Someone enlighten me

[paint94979]

From Steve at the DP

"The small differences in a LLY Vs LB7 do not mean all that much. The LLY has a smaller injector so it will delivery less fuel than a LB7 it's a simple fact but some take it completely out into left field. Both turbo's are pretty close in overall flow so the injector becomes the limit. This is why a LB7 will make more power than a LLY. Once you change injector tips out it really doesn't much matter. LLY's had somethings that worked differently than a LB7 but since most could copy/duplicate the LB7 stuff most of the work was already done. Different day, different problem you just find them and fix them then move on."

Is that true? LLY injectors cant supply the same amount of hp as LB7's?

 

[JOHNBOY]

From what I have seen they in stock are about the output wise.

The LB7 needs less pulse width but the turbo is fincky. You have to have your timing curve dead on. To much is just as bad as to little. LB7s are all about getting the turbo spooled at the right time.

The LLY needs a bigger fuel shot put you have more control over the air because of VVT.

The best stock engined Tune/Trans only LLY I have seen dyno on a 248c was 501hp. The best stock engined Tune/Trans (actually clutch) I have seen on a 248c was mine at 507hp.

Basicly IMHO that is translates to "I still have figured out the pesky LLY yet!":rofl:

 

[Diesel Pilot]

I've seen pretty much the same thing as Johnboy. The LLY should have a bigger duration than the LB7 because of smaller injectors. However, both the tune on my truck and v6 for the LB7 have the same injector duration maximum. The LLY does like more timing and that would be a result of the smaller injectors. I kept the durations the same because that's what I found to work for both, now they could likely be fine tuned a bit but I haven't been back to the dyno in awhile.

I think Steve is actually wrong about the turbos though. I think the LLY turbo is also at a small disadvantage to the LB7. Sure on paper they look to be very similar but the main difference between the two is what is holding the LLY back, the vanes. The vanes are creating more drive pressure which is hurting the output of the engine. Tuning the vanes is the big challenge with the LLY.

Now all these things add up to a very small sum, and are hardly noticable at all. Like Johnboy said, he's witnessed only a difference of 6 hp. I haven't put my truck up against a normal LB7 (not Ecc_33's freak) but I'd imagine the difference to be very small.

I think Cole just likes to bash the LLY because he missed the boat on tuning it and Pat has been shoving LLY down his throat for the past 3 years.

 

[LarryJewell]

Ttt