Good post and detail. Hopefully it gets figured out. Ever since Kaizen's post it was obvious it wasn't a matter of overboost but instead something else going on, possibly extremely protective ECU tuning from Ford...
Overboost isn't causing a peak WHP difference. The boost bleeds off at higher RPM regardless of whether was used or not earlier in the RPM band. Turbo is too small to keep up that level of boost at higher RPMs.What if you were able to tune it so the over boost function is constant. I don't know why they would have an over boost function that's accessible for 15-20 seconds and can be reset by a lift of the gas. I could understand a selectable over boost function. I have heard of some tuners utilize the cruise control on/off button to select tunes (while cruise is on the tune is off, vice versa) I would say tune out low boost function and that would likely fix these problems, but then again I really don't know much about tuning.
What?Stock tune and early modification teething problems.
Once total control of the ECU and good mapping is realized, I'd expect a full exhaust + custom tuned car to make 350whp Dynojet with ease on 93 octane.
The stock tune is clearly crap for repeatability, as verified by multiple dyno runs, magazine trap speeds that don't correlate to 350 crank HP, and now an independent dragstrip trap below 100mph.What?
This issue being discussed is how terribly inconsistent the car is stock. a ~50whp variance is insane. No one is talking about modifications in this thread.
My factory gauge has never hit the third line on the stock gauge. I have an autometer analog gauge referenced from the line off the compressor side before the solenoid as well and the needle shakes so much under full boost its hard to get an accurate read and i havent found any boost leaksAs a disclaimer, Ford could be inhibiting the cars performance for the first XXXX amount of miles to help the engine break in, which would be completely understandable, but that's something they need to tell their customers if they are actually doing that.
On Friday, my car went 13.9 at the track using the factory launch control and cutting a 1.9 sixty foot. The sixty foot could be a little better on street tires, but a 1.9 is decent for the first time out getting used to the car and experimenting with potential launching techniques outside of the factory launch control. The 99mph is what is really disconcerting, that indicates how far down on power the car was. This car with its weight and 350hp should trap with around another 10mph, even if my mother was launching it.
The second time down the track I noticed my car was only making 17 or 18 psi in all gears including 3rd and 4th. I couldn't video it with my phone and forgot my GoPro headrest mount, but I was able to have a passenger video it after I left the track and it was still doing the same thing on the highway. When I would row through the gears, at other times when I would stab it in a single gear the car would see 22 or 23psi on the factory gauge. Below is a 3rd or 4th gear pull on the highway and a pull on my dyno, the fluctuations (at least on the factory gauge) are pretty wild, once I install my other gauges I will verify whether that is the gauge or the system.
Focus RS poor boost levels:
Focus RS boost fluctuations:
Before "that guy" starts whining about reaction times, I was there to get used to the launch control and test that as well as race the clock, not the person in the right lane.
Because of this, I decided to dyno it. The car was dynoed in 2wd mode because I haven't purchased a 4wd Dynojet yet. Before "that guy" comes in talking about hero numbers, that wasn't at all the purpose, these were diagnostic numbers. I'll write something up on how to do that later when I have more time. The highest run the car made was 305whp and the lowest was 257whp and these 2 runs were within a few minutes of each other. That was the truly disheartening thing to see, I believe Kaizen saw a similar inconsistency. There is no reason a car should have a 48whp swing like that unless it is intentional, be certain it was not heat soak as this isn't my first rodeo. Boost was all over the place on the factory gauge in some of the runs and in the lower power run below, boost was exactly like it was at the track, 17 or 18 peak psi which would correlate with the awful mph.
After that I started playing with manual control of boost to get some consistency. I believe Ford is manipulating boost control near redline as well, I believe it bleeds pressure off when you shift with the variable cam, but that's speculation and I won't know until I can log. They are also manipulating timing to control power as well and I think that is why the car would make +/- 20whp after I got boost consistent with a manual controller. I'm hoping this is related to some sort of engine break in nonsense and not poor design or overly sensitive knock sensors, but it's speculation until I can log and get more mileage on the car. The car has 93 octane in it. I may try a higher octane to see if the runs become consistent from that.
FYI the car goes into limp mode when you overboost it even by a pound or two of pressure. The car has to be shut off and then turned back on to eliminate this. The annoying thing about that is Ford won't allow you shut the car off if you are doing over 5mph (although I have not tried a long press of the button, I think that'd be a happy medium for safety) so you have to completely stop the car. Hopefully Cobb eliminates this completely or allows you a long press to cycle the car while you are rolling down the road and might want to cycle the key for various circumstances such as triggering limp mode.
Anyway, hopefully this is temporary or an anomaly, if not I'll be selling mine and getting another GTR for a beater.
The OP already said it's not heat soak. I don't know what data he has backing that up but I'm inclined to believe him.View attachment 11808 heatsoak is so bad on the ST and the mustang, that an intercooler is a must have first or second mod
This makes me scratch my head more than the rest of the post.if not I'll be selling mine and getting another GTR for a beater.
that's fine, I'm not going to forget what I already know. consistent charge temps make consistent power. must be something wrong with the o.p. car. I think if this car was tuned it may have popped during these runs, i'd really like to see how early the timing hit its low limit on the last run cuz after all keeping it pinned down while all cylinder are at-6 is not good practiceThe OP already said it's not heat soak. I don't know what data he has backing that up but I'm inclined to believe him.