dynoed today..need bigger injectors...
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
RC Engineering made my 73lb injectors. They work ok.....Although I am running 66psi base pressure, with 1:1 boost referenced with 2 x 044's in parallel
I know the US people claim a single 044 is good for like 700+...but its the only place in the world Ive heard this. Its usually much lower.
Some UK people say its only good for around 400 dyno HP, after that it struggles....although I think thats right at the other end of the scale, and personally I dont believe that.
Schimmel make some 96lb high impedance injectors, and I have been told that they work well in other engines. Never used them myself though.
ive also been told the 60lbs can be redrilled to flow close to 96lbs or thereabouts.
I know the US people claim a single 044 is good for like 700+...but its the only place in the world Ive heard this. Its usually much lower.
Some UK people say its only good for around 400 dyno HP, after that it struggles....although I think thats right at the other end of the scale, and personally I dont believe that.
Schimmel make some 96lb high impedance injectors, and I have been told that they work well in other engines. Never used them myself though.
ive also been told the 60lbs can be redrilled to flow close to 96lbs or thereabouts.
please do not put an aeromotive pump on that NICE street car. you should have more pump than me with what you have now provided there are no clogged filters and good voltage.
if you are still worried then replace the stock pump with a walbro or if you are totally freaked out about it put another bosch 044 in the tank in place of the stock pump/walbro
i just have two walbro's in my tank
if you are still worried then replace the stock pump with a walbro or if you are totally freaked out about it put another bosch 044 in the tank in place of the stock pump/walbro
i just have two walbro's in my tank
Thread Starter
Joined: Apr 2005
Posts: 1,014
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From: san marcos, TX
I ordered a new 044 today just encase this ones weak. I'm going to check the aeromotive regulator this weekend and double check all the wires to the fuel pump to make sure its getting the proper voltage...
Thread Starter
Joined: Apr 2005
Posts: 1,014
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From: san marcos, TX
Sweet Problen solved. I just got back for a quick test drive. Short blast in third gear to 4800rpm and the fuel pressure went up to 72psi... 
I was thinking that the external bosch was pushing fuel/pressure back inside the drivers side tank past the stock intank pressure regulators that are set at 58psi. I think thats why the fuel pressure wasn't rising with boost and is staying at 61-62psi just above the factory 58psi. I ordered a check valve to put on the fuel feed line coming from the fuel tank. I installed a few mins ago. I had seen from the diagram of the fuel system there was a check valve after the fuel pumps, but didn't notice the pressure regulators after it. There's 2 pressure regulators in the FFS fuel system. 1 in the drivers dank and one in the passenger tank..So popped in a check valve right in the stock fuel line before the T with the Bosch fuel line and all is good now...
when I first built the fuel system I had thought about installing a check valve, but I noticed the intank check valve after the stock fuel pump...Just didn't notice it was before the filter and regulators...
Redyno later this week...
I was thinking that the external bosch was pushing fuel/pressure back inside the drivers side tank past the stock intank pressure regulators that are set at 58psi. I think thats why the fuel pressure wasn't rising with boost and is staying at 61-62psi just above the factory 58psi. I ordered a check valve to put on the fuel feed line coming from the fuel tank. I installed a few mins ago. I had seen from the diagram of the fuel system there was a check valve after the fuel pumps, but didn't notice the pressure regulators after it. There's 2 pressure regulators in the FFS fuel system. 1 in the drivers dank and one in the passenger tank..So popped in a check valve right in the stock fuel line before the T with the Bosch fuel line and all is good now...
when I first built the fuel system I had thought about installing a check valve, but I noticed the intank check valve after the stock fuel pump...Just didn't notice it was before the filter and regulators...
Redyno later this week...
Last edited by chriswtx; Oct 27, 2007 at 05:01 PM.
Teching In
Joined: Oct 2007
Posts: 4
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68 firebird 2001 LS1 motor This past winter I put a 2001 LS1 motor out of a Trans Am into a 68 firebird, and made some other mods,I had my car tuned,I was told my O2 sensors were bad due to running race fuel. We put in new sensors and it idled and ran much better. I took it to the track. Less than 100 miles after the tune. Just as I pulled into tech it stalled and idle started acting up again. But I did drop my 1/4 mile by more than .03. I'm guessing the sensors are bad again. Help!
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Sweet Problen solved. I just got back for a quick test drive. Short blast in third gear to 4800rpm and the fuel pressure went up to 72psi...
I was thinking that the external bosch was pushing fuel/pressure back inside the drivers side tank past the stock intank pressure regulators that are set at 58psi. I think thats why the fuel pressure wasn't rising with boost and is staying at 61-62psi just above the factory 58psi. I ordered a check valve to put on the fuel feed line coming from the fuel tank. I installed a few mins ago. I had seen from the diagram of the fuel system there was a check valve after the fuel pumps, but didn't notice the pressure regulators after it. There's 2 pressure regulators in the FFS fuel system. 1 in the drivers dank and one in the passenger tank..So popped in a check valve right in the stock fuel line before the T with the Bosch fuel line and all is good now...
when I first built the fuel system I had thought about installing a check valve, but I noticed the intank check valve after the stock fuel pump...Just didn't notice it was before the filter and regulators...
Redyno later this week...
I was thinking that the external bosch was pushing fuel/pressure back inside the drivers side tank past the stock intank pressure regulators that are set at 58psi. I think thats why the fuel pressure wasn't rising with boost and is staying at 61-62psi just above the factory 58psi. I ordered a check valve to put on the fuel feed line coming from the fuel tank. I installed a few mins ago. I had seen from the diagram of the fuel system there was a check valve after the fuel pumps, but didn't notice the pressure regulators after it. There's 2 pressure regulators in the FFS fuel system. 1 in the drivers dank and one in the passenger tank..So popped in a check valve right in the stock fuel line before the T with the Bosch fuel line and all is good now...
when I first built the fuel system I had thought about installing a check valve, but I noticed the intank check valve after the stock fuel pump...Just didn't notice it was before the filter and regulators...
Redyno later this week...
At 851rwtq, and 801rwhp, I have never replaced my lines. AND I run 60's. I will admit, I was pushing the envelope of the injectors (90%) but the lines were just fine.
I would say stay with the injectors, and bring your FP up. If your at 61psi on the rail, and your running 12lbs of boost, your only seeing 49psi.
There are more than a few that are in excess of 650-700rwhp on
I would say stay with the injectors, and bring your FP up. If your at 61psi on the rail, and your running 12lbs of boost, your only seeing 49psi.
There are more than a few that are in excess of 650-700rwhp on
stock lines are good to about 650rwhp but need a return for boost reference. You can get away with a bigger feedline and using the stock feed for a return or can even do it a cheaper way if you don't plan on going to extreme. That using you stock feedline as the feedline and your evap line for the return, but you do need a return none the less. This insures the right pressure having the reg downstream of the rails. Sounds like you should have enough pressure from that pump depends on the wiring and fuel line plumbing. Maybe try a bigger external pump, go dual intank pumps or get a boost a pump. The 60# are good for allot of power and the next step up start to get pretty extreme. I'd trouble shoot and look elsewhere before going with bigger injectors. Good luck.
I would skip to 83 or 96# injectors with an Injector driver... More room to grow and not have to swap injectors again.
I have an AEM Injector driver for sale... if you go that route. Either way good luck! Fueling always seems to be the hardest part in these builds!
I have an AEM Injector driver for sale... if you go that route. Either way good luck! Fueling always seems to be the hardest part in these builds!
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
He said he is boost referenced, so will be seeing a usable 61psi of fuel pressure if everything is functioning as it should.
