Compression ratio for flex fuel::::[
Thread Starter
Pro
Joined: Dec 2017
Posts: 724
Likes: 26
Compression ratio for flex fuel::::[
Hey guys just out of curiosity what compression do you guys run out there being on e85 primarily. lets say if I ran out of e85 and had to use 91 octane what compression would be safe for that but still have a high enough compression to use the e85s octane.
thanks
thanks
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
Unanswerable question without details..... people cant really guys if your boosted, N/A, stock, built, etc, etc.
Le Mans Master
Joined: Jun 2015
Posts: 6,328
Likes: 1,107
From: Austin Tx
Melting Slicks
Joined: Jun 2006
Posts: 2,492
Likes: 261
From: Miami Florida
LLSR N-A 14.1 to 1 run E85 full time but when necessary will get 93 octane to make it to the E85 pump no problems at all just see extra 10 degrees on the engine temps but no overheating or pre-ignition will prob run pretty good on gas but haven't try it nor will I be interested.
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Not just static compression ratio at play here. Dynamic compression ratio is an important consideration also. On an 11:1 static compression ratio LS3, the dynamic compression ratio can go from under 8:1 to over 9:1 depending on the camshaft employed. As realcanuck said, there's a whole lot of other variables that need to be taken into consideration too. Just stating the one CR or another is good is just a WAG without knowing the other variables.
Le Mans Master
Joined: Oct 2012
Posts: 8,434
Likes: 411
From: Texas
Seems like a question for a good tuner and engine builder.
My engine is flex fuel but I had my head guy give me a compression bump but told him I wanted to be able to run 91 Octane in a pinch. We have 93 here in TX but I want the option of selling it out of state or doing a road trip up the Western coast or something.
The Flex fuel is great during the summer months as it really prevents that really fluffy engine feeling you get on a 105 degree day. In the winter the flex fuel tune is so snappy that traction is really an issue, so I just run 93.
Good luck.
My engine is flex fuel but I had my head guy give me a compression bump but told him I wanted to be able to run 91 Octane in a pinch. We have 93 here in TX but I want the option of selling it out of state or doing a road trip up the Western coast or something.
The Flex fuel is great during the summer months as it really prevents that really fluffy engine feeling you get on a 105 degree day. In the winter the flex fuel tune is so snappy that traction is really an issue, so I just run 93.
Good luck.
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