im putting this here since this is the most likely place where someone will know..


i know that the LS1s injectors look diffrent, but is the OD of the Orings the same as the LT1/SBC/standard injectors?

if not, does someone make a oring so that they fit?

I've heard of LT1 guys running LS1 injectors, and I know the LT1 injectors are the same as ours, so I'd guess it will work fine.


But that's just a guess.

They fit in my L98 fuel rail just perfectly.

thanks!

You do know that the LS1 injectors will not necessarily flow more fuel for you.

They are flow rated at 58psi, while LT1,L98, etc are rated at 43psi. So the 26.5#/hr LS1 injectors flow almost the same amount of fuel as my old 22#/hr injectors from my L98 and the 28.5#/hr LS1 injectors flow the same as the 24#/hr LT1 injectors,,, given that all injectors are flow rated at the same fuel pressure.

Those injectors are the SLP injectors which they say are 25# at 43.5 PSI.. Dunno.. Actually, at this point, don't care, my duty cycles are all good..

I wish I had realized this over a year ago before I bought my set! I hadn't been reading on this board enough to know better by then! I'm still planning to try them out and see what happens when I get to that point!

FYI theres a company I can't think of the name right now.. But i think its racetronix that flow rates injectors.

They sell LS1 injectors and they flow them I think in the mid-high 20's on 43 psi so they are a larger injector.

The biggest problem I have with these is they are not always as advertised.. YOu might buy a LS1 injector thats actually a truck injector and not the same rating. Some how LS1 means anything gen 3

You can always check thge part number! I did, and mine ARE LS1, not LS!-Derivitave (Truck 4.8, or 5.3). I thought the trucks used a different injector all together? Seems to me the ones they use are quite a bit longer, and have a totally different connector. I'll have to watch the enxt few that come into the shop and see, just for future reference.

eh, thought i found a deal, but it turned out to be a dud...


what i really need are some 47lb (or bigger) injectors... but thoes are a lil hard to find used.

im probly going to have to bite the bullet and buy new ones.... injectors are going to cost more then the ECM did.. lol

Used injectors are like used underwear.
You had best get them cleaned and tested before putting them on. The service could end up costing you a good % of what it costs for new injectors.

i know...

but im all set now...

a close friend of mine just bought a LS6 intake, complete with injectors.... so im just going to take his old ones... i know they're working great right now...

LS6 injectors are 1/2 the size of what you quoted above as needing???

The firing strategy of the LS1 is sequential. This is NOT like batch fire in any way shape or form. With sequential they can run smaller injectors because the injector has twice the time to fire than batch. You can actually run really small injectors with sequential fire since you can leave them open for twice as long as you could a batch before running into duty cycle issues.
I'm suprised GM even made the injectors as large as they did. I expected them to be pretty small and run high fuel pressure. The advantage of the larger injector is that it doesn't have to stay open as long which might give them the ability to have the injector open during intake valve open. That's the only reasons I can think of. Emissions only.
Aren't the LS1 fuel system a dead-head design? The regulator is in the tank right?

Some are... I know a buddy of mine has a 98 and a 99 Vette and the 99 is dead-head but the 98 has a return.

JPrevost, sorry, you are incorrect there about Sequential using smaller injectors.

When you fire injectors in batch, you fire two pulses with half the fuel at a time.

With sequential, you fire one pulse with all the fuel.

Add it up, and flowrate doesn't make a difference between the two.

Actually when selecting an injector, batch will typically target a max duty cycle of 85-90% because they need as small an injector as possible for idle, but sequential typically targets 60-80% max duty cycle (meaning larger injectors) because the goal is to shoot it on a closed intake valve which is about 2/3 of the time allowed, and don't suffer the same small pulsewidth problems as batch. Batch will also typically switch to a double pulsewidth single fire mode at low PWs to get the fueling correct, but this has the drawback of some injectors spraying on open valves, which does not promote proper atomization.

Glad someone jumped on JPrevost's disinformation.
Everything you posted is correct except for what appears to be a typo in the above sentence. It should be 'closed' intake valves.

The batch fire is limited in time, because it has to fire every DRP, compared to sequential only needing to fire when a particular cylinder is ready... Correct? Therefore, you can have that injector on longer than 1 DRP.

