Who here is running 1000cc injectors?

[1NaudiA4]

I'm hitting 86-87% duty cycle at 7000rpm with my 870cc injectors and I'm starting to think it might be time to step up. Boost is only set to 23psi with an AFR of 11.7 at redline and fairly conservative timing.

Running a walbro 255lph with fuel pressure at 45psi.

I'm going to make a race gas tune once I get on the dyno and really wouldn't want to have my injectors be the limiting factor. I'm going to turn on my fuel pressure a bit and retune it but would that be enough?

In the future I plan on building a new head with cat 3652's, springs & retainers and upgraded valves so that would be even more reason to get the 1000cc

Those of you running the 1000cc injectors-


What brand?
Hows the idle?
Any issues in any other rpms?
Whats the max fuel pressure I could run?

[AudiA4_20T]

Delphi 1000cc... Ill be running them at the B6 3.7 bar for now

[bassed]

I may go up to 870's, I have 630's run 4bar and 30psi on a Turbo comprable if not slighlty larger in flow than a 30r. I have 87-90% duty cycle at 30psi. Unless you are runing a GT3582 or larger 1000cc seems to be a lot of over head to me at least in terms of fuel delivery.

[317ssayzarc]

Bosch high Z 1000's here... Idle is amazing, better/smoother/lower than the 630cc Tapp tune... You might be able to get away with those injectors, but not with a Walbro... Before you change anything in your setup, do yourself a favor and get an 044

[CTS Turbo]

Bosch high Z 1000's here... Idle is amazing, better/smoother/lower than the 630cc Tapp tune... You might be able to get away with those injectors, but not with a Walbro... Before you change anything in your setup, do yourself a favor and get an 044

what tune are you running with those?

[317ssayzarc]

what tune are you running with those?

Vems sem

[AudiA4_20T]

Vems sem

focker

[mike-2ptzero]

I'm hitting 86-87% duty cycle at 7000rpm with my 870cc injectors and I'm starting to think it might be time to step up. Boost is only set to 23psi with an AFR of 11.7 at redline and fairly conservative timing.

Running a walbro 255lph with fuel pressure at 45psi.

I'm going to make a race gas tune once I get on the dyno and really wouldn't want to have my injectors be the limiting factor. I'm going to turn on my fuel pressure a bit and retune it but would that be enough?

In the future I plan on building a new head with cat 3652's, springs & retainers and upgraded valves so that would be even more reason to get the 1000cc

Those of you running the 1000cc injectors-


What brand?
Hows the idle?
Any issues in any other rpms?
Whats the max fuel pressure I could run?

You should be able to make more power on those 800 injectors when doing a race tune and still not max them out.

[pac1085]

Bosch high Z 1000's here... Idle is amazing, better/smoother/lower than the 630cc Tapp tune... You might be able to get away with those injectors, but not with a Walbro... Before you change anything in your setup, do yourself a favor and get an 044

Is the Walbro really an issue with our cars? I don't see why it would, I know several people making around 700whp with a single walbro in other cars.

[bassed]

Is the Walbro really an issue with our cars? I don't see why it would, I know several people making around 700whp with a single walbro in other cars.

No it's not an issue. Many, many people run it witho out issue on B5 A4's and S4's alike.

[1NaudiA4]

Bassed: I highly doubt that your turbo will out flow mine. Especially at +30psi, isn't yours some really low a/r so you could have really good spool up? Keep in mind I'm running the HTA3076r which flows +57lb/min. But from the sounds of it your running your 630's at the edge.

I'm going to turn up the fuel pressure to 4 bar so I'm not so high in the duty cycle. I should be fine on the race gas tune since it allows you to run a bit leaner.

I'm planning on sticking with the Walbro... I cant justify the $300 price difference between the 2. If I'm to need a better fuel pump I would install an Aeromotive A1000 with upgraded stainless lines. Its would basically be the same price with a lot more head room. Why the heck are you guys so hung up on the 044?

[1NaudiA4]

Mike: Did you ever pick up a set of 3652 cams?

[djwimbo]

Bassed: I highly doubt that your turbo will out flow mine. Especially at +30psi, isn't yours some really low a/r so you could have really good spool up? Keep in mind I'm running the HTA3076r which flows +57lb/min. But from the sounds of it your running your 630's at the edge.

Why the heck are you guys so hung up on the 044?

Ian's will out flow a 3071, but not an HTA3076.

I have zero experience with the 044, but I know that most people don't understand the flow of fuel pumps. A Walbro 255 actually flows more volume at less pressure. Volume drops about 30% at "high pressure"(58-65psi) in comparison to standard pressure(44-48psi).
It's the same as boosted engines. Two identical engines, but one has a higher flowing head. The higher flowing head will make the same power as the other engine, but at lower boost. There's less restriction to flow at lower pressures.

[bassed]

Bassed: I highly doubt that your turbo will out flow mine. Especially at +30psi, isn't yours some really low a/r so you could have really good spool up? Keep in mind I'm running the HTA3076r which flows +57lb/min. But from the sounds of it your running your 630's at the edge.

