91 Octane Tune
09-10-2008, 05:56 PM
#11
1st Gear Member
Thread Starter
Join Date: Jul 2008
Location: Wisconsin
Posts: 89
I'm picking my car up tomorrow and the tuner uses SCT (he's licensed by them, whatever that means).
Random question: I read in the manual online that the SCT tuner can turn off my CEL if I run a o/r midpipe (which I am going to very soon). This means I don't need the MILs I ordered with the exhaust, right?
Random question: I read in the manual online that the SCT tuner can turn off my CEL if I run a o/r midpipe (which I am going to very soon). This means I don't need the MILs I ordered with the exhaust, right?
09-10-2008, 06:29 PM
#13
4th Gear Member
Join Date: May 2008
Location: Santa Monica, CA
Posts: 1,842
Creating a 91 octane tune, whether it's the Sniper Special Forces, Diablosport's Predator, Granatelli's Fuego, or buying an SCT with a few tunes created by a guru, is a lot more than just "bumping the timing and making the mix leaner/richer".
Each manufacturer of these things has there own ideas of how to create that 91 octane tune, and the actual tune created uses a number of algorithms (and tables) in closed loop mode, and a number of table and other dynamic considerations in open loop mode. These are multiple dimension tables that consider engine load, incoming air mass, rpm, throttle position, IAT, ECT, yada, Yada, YADA...
I had a Predator, it was nice. Sold it and bought a Fuego, it was also nice (much like the Predator, my brother is using it no on his '99), but grossly misrepresented*.
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* - JR is an arrogant ***, the product does not data log, is not "updateable over the Internet", nor will it "let you tune as many cars as you like, one at a time" (you get 5 vehicle swaps and then it locks up).
Anyway my brother got me the Sniper SF package as a late birthday gift, and after some teething problems (the first tune I loaded locked my car up over the weekend, Sniper fixed it in 20 minutes Monday morning), I have grown to like it. Unless you are racing or have some non-mainstream f/i mods there is nothing it cannot accomodate and let you tweak for a DD performance street tune...
Each manufacturer of these things has there own ideas of how to create that 91 octane tune, and the actual tune created uses a number of algorithms (and tables) in closed loop mode, and a number of table and other dynamic considerations in open loop mode. These are multiple dimension tables that consider engine load, incoming air mass, rpm, throttle position, IAT, ECT, yada, Yada, YADA...
I had a Predator, it was nice. Sold it and bought a Fuego, it was also nice (much like the Predator, my brother is using it no on his '99), but grossly misrepresented*.
--------------------------------------
* - JR is an arrogant ***, the product does not data log, is not "updateable over the Internet", nor will it "let you tune as many cars as you like, one at a time" (you get 5 vehicle swaps and then it locks up).
Anyway my brother got me the Sniper SF package as a late birthday gift, and after some teething problems (the first tune I loaded locked my car up over the weekend, Sniper fixed it in 20 minutes Monday morning), I have grown to like it. Unless you are racing or have some non-mainstream f/i mods there is nothing it cannot accomodate and let you tweak for a DD performance street tune...
So are you saying that tuning for 91 octane using different tuners will yield different results? I have the sniper now, how do they compare in the ownage rankings?
09-10-2008, 06:35 PM
#14
2nd Gear Member
Join Date: Feb 2008
Location: Ohio
Posts: 306
I'm picking my car up tomorrow and the tuner uses SCT (he's licensed by them, whatever that means).
Random question: I read in the manual online that the SCT tuner can turn off my CEL if I run a o/r midpipe (which I am going to very soon). This means I don't need the MILs I ordered with the exhaust, right?
Random question: I read in the manual online that the SCT tuner can turn off my CEL if I run a o/r midpipe (which I am going to very soon). This means I don't need the MILs I ordered with the exhaust, right?
09-11-2008, 09:21 AM
#16
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
In both cases the only significant change from the base 93 octane tune was to add in WOT spark advance; 1.0°, 1.5° and 2.0° in the three rpm ranges the Fuego offered.
With the SF tune I added 2.5° globally (any RPM), -0.5° in the low rpm range and -1.0° in the middle range.
Keep in mind however that these are only single settings applied by the tuning software to the appropriate base 93 octane tune timing tables. The base tables represent the opinion (for lack of a better word) of whomever created the base 93 octane tune.
It would appear therefore that Sniper's base 93 octane tune is better, for my engine, than the Fuego's.
Sniper's Commando software would allow me to open the timing tables and make detailed changes at specific loads, throttle position. rpm. etc.
09-11-2008, 01:36 PM
#17
4th Gear Member
Join Date: May 2008
Location: Santa Monica, CA
Posts: 1,842
Oh cool.
Well I posted in the sniper forums (which isn't very active) and I told them about how I tuned my car for 91 octane and whether or not there are any small tweaks I can do.
They told me to pull up my tune file again and select +2 global spark and +1 in low RPM spark.
I am worried about detonation and I thought that setting the tune for 91 octane had already advanced my timing. Does this just do so further? Should I do the settings as decribed and leave middle and high RPM spark untouched?
Well I posted in the sniper forums (which isn't very active) and I told them about how I tuned my car for 91 octane and whether or not there are any small tweaks I can do.
They told me to pull up my tune file again and select +2 global spark and +1 in low RPM spark.
I am worried about detonation and I thought that setting the tune for 91 octane had already advanced my timing. Does this just do so further? Should I do the settings as decribed and leave middle and high RPM spark untouched?
09-11-2008, 02:06 PM
#18
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
I saw your posting on the Sniper forum, as Chris (I think it was Chris) said the base performance tune created in the 1st pass through Special Forces is on the conservative side and will generally benefit from adding some global timing. They do this on purpose so that if your engine blows it's not their fault.
Here in Florida I have summertime (8 months) and "what passes for wintertime" tunes. The numbers I referenced above are the summertime numbers, when it cools off in late November I'll be able to add the low and mid range timing I pulled back in and maybe even add a bit.
Do what they suggested and listen for pinging/spark knock at lower rpms and WOT, if you hear any back off that +1° in the low range. You should be OK with the +2° global setting, but again if you hear pinging keep track of what rpm range it occurred and pull timing bit-by-bit in that range 'till it stops.
Here in Florida I have summertime (8 months) and "what passes for wintertime" tunes. The numbers I referenced above are the summertime numbers, when it cools off in late November I'll be able to add the low and mid range timing I pulled back in and maybe even add a bit.
Do what they suggested and listen for pinging/spark knock at lower rpms and WOT, if you hear any back off that +1° in the low range. You should be OK with the +2° global setting, but again if you hear pinging keep track of what rpm range it occurred and pull timing bit-by-bit in that range 'till it stops.
09-11-2008, 07:02 PM
#19
4th Gear Member
Join Date: May 2008
Location: Santa Monica, CA
Posts: 1,842
Oh ok. So with the global +2, that means my timing is advanced further by 2 degrees throughout? whats the low RPM +1 for? is that for a total of 3+ at the lower RPM's?
I wouldn't mind a BIT more extra umph, I don't wanna go to the extremes of boarderlining detonation.
So why is it that I can advance it further at the lower RPM's? is detonation less likely to occur at low RPM's rather than at higher?
I wouldn't mind a BIT more extra umph, I don't wanna go to the extremes of boarderlining detonation.
So why is it that I can advance it further at the lower RPM's? is detonation less likely to occur at low RPM's rather than at higher?