91 Octane Tune vs 93 Octane Tune...what tune to use?

[BigMikeCobra]

Ok, it turns out I've been driving my 03 cobra around and about on a 91 octane tune while putting 93 octane gas. I just found that out about 2 hours ago. I emailed the guy that did the custom tune 2 years ago, and asked for a 93 octane tune. I've read around here online and stuff that 93 tune is bad, i can see it being bad if you used 91 gas but 93 tune with 93 gas...how can it go bad? should i email the guy saying change the other stuff i asked for and keep it at 91 octane or should i go ahead and try the 93 octane tune. Thanks let me know if yal have any more questions

 

[KINGCOBRA86]

i would find a tuner in your area and get it dyno tuned, what are you mods

 

[MoKo_03SVT]

if you have been running 93 octane on a 91 octane tune, then no biggie. no harm done there. now if it were the other way around, ie: you have been running 91 octane on a 93 octane tune, that could be a different story (depending on how hard you have been driving, etc.)

if you have a 93 octane tune that you are able to run...and you also have access to 93 octane gas, then you should switch to the 93 octane tune! more than likely this tune has a bit more timing in it, which equates to more horsepower for you.

 

[BigMikeCobra]

if you have been running 93 octane on a 91 octane tune, then no biggie. no harm done there. now if it were the other way around, ie: you have been running 91 octane on a 93 octane tune, that could be a different story (depending on how hard you have been driving, etc.)

if you have a 93 octane tune that you are able to run...and you also have access to 93 octane gas, then you should switch to the 93 octane tune! more than likely this tune has a bit more timing in it, which equates to more horsepower for you.

Nice!...would you say 10-15 horsies? :beer::rockon:

 

[FromGTtoSVT]

why mess around with it.....I'd bring it to a dyno and have a dyno tune session done just to make sure

 

[89slowgt331]

your talking about a 2 pt octane diffenence, depending how agressive your old tune was 10-15hp could be made with 1-2 deg more timing, is it worth the retune cost? unless to plan to make other changes I would not spend $3-500 on a retune, look at the 2pt of oct as a safty blanket on a hot day. if you have a hand held, data log and post where you are at now. then some of the guy's can help you better.

 

[Posi]

You should easily be able to run 23*'s of timing on an Eaton no matter the pulley combo anywhere you can get 93 octane. Then still beat the crap out of the car because it's still perfectly safe.

Now it is better to dyno the car and see if it makes more power with that timing than 22*s or 21*'s but either way anybody should be able to run 23*'s of timing.


Yet most people are scared to do it and some tuners are scared to put that much in the tunes. I run it and a lot of others run it also. Has anyone ever made a thread spark knock, detonation, or I ran 93 octane with 23*'s of timing and my motor blew up with an Eaton on my car?:shrug: Nope and you guys that tell your tuners to run less timing for your 93 octane street tunes are only costing yourselves some hp/tq by doing so. Why?

 

[BigMikeCobra]

your talking about a 2 pt octane diffenence, depending how agressive your old tune was 10-15hp could be made with 1-2 deg more timing, is it worth the retune cost? unless to plan to make other changes I would not spend $3-500 on a retune, look at the 2pt of oct as a safty blanket on a hot day. if you have a hand held, data log and post where you are at now. then some of the guy's can help you better.

Well...It's free, It turns out I've got lifetime custom tunes with AmazonRacing. I'm just waiting for Rick to get back to me with the tune. It's a SCT X2. I'm really not familiar with tuner stuff and datalogs. I'm from Greensboro, NC...where 93 octane is available almost everywhere...i'd love to get to know more about tuning tho. Thanks