Spring E85 question

Klaus

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I took my gt500 out yesterday after sitting all winter. It started right up, no problem. When I parked it in October it had a full tank of E at 78%. When I started it up the E was only at 72%.

To increase my E content I filled it up at the place where I always go and it actually dropped my E content. Now I am sitting with a full tank at 68-69%.

What to do? My CR is 8.5 and my boost is set at 24 lbs. I assume it will be OK if I stay out of the boost.
 

2011 gtcs

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Usually E70 to E85 you're good to go. E68 is definitely getting a little low. But if you have a nGauge or something to monitor your knock sensors I would keep a eye on them.
 

11Sec_Lx

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I see five quick options:

1) drive the fuel out, staying out of boost
2) remove the fuel and replace
3) get a tune for the 68% or whatever it's at
4) pull a few degrees of timing (if you can)
5) reduce wot boost by 2-4lbs with a larger pulley

My $.02

Sent from my SM-G988U using Tapatalk
 

c6zhombre

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When you are originally tuned for spot on 85% and you get a tank of % less than that, the motor will run RICH

When you are originally tuned for 85% and you get a tank of % more than that, the motor will run LEAN

It's up to you and the tuner to decide what's too rich or too lean to neccisitate a revised tune to handle the difference.

Keeping an 85% tune and a 65% tune at minimum should cover most bases.
 

Dusten

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When you are originally tuned for spot on 85% and you get a tank of % less than that, the motor will run RICH

When you are originally tuned for 85% and you get a tank of % more than that, the motor will run LEAN

It's up to you and the tuner to decide what's too rich or too lean to neccisitate a revised tune to handle the difference.

Keeping an 85% tune and a 65% tune at minimum should cover most bases.
Its about more than the AFR. The octane difference and timing needs to be addressed.
 

c6zhombre

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Its about more than the AFR. The octane difference and timing needs to be addressed.

There are plenty of 8.5/1 03/04 Cobras making 800+ with E70 and a gen 4 or gen 5 whipple. And not just putting around, either....running 1/4 and half mile events with high timing. I think the op will be just fine with E69, it still has a massive amount of detonation suppression and even burn across the top of the piston. Ethanol % has to fall further than that before you start panicking.

But ask the tuner as I've already mentioned. Maybe he makes a slight adjustment that can be kept for future reference.
 

gimmie11s

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at 68-69% E content, the mixture is actually richer now than it was at 78%.

You still have an incredible amount of knock protection with damn near e70 (effectively what is in your tank).

I wouldnt sweat it.
 

Dusten

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There are plenty of 8.5/1 03/04 Cobras making 800+ with E70 and a gen 4 or gen 5 whipple. And not just putting around, either....running 1/4 and half mile events with high timing. I think the op will be just fine with E69, it still has a massive amount of detonation suppression and even burn across the top of the piston. Ethanol % has to fall further than that before you start panicking.

But ask the tuner as I've already mentioned. Maybe he makes a slight adjustment that can be kept for future reference.

I didn't say it is unsafe. I said the change in octane is more concerning than afr.

And I run e85 and make 700+ on a 2v that beat the **** out of.
 

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