll be information about their fitment. But I've heard Bosch don't like telling people anything.. Which leads us back to buying used injectors and .....

Frustrating.

It is a waste of money if you phrase it like that, its called research and development....it costs money.....like i said, the internet will go so far, and also things like ebay finding nozzles for said cars and looking at nozzle numbers etc etc....but at the end of the day, you HAVE to spend the money, either that, or wait for someone else to do it first, and then copy them....but how boring is that?

Welcome to diesel tuning, its not just a case of buying a product ready to go in most cases, at least on the psa scene, but I think this is almost a good thing, as it means the cars that come out the other end are all very much unique in there own ways....there not all just typical tdi with a typical turbo conversion with bosio nozzles making x hp just like all the others do....other than the few special ones really pushing them, which is again, NOT off the shelf bits therefore become interesting again...

---

VAG engine in a 306?

I measured up that v6 just for fun, as its a very compact unit, engine would fit fine / bulkhead would require a few inchs to fit the tranny in, but it would be do able if you really wanted to...

But who would ruin a french hatch with a shitty vag motor

[Jonny81191]

I'm not suggesting that it should be easy and cheap with bolt on parts. But what I am saying is that the documentation for all the injectors ever made exists. And that is why I see buying used injectors, (just to get information that already exists) as a waste of money. Well maybe a waste is wording it badly. If you get your answer, then it's not a waste. But it certainly is a long winded and expensive way of doing it..

[Ruan]

The nozzles are good to 200bhp on an appropriate pump.

Yes RP is high, but that is irrelevant.

RP is a function of how much flow you want to get into the engine and how big the nozzle is.

You could run huge nozzles and low RP, or high RP and small nozzles.

But you can't get BOTH without a BIG pump... and that is the problem, the pump.


The standard HDi pump is good to maybe 180bhp assuming all else is good, at about 4000rpm.

Big injectors, small ones, twice as many, it won't make any difference. No combo of rail pressure and tip size will get around the fact the pump just can't flow enough fuel for more power, no matter how it's injected.


So injectors, yes upgrade them, but only when you have a better pump too.


The old XUD pump is different. They can flow LOADS of fuel. The issue is they probably have higher parasitic losses due to being over-specced a lot of the time.
To a certain extent bigger nozzles are less precise, so over-sizing won't give exact injections at low IQ's, so idle and cold-starting and precise emissions control are less feasible.

Not saying that is bad, if power is what you want great, I personally live the XUD9 when tuned up!

But the HDi is different in a lot of ways, and beyond the small turbine on the stock turbos causing torque curves like mountains and peak power at ~ 3500rpm or below, the next problem is the HP pump!

Dave

This is where I 100% disagree...

The more pressure being produced, the more the flow rate will drop, the more power that is consumed and the more heat is produced...

A bigger pump will move MORE fuel at MORE pressure with LESS heat requiring less power due to inefficiencies...

Just in the same way as you can stick more RP at injector nozzles but you eventually get to a point where you can stick more and more pressure at them, but it's a law of diminishing returns, your injectors will continue to stay open for longer to flow the required amount of fuel - the RP keeps on rising at an exponential rate for little return - hence bigger nozzles required...

Big nozzles YES they do reduce refinement and reduce the resolution at which you can control the engine, but after experiencing VE/VP TDis with CHRONIC nozzles and seeing PD TDis with rediculous nozzles - they really are NOT the issue that people make out, I've seen injectors that are good for 400hp and they give a CLEAN, SMOOTH idle, no starting issues, no haze midrange or anything like that... But will happily let through MASSIVE quantities of fuel, all at SIGNIFICANTLY lower pressures than HDis can run at, the resolution and precision of EDC15 will happily cope with the nozzles given the mapping is good...

This is a flow chart for a positive displacement fuel pump, it's a lobe pump, but positive displacement same as a piston pump so explains my point perfectly -



With regards to the XUD pumps, they cannot flow a significant amount of fuel in stock form, but they are a completely different kettle of fish, with Indirect injection the nozzle is barely a restriction at all, they aren't VCO like HDi nozzles and the pressure is only built up by the spring and shim stack unlike HDis where it's built in the rail - you can build however much or little you like... But we know what happens with DI nozzles and trying to increase IQ on VE pumps - the line pressure builds and builds and the injection length gets longer to a point where you start damaging the pump etc because the fuel won't get through the nozzles fast enough... The pump itself is probably OK sure, but again, nozzles are the cause of the problem - bigger nozzles = less line pressure = more fuel over a shorter period of time, but you do get to the point where even the pump cannot cope - hence bigger injection heads to reduce duration, which means more flow, less time...

Even past all of this, you'll still get to a time where the OEM pump cannot cope, so bigger pump, bigger nozzles - off you trot... Keep the power up at 5000rpm and bring the torque in gradually, just because it "feels" epic to have that lovely wadge of torque at 1800rpm, it simply rapes clutches, doesn't do much for the big ends and rods etc, I personally rekon you could keep the torque lower and still even stay on an "uprated" clutch, maybe not stock, but no need for jerky, heavy paddle clutches...

[Tom]

This thread has taught me so much.

[darrenjlobb]

Rep blatently needed....

[Tom]

Rep blatently needed....

Dude i only have 2

[Poodle]

I think Darren probably meant for him, not you.

