87 octane?

[jmidolo]

Just curious....ordered my kit yesterday. Are you guys running 87 octane w/alky on the street or still running 93?

 

[Roger]

93

Why even consider anything lower??

93 costs about 4% more than the cheapest stuff you can find & for normal driving, you won't be burning expensive alcohol.

 

[Turbo1dr]

93

Why even consider anything lower??

It's cheaper and it makes other turbo guys jealous. That's why I run 87.

 

[jmidolo]

That's why I was asking...if you can run 93 on the street with 23-4 lbs of boost, it's conceivable that you could run 87 octane with 18lbs of boost. Just curious, like someone mentioned though, 93 is not a lot more.

 

[GNVYUS 1]

You could but you'd be pissed if you blew something up knowing you were cheaping out by saving 20 cents a gallon.

And alky assumes you are greedy for more power, so turn it up and run 93.

 

[Turbo1dr]

Running 93 with alky isn't going to save your engine any more if you're at the limits of that particular fuel combination. People have already proven how high you can push 93 so why is it any different than seeing how high you can push 87 with alky?

 

[Jerryl]

It's cheaper and it makes other turbo guys jealous. That's why I run 87.

Very true but ...........
You have a SUPER KILLER set-up to get away with it.

What boost levels can you get up to with 87?

 

[TURBOPOWERED68]

What got the wheels turning for alky to come about?
Was it the price of Race fuel?

Now 93 is getting as expensive as race fuel so why not play with 87?

It’s nice to have 50#of available boost anytime just like its nice to have a 502 big block but the fuel factor has to be considered.

What would be the likely out come of 87 and alky 10 or 13# of boost max? That’s still a fun DD.

 

[vacuum 6]

Depends on the setup...turbo, IC, etc. I can run straight 93 at 15 psi and 22° but nothing more. IMO stick to 93 octane or mix it up with 87/E85 = 93.

 

[vacuum 6]

Running 93 with alky isn't going to save your engine any more if you're at the limits of that particular fuel combination. People have already proven how high you can push 93 so why is it any different than seeing how high you can push 87 with alky?

IMO - Its just like you said "People have already proven how high you can push 93..." its proven with 93 not 87. I bought an alky kit because its proven.

 

[Razor]

I cant see why not, altho I wouldnt start tuning at a high timing level. If your chip was made to run 87.. meaning the timing was real low.. then I dont see an issue.

Most street chips on the TR's are 18-20 degree's timing. Most alky chips are 21-24 degree's. I bet an 87 chip would be like 15-16 degree's.

Guess the question would be for Eric as he sets up the timing maps on the chips. Or Bailey.. or??

One thing tho, to replicate the boost/timing levels run on 93 with 87 will take more alky. Not a problem unless you start getting really greedy.

 

[Turbo1dr]

I cant see why not, altho I wouldnt start tuning at a high timing level. If your chip was made to run 87.. meaning the timing was real low.. then I dont see an issue.

Most street chips on the TR's are 18-20 degree's timing. Most alky chips are 21-24 degree's. I bet an 87 chip would be like 15-16 degree's.

Guess the question would be for Eric as he sets up the timing maps on the chips. Or Bailey.. or??

One thing tho, to replicate the boost/timing levels run on 93 with 87 will take more alky. Not a problem unless you start getting really greedy.

Great post Razor. Just because people push the limits on 93 doesn't mean you can't push the limits on 87. I'd like to see what can be accomplished on 87 and alky without people bashing the person for at least trying. That's the difference between a leader and a follower.

 

[Buick_noob]

So what would BP 92 and E85 get you Octane wise. I never used E85 so would it be safe to mix?

 

[Dust]

What's the octane on race gas, above 100 right, lets say 104. The difference between race gas and 93 is 11 points, and the difference between 93 and 87 is 6. Doesn't seem like too far a leap to me. Drop timing or boost, and then work your way up.

 

[Jerryl]

What's the octane on race gas, above 100 right, lets say 104. The difference between race gas and 93 is 11 points, and the difference between 93 and 87 is 6. Doesn't seem like too far a leap to me. Drop timing or boost, and then work your way up.

I belief the "rule of thumb" is 1 psi/1.5 octane point
So 15 octane points would equate to 10 PSI boost.

We know that on 93 you average 19PSI boost.
So, on 87 I would expect a reduction of (93-87)/1.5 = 4 psi boost. (all else being equal)

In my HA I saw KR about that same number (4-5 PSI reduction) from a bad batch of gas.