Why new injectors?
Discussion
Ceejay
I bought 8 brand new 26LB injectors, these are capable of 330bhp as Im running them in my supercharged 3.5, for £90 a set. If the injectors are not capable of 12.5 afr at full throttle then power will be down, if they are capable of that, and I would think they must be, then they are fine, I will see if I can test a set within the next 2 days
Phil
I bought 8 brand new 26LB injectors, these are capable of 330bhp as Im running them in my supercharged 3.5, for £90 a set. If the injectors are not capable of 12.5 afr at full throttle then power will be down, if they are capable of that, and I would think they must be, then they are fine, I will see if I can test a set within the next 2 days
Phil
Here we go again 
- you guys (the same old names always cropping up) just don't give up do you.
Any opportunity you can find to knock either Austec, Mark Adams or Tim Lamont and you're there.
I personally know both MA and TL and one would have to go a VERY long way to find two more honest, ethical men with solid integrity!
Know what? - I have never found any of them making disparaging remarks towards Joospeed and his group of loyal followers.
May I suggest you take a good long look at the Rules of Posting and digest them. Here they are for ease of reference...
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Don't give us any crap
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Be reasonable and we'll all enjoy ourselves!
- you guys (the same old names always cropping up) just don't give up do you. Any opportunity you can find to knock either Austec, Mark Adams or Tim Lamont and you're there.
I personally know both MA and TL and one would have to go a VERY long way to find two more honest, ethical men with solid integrity!
Know what? - I have never found any of them making disparaging remarks towards Joospeed and his group of loyal followers.
May I suggest you take a good long look at the Rules of Posting and digest them. Here they are for ease of reference...
To ensure the forums remain a fun place to be without over regulation we ask you to abide by the following guidelines: You will not use the forums to post any material which is knowingly false and/or defamatory, inaccurate, obscene, threatening or an invasive of a person's privacy or in violation of the law.
Please treat people with the same level of respect you'd like to receive yourself.
Please don't name and shame companies with which you've had a bad experience. It's a legal problem for us to host such messages.
Please don't post adverts in the forums. Adverts should go in the section.
Messages should only be posted once. We ask that you don't post the same message in more than one forum.
Please don't promote your business without our consent - it's not fair to the paying
Please don't claim to have stumbled across a particularly great website that happens to be your own
Don't give us any crap
It doesn't happen often but in extreme cases of abuse we will report your IP address to your system administrator - whether this be your ISP, your educational establishment, or your employer. We also reserve the right to reveal your identity (or whatever information we know about you) in the event of a complaint or legal action arising from any message posted by you.
Be reasonable and we'll all enjoy ourselves!
According to one person who I very much respect, the cooling effect of well atomised fuel *is* worth more than the loss of volume of air the vapourised fuel displaces (which was my primary concern) .. even on road engines.
I'm prepared to believe this as the person who told it to me is one of only a very few people that I hold in very high regard based on their previous form.
This person though is the *only* one so far to agree with Mark Adams on this point when applied to a road engine that i've come across. i wouldn't normally accept that what holds for a race engine turning 17k rpm would transfer directly to a RV8 turning 6k rpm. I would also normally dismiss almost instantly anything MA tells me, though I nod my head in mock approval if ever he talks at me..
.. but seeing as this other person suggests there's a very real chance of the charge cooling being significant I'm going to test it out, after all if there's power to be had my customers should have the option of getting it.
There's plenty of injectors capable of a finely atomised spray pattern, I'll test some and tell you the findings. It could be that the bosch ones we have in the tasmin are good enough to work out if the effect is worth the change.
I'll send one down to emerald to compare the visual spray against a std RV8 injector and take it from there
I'm prepared to believe this as the person who told it to me is one of only a very few people that I hold in very high regard based on their previous form.
This person though is the *only* one so far to agree with Mark Adams on this point when applied to a road engine that i've come across. i wouldn't normally accept that what holds for a race engine turning 17k rpm would transfer directly to a RV8 turning 6k rpm. I would also normally dismiss almost instantly anything MA tells me, though I nod my head in mock approval if ever he talks at me..
