12:1 compression ratio on CA gas
07-01-2016, 02:20 PM
#1
Burning Brakes
Thread Starter
12:1 compression ratio on CA gas
Anyone running 12:1 on 91 octane for street car? Building an LS7 with a healthy cam and want to get some peoples personal experience with higher compression and tuning.
07-01-2016, 06:19 PM
#2
Platinum Supporting Vendor
Not gonna fly with the crappy 91 octane here in CA. Get with Ryne @ CMS and ask about getting it setup for E85 so you have enough octane for that combo.
07-01-2016, 09:34 PM
#3
Burning Brakes
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07-01-2016, 11:37 PM
#4
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St. Jude Donor '05
Why risk it?
Running a little over 11.5 and can do it if needed but adding some VP 100 unleaded leaves more room for error. In the long run a little good stuff is cheap piece of mind. Our gas isnt the best esp the "summer blend". Sure miss the old 93..
Running a little over 11.5 and can do it if needed but adding some VP 100 unleaded leaves more room for error. In the long run a little good stuff is cheap piece of mind. Our gas isnt the best esp the "summer blend". Sure miss the old 93..
07-01-2016, 11:40 PM
#5
Burning Brakes
Thread Starter
Will the stock fuel system support ~600rwhp on e85? Im currently making 576rwhp on a stock LS7 (11:1) bottom end N/A with 91 octane.
07-05-2016, 03:54 PM
#6
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I'm running a 1970 LT-1 11:1 cr. I have to pull timing to run on Cal pump 91.
07-05-2016, 10:14 PM
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Have anyone tested the octane from this state? I honestly dont think it is 91. I say this because I've re-fueled on all continental states, and the second I cross into Arizona it feels the car "gains horsepower", ergo it's the California gasoline.
07-06-2016, 03:35 PM
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St. Jude Donor '05
Get yourself a drum of VP 100 unleaded mix 50/50 min wiht 91
Our "summer blend" is the worst.
I run 11.5 on 91 sometimes, if Im drving easy. On VP mix I can crank up the timing car transforms like it had a 50 shot on it.
I LOVE the cackle of a high compression NA motor, grew up around 12-13;1 cars nothing sounds like em...solid lifters sweetest music ever.
Our "summer blend" is the worst.
I run 11.5 on 91 sometimes, if Im drving easy. On VP mix I can crank up the timing car transforms like it had a 50 shot on it.
I LOVE the cackle of a high compression NA motor, grew up around 12-13;1 cars nothing sounds like em...solid lifters sweetest music ever.
07-07-2016, 12:28 PM
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I run 12:1 comp on my my built LS3 C6. I run 91 mixed with Torco, and do have meth injection as well, but the car runs just fine...
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Here's a track day from last year...
07-07-2016, 10:00 PM
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Know this once I hit 190 deg it doesnt want to idle anymore and carb or fuel lines arent warm;anything less, sure all day long thats on a cam with 82 deg overlap....lots.
Theres something up with this garbage, many complain of the same thing. If I use a certain unnamed additive VP or the like its much happier. Ill say one thing gaskets dont like it very much have to replace them at least once a yr.
OP a big cam may bleed it off down low but when rpms and cyl pressure increase.....you need good stuff period. You spent a bunch on a great engine dont risk it for a few bux.
Last edited by cv67; 07-07-2016 at 10:02 PM.