SCT SF tuner suggestions

03GTvert

New Member
Nov 2, 2003
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OK, I just got my tuner ans flashed the PCM and test drove it. I flashed it with the 93 octane tune and didn't adjust any other parameters where spark/fuel were concerned. When I drove it i got a lot of pinging at WOT.

What should I adjust to get rid of the detonation? It only seems to occur when my foot is on the floor.

Oh, yeah - before anyone asks - YES I do have 93 octane gas in the car.

:UPDATE:

OK - I'm about at my wits end here. I gave up on the 93 tune, dropped it to the 91 tune while still using 93 octane gas in the car, I've backed off the spark -6 degrees in the 0-2000 band (where I'm getting horrible detonation, especially in 5th gear), -2 degrees 2000-4000 and -1 degree 4000-8000. Still get detonation, especially when the car warms up and really bad in the hot Texas afternoons.

I Seafoamed the crap out of my car (didn't tell a difference at all) - I ran it through thr PCV, poured in gas tank and in crank case. No help.

I'm about to go back to stock and sell this piece of crap.

Any ideas folks?
 
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I have a sct sf model too. At WOT my car hesitating so I put 4 % more fuel and 2 dergee timming but my car still hesitat. What should I do? I am using 91 gas.

Should I put more fuel at WTO or some things is wrong ?
 
How long ago did you put in 93? If you were previously running a lower grade, you should run it down, then fill it up with 93 again just incase.

Anywho, pull some timing in the upper RPMs, and test for pinging. Rinse and repeat until you're good.
 
Pull timing in the upper band it is then. Thanks Stangers.

BTW, I have been making it a point to not put that ethanol garbage in my car. The one time I did I immediately noticed a power loss and I've been putting premium in it since (I used to have detonation at lower RPM's before I flashed it).

I'll report back.
 
lvmustanggt said:
I have a sct sf model too. At WOT my car hesitating so I put 4 % more fuel and 2 dergee timming but my car still hesitat. What should I do? I am using 91 gas.

Should I put more fuel at WTO or some things is wrong ?

There is one more "trick" you may want to try since you are running 91 octane on a 93 octane tune. Install a 160* thermostat and adjust the electric fan temperature switch for it. This will give your engine a cooler air/fuel mixture and less pre-detonation. This worked for my used, cheap-o, Hypertech 93 octane tune so I can now run 91 octane (which is all that California has :().
 
RoadconeTuning said:
ever think about seafoaming the car? you might have some carbon build up.
+1, before I seafomed mine I had to pull lots of timing and add lots of fuel, and I still got a little ping. After the seafoam I can max my timing and have stock fuel trim and no pinging.
 
OK - I'm about at my wits end here. I gave up on the 93 tune, dropped it to the 91 tune while still using 93 octane gas in the car, I've backed off the spark -6 degrees in the 0-2000 band (where I'm getting horrible detonation, especially in 5th gear), -2 degrees 2000-4000 and -1 degree 4000-8000. Still get detonation, especially when the car warms up and really bad in the hot Texas afternoons.

I Seafoamed the crap out of my car (didn't tell a difference at all) - I ran it through thr PCV, poured in gas tank and in crank case. No help.

I'm about to go back to stock and sell this piece of crap.

Any ideas folks?
 
detonation is from 3 major reasons and a load of smaller reasons. 1 - too much spark advance/timing. this just means that you are getting the spark too far before the ideal point of combustion and now are getting issues.

2 - lean condition. this means you do not have enough fuel to fill the cylinder when in rotations.. thus the explosion is too hot and not properly balanced... boom.

3 - heat. the more heat you have the more chance you have for detonation.

i noticed 2 things about your post. 1 - you were running a higher grade before you got the tuner to chase out detonation... now you step up 1 grade (technically) and step up the ecm 2 grades (ecm doesnt know you are already on 89). this makes me think you have too too much spark advance, bring it down a bit and see what happens.

2 - you have exhaust and intake mods. this means you have more air comming in and going out... this does make more power.... however.. this has the ability to lean out your AFR, and this creating a lean condition, and now have detonation. try addding some fuel... maybe 5% across the band, then around 1-3 more from 3k+ and see how it settles.

once the detonation is gone (by either timing or fuel) slightly raise one or the other (not both) and compensate by lowering the other to see which sides gives you more power (money says more timing with more fuel will get you the good spot).

the major issue is you have mods, and the stock 93 tune (unless you had one setup from MPH with youd mod list)just advances timing and leans the tune slightly... nothing else. if you have already done mods then you are already lean. work from there and see what happens :)

its not hard to work with really... you just didnt have enough information before starting this process.

Torinalth
 
GREAT reply and great suggestions. Thank you for being so thorough. I have not adjusted the A/F as I was afraid to mess with something I knew nothing about. I will try all your suggestions and make myself more patient.

I will update if anyone cares...
 
I got mine from RPMoutlet.com for $379. May not be the best price out there but I've bought a lot of my mods from them.

Torinalth - thanks again for your suggestions. I re-flashed the 93 octane tune, backed off the timing a little bit (-4 degrees 0-2000, -1 degree 2000-4000 & -1 degree 4000-8000 and then increased the fuel 6%. BINGO.

It feels a lot smoother now throughout the whole power band and I have a noticeable increase in power, though not as much of a SOTP as my 4.10's of course.

Now that I understand this thing better, it has become one of my favorite mods. I can hardly wait until I can finish my exhaust and get cams...
 
knowledge makes a tuner a lot more usefull. oh, and dont call it a day yet... upp the fuel a bit more then slowly raise the timing, see if you cant pull a bit more power. tuners are great once you understand whats going on.

Torinalth
 
I'm having the same problem. I ened up using the 87 tune and increased the 2k-4k to +2 and 4k-8k to +1. I haven't started messing with the WOT yet. I have no problems with pinging in 5th now.