.. but seeing as this other person suggests there's a very real chance of the charge cooling being significant I'm going to test it out, after all if there's power to be had my customers should have the option of getting it.
There's plenty of injectors capable of a finely atomised spray pattern, I'll test some and tell you the findings. It could be that the bosch ones we have in the tasmin are good enough to work out if the effect is worth the change.
I'll send one down to emerald to compare the visual spray against a std RV8 injector and take it from there
Lucas Injectors - do we need to upgrade them? Sorry if much of this post is a repeat, but it seems that there are certain parties who have read this before and not taken any of it in.
The standard 5.0 Litre motor as it comes does not need the injectors changed to provide adequate fuelling, as long as no other mods have been done to it. This is based on the proviso that the injectors are in good condition with good spray patterns.
As the various modifications to the breathing of the engine have improved, so now the limits of the injectors are being reached.
There are two problems with the standard injectors, which are related to both the basic design and the flow capacity in 5.0+ Litre motors.
Lucas injectors are a disc type design - that is they have a disc that sits over a metering hole in a plate. The disc is lifted off the hole by the solenoid to allow fuel to flow. The more you increase the fuel pressure, the more difficult it becomes to lift the disc off the hole. There comes a point at around 3.3 Bar where the fuel flow actually starts to drop as you increase the pressure.
Furthermore, increasing the fuel pressure actually changes the battery voltage corrections required for the injector. This requires the corresponding rework of the ECU software including cranking tables. So it is not just a simple matter of increase the pressure no worries, unless you have no understanding of the implications.
Yet another factor to be considered is that of fuel pump flow rates. Flow rates drop exponentially with increasing pressure, so again it is desirable to keep the pressure as low as possible, commensurate with good atomisation.
When I remap the 5.0 Litre cars, it is almost always necessary to increase the fuel pressure from the standard 2.5 Bar (36PSI) to 3.0 Bar (45PSI). Even with this assistance they are nearing 100% opening at full power. Injectors that are ideally sized should not really be open more than 80% duty cycle, to allow room for transient enrichment and high load operation of a cold engine.
V8 Developments and John Eales get more power and torque out of available fuel by producing exceptionally efficient heads.
Lastly there is the issue of droplet size. Since the flow from a disc-type injector is only partly atomised as it comes through the metering hole, the job is completed by a plastic diffuser under the hole. What you end up with is fairly large droplets, or sometimes just a jet of fuel.
An obvious truth I learnt from someone at Ilmor Mercedes (Formula One for those who don't know) is that fuel droplets burn from the outside in. The corollary of this is that the smaller they are the quicker they burn, and the more energy you get out of them. In Formula One, they don't get long to burn the fuel and fuel economy is also important (although the concept is where the similarity to our cars ends).
At Austec, we did several back-to-back tests on a healthy late 5.0 Litre Griffith. This car was perfectly healthy in all respects except for a major injector problem. It was first fitted with a set new flow-matched standard injectors (we have three flow grades just for new standard injectors) and fully mapped. It was then fitted with Bosch injectors and reprogrammed to suit. The car picked up 9lb/ft of torque across the board, and even sounded different. These upgrades are always money-back guaranteed anyway - no gain - no pain!
It is a great pity that the injectors are so expensive, because it would be a no-brainer to fit them if they were cheap enough. Although the gains are clear, it is the killing price that puts people off. We are trying to source some cheaper ones, so watch this space.
With regard to making the part numbers available, those of you who are sufficiently interested will find out anyway. In the meantime I am not broadcasting it for obvious reasons. The selection of the best injectors has been reached after many hours of dyno testing, and a few sets of binned injectors! I am in business to make money, and that is why I am still able to support all my clients and products after fifteen years (during which time I have seen many come and go). For anyone running a business, it is in their interests to learn how to make money as well as achieve technical excellence.