I'm going to turn up the fuel pressure to 4 bar so I'm not so high in the duty cycle. I should be fine on the race gas tune since it allows you to run a bit leaner.

I'm planning on sticking with the Walbro... I cant justify the $300 price difference between the 2. If I'm to need a better fuel pump I would install an Aeromotive A1000 with upgraded stainless lines. Its would basically be the same price with a lot more head room. Why the heck are you guys so hung up on the 044?

Yes I run a .55 a/r presently. The turbo is rated at 55lbs, so yes then I flow a bit less than you especially considering all comp maps are for the largest a/r U.N.O. 1000cc is still to much even the EVO guys are not running that much injector with that turbo on motors that flow a sizeable amount more than ours can. Walbro or 044, either will do.

Ian's will out flow a 3071, but not an HTA3076.

It'll flow more than a 30r, just not HTA. I didn't notice he was running that till I saw his siggy.

[317ssayzarc]

Walbro flows, but doesnt like pressure

[Don Supreme]

Go with the 1000s..................

I recently rode in a 1.8t with 1000s running Autronic and it idled fine and had no injector related issues as far as I could tell... Regardless, you may need to put another pump inline or provide extra juice (electrical power) to the Walbro if you plan on breaking 500 AWHP.

You wil eat up that duty cycle quick, especially when you start revving (8K +)

[1NaudiA4]

Go with the 1000s..................

I recently rode in a 1.8t with 1000s running Autronic and it idled fine and had no injector related issues as far as I could tell... Regardless, you may need to put another pump inline or provide extra juice (electrical power) to the Walbro if you plan on breaking 500 AWHP.

You wil eat up that duty cycle quick, especially when you start revving (8K +)

The whole fuel pressure/volume thing is definitely backwards from my regular thinking of pressure/volume. I'm used to volume increasing with pressure as in a home water system. I wonder what the max pressure to run the walbro is.

[Don Supreme]

The whole fuel pressure/volume thing is definitely backwards from my regular thinking of pressure/volume. I'm used to volume increasing with pressure as in a home water system. I wonder what the max pressure to run the walbro is.

A single Walbro flow drops off like a rock @ high pressure. There are test charts, which have been posted on this forum. I don't have enough time to go dig it up right now.... search around.

[Tifun]

[mike-2ptzero]

Mike: Did you ever pick up a set of 3652 cams?

Nope, still running Schricks 252/260.

The whole fuel pressure/volume thing is definitely backwards from my regular thinking of pressure/volume. I'm used to volume increasing with pressure as in a home water system. I wonder what the max pressure to run the walbro is.

I started to run into pressure drop issues when I hit around 500whp running 35psi with a base fuel just slightly higher then 3 bar. Walbro pumps start to fall off at 80psi which means if your running a 4 bar base fuel(58psi), running 22psi will put you at that 80psi. Running more boost then that you will need to run the pump at 3 bar. I got tired of dealing with the pressure dropping so I went to a 044 pump and a -6 fuel feed line from the pump to the rail.

Here is a graph for the standard High Pressure walbro pump.




Graph showing the bosch 044 vs the Walbro

[djwimbo]

Since we're on the topic of fuel pumps is there a general rule for when to upgrade on the B5? Like 400bhp you should either upgrade the intake or add an inline, and >450bhp you NEED at least a 255 intake?

I never got a straight answer before, so I'm asking. Obviously if you're having issues with fuel pressure dropping off, you should upgrade. I'm just curious what the limits are of the stock pump @ 3-4Bar.

[t1demont1]

I think the s4 fuelpump flows at like 220lph or somewhere around there, so id imagine a a4 1.8t fuel pump would flow considerably less with two less cyl, and one less turbo

[bassed]

Since we're on the topic of fuel pumps is there a general rule for when to upgrade on the B5? Like 400bhp you should either upgrade the intake or add an inline, and >450bhp you NEED at least a 255 intake?

I never got a straight answer before, so I'm asking. Obviously if you're having issues with fuel pressure dropping off, you should upgrade. I'm just curious what the limits are of the stock pump @ 3-4Bar.

Anything north of 300whp IMO, especially since most people are up there in milage these days. 1naudia4 is seeing the issue of what happens when you're on the OEM pump and more than doubling the whp from the factory. If he would switch the pump his problem will go away, but if the pump stays and the injectors increase the problem will persist. The data doesn't lie, the Walbro is good for all BT setups I'd say, but when pushing high boost on a BAT it's a risk.

[Don Supreme]

Anything north of 300whp IMO, especially since most people are up there in milage these days. 1naudia4 is seeing the issue of what happens when you're on the OEM pump and more than doubling the whp from the factory. If he would switch the pump his problem will go away, but if the pump stays and the injectors increase the problem will persist. The data doesn't lie, the Walbro is good for all BT setups I'd say, but when pushing high boost on a BAT it's a risk.

What OEM pump? He says he is running a Walbro pump.

[bassed]

What OEM pump? He says he is running a Walbro pump.

