LTX and LSXPutting LT1's, LS1's, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects, including repairs, swap info, and performance upgrades.
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Okay, so I know there has been tons and tons of debating on what the LS1 injectors actually flow... I had purchased a set of them for my new engine, and shortly after I had found a few different flow ratings for them... So I kept searching, and found even more information, and so much of this information was conflicting information.
So... I decided to send one out and have it flow tested. The part number of my injector was GM - 12561462, Bosch - 280 155 931. This was one of the set I got from SLP as Take Outs. Rich at Cruzin Performance did the flow testing for me, he also compared it to another LS1 injector, GM #12555894, Bosch #280 155 890. So now, heres the results directly cut from the e-mail Rich sent me:
Quote:
Due to the variations in fuel blends available across the nation, I tested them at two different Specific Gravities (sg). One was 0.685sg and the other was 0.770sg. By doing this, it covers most of the ranges of available fuels.
Just for further reference, on the day they were tested, I also measured some fresh 87 Octane regular unleaded fuel and it measured 0.725sg.
The common conversion factor of 10.5 was used to convert mL/min into Lb/hr.
Injector #280 155 931 GM #12561462
60 Second static flow test @ 0.685sg @ 3Bar = 270mL divided by 10.5 = 25.714 Lb/hr
60 Second static flow test @ 0.685sg @ 4Bar = 315mL divided by 10.5 = 30.00 Lb/hr
60 Second static flow test @ 0.770sg @ 3Bar = 255mL divided by 10.5 = 24.285 Lb/hr
60 Second static flow test @ 0.770sg @ 4Bar = 297mL divided by 10.5 = 28.285 Lb/hr
Injector #280 155 890 GM #12555894
60 Second static flow test @ 0.685sg @ 3 Bar = 250mL divided by 10.5 = 23.809 Lb/hr
60 Second static flow test @ 0.685sg @ 4 Bar = 295mL divided by 10.5 = 28.095 Lb/hr
60 Second static flow test @ 0.770sg @ 3Bar = 240mL divided by 10.5 = 22.875 Lb/hr
60 Second static flow test @ 0.770sg @ 4Bar = 275mL divided by 10.5 = 26.190 Lb/hr
As you can see from the test results, the flow rate of the injector varies considerably depending on the specific gravity of the fuel and also the pressure they are operating at. Other factors such as the temperature, barometric pressure, humidity, test altitude and the test equipment all have to be taken into consideration when testing injector flow. Given that, I performed these tests twice, on two of my flow benches and the results remained consistent each time.
This is not an exact science due to all the variables involved. Because all injectors are manufactured within a range of tolerances, and in this case only one of each part number was tested, the test results would not necessarily represent what a complete set of injectors would flow. I hope however this provides you with data you requested and that you can use it to help dispel some of the "myths" concerning these injectors.
I'm sure someone out there in "cyberland" will cry "foul" and say the data is biased or untrue. All I can say to that is that I call it as I see it when testing them. I don't sell injectors so I have no "conflict of interest" in recording or reporting data and I'm not interested in debating what injectors are advertised to flow vs what they actually test at.
Remember:
1 bar = 14.503 psi
92 Octane tested at 0.745sg.
87 Octane tested at 0.725sg.
3 bar = 43.509 psi
4 bar = 58.012 psi
I hope this information helps clarify a lot of things for us... if you need to know the flow rate of other injectors, I believe you can just email Rich at Cruzin Performance, and he may know what they flow if he has recently tested any. After dealing with Rich, I have to say he provided the best service I have ever received from a business, I urge you to have him service your injectors if you need them serviced. He promptly responded to my emails and let me know exactly what was happening.
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__________________
Mods: TB Bypass, Jeg's RedHot Coil and Ignition Module, K&N Air Filter, Ported Plenum, 3" cat back with Flowmaster Muffler dual 2-1/2" Out the back with Chrome Y tips, 180* thermostat, Manual fan switch, Accel 8mm Super Stock Plug Wires.
Soon: Project 383 TPI nearing compleation... Forged Pistons and Rods, AFR 195 cc Heads, TPIS BigMouth Majorly ported and matched, Edelbrock Runners, Edelbrock Headers, TPIS zz9 Copy Cam, LS1 Injectors, Custom Prom, 2400 Stall Converter, TransGO Shift Kit, and new almost everything with the engine. Lets hope I push 300+rwhp and 400+rwtq.
Best 1/4: 15.923@84.59 w/ 2.298 60ft.
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Good job and excellent data. I want to point out that the LS1 Camaros (I have a '99 SS) came with two different flow rates.
The '98, '01, and '02 LS1 Camaros came with the 28.x lb/hr injectors, while the '99 and '00s came with the 26.x injectors.
These values are measured at 58psi (4 bars).
It appears that you flow tested one of each, one LS1 injector is from a '98 and the other is from a '99, for example.
This compares very favorably with the comparison between the L98 and LT1 Camaros, 22 vs 24 measured at 43.5psi (3 bars).
BTW: Rich is the MAN when it comes to injector testing!
