Has anyone installed bigger fuel nozzels

Adamrm

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Oct 19, 2009
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I have been reading bout tdi tuning because I have recently ordered black 4 door golf tdi. Sounds like hp gains can most easily be made with computer mapping and higher flow fuel nozzels. Has anyone done these mods?
 

Adamrm

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I'm not that brave. Hope to hear about someone else doing it first. I would think after more motors break in this would be more common
 

apaterso

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Livermore, CA
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Jetta 2009
You just have to wait for this summer as the first 09s begin to come out of warrenty (mileage). I suspect we'll begin to hear about mods for the CR engine/exhaust them.
 

TDInownow

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West End, NC (27376)
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None right now...
You may hear about engine mods, but you won't hear about exhaust mods (at least not here) because the government isn't too keen on emissions systems deletions, and as such, neither is the Site.
 

Souzafone

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'99 Jetta A4, Whitish
There are no nozzles in a MKVI. Exhaust mods are fine as long they don't interfere with the emissions requirements. This can be used to advantage on earlier cars, but on a MKVI I think it's going to be more complicated and the gains may not be the same.
 

Red Lion

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Not sure who would be checking emission mods here in PA. Diesels are "exempt" from emission inspection......PSI sticker on windshield no PEI sticker.
 

Adamrm

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This will be my first diesel so please excuse me if thus is a stupid question. If nozzels aren't used how is the fuel introduced to the system. I'm guessing the common rail system is what sprays the fuel. Wouldn't there be a nipple or nozzle on rail or is it just a bore in the rail.
 

Pelican18TQA4

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'13 Jetta Hybrid
I think what Souzafone means is that the injectors on the common rail TDIs are completely electronic (Piezo-electric, to be exact). The amount of fuel they release is largely dependent on rail pressure (which is already higher than need be for some situations, and excess fuel pressure and quantity is bled off automatically by the injection system) and how long the ECU tells the injectors to stay open and how many shots of fuel (up to 7 I think, including a post-injection) they give. It would take ECU tuning to increase fuel flow, not necessarily larger injectors, though I'm sure they have a physical limit of how much fuel they can flow.

As for exhaust mods, Red Lion is correct, diesels are exempt from emissions testing in PA (and some other states) but I'm pretty sure that any state with a mandatory inspection will not pass a car with a MIL on and removing any of the emissions equipment on the '09+ TDIs will result in a MIL as well as potentially other issues.
 

dzcad90

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Pelican18TQA4 said:
I think what Souzafone means is that the injectors on the common rail TDIs are completely electronic (Piezo-electric, to be exact). The amount of fuel they release is largely dependent on rail pressure (which is already higher than need be for some situations, and excess fuel pressure and quantity is bled off automatically by the injection system) and how long the ECU tells the injectors to stay open and how many shots of fuel (up to 7 I think, including a post-injection) they give. It would take ECU tuning to increase fuel flow, not necessarily larger injectors, though I'm sure they have a physical limit of how much fuel they can flow.
I would think that fuel quantity injected would be directly affected by the size of the nozzle. The ECU uses it's fueling map to determine the amount and duration of electricity to provide to the piezo element in the injector. I can only assume that the ECU is working off of a map based on nozzle size. Larger nozzle, more fuel would flow during a given injection event of the same duration.

Now if this is the case, I don't think I would want to put a larger nozzle on the new CR without the appropriate tuning. This would also inrease the quantity of the post-combustion injection and and lead to much higher EGTs, which could possibly put the DPF out of it's efficiency range or even worse cause a premature failure.

Again, I'm not saying I'm wrong or right, I don't know for sure and this is just me thinking aloud.
 

dpg

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dzcad90 said:
Again, I'm not saying I'm wrong or right, I don't know for sure and this is just me thinking aloud.

nothing wrong with thinking out loud. gets the brain moving and ideas/troubleshooting/solutions flowing

i think the only true way of doing this would be to go to a tuner(or if you have a vcds and know what to look for) with the larger injectors and see what is going on with the vcds and be able to monitor changes in real time. especially being able to monitor the EGTs would be key here
 
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Pelican18TQA4

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dzcad90 said:
I would think that fuel quantity injected would be directly affected by the size of the nozzle. The ECU uses it's fueling map to determine the amount and duration of electricity to provide to the piezo element in the injector. I can only assume that the ECU is working off of a map based on nozzle size. Larger nozzle, more fuel would flow during a given injection event of the same duration.

