Cars still at shop. Car made 550hp 515 tq and at 5500 rPms start to break up and misfire. Changed and gaped the plugs one step colder and no change. Running e85 850 cc injectors aeromotive 34O pump cjm stage 2 return system. Osiris tuned gt maf sensor gt35r turbo powerlab kit

 

what's the gap?

I'm not sure what people think heat range does for misfires but going 1 step colder won't stop a misfire.

Sounds like it could be spark blow out. I would gap the plugs down to .030 first and try that. If not i would look into there being an issue on that load cell in the map. maybe a disturbance in the airflow across the maf at that specific rpm

 

The gap is set right. I'm not sure abOut the tune my tuner is doing that. Could it be the fuel pumP

 

Can you tell if you're going rich or lean during the misfire?

 

Il have to call the tuner on Tuesday when there open. All he told me was they are going to look into it and fix it when they figure it out.

 

In the past, on stock alternator, I noticed a voltage dip on the power line feeding the ignition coils at high rpms. It could be that your alternator is getting hot/weak, or battery is low, or wiring possibly exacerbating the issue.

 

Alternator was fine before the engine swap. The battery died over 3 months but charged fine.

 

What ems

 

Uprev Osiris tune

 

550hp already at 5500rpm is high, it might be to high idc.

 

550whp on E85 is alot for a single pump and those injectors... you are probably out of fuel.

 

^ +1 - oh yeah, didn't see e85. You could use a fuel pump voltage bump (boost a pump) and maybe larger injectors. Check duty cycle and fuel pressure to decide which to do first.

 

Even with enough pump/injector, the stock hard line could still be a restriction.

 

wow, completely missed the fuel thing. I was thinking this was a misfire only at that rpm and it cleans up.

mid 500 hp is where i calculated the 340 to run out of fuel on an e85 tune when someone else was asking. I would be a little scared if it's just running out of fuel and the tuner didn't notice this though.

edit: i see why i missed the fuel thing. He added it after my post.

 

Nobody needs to believe me because I'm a know-nothing... but I'm celebrating inside a little bit because if it is in fact E85 taxing that pump and those injectors it means you are all TEACHING me something because I had that one nailed.

So maybe I'm boasting a bit- but boasting on YOUR behalf! I think it's finally starting to make a little bit of sense.

Sorry- just sayin'

 

I am with the above posts. If you are running ~550whp with e85 on 850's, I would bet your out of fuel also, your pump as well as your injectors are probably at threshold.

 

Would I be better off tryIng to make the same power on 91? Or should I just throw in that new wallbro 400 something PumP and 1000cc injectors and try again?

 

You will make more power with e85. You will likely be able to finish your tune with pump gas without spending any more money on hardware. Your choice.

 

2 step kicking in @5500RPM

 

def not 2 step