I don't like to blow my own trumpet but I have over fifteen years experience, dyno'd over 2,500 engines, and racked up more than 6,000 dyno hours. It is right to question new findings, but it is also of interest to note that the people who are most anti have actually got no relevant experience at all - only conspiracy theories. I take my advice from someone who has over thirty years experience and over 18,000 hours dyno time, amongst others. I am always interested in learning from people who know more than me...
Jools - what has happened to you? In the past we haven spoken a lot, and it has always been positive. You've had lots of free advice, and I have learnt from you too. What has changed? I've never done anything to undermine you at all - quite the reverse in fact. Just recently you seem to be trying to undermine many things I say - really I have no idea why. Please come clean, or desist
Out of interest I have done the AFM/no-AFM test many times to test it in different installations, which is why I am able to cite it as a fact. In fact I did it two weeks ago on a 5.0 Litre (standard motor, Bosch injectors, Omex 700) and yet again it made no difference. Again the experience shows through here, because I can produce some installations where even fitting a bigger AFM will actually lose power.
The recent Griff 5.3 featured in Sprint (385BHP without the NOS) runs an airflow meter, and there is no pressure drop across it.
Many of my top race clients have to run with inlet restrictors, and there are lots of interesting things to be learned from this area too.
>> Edited by Mark Adams on Monday 18th July 23:26
The standard 5.0 Litre motor as it comes does not need the injectors changed to provide adequate fuelling, as long as no other mods have been done to it. This is based on the proviso that the injectors are in good condition with good spray patterns.
As the various modifications to the breathing of the engine have improved, so now the limits of the injectors are being reached.
There are two problems with the standard injectors, which are related to both the basic design and the flow capacity in 5.0+ Litre motors.
Lucas injectors are a disc type design - that is they have a disc that sits over a metering hole in a plate. The disc is lifted off the hole by the solenoid to allow fuel to flow. The more you increase the fuel pressure, the more difficult it becomes to lift the disc off the hole. There comes a point at around 3.3 Bar where the fuel flow actually starts to drop as you increase the pressure.
Furthermore, increasing the fuel pressure actually changes the battery voltage corrections required for the injector. This requires the corresponding rework of the ECU software including cranking tables. So it is not just a simple matter of increase the pressure no worries, unless you have no understanding of the implications.
Yet another factor to be considered is that of fuel pump flow rates. Flow rates drop exponentially with increasing pressure, so again it is desirable to keep the pressure as low as possible, commensurate with good atomisation.
When I remap the 5.0 Litre cars, it is almost always necessary to increase the fuel pressure from the standard 2.5 Bar (36PSI) to 3.0 Bar (45PSI). Even with this assistance they are nearing 100% opening at full power. Injectors that are ideally sized should not really be open more than 80% duty cycle, to allow room for transient enrichment and high load operation of a cold engine.
V8 Developments and John Eales get more power and torque out of available fuel by producing exceptionally efficient heads.
Lastly there is the issue of droplet size. Since the flow from a disc-type injector is only partly atomised as it comes through the metering hole, the job is completed by a plastic diffuser under the hole. What you end up with is fairly large droplets, or sometimes just a jet of fuel.
An obvious truth I learnt from someone at Ilmor Mercedes (Formula One for those who don't know) is that fuel droplets burn from the outside in. The corollary of this is that the smaller they are the quicker they burn, and the more energy you get out of them. In Formula One, they don't get long to burn the fuel and fuel economy is also important (although the concept is where the similarity to our cars ends).
At Austec, we did several back-to-back tests on a healthy late 5.0 Litre Griffith. This car was perfectly healthy in all respects except for a major injector problem. It was first fitted with a set new flow-matched standard injectors (we have three flow grades just for new standard injectors) and fully mapped. It was then fitted with Bosch injectors and reprogrammed to suit. The car picked up 9lb/ft of torque across the board, and even sounded different. These upgrades are always money-back guaranteed anyway - no gain - no pain!
