Any suggestions for higher-flow fuel injectors that will drop into the stock Fiero V6? Same physical form factor, same connector, and high impedance like stock.
I am hitting 90% duty cycle with my 30 lb/hr Accel injectors. I guess I'm looking for injectors in the 44 lb/hr to 50 lb/hr range in order to up the power. Published dead-time data would be a plus, but not required.
I'm not sure Accel is good. Olejoedad doesn't seem to think so either. So I'm open to changing brands, or maybe OEM injectors from another car.
Before pulling the trigger, I'll be sure to check that my fuel pump is indeed maintaining enough fuel pressure.
The stock Fiero V6 engine had 15# injectors. (3.4L has 17#) I'm running 21# GM/Rochester injectors with my 3.4L V6 with Supercharger and have no problems.
The Fiero uses Bosch EV1 jectronic style high impedance injectors. I've only seem them in 42# and 52# ratings at retailers. Chart http://users.erols.com/srweiss/tableifc.htm
Any suggestions for higher-flow fuel injectors that will drop into the stock Fiero V6? Same physical form factor, same connector, and high impedance like stock.
I am hitting 90% duty cycle with my 30 lb/hr Accel injectors. I guess I'm looking for injectors in the 44 lb/hr to 50 lb/hr range in order to up the power. Published dead-time data would be a plus, but not required.
I'm not sure Accel is good. Olejoedad doesn't seem to think so either. So I'm open to changing brands, or maybe OEM injectors from another car.
Before pulling the trigger, I'll be sure to check that my fuel pump is indeed maintaining enough fuel pressure.
You are using 30lb injectors running 90% duty cycle on a stock Fiero V6? Running twice the original fueling flow rate? That doesn't sound quite right. You should be fine with the stock #15 injector size and with mods #17 should do. As for choosing new injectors, beware, the market is becoming flooded with inferior Chinese units that do not perform well.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
You are using 30lb injectors running 90% duty cycle on a stock Fiero V6? Running twice the original fueling flow rate? That doesn't sound quite right. You should be fine with the stock #15 injector size and with mods #17 should do. As for choosing new injectors, beware, the market is becoming flooded with inferior Chinese units that do not perform well.
On my highly modified turbo 3.4L, I run #24 injectors and with 15 psi of boost . With some changes to the CM program I can the engine with fuel to the point where the exhaust smoke turns black. It was was a matter of adjusting the BPC number in the constants table to suit the flow and making some small changes, adjusting the VE table and PE a bit. I guess if the OP is running super high boost then larger injectors would be necessary but whos going to put that much boost in the 60* V6. The rods and crank just won't hold up.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
On my highly modified turbo 3.4L, I run #24 injectors and with 15 psi of boost . With some changes to the CM program I can the engine with fuel to the point where the exhaust smoke turns black. It was was a matter of adjusting the BPC number in the constants table to suit the flow and making some small changes, adjusting the VE table and PE a bit. I guess if the OP is running super high boost then larger injectors would be necessary but whos going to put that much boost in the 60* V6. The rods and crank just won't hold up.
Injector requirement is not based on displacement, it is based on fuel required for a horsepower target regardless if its turbo charged or naturally aspirated. I ran out of injectors with the #36 when my car did 277WHP on gasoline.
Any suggestions for higher-flow fuel injectors that will drop into the stock Fiero V6? Same physical form factor, same connector, and high impedance like stock.
I am hitting 90% duty cycle with my 30 lb/hr Accel injectors. I guess I'm looking for injectors in the 44 lb/hr to 50 lb/hr range in order to up the power. Published dead-time data would be a plus, but not required.
I'm not sure Accel is good. Olejoedad doesn't seem to think so either. So I'm open to changing brands, or maybe OEM injectors from another car.
Before pulling the trigger, I'll be sure to check that my fuel pump is indeed maintaining enough fuel pressure.
60mm with an EV1 connector will drop right in. It's a common size with at least GM and Ford. Personally I'm using Siemens Deka.
Easiest way I've found to check fuel pressure is to tape the test gauge to the back window and have the passenger watch it under acceleration. That way you can confirm the pump is keeping up under boost.
Easiest way I've found to check fuel pressure is to tape the test gauge to the back window and have the passenger watch it under acceleration. That way you can confirm the pump is keeping up under boost.
