Adaptives Pulling the fuse CLEARS the ECU adaptives. While driving or cruising around the ECU adaptives are in closed loop and base all parameters from the information received from the 02 sensors. This is gas mileage/emissions and overall driveability. Same thing when you clear them you also wipe out the WOT(wide open throttle) adaptives it learned from open loop. In open loop it is running off preprogrammed tables and will switch to the most optimum and will store those adaptives. So the next time you punch it the performance could increase due to the fact that it learned or set a higher parameter. It will never set backwards and it stores up to three different parameters. Remember all these decision the ECU makes happens in seconds. In WOT the ECU does not learn or record information from the 02 sensors but rather the preprogrammed WOT tables. Those tables are obviously generous and have some "slack", of about 10% I understand and that helps when you modify the vehicle. So when you clear the adaptives you are taking a step backwards. I :shok: shudder when i hear that some did that because now you have to go out and run the piss out of it to reestablish the WOT tables you wiped out:shok:!!
Boy oh boy do I feel the pain on this. Dynoed with a JBA/Borla catback, Magnaflow H/F cats, GSM CAI with a DIRTY filter, B&G Stage II, GSM Phenolic spacers and 190 t-stat prior to a PPP Road warrior cam install back in June: 375.19 hp and 390.1 tq So you know that I was expecting a nice gain from the cam install. Did the cam install with a BRAND NEW filter and the car dynoed: 379.7hp and 388.3 tq WTF!!! Did NINE (9) pulls on the car and it dynoed -1/+3 each and every time, so there was minimal variation. The car felt strong but the dyno numbers were crap. I was miffed to say the least at the dyno numbers. Started doing my research on new mods so since my last dyno I installed Kooks LT headers, Volant CAI, Motorad 180 t-stat and a fully ported and thermal coated manifold. Surely the car was going to show a major gain with all of these installed since the last dyno, RIGHT? Upon installing the ported manifold yesterday (which was the cherry on the Sundae for me so it was my last mod to tie everything in) I put the car on the dyno. Surely with my mods now being: PPP Road Warrior cam, Kooks LT headers with h/f cats, fully ported manifold, B&G Stage II, Volant CAI, Motorad 180 t-stat, and JBA/Borla exhaust I was now looking at something in the 425-440 range: 386.3 hp and 388.8 tq.....WTF!!!!! I GIVE UP!!! Now, the car feels MUCH faster than it ever has so I know that the power is there. I jsut have to keep telling myself: "Dynos are for tuning. Dynos are for tuning" Now, I still want to get the car tuned to dial everything in with the optimal air to fuel ratio but I DO NOT expect it to dyno too much higher than it did yesterday. I do have the following track benchmark results to show my progress though: JBA catback,190 t-stat, GSM CAI - 13.7 1/4 ET - October 2006 JBA/Borla "hybrid" catback,190 t-stat,Magnaflow h/f cats, TCM TSB, GSM Phenolic spacers - 13.444 1/4 ET - March 2007 JBA/Borla "hybrid" catback, 180 t-stat, GSM Phenolic spacers, Volant CAI, B&G Stage II, Kooks LT headers with h/f cats and PPP Road Warrior cam - 12.8 1/4 ET - November 2007 I now use the track to let me know how my car runs so the low dyno numbers don't depress me so much now. I know that I am making progress with the mods that I have done.
mjc - yep, pretty much what i experienced. my issue as it turns out, was likely caused by me pulling fuse 11 that day and reseting the adaptives. like sarge pointed out in a previous post, it hurts, not helps!!! that and when we did one srt which was pulling 385rwhp, and after a fuse pull dropped to 372 rwhp. also, i filled up that morning at a place i never use for gas. as it turned out, they were not running 93 octane in that tank and my car ran like crap for almost two weeks until i burned the gas out. went back to the station and they apologized, told of the mix up and offered me a free fill up! i used if for my wifes car!!! hahahaha anyway, yeah, tracks are the real test.
On my Dyno, which is always set to SAE correction and at smoothing set to 5 I see stock SRT 8's laying down @370 ish rwhp. Keep in mind that yes all dyno's are different and between Dynojet's it's about 4 to 5 rwhp difference. I know we just did Miesters car after he left GSM and the results where like splitting hairs, hardly a difference between Dynojet's. Now what you care about is staying on the "same" dyno it's purely for measurement gains. You said it was the same dyno as last year, well lets find a common denominator: By pulling fuse 11 you in a sense reset adaptions. The adaptions you set are your LTFT's or known as Long Term Fuel Adaptations. This will effect your WOT AFR and will lower your rwhp. If your fuel on that run was below 12.5:1 your gonna see low numbers. By pulling fuse 11 you do not effect your timing maps. Is the dyno running on the current software version. I know that at least once every two months dynojet has a new version for my winpep software. It's important to stay up to date. Also what condition is the dyno in? It's important to keep the dyno serviced remember it's basically an accelerometer, it does have serviceable bearings and sensitive electronic equipment that is located in a somewhat hostile environment. The difference between STD and SAE is that STD reads 10 to 11 horsepower higher. The correction factors are different based on ambient temperature and Baro. You can actually do a search about this on the web. Smoothing does exactly what it says, it smooths the curve, so if your curve is really bumpy do to tires or a funky tranny you could see higher numbers because of the bumps. The dyno software calculates the peak numbers. So yes a dyno operator "could" give you a run with "cooked" numbers. By changing some stuff around, it's best imop to go to a dyno shop that is reputable and knows his equipment. Many places like to boast "peak numbers" but we all know it's about the area "under the curve" The longer the torque and horsepower stay up the more efficient and faster the car will be.
josh - well said and thanks. yes, the dyno was SAE corrected and smoothing set at 5. the operator is a local viper tuner who is reputable. the fuse pull along with crappy gas did not help matters. bottom line, the car (with better gas now) feels like it did before..... strong and consistent. i am not stressing about the numbers, only that it left me scratching my head when we were done. fwiw, just had my neighbor dyno his chsrt with airraid,diablo, cat back on another local dyno and it showed 455rwhp......hahahahahah he told the guy it was waaaay to high and the operators said no, all was good!! yeah right!!! still have not seen the dyno sheet, but even corrected, seems very high!!!
fuse 11..... reset the pcm adaptives..... some say it is a good thing and "wakes" the car up..... i saw first hand that is NOT true!!! mine dropped 19rwhp and another chsrt did 385rwhp (airraid,diablo,catback) and then we pulled his #11 fuse. next pull, 372rwhp followed with 373rwhp. throw in the fact i had bad gas in the car (filled up that morning at a new place that did not have 93 oct in the tank but customers would not know) and my numbers were waaay lower than previous pulls on the very same dyno in almost identical weather.....
Dyno Results Hey Josh I heard alot of good things about your shop this weekend from Cam, Chris and Meister and I do remember your shop from the AMG forums. It is so refreshing to hear that Meister's dyno results from GSM to your dyno were "like splitting hairs". I used another 4 wheel dynojet in Torrance and theirs was like 3hp difference from GSM........so that is good to know. Just to back up my 4 wheel dyno results.....I will call you and set an appointment.