It is a great pity that the injectors are so expensive, because it would be a no-brainer to fit them if they were cheap enough. Although the gains are clear, it is the killing price that puts people off. We are trying to source some cheaper ones, so watch this space.
With regard to making the part numbers available, those of you who are sufficiently interested will find out anyway. In the meantime I am not broadcasting it for obvious reasons. The selection of the best injectors has been reached after many hours of dyno testing, and a few sets of binned injectors! I am in business to make money, and that is why I am still able to support all my clients and products after fifteen years (during which time I have seen many come and go). For anyone running a business, it is in their interests to learn how to make money as well as achieve technical excellence.
I don't like to blow my own trumpet but I have over fifteen years experience, dyno'd over 2,500 engines, and racked up more than 6,000 dyno hours. It is right to question new findings, but it is also of interest to note that the people who are most anti have actually got no relevant experience at all - only conspiracy theories. I take my advice from someone who has over thirty years experience and over 18,000 hours dyno time, amongst others. I am always interested in learning from people who know more than me...
Jools - what has happened to you? In the past we haven spoken a lot, and it has always been positive. You've had lots of free advice, and I have learnt from you too. What has changed? I've never done anything to undermine you at all - quite the reverse in fact. Just recently you seem to be trying to undermine many things I say - really I have no idea why. Please come clean, or desist
Out of interest I have done the AFM/no-AFM test many times to test it in different installations, which is why I am able to cite it as a fact. In fact I did it two weeks ago on a 5.0 Litre (standard motor, Bosch injectors, Omex 700) and yet again it made no difference. Again the experience shows through here, because I can produce some installations where even fitting a bigger AFM will actually lose power.
The recent Griff 5.3 featured in Sprint (385BHP without the NOS) runs an airflow meter, and there is no pressure drop across it.
Many of my top race clients have to run with inlet restrictors, and there are lots of interesting things to be learned from this area too.
>> Edited by Mark Adams on Monday 18th July 23:26
Mark Adams said:
Lots of good stuff, including ...
The recent Griff 5.3 featured in Sprint (385BHP without the NOS) runs an airflow meter, and there is no pressure drop across it.
That's curious. On the V8S the drop in static pressure across the 5AM was enough to be visible on a simple boost gauge, and I almost pursuaded myself that there was less of a drop with the bigger 20AM. Calculating the dynamic pressure seems to account for less than half the observed drop, and I assumed the remainder was due to friction and turbulence. (Removing the air filter made no noticeable difference, to be fair the profile without the filter was not brilliant though.)
It's hard to be very scientific about it when you're in the hot seat on public roads at full throttle with the needle throwing itself at the red line, all the same it did seem that there was a significant pressure drop that reduced when I fitted the bigger meter ...
trackcar said:
In the interests of keeping this thread open I'll politely decline your offer for me to *come clean* ...
we've discussed this issue on the 'phone before, i don't think I have anything else to add.
best wishes, Joo.
No Jools. I have no idea what you are talking about.
You are happy to make defamatory remarks about my work and business integrity on a public forum, but I have had enough. What are you on about?
If you wish to consider yourself as competition, then it is a free world. But don't have the cheek to start with a smear campaign.
Hi Hoover33
You would never need to change the injectors to achieve correct fuelling on a 4.3, or even a 4.6.
There are gains to be had by changing the type of injector, to achieve better atomisation. It is currently not cost-effective to do so with brand new injectors, however it looks like some newer ones will be coming through to mak it worth while.
Incidentally, if you ask Jamie at TVR Power why they recently got a new injector cleaning machine, you may find it happened after he saw some of our research in action!
You would never need to change the injectors to achieve correct fuelling on a 4.3, or even a 4.6.
There are gains to be had by changing the type of injector, to achieve better atomisation. It is currently not cost-effective to do so with brand new injectors, however it looks like some newer ones will be coming through to mak it worth while.
Incidentally, if you ask Jamie at TVR Power why they recently got a new injector cleaning machine, you may find it happened after he saw some of our research in action!