Ruan, that's how i understood it, which is why i've been looking into ways to reduce the strain on the hp pump. My thoughts so far, which have mostly been flamed, are fuel cooler pre-hp pump and a higher-rated lp pump... Also, from looking at the internals, there's numerous restrictions to flow in these hp pumps, not all of which i can work out the purpose of. Unless their purpose is purely to reduce flow, in which case... Think uberderv was looking at modifying one, but the thread petered out and he stopped answering emails... How much do you know about bosch CR pumps in general?

In fact, YHPM. Lol.

[Mr Whippy]

Jeez this thread is going mad

To make a lot of injection you need a big pump.

To a certain extent it's IRRELEVANT what the pressure is. That is just the nature of CR systems. They want high pressures, so that is what we work with.

Have big holes at low pressure or small holes at high pressure. You can achieve your goal either way.

I personally don't give a damn if they run at 1bar or 100000000bar, you work with what you have, and that is a CR system, an ECU and all the calibrations running in the range of ~ 300 > 1500bar max injection pressure. You might come back 10%, or run 10% more or so, but going much out of those ranges is gonna cause you a real headache!

Working back from the standard makes a lot of sense if you ever want to have a car that even starts, or don't have £15k of simulation gear, a dyno, and weeks to re-build the entire bulk of maps to make the car work with a fundamentally different approach (say running 500bar peak and huge injector nozzles to make up the IQ's)


Yes, the flow is roughly inverse square with pressure increase, fluid dynamics basics. I didn't design the CR system, I just tune using it. If you can take a CR system and fundamentally change the raison d'etre for it, and make it relatively low pressure with huge flow nozzles, then you are kinda taking a walk into the unknown.


If someone is willing to spend the money and time on a project that starts with a blank sheet on injection, then they may as well start with a blank sheet on the engine as the costs are gonna be the same or more to do your own thing.

Ie, throw in a 123d engine and making it work will be cheaper by half or more I'd say!



Not trying to be negative, but there is some serious over-thinking in this thread.

Set a target, decide what you NEED to achieve it.

YES, the HP pump makes fuel hot.

YES, you can flow more with bigger nozzles and lower RP.

YES, it's not massively efficient doing that for big power needs.

YES loads of other things.

But it's your starting point.


If you can re-engineer from the ground up do-so... but I personally think you could just get 300bhp with a high flow pump (or two!?) and big injectors running near standard RP's from 300bar > 1500bar.

Why re-invent the wheel doing something mad like running 500bar max, or 100bar?

Dave

[Ruan]

That's precisely my point... I'm not saying high pressure is a bad thing, but it seems there's an argument that running standard nozzles is a good thing and achieving power at higher RPMs is a bad thing which is where I disagree... You can achieve shorter injections with bigger nozzles at the same rail pressure, but you aren't having to strive for the full 1500bar ALL the time, that's going to cause parasitic loss from the HP pump, you could be making the injections happily in time at 700bar (im not condoning that, but its to prove a point) with bigger nozzles...

But there seems to be some hatred of big nozzles... There seems to be some reputation that bigger holes = shit running which is totally untrue and unfounded... The point I've tried to make is that CHRONICALLY (100hp/cyl) big nozzles at 200bar injection is not an issue, so drop the size a little since you can get away with higher RP and you wouldn't have a problem...

[Mr Whippy]

Yeah, maybe a confusion of what is going on/being suggested.

I've never said push RP to the max. I've never 'got' 1800bar sensors except as a cheap replacement to the 1500bar one, OR where you might just want to get to around 1500bar with BIG injections on a BMW pump on the standard sensor and have some headroom with things. I've certainly never mapped a request for 1800bar, or even 1550bar+... the maths doesn't stack up for the injections and power requirements.
That isn't to say they are really great mods to make, but as you guys rightly point out, just because it 'can' reach 1800bar doesn't mean it should use it all to be considered good or worth doing! The BMW pump at 1500bar can make IQ's the standard pump can only dream about at 1500bar! (at the same rpm hehe)



It's all pretty much just a balance scale depending what you want and your budget I think.

High rpm = good because CFM is naturally higher = power. CR pumps run faster = can do more pumping to make that power.
High rpm = bad because crank inertial loads go up with square of speed = expensive to sort. Injections need to be done faster = need bigger nozzles or higher pressure, or both.

Low rpm = good because inertial loads are low, so even standard internals might run 500bhp at low enough rpm. Low rpm is good as piston speed is low, so injections can be slower.
Low rpm = bad because massive torque = bad for gearboxes/clutches designed for less. Need longer final drive ratio = hard to do? Pump probably still needs to be upgraded to flow a load of fuel at moderate to high pressures to get the IQ's needed for big power.


Loads more besides.


If you just look at things as a bunch of downsides and efficiencies then you start to hit many brick walls at different points, where adding X gets you an increasingly small benefit and increasingly large problems such as heat etc.


This is kinda why it's good to plan a goal output, budget, and intermediate steps. The 'stage' system kinda does that already but it gets confused after stage 2 currently.

If you want under 180bhp, don't get injectors or a pump. If you want 180bhp - 200bhp, get a pump and maybe injectors, or possibly vice versa depending on planned torque curve shape. Want over 200bhp, get both!

Not ideal but then we are building high powered engines to a low budget in most cases!


Dave