Mods and Tune

[GodWentPunk]

As I look at my mods and tune, I noticed that many offer different octane levels tunes. I know my SS is rated for 91 octane but here in IIllinois, it skips 91 right to 93 so that the price difference between 87 and 93 is $1 per gallon at my Shell. I realize that 93 octane will run better then mid-grade 89 but if I'm to save .50 a gallon, and if I get a 89 tune, would there be a noticeable change in performance that would scream to get the 93/91 tune?



joe...

[qcman]

Originally Posted by GodWentPunk

As I look at my mods and tune, I noticed that many offer different octane levels tunes. I know my SS is rated for 91 octane but here in IIllinois, it skips 91 right to 93 so that the price difference between 87 and 93 is $1 per gallon at my Shell. I realize that 93 octane will run better then mid-grade 89 but if I'm to save .50 a gallon, and if I get a 89 tune, would there be a noticeable change in performance that would scream to get the 93/91 tune?



joe...

I assume you run the 93 currently? If so I would try the 89 and see how the car feels (Many came from dealers with 87 hence the Fuse Pull trick with no issues later). It will pull timing no doubt and maybe give you an idea of what you can expect. If it were me I'd eat the cost and go 93 all the way. I have 2 tunes for my car. A 91 and a 94. I'm on the 91 right now due to traveling where I couldn't buy 94 recently. After the next tank of 94 (clearing out the 91 currently) I'm going back to the 94 tune as the car just pulls better than on 91. Its not huge but its there.... on my butt dyno.

[lazerlemonta]

Originally Posted by GodWentPunk

As I look at my mods and tune, I noticed that many offer different octane levels tunes. I know my SS is rated for 91 octane but here in IIllinois, it skips 91 right to 93 so that the price difference between 87 and 93 is $1 per gallon at my Shell. I realize that 93 octane will run better then mid-grade 89 but if I'm to save .50 a gallon, and if I get a 89 tune, would there be a noticeable change in performance that would scream to get the 93/91 tune?



joe...

Lower the octane the faster the burn. You would reduce timing to prevent spark knock and it would be less efficient making power. As far as headers go I took my C6 to 11.0s@126 on stock exhaust, stock cam and stock heads. You can really get decent power out of an LS3 with out headers.

[GodWentPunk]

As I look at my exhaust upgrade, I found a system I like but it's a 3in system and my bolt-on mufflers are 2.5. Is there any big reason for concern in using my existing mufflers? I really would like to in order to keep my cost down from buying a new set of mufflers. The outlet on the muffler is 3in... Maybe cut the muffler inlet as close to the muffler and then put on a reducer?



joe...

[christianchevell]

someday you can change out the mufflers......

[xc_SS/RS]

Originally Posted by GodWentPunk

As I look at my exhaust upgrade, I found a system I like but it's a 3in system and my bolt-on mufflers are 2.5. Is there any big reason for concern in using my existing mufflers? I really would like to in order to keep my cost down from buying a new set of mufflers. The outlet on the muffler is 3in... Maybe cut the muffler inlet as close to the muffler and then put on a reducer?



joe...

Going from a 3" x pipe to 2.5" mufflers will probably cause you to lose 0.556743 horsepower so I'd say you'll be fine

Are you going with shorty or longtube headers?

[GodWentPunk]

Originally Posted by xc_SS/RS

Going from a 3" x pipe to 2.5" mufflers will probably cause you to lose 0.556743 horsepower so I'd say you'll be fine

Are you going with shorty or longtube headers?

I'm getting this package:


https://www.rdpstore.com/p-11044-arh...78300lswc.aspx


joe...