Injector sizing

[PolarBear]

I will be in need of some injectors for my LS1 I am working on building.
Will be stock displacement LS1, compression will be slightly higher than stock, maybe around 11:1? CNC ported 243 heads, valve job, BTR stage 3 cam (can get the specs), LS6 intake, 1-7/8" longtube headers, 3" dual exhaust. I am guessing I will be well under 500 horse at the crank, but this is really my first time building an engine, so I don't know what to expect and don't know where to spec the injectors. The one vendor I have talked to sells Bosch III's and thinks I will need about a 36lb injector at stock pressures. Does that sound like it's in the ballpark?

[LTb1ow]

Sounds like to much, but err on the side of what a cheap OEM injector is available.

[PolarBear]

Too much? I am way over on the estimate, or too much injector for the power expected?
Not sure what you mean about cheap OEM injector. These would be $144.5 plus shipping for new, flow matched, Bosch III's

[unstable bob gable]

Which car is this for, Polar Bears?

[PolarBear]

The Camaro

[MDSheds_SS]

Maybe consult with whoever is going to tune it, some injectors are easier to tune then others from what TTP told me. He wanted me to go with TBSS injectors with LS1 pigtails.

[KirkEvil]

36lb at 58psi (stock ls1 pressure) will be fine for that setup. Go 42lb if you want a little room to grow.

[wretched73]

Stock injectors will be fine

[PolarBear]

My take on what you've all said;

Maybe consult with whoever is going to tune it, some injectors are easier to tune then others from what TTP told me. He wanted me to go with TBSS injectors with LS1 pigtails.

Ask someone else :lol:

36lb at 58psi (stock ls1 pressure) will be fine for that setup. Go 42lb if you want a little room to grow.

Fine (and too small) :rofl:

Stock injectors will be fine

Too big :kneeslap:

[PolarBear]

The place I was going to buy from says they will take them back if I have any problems with them, no questions asked. SO I guess if they are way too big or too small, I can just return them for different ones.

[PolarBear]

Go 42lb if you want a little room to grow.

I probably won't ever do any more to this engine, I am planning on an LS9 after this LS1 :rofl:

[unstable bob gable]

I probably won't ever do any more to this engine, I am planning on an LS9 after this LS1 :rofl:

For which car?

[PolarBear]

For which car?

The Camaro

:facepalm:

[SRGN]

I use the 60lb motron injectors in most of the stuff I put together. Great spray pattern at low pulse widths and easy to tune. Capable of handling more than you need now, but if you upgrade the engine you won't have to buy more injectors. I ordered 220 lb for mine and hoping it's enough :)

[KirkEvil]

I probably won't ever do any more to this engine, I am planning on an LS9 after this LS1 :rofl:

I ran ford 30lb svo injectors which are 36lb at ls1 fp to 400rwhp and trapping 118. Then upgraded to 42lb after other mods to 460rwhp and trapping 125. If you eventually throw on an UDP, EWP, and fast intake the 42lb would be better. Overall the price difference is close so worth doing from the start IMO.

[PolarBear]

I ran ford 30lb svo injectors which are 36lb at ls1 fp to 400rwhp and trapping 118. Then upgraded to 42lb after other mods to 460rwhp and trapping 125. If you eventually throw on an UDP, EWP, and fast intake the 42lb would be better. Overall the price difference is close so worth doing from the start IMO.

Good to know. I think I will be happy with what the LS1 gives me with what I listed. I actually would rather the LS9 but the LS1 stuff I got was a good deal, and there were extras I am using to complete my 5.3 for the other project. I am not looking for max effort out of this engine, just something with a bit more power than the 4.8 that I have in the Firebird. Once I find a takeout LS9 I am planning on putting more money into that, 427 ci, Lingenfelter snout, smaller pullies, ported heads, etc. so the little bit of money I will spend on this will be enough for now.

Oh and UBG, the 5., 5.7 AND the LS9 are all destined for the Camaro :kneeslap:

[unstable bob gable]

What is the Cummings going into?

[PolarBear]

What is the Cummings going into?

The CAMARO BOB! IT'S ALWAYS THE CAMARO!! :kneeslap:

[unstable bob gable]

The CAMARO BOB! IT'S ALWAYS THE CAMARO!! :kneeslap:

The yellow 92 Camero?

[PolarBear]

The yellow 92 Camaro?

That one too

[Featherburner]

How is the yellow Camaro's torque arm mount holding up?:lol:

[PolarBear]

How is the yellow Camaro's torque arm mount holding up?:lol:

:kneeslap:

Feels good to be able to drive it normal again

[unstable bob gable]

Polar Bears and his Camaros RULE!!!

[Dave@EFX]

We use Deatschwerks 42lb/hr injectors on most of our naturally aspirated stuff.

[PolarBear]

We use Deatschwerks 42lb/hr injectors on most of our naturally aspirated stuff.

Those are pretty expensive, no?

I wound up getting some Gen III Bosch 42s with a no questions asked return/exchange policy from the seller. Inexpensive and I can change them if necessary. I think I paid ~$150 and they forgot to charge me shipping

[unstable bob gable]

Those are pretty expensive, no?

I wound up getting some Gen III Bosch 42s with a no questions asked return/exchange policy from the seller. Inexpensive and I can change them if necessary. I think I paid ~$150 and they forgot to charge me shipping

Since you are an honest Bear I know you let them know about the shipping mistake, yes?

[LS1ow]

Those are pretty expensive, no?

I wound up getting some Gen III Bosch 42s with a no questions asked return/exchange policy from the seller. Inexpensive and I can change them if necessary. I think I paid ~$150 and they forgot to charge me shipping

WHAT ! from were, ill buy a set

[PolarBear]

Since you are an honest Bear I know you let them know about the shipping mistake, yes?

I did! He said, "oh well, next time". This was the second time I had ordered from them.

[unstable bob gable]

I did! He said, "oh well, next time". This was the second time I had ordered from them.

You're a good Bear, Polar Bears!

[chknhwk01]

40 ibb...............like new match tune.....for sale.... 200$..

[PolarBear]

WTF? I have no idea what you're talking about and you obviously can't read since I said I got injectors already

[V]

I had racetronix 37lb injectors, about 42lbs at ls1 fuel pressure. Car dynoed 425 rwhp.
Motor was LS6, stock ls6 heads, texas speed ms3 cam, electric wp, 1 3/4 LT headers ory-pipe, magnaflow catback, ported/polished stock TB, stock ls6 intake manifold, descreened maf. Tuner said I could have went to a 90/90 setup keeping injectors and get close to 450rwhp.

[chknhwk01]

oh yeah tune like new...200$....:nod:

[xrelapse13]

Day late and a dollar short but make sure the injectors you get (got already in your case) come with the proper data for tuning. Your tuner will thank you and having that data makes every part from idle to start up to part throttle smoother to dial in and better mapped.

On stock c.i. N/A LS1 stuff you can use the white FAST 36lbers, OEM LS3 injectors with adapters, DW 42lb like Dave mentioned, etc. All of those will flow ample fuel with good characteristics for part throttle.