Installing Bosch 42LB 440CC Green Giant injectors into stage 3 minus car?

[V1nny]

Noticed some uneven acceleration after reaching 80 miles/hour. Thinking that maybe my stock injectors with 5 bar fpr (not "crushed", original Bosch made 5 bar fpr) not able to cope with the Jfonz stage 3- "minus" tune. I also have huge cone air filter, and RS6 intercoolers. Got a set of used Bosch 42LB 440CC Green Giant injectors, and took them to the local shop in Alexandria for cleaning and flow matching. Originally it was for my future upgrade to full stage 3, but thinking now, if there would be any harm to replace the stock injectors with green giants, before doing rest of the full stage 3? Would I have to put the stock FPR back? Maybe buy a new, 4 bar FPR to work with green gaints?

[A62TURBO]

What turbos are you running? I wouldn't change around injectors without getting an opinion from your tuner first. I would also just put the stock fpr back in, I'm at full stg 3 with meth and my car is still running stock fpr and fuel pump without any issues at all.

[V1nny]

In your car it may make sense, depending on the type of injectors.

Just regular K04's turbos. Speaking of fuel pump, I have walbro 255LPH. My main question, would green giants do any harm? Make me run too rich?

[aysix]

J-Fonz needs to be aware of the new injectors and he needs to revise your current file before you install those.

440cc injectors are still kind of small for stage 3 these days. May be a good idea to keep the current 5 bar FPR.

Just get the proper maf housing (170 on 034) and have J-Fonz send you the proper file for your setup.

[V1nny]

I understand and totally agree, that new file would be required to make maximum power, but Jfonz is not going to do it for free, and it's not like he runs 9 to 5 helpline to answer my questions. Hope he is reading it, and will have something to say. I am curious, what would happen if I just install the injectors, no other changes made? Run too rich? Cause any other harm? Or new injectors just going to run at a lower duty cycle?
Maybe I should post this in B5 S4 section..
Actually I have a used 85mm MAF housing, but Jfonz only gives 20% discount when you go from 3- to full 3, so can't afford it right now.

[A62TURBO]

I understand and totally agree, that new file would be required to make maximum power, but Jfonz is not going to do it for free, and it's not like he runs 9 to 5 helpline to answer my questions. Hope he is reading it, and will have something to say. I am curious, what would happen if I just install the injectors, no other changes made? Run too rich? Cause any other harm? Or new injectors just going to run at a lower duty cycle?
Maybe I should post this in B5 S4 section..
Actually I have a used 85mm MAF housing, but Jfonz only gives 20% discount when you go from 3- to full 3, so can't afford it right now.

Honestly, I wouldn't change injectors without the proper tuning to go along.

[034Motorsport]

You can't just change injectors willy nilly, tunes are written specifically for injector size and fuel pressure.

You need a retune. Running pig rich is not good for your car, you can wash the cylinders, etc.

And definitely don't change your MAF housing without a retune, that's even worse.

[V1nny]

Agree with you on a MAF housing, feeding extra unaccounted air is obviously not a good idea. Not so clear with the injectors for me... These are not some huge injectors, just one step up. Wouldn't my ECU just reduce impulse length based on a O2 signal sensor data, and reduce the duty cycle of the injectors to keep the mix ratio approximately constant? Wish Jfonz come across this topic.

[V1nny]

You guys scared me into purchasing 4.0bar FPR for $15 off Ebay, to replace my 5bar FPR when I am going to install green giants. Injectors came today from local cleaning/balancing shop, and one of them flows 3% less than others. Would that cause problems?

[aysix]

Agree with you on a MAF housing, feeding extra unaccounted air is obviously not a good idea.

Your current tune wouldn't allow this anyway


These are not some huge injectors, just one step up.

What dont you get? DO NOT run 42lb injectors without being tuned for the proper hardware.

-Stock injectors flow at 349cc with the stock 4 bar FPR.

-Green giants flow at around 550cc with the stock 4 bar FPR.

-Stock injectors flow at 390cc with a 5 bar FPR.

Even if you got a 3 bar FPR, you will still be flowing more than stock injectors with a 4 or 5 bar fpr.

Thats quite a difference, running 35% rich(someone correct me if im wrong) is no bueno. I'm suprised nobody mentioned the different latency times.

[V1nny]

...

-Green giants flow at around 550cc with the stock 4 bar FPR.

-Stock injectors flow at 390cc with a 5 bar FPR.

Even if you got a 3 bar FPR, you will still be flowing more than stock injectors with a 4 or 5 bar fpr.

Thats quite a difference, running 35% rich(someone correct me if im wrong) is no bueno. I'm suprised nobody mentioned the different latency times.
Green Giant (Volvo) 420cc/42#@3bar, 450cc/43#/4bar, 520cc/50#/5bar
My understanding that unless I exceed flow by a very large margin, ECU, based on the O2 sensor output, would just reduce impulse length, and injectors would run at a lower duty cycle.