Aghhh so so are saying that cleaning of the injectors gives a decent boost...
I was also told that 4.3 have over fueling in low n high revs but under fueling mid range hense my pinking circa 4000 revs under load... and i would need a re-map... to be done at the same time as clean/new injetcors
I was also told that 4.3 have over fueling in low n high revs but under fueling mid range hense my pinking circa 4000 revs under load... and i would need a re-map... to be done at the same time as clean/new injetcors
Peter - with the induction layout you have, you are correct that the 5AM would show a pressure drop (as you saw).
The 20AM is much better in this respect. Note that the 385BHP Griff uses a Bosch hot-film item, but this gives similar results.
In every case, the layout of the trunk between the throttle body, AFM, and air filter make a huge difference to the results you get. Recently I did a 4.6 Morgan, where the 5AM AFM is behind the engine. I tried fitting a larger AFM which reduced the pressure drop, and the car promptly lost 15BHP!
The 20AM is much better in this respect. Note that the 385BHP Griff uses a Bosch hot-film item, but this gives similar results.
In every case, the layout of the trunk between the throttle body, AFM, and air filter make a huge difference to the results you get. Recently I did a 4.6 Morgan, where the 5AM AFM is behind the engine. I tried fitting a larger AFM which reduced the pressure drop, and the car promptly lost 15BHP!
Hoover33 said:
Aghhh so so are saying that cleaning of the injectors gives a decent boost...
I was also told that 4.3 have over fueling in low n high revs but under fueling mid range hense my pinking circa 4000 revs under load... and i would need a re-map... to be done at the same time as clean/new injetcors
I know Mark will post a more intellegent answer, however if its pinking around 4Krpm are you positive its not just over advanced ignition which would show itself at around the peak Torque point. Unless you've had a AFR meter on it that shows the mixture weakening at this point
. H
Hoover - sometimes pinking is caused by dirty injectors, even if the fuelling appears correct.
The most common cause is when the injectors produce a jet of fuel instead of an atomised cone. This leads to enormous droplet size, which is consequently slow burning. As a result the droplets are usually still burning on their way out into the exhaust, which means that the mixture in that cylinder appears weak.
With an experienced ear you can tell if the pinking is on just one or two cylinders, or the whole lot. Injector cleaning is always a good idea anyway.
As Harry says though, you can only tell if it is an overall mixture problem by running it on a dyno. In my time I have seen 4.3s that are weak or rich, so I wouldn't generalise...
>> Edited by Mark Adams on Tuesday 19th July 00:05
The most common cause is when the injectors produce a jet of fuel instead of an atomised cone. This leads to enormous droplet size, which is consequently slow burning. As a result the droplets are usually still burning on their way out into the exhaust, which means that the mixture in that cylinder appears weak.
With an experienced ear you can tell if the pinking is on just one or two cylinders, or the whole lot. Injector cleaning is always a good idea anyway.
As Harry says though, you can only tell if it is an overall mixture problem by running it on a dyno. In my time I have seen 4.3s that are weak or rich, so I wouldn't generalise...
>> Edited by Mark Adams on Tuesday 19th July 00:05
On a tangent, I've learned a great deal by listening to Joolz, Mark and Tim over the years and I've got a great deal of respect for them all. It's clear that there has been a falling out of some sort, but I'd like to think they can agree to disagree, or at least continue to put a polite face on it in public. If things descend into battle lines then we all lose.
Mark Adams said:
In the interests of keeping this thread open I'll politely decline your offer for me to *come clean* ...
we've discussed this issue on the 'phone before, i don't think I have anything else to add.
best wishes, Joo.
No Jools. I have no idea what you are talking about.
That's because you talk *at* me on the 'phone and rarely listen to what i say back.
I'm not aware that i've taken any shots at you on this thread though. In fact I've said I'm prepared to agree with you on the finely atomised injector thing, and the air flow meter thing *if our findings agree with what you've been saying all this time*... until then I remain highly sceptical as ever (just as I am over the cerbera induction press release you have your name on Hedgehog : read the ASA rules as well as the PH posting rules, you'll see the rest of us actually play pretty fairly ...).
