91 octane going to cut it?
91 octane going to cut it? 799s milled down .030
Cam specs 222/233 115+3, .600/.575 Lift
36lb GTP Injectors
Racetronics R255LPH w/hot wire kit
98mm FTP lid
SSRA
1 7/8 headers merged to 4"
25% powerbond pulley
As the title says, would 91 octane cut it right now?
after I install my TPIS 90mm intake and 90mm throttle body, 85mm maf, will it be enough?
93 is very hard to come by around here. The car currently sits with about 3/4 tank of 91 as the work is being performed.
Cam specs 222/233 115+3, .600/.575 Lift
36lb GTP Injectors
Racetronics R255LPH w/hot wire kit
98mm FTP lid
SSRA
1 7/8 headers merged to 4"
25% powerbond pulley
As the title says, would 91 octane cut it right now?
after I install my TPIS 90mm intake and 90mm throttle body, 85mm maf, will it be enough?
93 is very hard to come by around here. The car currently sits with about 3/4 tank of 91 as the work is being performed.
Saying that a bump in compression will prevent knock is absolutely backwards, but given that the op is not at sea level, and has a cam big enough to bleed off some static compression, I see no reason this could not work.
Not enough information, You would need to know what the compression ratio was before the heads were milled. Are the heads original to the engine? There is a big difference when you throw milled 799/243 heads on an engine that originally came with 317's versus a 4.8/5.3 that came with 799/243 heads from the factory.
Not enough information, You would need to know what the compression ratio was before the heads were milled. Are the heads original to the engine? There is a big difference when you throw milled 799/243 heads on an engine that originally came with 317's versus a 4.8/5.3 that came with 799/243 heads from the factory.
The engine is an LS1 with the stock heads and I'm going to the 799 heads, milled. Compression will be around 11.3:1
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Joined: Oct 2016
Posts: 2,513
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From: PDX-OR-USA
Frop the OP's sig hes in IA,,
On average, Iowa is at an elevation level of 1,100 feet above sea level. At its highest peak, Iowa's Hawkeye Point boasts an impressive 1,670 feet above sea level.
Altitude isn't much of a factor in this question i'd guess..
On average, Iowa is at an elevation level of 1,100 feet above sea level. At its highest peak, Iowa's Hawkeye Point boasts an impressive 1,670 feet above sea level.
Altitude isn't much of a factor in this question i'd guess..
Last edited by pdxmotorhead; Feb 6, 2022 at 07:43 PM. Reason: My spelling sucks.
Would you be able to run more timing with a different fuel, probably, will 91 work, yes.
I tune on a LS1, with 799 heads, and a LSA on it on 91. Granted, they haven't been milled, but even not milled it's at or near 11.0:1, and this has 9# of boost on it. Oh, and it iats tend to run a little hot on this particular car.
I tune on a LS1, with 799 heads, and a LSA on it on 91. Granted, they haven't been milled, but even not milled it's at or near 11.0:1, and this has 9# of boost on it. Oh, and it iats tend to run a little hot on this particular car.
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So just my opinion, we all pick the risk-cost factor we like...
If I'm driving on the street say 90% of the time,, I would tune for 91.
Additives are always a crap shoot if your not running a consistent main fuel source..
Same as mixing race as and pump, you wont know the result till the
expensive engine inside bits become outside bits..
Especially right now with supply chains heavily affecting chemical companies,
the additive packages are all over the place between loads of delivered fuel.
Only ones that are consistent are race gas out of a drum or Aviation fuel from a airport,
but your still in a bind with either from cost of the fuel or the cost of a additive to get the fuel
where it needs to be for your engine.
Not to mention the fed WILL hunt people down and fine them on using AV gas on the street. (Seen it up close...)
Your other option is do 2 ECU's 1 with a 91 street tune and 1 with a race gas/meth track tune
and always run a good gauge package so you know its playing nice.
At the end of the day I quit building street cars years ago, dual purpose is always a compromise in something..
If I want to race I run a race car..
since I don't street race.
If I'm driving on the street say 90% of the time,, I would tune for 91.
Additives are always a crap shoot if your not running a consistent main fuel source..
Same as mixing race as and pump, you wont know the result till the
expensive engine inside bits become outside bits..
Especially right now with supply chains heavily affecting chemical companies,
the additive packages are all over the place between loads of delivered fuel.
Only ones that are consistent are race gas out of a drum or Aviation fuel from a airport,
but your still in a bind with either from cost of the fuel or the cost of a additive to get the fuel
where it needs to be for your engine.
Not to mention the fed WILL hunt people down and fine them on using AV gas on the street. (Seen it up close...)
Your other option is do 2 ECU's 1 with a 91 street tune and 1 with a race gas/meth track tune
and always run a good gauge package so you know its playing nice.
At the end of the day I quit building street cars years ago, dual purpose is always a compromise in something..
If I want to race I run a race car..
since I don't street race. Very sound reasoning if you ask me. I use Top Tier brand gasoline from Kwik Star at 91 octane. Always imagined buying additives would be kind of a crap shoot. Quality of everything these days has suffered, so I agree with that comment as well.. sounds like 91 will be the ticket.