I thought he was still on the stock, been a couple hours since I read the original post. Perhaps he will have to run a inline as well or go to the 044. Mah bad, reading and posting from an iPhone is not ideal, I miss and rush a bit.

[AudiA4_20T]

btw 1NAudiA4 if I do a return fuel system we will almost have identical setups

[bassed]

Just to clarify how you're coming up with duty cycle. You are logging block 02 and than taking the injector pulse width in ms* RPM / 120000 correct?

Just for shits and giggles I just went out and did a pull it's 61* and 71% humidity and I am running at 81.28% on 630'sat 4bar. I was running 26psi and had a afr of 11.56 at 6890 rpms (looks like I need to go bigger myself to not push it so hard at 30psi). How long ago did you put the walbro in? How many miles? Was it used? Wabro's clearly drop based on data, but with those injectors and with that turbo it just seems stretching it that you're maxing out those injectors just yet. Ever change the fuel filter? What are you putting down BTW? I think you had a build thread a while back, you really should put it in the Projects/Builds area!!

[mike-2ptzero]

btw 1NAudiA4 if I do a return fuel system we will almost have identical setups

He has a 30r you have a 35r.

[1NaudiA4]

Just to clarify how you're coming up with duty cycle. You are logging block 02 and than taking the injector pulse width in ms* RPM / 120000 correct?

Just for shits and giggles I just went out and did a pull it's 61* and 71% humidity and I am running at 81.28% on 630'sat 4bar. I was running 26psi and had a afr of 11.56 at 6890 rpms (looks like I need to go bigger myself to not push it so hard at 30psi). How long ago did you put the walbro in? How many miles? Was it used? Wabro's clearly drop based on data, but with those injectors and with that turbo it just seems stretching it that you're maxing out those injectors just yet. Ever change the fuel filter? What are you putting down BTW? I think you had a build thread a while back, you really should put it in the Projects/Builds area!!

The 034 IIC software has a datalogging feature that records everything so I was just going off what the ECU was telling me.

The thing is that usually with race gas the tune is a bit leaner 12.0-12.2 and its not unusual to see a point afr drop by just dropping in race gas due to it burning differently so that compensates a bit for the power/boost increase.


I've so far done 2 motor builds and had to pull the motor out 3 times (main bearing girdle/main seal leak) but I just put the Walbro in about 1000 miles ago. The first motor got wrecked due some detonation issues that put some stress fractures in pistons 2,3 and 4 and completely f'd my rings. I was running way too much timing which was the cause of the detonation.


I was running the stock fuel pump for a while which was working out fine but I wanted some peace of mind so I went ahead and ordered up the walbro. I was running the stock pump at 35psi static fuel pressure and running 22lbs of boost. I bought the walbro new from http://www.autoperformanceengineering.com/

the whole kit with everything was about $120 shipped and the install was a breeze.

I haven't had it dyno'd yet but on my previous engine I was able to stay dead even with my buddys FP Green Evo that made 380whp on a mustang so I would have to assume that its making at least that much if not more now that I'm running more boost and have the tune pretty well dialed in now. I'm waiting until I get some cams/springs/rertainers until I have it dyno'd because I would just have to go back if I were to get it tuned now.

I'll def make a build thread... I'll probably have to make a new thread since all my information is pretty scattered around in all my threads.

[Kyle H]

Just curious, are you running 2.0L or still 1.8?

[1NaudiA4]

Still 1.8

-Mahle 81.5mm 8.5-1 compression pistons
-Scat Rods
-Rosten main bearing girdle
-Rebuilt stock head

thats about it for the motor other then the basic balancing, blueprinting that everyone does.

[bassed]

Still 1.8

-Mahle 81.5mm 8.5-1 compression pistons
-Scat Rods
-Rosten main bearing girdle
-Rebuilt stock head

thats about it for the motor other then the basic balancing, blueprinting that everyone does.

I don't think most are balancing and blueprinting, just few out of the bunch. Curious about the girdle/rear main seal leak, was it the seal primarily or the girdle being that the drop the pan a 1/4 to 3/8"? My oil consumption stems from my seal leaking a small amount, but I also run a girdle and may need to go over the seal again. 20k on the motor, so it's time to go over some things now.

[1NaudiA4]

I don't think most are balancing and blueprinting, just few out of the bunch. Curious about the girdle/rear main seal leak, was it the seal primarily or the girdle being that the drop the pan a 1/4 to 3/8"? My oil consumption stems from my seal leaking a small amount, but I also run a girdle and may need to go over the seal again. 20k on the motor, so it's time to go over some things now.

The seal with the pan>girdle>block was perfectly fine, it was where the girdle met up with the rear mail seal on the back. It was hard to tell precisely where it was coming from but I would of had to assume it was coming from the corners by the main seal opening.

So I took out the motor and put a new main seal in making sure there was no oil where the silicone sealing surface. I also sanded the girdle with some 300grit since it was a pretty smooth surface. I still have a tiny drip but its absolutely nothing compared to what it used to be. I have a feeling its just from there not being enough silicone around the oil pan bolts.