boduke0220

So i've had my sniper for a while now and i've decided to run 93 octane. I know how to set it to that and stuff

What else can i do to get some more performance outta it

My choices are


Low RPM fuel mod

Mid RPM fuel mod

High rpm fuel mod

low rpm spark mod

mid rpm spark mod

high rpm spark mod

Global spark mod

Global fuel mod PT

Global Fuel mod FT




And how do i bump it? says like -5.0 -4.0...etc all the way to +5.0

devongarver

have you inquired at snipers own website? they have a tuning forum, been ages since ive been on there though.

black35th

Don't touch anything to do with the fuel. You can bump your global spark a few degrees with 93, but you have to listen for pinging when the motor is under high load.

boduke0220

oh ok. do maybe bump the global spark 2 degree ( which would be +2 on the sniper thing, correct?) and run 93. this is my only car so i cant afford for it to tear up.

cliffyk

First--Do not change anything related to fueling unless you have a wideband O2 sensor and know what you are doing!!! Our cars run a bit rich with the factory settings, however you can seriously damage your engine if you make it too lean...

I.e. do not mess with:

Low RPM fuel mod
Mid RPM fuel mod
High rpm fuel mod
Global fuel mod PT
Global Fuel mod FT


What you can do safely, if you are really running 93 octane fuel (and have not just put 1/2 tank of 93 on top of 1/2 tank of 87), is advance the timing.

Add 1.5° to 2.0° to the Global Spark modifier, 1.0° to the Low RPM modifier, 1.5° to the Mid RPM modifier, and 2.0° to the High RPM modifier.

The RPM based modifiers change the Borderline Spark table to allow (not force, the PCM still calculates the advance, ) more spark advance at higher loads, and in the specific RPM ranges.

The Global modifier adds the specified value to the PCM's calculated timing--this is "on-top" of the calculated, and allowed (by the Spark Borderline table), timing. It affects all rpm ranges and loads.

Last--Do not change anything related to fueling unless you have a wideband O2 sensor and know what you are doing!!!

BTW, and just in case you missed it:

Do not change anything related to fueling unless you have a wideband O2 sensor!!!

boduke0220

ok I will NOT touch the fuel settings lol.

thanks cliffy i was hoping you would chime in!

and also, what does your 180 degrees T-stat do exactly? would i benifit from one?

cliffyk

I do not generally talk about this on forums (*-see footnote), however your kind words have inspired me.

Using a 180° thermostat will obviously lower the coolant temperature by some 20° versus the OEM 200° unit, this is in turn lowers combustion chamber temperatures by close to the same amount, which allows a bit more (0.5° to 2.0° depending on IAT, fuel quality, load, etc.) spark advance.

I run my WOT AFR at 12.0:1 to 12.5:1, a bit richer than many recommend for n/a, and the 180° t-stat--this let's me push the timing to 28°+ at WOT in the upper mid-range/lower high-end revs (I.e. the "meat" of the powerband)--and in part is why we were able to coax 262HP/305tq out of a mildly modified, simple "bolt-on" engine.

I will have to back that off a bit, with my "summer" tune, now that the HOT weather is coming along and IATs are getting into the 90° to 100°+ range.

180° is as low as I would go for a street car, and if you live in a northern clime I would recommend re-installing the OEM unit when cold weather comes. A 160° unit can provide further benefit for track only use, or even no thermostat for 1/4 mile only cars in hot weather.

---------------------------------
*-There is always someone that will chime in and say a lower temperature thermostat doesn't do anything for performance, including some who will quite foolishly claim it doesn't even lower the coolant temperature.

I do not care to argue these points, and to those who wish to make such statements I suggest you read a few books about the internal combustion engine theory (John Heywood's Internal Combustion Engine Fundamentals is the definitive work), and tuning (Greg Banish's Engine Management: Advanced Tuning is good), so that you will be less inclined to make silly pronouncements in the future.

boduke0220

Thanks again cliff! i think i understand all that.


also, whats a good way to learn how to tune a car and get more power out of it that way versus bolt ons and crap?

If i bought a Wideband gauge and saw what my AFR was could i make adjustments based on that?

cliffyk

Greg Banish's Engine Management: Advanced Tuning book...

Kdaddy

I know your not suppose to muck around with fuel setting But I called Up Patrick and asked him what HE would do for a 93 octane performance tune.

He said:
Low RPM fuel mod: +0.4

Mid RPM fuel mod: +0.4

High rpm fuel mod: +0.4

and +5 to Global spark mod

I than question messing with the fueling, as it is suggested not to do so. He replied "I designed the software i know what can safely be leaned". Of course this was after me telling him my car was running like a top with +2 to all the thing your normally safe to mess with (Global Spark Modifier, Low/mid/high rpm spark). However i strongly recommend you calling Patrick and asking for his advice.

BTW: Car is running great.