The needle in the gauge should be steady, if it bounces up and down is because the injector when pulsed, empty the rail faster than the fuel pump can refill it.
The needle in the gauge should be steady, if it bounces up and down is because the injector when pulsed, empty the rail faster than the fuel pump can refill it.
Yes, but pressure can be steady at idle or engine off/pump test, but drop like a rock when fuel demand increases(WOT) if/when the pump can't keep up.
And if he’s using the stock regulator, fuel pressure should be referenced to manifold. Mine tests out at around 45psi fuel w/engine off (96-ish kpa) and rises to 55psi fuel under boost (170-ish kpa)
[This message has been edited by Honest Don (edited 05-28-2020).]
I decided to make a thread separate from my project diary. This is generic information, applicable to anyone modifying a 2.8. Archived information is easy to find when it's in its own thread. It's hard to find information that is buried in people's project threads.
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Originally posted by fierosound: The Fiero uses Bosch EV1 jectronic style high impedance injectors. I've only seem them in 42# and 52# ratings at retailers. Chart http://users.erols.com/srweiss/tableifc.htm
That's a lot of chart to swallow
I thought I was going to have to familiarise myself with all this stuff, but after seeing this thread, someone came out of the woodwork and offered me a set of 42 lb/hr Bosch injectors. If they work out for me, I'll repost with a part number and comments, for the future reader of the Archives.
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Originally posted by Dennis LaGrua: On my highly modified turbo 3.4L, I run #24 injectors and with 15 psi of boost .
There's something a bit off, because my absolute manifold pressure is only 155 kPa. So it's like I need more injector with less boost, and less displacement (3.2 L). Strange. Do yours go static at maximum power?
Same for fierosound; it seems strange to me that 21 lb/hr injectors are able to feed a supercharged 3.4 L.
I guess every setup is different, and you gotta do what you gotta do to make each one work.
Yesterday I hit only 81% duty with an AFR of 11.4 on a 1st gear pull. There has been a heat wave (like 32 °C) here this week, so I guess the air is less dense than previous tests I did with an ambient temperature of 10 °C or so. I guess you need to size injectors with enough headroom for the coldest weather the car is likely to see.
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Originally posted by Honest Don: 60mm with an EV1 connector will drop right in. It's a common size with at least GM and Ford. Personally I'm using Siemens Deka.
Easiest way I've found to check fuel pressure is to tape the test gauge to the back window and have the passenger watch it under acceleration. That way you can confirm the pump is keeping up under boost.
Siemens is a good brand.
I think I'll be the riding mechanic watching the gauge while someone else drives. I'll have less explaining to do to my helper that way!
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Originally posted by La fiera:
The needle in the gauge should be steady, if it bounces up and down is because the injector when pulsed, empty the rail faster than the fuel pump can refill it.
On a stock Fiero, all six injectors (15 lb/hr each) are opened together. So that's 90 lb/hr emptying the fuel rail!
I don't think this will be a problem on my Fiero, since I have sequential injection. With only one injector opening at a time, it should cause less bounce than with a stock Fiero.
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Originally posted by Honest Don: And if he’s using the stock regulator, fuel pressure should be referenced to manifold. Mine tests out at around 45psi fuel w/engine off (96-ish kpa) and rises to 55psi fuel under boost (170-ish kpa)
I have completely stock fuel plumbing, the stock rail + regulator, and the stock manifold reference line. No need to touch something that ain't broken! At idle, the stock regulator has enough flow capacity to return the excess flow of my EP-381 to the fuel tank.
I've configured my computer to expect a constant pressure across the injector. Also, this way you don't have to worry about pressure variations affecting the injector dead time, since you've taken out that variable.
I don't think this will be a problem on my Fiero, since I have sequential injection. With only one injector opening at a time, it should cause less bounce than with a stock Fiero.
Between 67% & 84% DC, you will have 5 injectors open at a time.
I guess if the OP is running super high boost then larger injectors would be necessary but whos going to put that much boost in the 60* V6. The rods and crank just won't hold up.
Shaun (yes, *THAT* Shaun) made over 500 wheel on a stock bottom end LX9.
On the other end of the scale, my Northstar made 312 WHP with 19# injectors (Ford Motorsport orange tops).
