Weird Issue, Not Sure If Misfire R32 Gtr

[SiR_RB]

Now my car doesn't misfire giving it stick in 1st, 2nd, 3rd gear all the way to redline, but when I'm cruising in 4th gear and lay into it, soon as the gate cracks open I get this unusual jerking/misfire/popping action

Not sure why it doesn't do it in other gears but only in 4th when ramping it up to max boost?

Thought my old splitfires were tired so I put brand new ones in, and fresh plugs at .8mm,

Issue still there

Checked and cleaned all the earths too

New alternator

Last time i gave it a hit in 3rd and into 4th at high revs it didn't do it, but I wanna test that again and see

I'm stumped, any ideas ?

[niZmO_Man]

AFM

[iruvyouskyrine]

What ECU? Data log if possible and report back.

[SiR_RB]

Adaptronic

Might have to log it and see

Very strange

[SiR_RB]

Lol afm

[XKLABA]

New alternator before or after problem started ?

[Ben C34]

Could be using load points that aren't well tuned due to being loaded up in 4th.

[SiR_RB]

Was doing it before alternator change

New one plus new coilpacks etc didn't change anything

Taking it up to Jez in afew weeks to have a look on the Dyno

[SargeRX8]

Do you have a wideband? Is she leaning?

[SiR_RB]

Yes I do and I didn't pay attention

I'm taking it out tonight so il keep an eye on it and see

Thanks for the replys guys

[Dose Pipe Sutututu]

Sounds very crazy but how rich is your car running on noise?

Remember E85 doesn't like being too rich. If you convert to gasoline scaling E85 likes to burn around 12.2 to 12.7.

I did have issues with my shitbox misfiring completely when my AFRs dropped below 11.6 another crazy thing about E85 if you run very low timing it will also miss. This was what I've read and also experienced when I was tuning my car.

I used 98 timing on E85 at high boost as a starting point when I was tuning and it would misfire.

Now I've ironed out those issues, I've got a freaking voltage drop problem lol