Now if this is the case, I don't think I would want to put a larger nozzle on the new CR without the appropriate tuning. This would also inrease the quantity of the post-combustion injection and and lead to much higher EGTs, which could possibly put the DPF out of it's efficiency range or even worse cause a premature failure.

Again, I'm not saying I'm wrong or right, I don't know for sure and this is just me thinking aloud.
Like I said, I'm sure that the factory injectors have a physical limit to how much fuel they can flow and I think it's reasonable to believe that "larger" injectors potentially can flow more fuel. However, it's also reasonable to believe that without the appropriate ECU tuning to take advantage of the "larger" injectors, there will likely be no gain at all, if for no other reason than the fact that the ECU monitors numerous factors that earlier TDI ECUs could only dream of; e.g., EGTs, combustion pressure, etc.
 

pyankura

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If you are saying this and then giving a wink, wink and a nudge, nudge...Then I gotcha! wink, wink, nudge, nudge!


TDInownow said:
You may hear about engine mods, but you won't hear about exhaust mods (at least not here) because the government isn't too keen on emissions systems deletions, and as such, neither is the Site.
 

TDInownow

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None right now...
pyankura said:
If you are saying this and then giving a wink, wink and a nudge, nudge...Then I gotcha! wink, wink, nudge, nudge!
No, not really. In the past, you've seen threads locked down (or threatened to be locked down) when detailed discussions began to form about how to go about disabling or deleting the DPF on the 09+ cars, and how to get CELs and/or DPF fault indicator lights to go away without actually having the DPF present.

Yes, there have been general "off-road only" discussions on this site for some time, and I for one had a 2003 Jetta that wasn't legal for street use, technically...but certain discussions here are moderated very closely, and this topic can turn into one of those.
 

pyankura

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I agree with most of that BUT! There are very few on this site who are running an egr or cat! However useless they may be they are deemed "useful" by the man. And knowing this we still do it anyway... The dpf delete is only a matter of time before it gets here! It is already being done across the pond. I guarentee you this: if I owned an 09 I would rip the dpf off and have a pipe fabbed for me, quickly! The mpg gain is huge!!!! So, if you get better mpg aren't you doing the environment better anyway?

APR, REVO, GIAC(maybe) and UNitronic all have the cat delete for their software. SO it's coming!
 

dzcad90

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pyankura said:
I agree with most of that BUT! There are very few on this site who are running an egr or cat!
Got any data to support this claim about the catalyst?
 

pyankura

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You people and your proof! Are we talking tdi or 2.0t?

On the tdi sure, come on down to P'burgh and I will show you mine. But it is for off road use only!:D If you want proof on this site, just type in cat in the performance section, get a comfy chair, and somethging good to drink and read many, many pages.

On 2.0t, we tune them with the cat! The gain without is negligible, maybe a few hptq. We get with a cai 45+hp and 90lb.ft. from tuning. We do have proof of that. But if you want proof, go to vwvortex and use suggestions from above! They also claim for off road use only!

dzcad90 said:
Got any data to support this claim about the catalyst?
 

GoFaster

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Jun 16, 1999
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Brampton, Ontario, Canada
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2006 Jetta TDI
The European version of the common-rail engine has slightly larger nozzles - but it is only slight. And, I have no idea whether the electronics will be happy about changing something like that. There is a lot of monitoring done by the ECU.

And, it's BS to say that "most" people on this site are running without an EGR or catalyst. That's nonsense. The number of people who don't modify their cars, or who only do minor modifications and leave the emission systems intact, far exceeds the number who tamper.

Removing or disabling catalytic converters is a Federal offence in the USA and it is illegal in Canada as well. Whether your local inspection authorities (or lack thereof) will find this out is immaterial and doesn't change the illegality of doing it, so this train of discussion ends NOW.
 

dpg

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it amazes me how a thread goes from bigger nozzles to deleting emissions equipment. 99% of the people on these threads know that there are big gains to be made by deleting emissions equipment. we get it! now figure it out so we can keep emissions for those that want to stay legal and still make power. Is it harder? sure it is, but isn't that part of the challenge ;)
 

TDInownow

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Location
West End, NC (27376)
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None right now...
Like I said...

Anyway, rather than nozzles, I think the biggest bang from this engine will be tuning, and I know that a few companies are starting to put programs out there. Revo comes to mind. Frankly, if I don't have to monkey with the nozzles to get performance out of this car...great.

The last time I saw Jeff he was commenting that he didn't even know if he was going to do a CR Rocketchip. I hope he reconsiders, but I have time because I'm certainly not doing anything until the warranty is up, and until a few of the trailblazers have run ECU coding for many thousand miles.
 
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