The bit about dismissing what you say refers to the fact that you yourself admitted to me that you run your business from a fiscally biased footing and are keen to protect your market share as it pays your mortgage (you've used that reference here on PH too), and I think I upset you by saying I would never compromise my business ethics in the pursuit of monetary rewards.
I know you wanted me to raise the cerbera emerald prices so you could charge more for your MBE mapping, i refuse to do that as it's only good value at this current price .. any higher and I'd not feel good about the situation. I certainly wouldn't raise the price so you could inflate yours ... I find it very distasteful that you should even offer that scenario to me.
It was around this time that you were preaching at me and trying to tell me how to run my business that i started holding you in less and less regard.
I hope you don't mind me mentioning this on PH, but you pressed the point ...
Heath view of engine tuning.
1. More bang in cylinders, more grin on face.
2. More bang needs more fuel mixture.
3, More fuel mixture means more air + more petrol.
4. More air means more throttle bodies.
5. More throttle bodies means firehoses not injectors...
6. More bang becomes same bang so repeat sequence...
I've been through three or is it four injector upgrades so far on the 520 with Mr Eales and they usually coincide with a major induction upgrade so that the ability to deliver both fuel and air into the engine is matched. As the engine power increases, fuelling starts to perform other functions such as preventing predetonation by overfuelling and so on. For the next stage of development, the firehoses may need to be replaced with pipelines with a direct feed from the refinery...
The Griff shopper is providing 300 bhp with its standard injectors and relatively small mods to the induction system. After that, the injectors can start to become an issue, especially if the induction system is capable of delivering more air than the injectors can support.
Yes the pressure can be increased but that can lead to reliability issues and trust me the last thing you want is an injector failing to do its job. So to me going to bigger injectors is just part of the natural evolution of things. It is not mandatory and there can be a hidden cost caused by the remapping needed but if the max out of the upgrades is needed, it is usually on the list.
1. More bang in cylinders, more grin on face.
2. More bang needs more fuel mixture.
3, More fuel mixture means more air + more petrol.
4. More air means more throttle bodies.
5. More throttle bodies means firehoses not injectors...
6. More bang becomes same bang so repeat sequence...
I've been through three or is it four injector upgrades so far on the 520 with Mr Eales and they usually coincide with a major induction upgrade so that the ability to deliver both fuel and air into the engine is matched. As the engine power increases, fuelling starts to perform other functions such as preventing predetonation by overfuelling and so on. For the next stage of development, the firehoses may need to be replaced with pipelines with a direct feed from the refinery...
The Griff shopper is providing 300 bhp with its standard injectors and relatively small mods to the induction system. After that, the injectors can start to become an issue, especially if the induction system is capable of delivering more air than the injectors can support.
Yes the pressure can be increased but that can lead to reliability issues and trust me the last thing you want is an injector failing to do its job. So to me going to bigger injectors is just part of the natural evolution of things. It is not mandatory and there can be a hidden cost caused by the remapping needed but if the max out of the upgrades is needed, it is usually on the list.
I'm no technical expert and all I can say is that I've been dealing with Mark and Tim for a couple of years now and I find both gentlemen to be very correct, friendly and upright. In a few instances both have charged me a lower rate or given me free parts where they could have just charge me the normal price. They have given me a lot a free advice too.
Lately my car has been "treated" by Paul, V8D and Mark and although the cost has been substantial (but then I did have a knackered engine), they were the only ones who could fix it after spending years of trying to find what the h@ll was wrong with it.
And what an engine it is now! (with Bosch injectors)
Lately my car has been "treated" by Paul, V8D and Mark and although the cost has been substantial (but then I did have a knackered engine), they were the only ones who could fix it after spending years of trying to find what the h@ll was wrong with it.
And what an engine it is now! (with Bosch injectors)
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