Agree, I might appear to be slightly retarded by "not getting it", but I wish JFonz would give away custom tunes based on whatever injectors I might happen to have.

[aysix]

Green Giant (Volvo) 420cc/42#@3bar, 450cc/43#/4bar, 520cc/50#/5bar
My understanding that unless I exceed flow by a very large margin, ECU, based on the O2 sensor output, would just reduce impulse length, and injectors would run at a lower duty cycle.

Go ahead and find out. This is why remote tuners pull their hair out.

[ddillenger]

It's going to run like shit, he's going to unhook the MAF, it's going to run great. He's going to assume it's the MAF, then replace that. Then everything will be fucked.

Been there, pulled my hair out over that. Get someone to write you a tune for the 42lb injectors. It's not all that hard if you have the part numbers, and you can keep your 5bar FPR.

[V1nny]

It's going to run like shit, he's going to unhook the MAF, it's going to run great. He's going to assume it's the MAF, then replace that. Then everything will be fucked.

Been there, pulled my hair out over that. Get someone to write you a tune for the 42lb injectors. It's not all that hard if you have the part numbers, and you can keep your 5bar FPR.

I have a used 85mm MAF housing and RS 4 accordion hose, so if I had money for a new tune, would go with full stage 3. JFonz gives only 20%, though i got stage 3 minus just couple a months ago.

[napolean]

I can get you up and running for almost nothing

[4ringAR]

LISTEN TO WHAT PEOPLE ARE SAYING. you don't just magically get more power by throwing extra fuel at it, the tune has to be dialed in for that setup.

There's a chance the car won't even run with tthose injectors and that tune. My frankenturbo car wouldn't idle with Bosch 52# and my dahlback stg1 file. I was just wanting to drive it 5 miles no performance driving just to pick something up but it wouldn't even idle it was so rich

[slowguy]

You would need to modify TVUB settings to accommodate different injectors. An experienced tuner can work with you to get it set properly for your injectors. I can give you, what I think, would be the proper TVUB map for your injectors.

[V1nny]

You just convinced me (thank you everyone for doing amazing job at that) to go proper full stage 3. I was able to find a spare 4Z7907551K ECU, and I already have green giant injectors, and 85mm MAF housing.
All I need is to flash that spare ECU with stage 3 91 octane for regular K04's, headlight leveling removed (aftermarket headlights), EGT sensors, rear O2's, SAI and immobilizer coded out as well. Maybe launch control, if that even possible with manual transmission?

[ddillenger]

You just convinced me (thank you everyone for doing amazing job at that) to go proper full stage 3. I was able to find a spare 4Z7907551K ECU, and I already have green giant injectors, and 85mm MAF housing.
All I need is to flash that spare ECU with stage 3 91 octane for regular K04's, headlight leveling removed (aftermarket headlights), EGT sensors, rear O2's, SAI and immobilizer coded out as well. Maybe launch control, if that even possible with manual transmission?

All of that is possible with the exception of headlight leveling.

[aysix]

headlight leveling.

lolz

[ilyafil]

Just curious what is the limit of the green giant injectors as far as power and torque? I'd like to see logs of this when you're done.

[V1nny]

Just curious what is the limit of the green giant injectors as far as power and torque? I'd like to see logs of this when you're done.
A month later I am done with new O2 sensors, full stage 3, Green Giants, 4 bar FPR, 85mm MAF housing, and JFonz 91 octane ECU flash. Car seems to have little bit more power comparing to stage 3 minus, especially noticeable at the top end, being able to impress local cops, accelerating from 80 to 90 mph in a fraction of a second. As for logging, hate to drive around with the laptop and the cable plugged in my OBD port. I have Bluetooth adapter and Torque application in my Android phone, and wonder if that can be used for logging? Or maybe a reasonably priced dyno in Washington DC area?
PS. Still looking for my aftermarket headlights leveling motors fix.

[aysix]

A month later I am done with new O2 sensors, full stage 3, Green Giants, 4 bar FPR, 85mm MAF housing, and JFonz 91 octane ECU flash. Car seems to have little bit more power comparing to stage 3 minus, especially noticeable at the top end, being able to impress local cops, accelerating from 80 to 90 mph in a fraction of a second. As for logging, hate to drive around with the laptop and the cable plugged in my OBD port. I have Bluetooth adapter and Torque application in my Android phone, and wonder if that can be used for logging? Or maybe a reasonably priced dyno in Washington DC area?
PS. Still looking for my aftermarket headlights leveling motors fix.

Drive out to the boons and log your car or something. Your car is slow until you are dialed in. Huge difference.

[keithwbloom]

Got a set of used Bosch 42LB 440CC Green Giant injectors, and took them to the local shop in Alexandria for cleaning and flow matching.

Which local shop did you take your injectors to in Alexandria? I am looking for a set of used green giants too (but I need 8 of them) and was going to send them out to WitchHunter Performance for servicing and testing.

[wrench]