__________________ '87 L98 TPI IROCZ, 395cu.in. ZZ4 block (.030" over bore), ported Holley StealthRam; 3.875" Callies DragonSlayer crank, 5.85" Eagle H-beam rods, 14cc dished SRP pistons part# 148988, AFR190 heads, 3.70 rear gears, 224*/230* 114*LSA 0.530/0.536 lift CompCams cam, 1.6 roller rockers, 3000 Art Carr TC, SLP 1 3/4" headers, SLP cat-back, no cat, no AC, MAF w/o screens, 30#/hr Ford injectors, 52mm TB with airfoil, TB coolant bypass, Lay Ind. ram air kit, SS Brakes 1LE upgrade 12" rotors dual piston calipers, turbo TransAm fuel pump, K.Brown weld-on subframes. Rear tires: P295/35R18 BFG Drag Radials.
Best ET 12.12 sec @ 110.55 mph @ Milan.
With 395, ET 12.197 sec @ 113.65 mph @ Milan.
With 350, ET 12.97sec @ 105mph M/T ET Streets.
Best with HSR: ET 12.385 sec @ 108mph @ OSW.
Okay I have 2 more bits of info relating to this...
I was looking at the injectors and the stock clips... The clips can't be modified to hold the injectors... so I tried to make some clips with little success.
I then decided that it might work out if I cut the grove in the top of the injector so it goes all the way around, like an older style injector. So I tried it, works like a charm.
Then I tried to seat them in the intake while they were clipped in the fuel rail... looked pretty good, but what about flow? Will the intake block the plume of fuel?
I tested that also, no matter how far the injector is in the intake, the plume stayed the same, from all the way seated in the intake, to barely in the intake at all, the intake didn't block the injector.
Looks like I'm going to be fine with these injectors in those 2 respects. We'll see about flow once I get this thing up and running, I have a feeling I will need more pressure to get them to satisify the engine.
Originally posted by TheMysticWizard Okay I have 2 more bits of info relating to this...
I was looking at the injectors and the stock clips... The clips can't be modified to hold the injectors... so I tried to make some clips with little success.
I then decided that it might work out if I cut the grove in the top of the injector so it goes all the way around, like an older style injector. So I tried it, works like a charm.
Then I tried to seat them in the intake while they were clipped in the fuel rail... looked pretty good, but what about flow? Will the intake block the plume of fuel?
I tested that also, no matter how far the injector is in the intake, the plume stayed the same, from all the way seated in the intake, to barely in the intake at all, the intake didn't block the injector.
Looks like I'm going to be fine with these injectors in those 2 respects. We'll see about flow once I get this thing up and running, I have a feeling I will need more pressure to get them to satisify the engine.
What type of tool did you use to cut the groove in the LS1 injector? And also, how well do these really seat themselves in the TPI manifold. I noticed a difference in Injector length, the LS1 being much shorter. It looks to me like once the fuel rail is tightend down that the LS1 injector will definitly come up short and that the O-ring will not be able to seal and do its job?....You stated it will still spray but will performance suffer from this? Please let me know how you made out. I am attempting the same swap and would prefer to learn from someone elses mistakes (or successes)!!!
Next question would be for optimum performance how close in performance should each injector be in a set of eight. I have read where they can vary maybe 6% which is quite abit.
If Rich were to test a set of eight and two were off by quite abit how would one go about finding two more that match? Or do some cylinders not draw in quite the same amount of air that others might. Such as the 5-7 cylinders??? Just food for thought.
Would this not be a reason why one motor will out perform another with identical parts? The closer the injectors match in performance I would think the better the overall horsepower would be.
If two cylinders were slightly rich, another two slightly lean the O2 sensor might read 13.0 but in reality the cylinders were not in fact buring 13.0. They could be 12.5 and 13.5 respectively. Just thinking.
__________________ Best et of 12.12 and best mph of 111.27 mph. Motor specs as follows: 355ci, Dart Pro One 200cc heads, 10.72:1 compression, 8.5:1 dynamic compression ratio, TPI with highly modified 1st style SLP runners, moded GM plenum and First Injection TPI intake manifold, Mike Jones 228/228 cam, Yank SS3600 converter, Dyno Don 1 3/4" shorty headers with excellent Dyno Don custom exhaust, custom cold air intake, AS&M monoblade throttle body. Race weight 3760 with driver. Meziere electric water pump. Mufflex 3.5" exhaust catback. Magnaflow 3.5" muffler#12909. Kevin91Z Tune. 4L60E installed.
Standard correction/unlocked 380RWHP, 371 RWTQ. SAE numbers are 370RWHP, 361RWTQ. Switched to MAP. At the motor that is 462HP SAE.
A 370 cubic inch motor based on the Dart SHP block is under construction. Using AFR 195cc Comp Heads.
Your comment about cylinders 5 and 7 drawing more air, is a good reason to put the two highest flowing injectors in those two positions, provided of cource that you flow tested all 8 injectors.
Do people have more of a problem with cylinders 5 and 7 running lean? Or having detonation damage?
