Hot Air E85

[Boy Buick85]

Hey guys I was wondering I have been running E85 in my 85 T for some time now with nothing but great things coming from it. I had the car up to 12 pounds of boost with ZERO KNOCK . Then I tried to run 15 pounds and got 5.9 Degrees of knock I was running 10 gallons of 93 and 5 of E85, Why was I getting knock?? I figured with the E85 I could atleast run 15 pounds ? Do I need to add a Touch more Say a Gallon ?? My mods are in my Sig ported heads and intake Small cam 3inch DP Etc Is it just too much air flow ?

 

[novaderrik]

i try to run it mixed 50/50 with 87 octane, and i've had close to 17psi showing on my Autometer boost gauge with no noticable knock. on straight 93 octane, it won't go past about 10 psi under load without rattling like crazy. granted, i don't have any sort of a scanner or anything (which i probably should have) but it does run a hell of a lot better with that brew than it does on straight 93.

 

[87grandnational]

Back when I had my 84 GN I ran a 75% mix of E85, 25% mix of 93oct and 1 bottle of the N2O octane booster (1 bottle treats 30 gallons and raises octane 6pts) I think I was around 110 octane. I had two chips, one set at the 110 octane, and one at 93. I had custom tubular headers, crossover pipe, full turbo back 3" exhaust. cold Air intake that came out behind the grill.
I also had a cam and ported and polished heads that I did myself.

I was able to run 26psi with 1.1 degree of knock on my Scanmaster. What did I run? It was a fully optioned car. w/3200lb stall converter and ET Streets.

I dyno'd: 355rwhp and 380rwtq with a RED HOT EXHAUST SYSTEM, after that I retuned it and i was running too lean, and after the retune I hit 337hp/351tq

I ran a best of 7.99 @ 89mph 1/8th and a 12.56 @ 107mph 1/4th w/a 1.68 60' yeah it sucked at the top end... Never got the chance to upgrade to a TA49 like I wanted... oh yeah i had an upgraded fuel system too.

 

[novaderrik]

Back when I had my 84 GN I ran a 75% mix of E85, 25% mix of 93oct and 1 bottle of the N2O octane booster (1 bottle treats 30 gallons and raises octane 6pts) I think I was around 110 octane. I had two chips, one set at the 110 octane, and one at 93...

a "point" of octane is 1/10th of a "number".. if you raise 93 octane by "1 point", then you have 93.1 octane.. so it's time to recalculate your fuel rating.
by my math, my 50/50 ratio of 87 octane to the 105 or so octane E85 comes out around 96-97ish, and works fine for what i do without any sort of "octane booster" snake oil that totally kills off any savings i see by running the E85 in the first place. the 50/50 ratio is the magic balance point on my car where i get the benefits of the increased detonation resistance of the fuel, but don't lose any mileage compared to straight 87 octane. in fact, it is actually slightly better with the mix. i actually save a few bucks per tank by running E85 mixed with gas.
in the end, tho, each car will be different, so each person will need to see what their car likes.

 

[T-Type85David]

any of you guys try using lucas octane booster????? that's the only one that really works, 8 bucks a bottle. I use marvel mystery oil (big bottle) lucas fuel treatment, lucas octane booster and 93 gas and put about lil over half a tank that will make you smile as soon as you turn her on.