Yes, because you have 8 injectors feeding 8 cylinders to make 312WHP. For a 6 cylinder to make 312WHP would take six 32# injectors. The less cylinders the bigger injector you needto match a power level of an engine with more cylinders.
I second the EV6 recommendation. Those are the rotating disc style injectors. They have a better spray pattern than the old pintle style injectors. You can find sets of rebuilt EV6 injectors on eBay pretty cheap. Just make sure the seller is reputable.
Side note: Not sure how some of these guys are getting away with such small injectors. Maybe they aren't revving their engines very high? My 3.4 V6 (naturally aspirated, 93 octane) needed 24 lb/hr injectors to keep it happy at high RPM. The 19 lb/hr injectors didn't flow enough.
Yes, because you have 8 injectors feeding 8 cylinders to make 312WHP. For a 6 cylinder to make 312WHP would take six 32# injectors. The less cylinders the bigger injector you needto match a power level of an engine with more cylinders.
6*32 = 192 (or is it 36? 6*36 = 216) 8*19 = 152
Anyway... Northstars seem to end up with freakishly low BSFC at peak power.
When I installed the upgraded manifold, the AFR gauge was pegged lean, even revving it in the driveway. I used the Autotune feature to have an idea of how much fuel the engine was asking for and it was a lot. I took it up and down the street at part and some WOT and when I saw the increase in VE I couldn't believe it! Based on the percentage Autotune increased the VE I re did the entire VE table +30% all around to start. I'll check the Duty Cycle this time to see if I need more injector. Right now I have enough injector for 380WHP
Originally posted by Blacktree: Side note: Not sure how some of these guys are getting away with such small injectors. Maybe they aren't revving their engines very high?
Every time I hit maximum duty cycle, it happened at the fastest speed I've turned the engine: 6300 RPM
Same for fierosound; it seems strange to me that 21 lb/hr injectors are able to feed a supercharged 3.4 L.
Oops. I thought they were 21 lb'ers...
I know I was given new Rochester/GM injectors for the 3.4L DOHC V6 engine when I built my roller cam 3400 block, iron head hybrid. When I added the S/C with 8lbs boost, the fuel tables were adjusted and there never appeared to be a fuel shortage.
Rochester/GM part number is 17090849 and is on Stan Weiss' list and appears to be a 30 lb injector. From online searches it appears the 849 and 844 above it are interchangeable.
[This message has been edited by fierosound (edited 05-30-2020).]
Originally posted by fierosound: I know I was given new Rochester/GM injectors for the 3.4L DOHC V6 engine when I built my roller cam 3400 block, iron head hybrid. When I added the S/C with 8lbs boost, the fuel tables were adjusted and there never appeared to be a fuel shortage.
Rochester/GM part number is 17090849 and is on Stan Weiss' list and appears to be a 30 lb injector. From online searches it appears the 849 and 844 above it are interchangeable.
Does that injector spray two plumes of fuel, one towards each intake valve of the DOHC?
With just one intake valve, I think I would prefer an injector that sprays a single plume of fuel.
Does that injector spray two plumes of fuel, one towards each intake valve of the DOHC? With just one intake valve, I think I would prefer an injector that sprays a single plume of fuel.
After running this engine for 20 years, I JUST thought about that after I found the part number this past hour. Never considered it before (if I knew THEN what I know NOW) and while NOT ideal, it has never presented a problem.
Clearly the shop that got them for me considered the flow, but overlooked spray pattern as well...
Now considering swapping to OEM 3800 S/C Bosch EV6 injectors - rated at 34 lb. PN 0-280-155-868 - but spray pattern doesn't fan out much.
[This message has been edited by fierosound (edited 06-02-2020).]
The green injector is known as the "Green Giant", or Bosch 0280155968.
This is how they look like installed in the Fiero V6:
These are my comments regarding these injectors from my project thread:
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Originally posted by pmbrunelle: With La Fiera's injectors, I haven't noticed much different in how the engine runs hot, at the present boost level.
The biggest improvement was in cranking and starting the engine.
With the Accel injectors, I had a hard time to inject the correct amount of fuel when cranking. It was not easy to find the happy medium between flooding the engine, vs. firing up quickly.
With the Green Giant injectors, the tuning window was wider; I converged on a suitable cranking fuel quantity quickly. I suppose that they make a better quality mixture.
At this time I want to see how far I can push the 3.4. Can you imagine If it wants more injector!!!
