Speed Density tune......should I do it....?
If the throttle response if better, then the maf tune was off, I have done both and cannot say one to the other, A member way back stated the same thing that he got better throttle response with a SD tune, When I asked how could he tell, he had some comparisons of something on MAF vs SD and quoted that the SD tune was x milliseconds faster. MILLISECONDS? and he could feel that, wow.
Please don't call me a name....
Teching In
Joined: Nov 2011
Posts: 18
Likes: 0
No matter what tune you run you do not want to toss the O2 sensor. The O2 sensor is used to keep the car in closed loop which allows the computer to trim the injection pulse to keep the car operating at stoich. What appears to be happening in this case is you tune is way off on fueling and the O2 sensor is trimming the injection pulse to give you some reasonable mileage. When the sensor fails the car goes to open loop and no longer trims the injection pulse and the car gets poor mileage. With a MAF tune or SD tune the O2 sensor still operates the same way. What you need is a better base tune so the car runs closer to stoich and does not need to correct the pulse width as much as it is currently doing. Your tuner needs to correct the MAF tables and the SD tables in you computer so the fuel trims are near zero and the car should work much better at all times.
On The Tree
Joined: Jan 2013
Posts: 191
Likes: 0
From: Newcastle
If the throttle response if better, then the maf tune was off, I have done both and cannot say one to the other, A member way back stated the same thing that he got better throttle response with a SD tune, When I asked how could he tell, he had some comparisons of something on MAF vs SD and quoted that the SD tune was x milliseconds faster. MILLISECONDS? and he could feel that, wow.
Its personal preference i guess, mafs are great and have there benefits for sure, I've done a number of comparisons and i like speed density, I've spent 12 months on and off refining the tune in my daily driver, and i always go back to speed density response is always better than the mafs, I don't know about the milliseconds thing, all the cars I've tuned always feel much better, its the same for a lot of other tuners in Australia too, its very interesting in the US the maf seems to be preferred and in Australia speed density is the preferred option, GM Holden here in Australia released between 1999 and 2004 the Holden GTS fitted with LS1, it was a factory speed density system, no maf at all, it had cnc heads, mild cam 213/223 116 560 lift, shorty type headers and larger billet throttle body 78mm i think from memory, all holden fitted parts, A good friend of mine has one of these vehicles and it drives good everyday in all weather conditions
Both but whatever works best
