[LiqTenExp]

Where are you guys timing wise in your table around 1600 mg Airmass?

Hitting the dyno tomorrow and I have some minor fueling to correct, was planning on leaving timing alone.

I'm running 93 + Water/Meth injection. Injectors are around 4.6-4.8 ms, fuel rail around 3400 psi, fuel pressure about 75 psi. Running around 0.83 +/-0.01 lambda on a pull. I will typically throw a little Boostane at it for safety on the dyno just in case

Attached is where my High Octane timing table is along with where timing landed the last time I was on the dyno.

[Camaro1973]

Originally Posted by LiqTenExp

Where are you guys timing wise in your table around 1600 mg Airmass?

Hitting the dyno tomorrow and I have some minor fueling to correct, was planning on leaving timing alone.

I'm running 93 + Water/Meth injection. Injectors are around 4.6-4.8 ms, fuel rail around 3400 psi, fuel pressure about 75 psi. Running around 0.83 +/-0.01 lambda on a pull. I will typically throw a little Boostane at it for safety on the dyno just in case

Attached is where my High Octane timing table is along with where timing landed the last time I was on the dyno.

15lbs boost 21 degrees up top from
6k to 7200 on 93. Nothing else.

Water meth , I don’t see a reason why you would need boostane.

You couldn’t go higher then 21.5 on water meth?

[LiqTenExp]

I can hit 24-26° as the log shows above

[Camaro1973]

Originally Posted by LiqTenExp

I can hit 24-26° as the log shows above

From what adders? I assume intake/MAT table is adding ?

[7LitreC5]

My high octane table has 22 degrees in the range that you are asking about. It was tuned on 91 but I am at high altitude so I can get away with more timing on less octane.

[KingLT1]

What somebody else has in there high octane table is irrelevant without knowing how all the other spark modifier tables are populated. I have 16 degrees in my brother's H/C 2650 C7Z but after all the modifiers add spark it's seeing about 22-23degrees on 16 psi. It's a built LT4 with 11:1 compression on E60.

[laynlo15]

I used to run 26 degrees on mine with Meth/water injection and MS109 race fuel.

[KingLT1]

Originally Posted by laynlo15

I used to run 26 degrees on mine with Meth/water injection and MS109 race fuel.

How long did it last?

[laynlo15]

Till it broke the crank, but timing didn't cause that, it broke internally. When I did the Lt4 short block and got it ready to sell we went down to 22 degree on race fuel and no meth, made 847 rwhp and the new owner actually went faster at 9.33@149, he did weigh at least 50 lbs less then me and had really good DA and low 60 degree temps. Then on 93 just 18 degrees and it still made about 730 rwhp on 12 lbs of boost for a nice street tune.

[KingLT1]

Originally Posted by laynlo15

Till it broke the crank, but timing didn't cause that, it broke internally. When I did the Lt4 short block and got it ready to sell we went down to 22 degree on race fuel and no meth, made 847 rwhp and the new owner actually went faster at 9.33@149, he did weigh at least 50 lbs less then me and had really good DA and low 60 degree temps. Then on 93 just 18 degrees and it still made about 730 rwhp on 12 lbs of boost for a nice street tune.

Not surprised...26 degrees is simply too much. 18-22 is all that is needed depending of fuel and setup. 26 is pushing the engine on the ragged edge for little gain. Good way to rebuild shit frequently...I could see it for a track car not a street car.

[radz28]

I've seen about 22* in those areas on about 15-16-lbs on a 91/Racegas blend to about 93-94 octane.

[laynlo15]

Never drove it on the street till I got ready to sell it except to do some logs and that was with drag radials and still very dangerous. We think the reason it broke the crank is that it over revved when it was supposed to shift at 6800 it didn't shift till over 7600 rpms and went right into limp mode but not because of timing. I ran 26 degrees on my old 2300 setup up we just ran too much boost and not enough crank ventilation till it was too late, it finally gave up after 180 runs and broke a couple ring lands. We only had about 60 runs on the 2650 setup. I always push stuff to the limit but thats my nature and I suppose that's a flaw but hey you just live once. My C7 is close to the limit also but so far its surviving but I don't run that tune on the street, its pretty conservative.

[Camaro1973]

Originally Posted by KingLT1

Not surprised...26 degrees is simply too much. 18-22 is all that is needed depending of fuel and setup. 26 is pushing the engine on the ragged edge for little gain. Good way to rebuild shit frequently...I could see it for a track car not a street car.

What? No. Every tune i've looked at with race fuel or high ethanol content their timing has been as high as 24-27.


19-20 Degrees is common on pump 93 for a 2650 and cam/heads, not for race fuels/meth or ethanol.

[LiqTenExp]

Put down ~760whp on a miser mustang dyno on drag radials, translating that to dynojet is ~847 whp. A stock LT4 on their dyno 510-520 whp depending on transmission. Would have made more if I wasn't on my 345/30R19 drag radials (~20 whp they said). Didn't even think about that, could have at least brought them up in PSI, oh well. Basically I know I've picked up ~250 whp from stock, that's not bad on a 2300.

Touched 26° timing (on meth (50/50) and a little bit of Boostane). Brought timing down a degree for just meth only use. It was happy at 26°, no knock, made 2 pulls within 2 whp with 5-10 min cool down between. The car picked up 40 whp going from 22° peak to 26° peak, hp curve also stood up at the end and didn't flatline above 6400 like it did at 22°. Car goes from 0.86, then 0.85, to 0.84 lambda from 3000-7000 rpm, very accurate WB02 vs. commanded fueling by the final 3rd pull. I'm doing the tuning for the past year and very happy that I've got the Gen5 stuff figured out. Shout out to Goat Rope Garage for the help!

I wouldn't run a non ethanol/methanol car much above 22° based on how my car has responded over the past 4 years, that is about where I topped out before methanol on 93 octane.

This is maximum "safe" effort on a 2300 for me, maybe a 2650 could be a good winter project... but in reality sticking this HP down is hard enough.