Don't be sorry. I can stand to be corrected if you back it up, which you have obviously done.
The only thing I need to correct you on is the fact that an injector fired once for t seconds will flow more fuel than the same injectore fired twice each at t/2 seconds. That isn't an opinion, it's fact. The newer injectors are much better than older styles because they've reduced the weight of the moving parts from 4 to less than 1gram. Hence the ability to use large flowing injectors and having very low pulse widths avail to control idle emissions on high reving motors. The peak and hold designs are much better at flowing fuel because of the opening rates. This isn't what we're talking about though. High impedance injectors will not flow the same between batch and sequential, sequential can support more power no if ands or buts about it.
Keep in mind we're talking about very little differences but those differences become an issue at higher revs of todays engines.

Ok, neglecting turn-on/off time, what I said was accurate, I just left it out for sake of argument on the other part about them typically being smaller. I'm quite familiar with injector turn on time and non-linearity in general with fuel injectors - I've measured it with our test bench, designed the quasi-asynch algorithm for our ECU, and calibrated it.

Also, it is a huge misconception about sequential. The goal is TO SHOOT ON A CLOSED INTAKE VALVE. This allows time for the fuel to absorb heat from the valve and vaporize, and also, when the valve opens, there is a small exhuast pulse going up the intake port (at throttled conditions, WOT can be an exception with a tuned exhaust), which blasts the fuel into smaller pieces, and also, the small cross section of the valve opening and huge turbulence will create excellent mixing and vaporization. You will see that most OEM's, and even aftermarket ECUs will target an end of injection to coincide with the opening of the intake valve, which takes a little calculation to get the beginning of injection, and transients have to be added to the end reluctantly, unless time was allowed for.

Do you have any information about the sequential injection I could read up on? I noticed no gains in horsepower when we changed the phase of the sequential injection on a 600cc Honda F4i. We also noticed no difference between that, CNP, wasted spark, and batch fire injection. All with a tenth of a ft-lb and in a relatively controlled facility. I bet it has more to do with emissions on larger engines than it does motors that rev to 14000rpm .
I've also been looking for some time for charts showing high impedance injectors vs low impedance. I found some for the low impedance but the high I still need. Cool stuff but I fear I've hyjacked this thread. PM if you could help.
As for the LS1 injectors, where is everybody getting them? I've seen them on ebay and a couple of websites selling for pretty cheap. I just want to hear what they REALLY flow, not this 43 vs 53psi again. I say this because the Holley delphi injectors for TBI are the same way. Nobody can confirm with actual data the flow rates

Dunno if SLP still has them (they're still listed on the website - slp part # 23051), but they are selling sets of 8 for $100 (these aren't flow-matched like racetronix' are). I ordered a set from them last year and they're working great.

Now for the interesting part. They list them as 25#/hr injectors (at 3 bar, 43.5 psi, 300kpa). However, Racetronix says that the 12561462 injectors flow 28#/hr (at 300 kpa, 43.5 psi, 3 bar, etc). I trust them. That explains why upon initial start-up on my car, all my BLM's were pegged down at 108. I had to drop the VE table by quite a bit before I could get to 128. (this is all with a 25# injector constant, $8d btw). I'm kind of excited about starting over (trying a 28# constant like it should be, and starting from the base fuel map), as my WOT has been a little rich (don't have the WB yet though) according to the narrow band (yeah yeah, I know ).

eh, they'll work while the motor is NA and under boost to a point...

this is a low buck effort, so when you can get the car running and drivable for $20 in injectors, its worth it.

im seriously considering making a flyback board and just running 2 injectors per cyl.... my only problem being packaging.. lol.

perhaps some design like the superfueler would work for me.. i donno....




as much as id LOVE to plan out a badass setup part by part, the reality for me is, i use what i can get and take it to the highest level i can.

I've been searching for more info on these 12561462 injectors, and most people (some c5 corvette) are citing them as 28lb at 4 bar and ~24.7 at 3 bar... Racetronix, are we sure about the specs you listed on your site?

EDIT: Oh boy!! I found a great site with a boat load of injector specifications. This site seems to back up Racetronix' data about the 0 280 155 931 (or 12561462) injectors. Check it out guys:

http://users.erols.com/srweiss/tableifc.htm

Sure would be nice to get a definitive answer on this. I'm planning to put some in (this weekend most likely....)

what size are these damn things really?


