LT1 11:1 compression-octane boost?
Cruising
Joined: Oct 2004
Posts: 14
Likes: 0
That canned octaine boost stuff is "snake oil." Plain and simple. It won't add enough boost to the gas to say so. Don't waste your time or money.
If premium in your area doen't workgood enough then mix 100LL av gas with the high test. I know it's a PITA.. Been there done that.
If premium in your area doen't workgood enough then mix 100LL av gas with the high test. I know it's a PITA.. Been there done that.
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
this is what i and a few others (larry for sure swears by it) use , i run 1 o.z. per gallon w/93 pump octane to get 101 but do not go thru emmisions testing with it,,lead is banned and i dont know what would happen, i dont care what some guys here on the forum say,,i met the owner of this co at chevy vette fest and seemed like he couldnt believe i even asked him about it and emissions,,you'll have to run -3 -4 ----tanks of unleaded before taking the emissions test--to ''get the led out'' is what he even told me-this is the same lead they took out in the 70's your just puttin it back in-------------http://www.maxlead2000.com/-------------
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
You would not believe the difference max lead made. My engine runs noticably cooler, idles better, never pings even under load in fourth gear which was impossible without the lead. Mileage went up by about 3-4 mpg. Plus the nasty eye burning exhaust smelll went away. I highly recommend it in engines made to run leaded fuel. Pre 75 for us.
Drifting
Joined: Dec 1999
Posts: 1,462
Likes: 1
From: Reno nevada
Originally Posted by Sacredgrooves
i assume a 70 LT1 would need octane boost. what does everyone use and what does it cost you per tank? thanks!
In the past I had motors that required Morroso 104+ octane booster. But with modern ignitions. (optical & multispark with adjustable vacuum advance) I have driven the last 10 years without a drop of octane boost other than methanol for the drags and I have a true 10.7 compression in my LT1 355 ci
Pro
Joined: Jan 2003
Posts: 642
Likes: 0
From: Baton Rouge LA
Before I'd go investing in expensive fuel I would make sure you are truely 11:1 and even then you should be able to get away with 93 octane. you are only a half point over stock. Depending on the cam and tuning 11:1 isn't really that high on an LT1 so I doubt you'll really need anything other then premium fuel. Worst case is you pull a few degrees of timing out and you'll be fine. I daily drive my 99 Z28 with over 12:1 compression on 93 unleaded but I only run about 22 degrees of timing but hey it still make over 450rwhp like that. 
.
.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by Sacredgrooves
i assume a 70 LT1 would need octane boost. what does everyone use and what does it cost you per tank? thanks!
Team Owner
Joined: Jul 2004
Posts: 40,353
Likes: 787
From: Redondo Beach, California
I think the article on making your own octane booster is interesting.
http://www.vtr.org/maintain/gasoline-octane.html
At the end of the article is a receipe for making a fuel additive that is supposedly the same/similar to the ones you buy at automobile stores, except instead of $5 for 8 ounces of store bought, you can make your own for a fraction of the cost.
Many years ago I bought av gas for my 11.5:1 Big Block. At first I brought gerry cans to the airport to transport it home. After the guy got to know me, he would pump in right into my car. Neat.
http://www.vtr.org/maintain/gasoline-octane.html
At the end of the article is a receipe for making a fuel additive that is supposedly the same/similar to the ones you buy at automobile stores, except instead of $5 for 8 ounces of store bought, you can make your own for a fraction of the cost.
Many years ago I bought av gas for my 11.5:1 Big Block. At first I brought gerry cans to the airport to transport it home. After the guy got to know me, he would pump in right into my car. Neat.
Melting Slicks
Joined: Oct 2000
Posts: 3,023
Likes: 2
From: TEXASTEXASTEXASTEXAS TEXASTEXASTEXASTEXAS
St. Jude Contributor
Maxlead works for me. If you have a buddy who works at the local commuter airport (or an airport manager that doesn't care that it's illegal), mixing in blue leaded aviation gas really does the trick nicely as well. But like the others said, drive it, and if you don't get knocking, don't worry about it.
JB
JB
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Originally Posted by JB
Maxlead works for me. If you have a buddy who works at the local commuter airport (or an airport manager that doesn't care that it's illegal), mixing in blue leaded aviation gas really does the trick nicely as well. But like the others said, drive it, and if you don't get knocking, don't worry about it.
JB
JB
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 3,036
Likes: 5
From: Raleigh NC
Originally Posted by Lt1er
First of all what makes you think that you actually have 11:1 compression? I would like actual piston to deck, piston popup cc and chamber cc.
In the past I had motors that required Morroso 104+ octane booster. But with modern ignitions. (optical & multispark with adjustable vacuum advance) I have driven the last 10 years without a drop of octane boost other than methanol for the drags and I have a true 10.7 compression in my LT1 355 ci
In the past I had motors that required Morroso 104+ octane booster. But with modern ignitions. (optical & multispark with adjustable vacuum advance) I have driven the last 10 years without a drop of octane boost other than methanol for the drags and I have a true 10.7 compression in my LT1 355 ci
it is on a car im considering buying. just trying to cover all the bases
thanks for all the advice everyone!
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Originally Posted by Paul @ Thunder
I daily drive my 99 Z28 with over 12:1 compression on 93 unleaded but I only run about 22 degrees of timing but hey it still make over 450rwhp like that.
Pro
Joined: Jan 2003
Posts: 642
Likes: 0
From: Baton Rouge LA
Originally Posted by mandm1200
Glad to hear the runs on pump gas with 12:1 compression. I was a little worried as the 388 I'm working on is over 11:1 compression.
Usually we can get by up to about 11.3:1 with 93 pump gas and full timing. It just really depends on you cam selection and tuning.
Paul
Melting Slicks
Joined: Apr 2002
Posts: 2,103
Likes: 0
From: Tucson AZ
My 70 LT-1 runs on 91. Short of 100 octane, its the best I can get in AZ. My temp needle NEVER gets above 180, even in 100+ temps.
I did just as Oliver suggested above: retuned the car to run a little richer and retarded the timing. I do lose some power, but the car moves quite nicely that it really isn't missed. I can also adjust the jetting and timing and run 100 octane or substitutes like MaxLead and others if I truly want the extra hp.
I did just as Oliver suggested above: retuned the car to run a little richer and retarded the timing. I do lose some power, but the car moves quite nicely that it really isn't missed. I can also adjust the jetting and timing and run 100 octane or substitutes like MaxLead and others if I truly want the extra hp.
