[KingLT1]

Originally Posted by Joshinator99

This 100%. Not to mention guys that still have cats and Cat Over Temp gets shut off by the tuner… saves a ton of fuel headroom but nukes the cats. So the tuner gets to brag they did “XXX” HP on stock LT4 fueling but you get to buy new cats lmao

Agreed...with Cats you really don't want to be leaner than .80-.82 imo.

[arpad_m]

Always a pleasure to hear solid info from the horses' mouths

My car has LT4 injectors and the LT4 high side/low side fuel pumps, it's tuned for 0.82-0.83 lambda at WOT, and it can drink corn juice up to E60, producing ~735 rwhp while reaching only 5.1 to 5.2 ms injector pulse width. I'm happy to stay in this safe zone, no need to chase the last couple horsepower and ethanol percentages with its heavily diminishing returns, risking the cats or the engine in the process, at least from my POV.

[JSH]

Originally Posted by KingLT1

You might want to consider bumping the converter up to around 3-3200. The stage 2 BTR is right on the edge with a stock converter. Yes I know plenty run that cam with a stock converter, I have tuned a few of them but it's not ideal imo. The stage 1 is better with a stock converter.

You mentioned max I/E overlap with stock converters in one of my threads. When I told LME that I only picked up 15 hp with the CID heads but also picked up 50# of torque, they said, "Your cam isn't right, then."

This morning they proposed, 242 / 266 @ .050", .647" / .638" lift w/ 1.8 rocker ratio, 118+4. I calc'd 18 degrees overlap.

My current cam is, 235 / 248 .644" / .631" 1.8 / 1.8 118+4, with 5 degrees overlap.

What do you think?

[SammYyYyY]

Originally Posted by KingLT1

Target AFR plays a huge part in that. Some tuners will run these cars really lean on E85...like .86-.88 lambda lean and that will stretch the fuel system out a lot further than .82-.84.

Then my next question would be...what does the car trap in the 1/4 mi and 60-130?

That would not surprise me at all. We have not collected any data here personally, though being in Utah our DA is so trash that it'll look bad regardless.

However, I do have some data from the prior owner who trapped 131.19 in the 1/4.

Another oddity; this car was set up on flex but was exclusively run on E85 when it was in California. We don't have as much E around here so my brother mostly runs it on pump gas; we noticed the car was running extraordinarily rich, so we had my tuner data log it when we threw it on his dyno. Turns out it was running at a lambda 0.74 average through the rev range, so we immediately retuned it; we did not datalog the old E85 tune. I'm guessing this had something to do with the elevation change from CA to UT, but I also figured MAF would do a better job at correcting that. Regardless, the car went from 610 WHP to 710 WHP on pump gas from this retune lol.

[SammYyYyY]

Originally Posted by Joshinator99

This 100%. Not to mention guys that still have cats and Cat Over Temp gets shut off by the tuner… saves a ton of fuel headroom but nukes the cats. So the tuner gets to brag they did “XXX” HP on stock LT4 fueling but you get to buy new cats lmao

This also explains a lot; thank you!

[KingLT1]

Originally Posted by SammYyYyY

That would not surprise me at all. We have not collected any data here personally, though being in Utah our DA is so trash that it'll look bad regardless.

However, I do have some data from the prior owner who trapped 131.19 in the 1/4.

Another oddity; this car was set up on flex but was exclusively run on E85 when it was in California. We don't have as much E around here so my brother mostly runs it on pump gas; we noticed the car was running extraordinarily rich, so we had my tuner data log it when we threw it on his dyno. Turns out it was running at a lambda 0.74 average through the rev range, so we immediately retuned it; we did not datalog the old E85 tune. I'm guessing this had something to do with the elevation change from CA to UT, but I also figured MAF would do a better job at correcting that. Regardless, the car went from 610 WHP to 710 WHP on pump gas from this retune lol.

Elevation also plays a big factor as the dyno is using a larger correction factor when using SAE or STD which shows you are making more power then actual as elevation climbs and less as you go down. So cars always tend to show the ability to run more E85 @ high elevation because you are making less power uncorrected vs a car @ sea level.

[SammYyYyY]

Originally Posted by KingLT1

Elevation also plays a big factor as the dyno is using a larger correction factor when using SAE or STD which shows you are making more power then actual as elevation climbs and less as you go down. So cars always tend to show the ability to run more E85 @ high elevation because you are making less power uncorrected vs a car @ sea level.

This is true, however the aforementioned 760 WHP on E85 run was in Cali around sea level. The only time we've had the car on a dyno up here at elevation was on pump gas when it made 610 WHP running rich, and then again once it was retuned making 710 WHP at lambda ~0.83-0.84.

I wonder if the tuner has logs of this car on the dyno running E85 at sea level. Would be interesting to see if their fueling headroom was from running it lean with catalytic protection disabled. I might shoot the tuner a message out of morbid curiosity.

[2018zl1-1le]

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Yes new katech oil pump going in. Next mods are going to be Kong x porting and port injection and ported heads. Thanks for inputs