28.8# @ 58 ---------> 24.94# @ 43.5?

28# @ 58----------> 24.24# @ 43.5?


OR

28# @ 43.5---------> 28# @ 43.5?????????????????????????

According to the link provided above (Thanks!) they are 28.0 at 43.5 psi. That is a pretty cool link to hang on to....

Well, I decided to kind of start over on my tune now that I have a lot more experience then I did a year ago (was also thinking about how Grumpy says sometimes its good to just start fresh, Thanks, BTW!). I took Super AUJP and made my initial modifications (I still have an AIR system, cooling fan temps, etc) along with updating the injector constant to 28# this time. When I ran it in the car, I was rich (about 108 to 120) in most lower ranges (keep in mind that the SAUJP has a minimum BLM of 96) but after I ran the log through VEMaster, it took fuel out of the bottom regions (lower RPM, low load areas), but actually added some in the areas where the motor starts breathing easier. This was kind of what I expected when I put this car together the beginning of this year. I used a 25#/hr constant before and I ended up slashing the VE table pretty severely (which makes sense if the injectors are really 28#/hr) in order to get close to 128 BLM. Now, after 4-5 chips (as opposed to the uncountable number I was up to before), I'm pretty close to 128 in most ranges, and the drivability is real good.

One other thing I'd like to add and support is Grumpy's recommendation of starting over in certain cases. I learned a lot by messing with things over the last year, but I have discovered that much of it was unnecessary and merely trying to counter simpler errors. Chalk it up to learning.. Sorry if this post is a little out there..

Oh, and just incase somebody just skimmed and skipped to the end, I think I've added support to the fact that 12561462 (0 280 155 931 Bosch) are 28#/hr at 43.5 PSI. Thank you for reading!

LS1 injectors are the physical same size as L98 and LT1 injectors. All are interchangable by physical size. That is why you can see in the pic at the top of this post, LS1 injectors in the L98 fuel rails. No problem its a direct fit.

However, as with our L98 and LT1 injectors having two different flow rates when measured at 43.5psi (22 and 24#/hr), the LS1 injectors have two flow rates: 26.5 and 28.5 when flowed at 58psi. If you run the pressure equation to rate injectors at varing fuel pressures, you will find that the L98 22#/hr injectors will flow 25.5 or there abouts if rated at 58psi. Also, the LT1 24#/hr injectors will flow about 27.7#/hr. so we are basiccally looking at the two LS1 injectors. 1998, 1001 and 202 LS1 injectors are the higher flowing ones at 28.5#/hr, while the 1999 and 2000 cars had the 26.5#/hr injectors.

So if you took a set of 1998 LS1 injectors and stuck them in an L98 using stock fuel pressure (43.5psi), you will get a flow rate of about 24.7#/hr, thats close to the 25#/hr stated above somewhere. The statement above about the LS1 injectors are 1/2 size of L98 injectors is totally wrong.

I know this to be true because I own and modify both a 1999 Camaro SS and a 1987 Camaro IROCZ.

I really dont want to get into the sequential vs batch fire stuff, but on my '99 LS1 car at 6,000RPM, I am at 100% DC with a PW of 20.0msec,,, while with my batch fire '87 at 6,000RPM, I'm at 100% DC with a PW of 10msec. Since the batch fire car fires the injectores all at once each crank revolution, and the sequential car fires the injectors separtely but at once per 2 crank revolution, I do get the same total fuel because the PWs are ratiod 1 to 2.

I got a set of the 28lb LS1 injectors from SLP a while back and they run great. They are a direct fit for the stock injectors. If you stand the old ones next to the LS1 injectors they are just a little bit shorter in length than originals but it doesn't cause any issues.

When I installed the 28lb injectors I did have to bump up the injector constant due to the increased fuel. So the LS1's definitely flow more than stock.

Another injector at a reasonable price in the same ballpark size range: http://www.racetronix.com/621020.html

set your injector constant to what this calculator spits out.
http://www.csgnetwork.com/fiflowcalc.html

On my 383 SR 219 combo I had to set my constant to 28 for it to be in the 128 range. At the 25# I was at 108 everywhere.

Ive always wondered how close that/equations are to the actual change in flowrate with pressure increases