EXPERIENCED HELP NEEDED!!! fuel injector fine tuning

[ezdaar]

well explain it hotrod.
why so dumb.

 

[jough]

Why 243 heads on a 6.0 Lq4? I understand that is not a good combo. 243s would work great on a 4.8 or 5.3, but not so much on the 6.0 due to the bore size on the 6.0 versus the chamber on the 243 heads. I think it would raise your compression ratio, maybe too much.

 

[ezdaar]

243's are great heads, even on a 6.0. But they do in fact drop compression.
This is why everyone cuts them 30-40 thousandths, to bring compression back up.

 

[01ssreda4]

243's are great heads, even on a 6.0. But they do in fact drop compression.
This is why everyone cuts them 30-40 thousandths, to bring compression back up.

Not on an LQ4 they dont. LQ4s (which is what he specifically cited) came with 317s which have bigger chambers then 243s. Adding even LS1 241 heads have more compression then 317s, the largest chamber of all the gen3/4 heads.

317s = 72cc
241/853 = 67
799/243 = 64
806 (or whatever those junk things are numbered) = 62 or 1

That's just off the top of my head to give you an idea. The old 5.3 heads are ******* junk and flow the worst of any Gen3/4 head.

 

[01ssreda4]

Why are you running a 102 fast with a 80mm TB? Choked off much? Yup. Atleast get a 90, better yet a eBay 100.

Though this appears choked, lots of your gain comes from plenum volume, which the 102 has plenty of. Its the same reason the old FAST 78s showed gains on LS1s. While the above setup is not optimal, its still ok, and definitely fine for a truck.

That cam, heads, intake with a 2500 verter?

You do remember this is a truck right? Much bigger then this and you are pissing all your towing capabilities away. This combo may have a little bit of a mediocre midrange but it wont be worse then stock and it will still love to rev.

What's comp ratio? Did you go up any with Pistons? Since you didn't cut the heads of you didn't, you actually dropped compression with that combo.

LQ4s came with 317 heads which are about 72cc chambers, he went to stock 243s which are about 64cc. His compression is up quite a bit over stock

Are you building for a turbo?

Only in your mind fella.

You have a 2-6k cam with a 3-7500k heads and intake combo along with a 2500 verter.

Wow, how about no. Stop making up numbers. Fast and stock style intakes don't flow good to 7k, I don't care what heads you've got. Unless you're throwing a Victor Jr/Super on there with a 4150TB you aint making no power at 7500.

Mis matched system to say the least bud.
You would be better off with a nnbs intake port matched to a ported oem TB with your combo. It would make waaayyy more power below 4k and be very close above.

While I agree the NNBS intake would have been the cheaper route, it would not have made more power. The Fast intakes generally give up nothing anywhere in the powerband. Now it might not gain everywhere, but it definitely isn't losing anything.

Toss that 2500 verter for a tight 3k or 3200. With the right verter so will still be able to tow np, if needed.

Tow how much though? You don't know his wants or needs so that's a loose assumption. I personally wouldn't build a truck to go fast (seems counter-productive to me) but if I did it wouldn't get a 2500 or a 3200 and it wouldn't be able to tow when I got done either. He may have gotten a good deal on it whole knows. Maybe he doesn't wanna pull it at this point. I don't necessarily think its completely justified at this point.

Give yea props for the effort and high quality parts, but the combo is way off.

Hey, No

My thoughts are in BOLD. You asked, so there it is.

You have just enough knowledge to be dangerous. You've done some reading, but not near enough. You don't know basic powerbands, basic specifications of stock parts. If you can't keep up with all that maybe you shouldn't be chiming in on these types of threads. Just a thought.

---------- Post added at 08:22 AM ---------- Previous post was at 08:20 AM ----------

And yeah, I may have been around a while......

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