I know, I know... I'm just a newbie. And yes I did mulitiple searches that led only to one thread about a guy in FL... My EVO is stock and I have no aftermarket gauges therefore have no idea what my boost levels are at a given RPM.

One weird phenomena I've noticed with my car is that it pulls harder with partial throttle inputs vice WOT in any given gear at any given RPM in it's powerband. I understand the boost taper towards the top end of the RPM range and have read multiple threads about our stock diverter valves having a tendancy to leak, but if my diverter valve (BOV) was leaking wouldn't it just feel like I was down on power whether I floored it or not?

As for the guy if FL, the conclusion that they came up with was the weather over there being a lot more warmer and humid than here in SD, supposedly was causing knock and the engine was pulling timing. I didn't think that would apply here having nice and cool 60s - 70s weather here in the evening aside from our crap would be 91 octane gas. But even so, if I get the car rolling in 1st gear and then floor it while waiting for the turbo to spool up, the pull is nowhere near as strong as the same method with just a partial throttle input all the way to 7K. Or even rolling in 2nd or 3rd gear... The power delivery is still linear under WOT but partial throttle just seemed to pull harder and just as linear.

Just for reference, I used to have a 2G talon TSI which did the same thing. It too pulled harder with partial throttle inputs. This is something I have yet to understand about my car or if it holds true to other DSM/EVO owners out there.

In an attempt to understand this dillema better, I tried a couple of freeway runs ( 5th gear pulls) against my friend's Honda 600 RR bike who kept it in forth gear. and I kept up better with partial throttle inputs and got up to 130MPH+ in less distance down the same stretch of freeway with the partial throttle input vise WOT.

I don't know if I'm explaining my case very well but if anyone can explain why this is I'd really appreciate it. I don't know if I'm explaining my case very well but if anyone can explain why this is I'd really appreciate any kind of input. Thanks in advance.

 

i know what you mean.. except for when i start with WOT from the start, but from a roll, i feel that i get a bit more pull. weird...

 

It may have to do with the fact that you are running a much leaner a/f ratio at partial throttle and really rich at full throttle. I wouldn't recommend doing too many partial throttle/full boost runs b/c you will run high egt's and may harm your engine.

 

You're just feeling the torque from a different map... In WOT, you're running a open loop lap whereas in partial, you're running econo map settings sorta or a merge in between (for saving fuel).

It may feel fast, but the majority of the time, you're not going fast. Remember: torque = fast FEELING, hp = fast going

that's why domestic cars feel so fast.. tons of Torque low and midrange... and why 'fast 14sec hondas' feel soo slow... hondas != good torque

If you can do calculus, you can calulate the double derivative of the change in velocity ... that'll give you the amount of jerk you're feeling.. lol

 

Well, once you go past about 30% throttle, your in open loop.. However one of the previous posts was likely the closest explanation, since your at a lower load cell, the engine is running a little leaner, and therefore making a bit more power.. I experience the same thing on occasion.

 

That depends on your car also. I don't know the settings for the factory evo.. but in my dsm, my standalone settings for WOT is about 70% throttle. Between 30% - 70ish % is a mix of open and close looped fuel maps.

 

Check to see that the fasteners that hold your air intake duct are still present.

If you are missing them, your air intake duct may be moving up and down during WOT causing a noticeable performance loss.

 

Well, on the Evo, your either in closed loop, or open loop.. If your in closed loop operation (30% TPS or less, when the O2 sensor is warmed up and the coolant temp is warm enough) Then you will run according to the readings on the O2 sensor, and it will hover around where the fuel trims find it maintains 14.7 AFR (assuming the ECU has had time to learn) Whereas in open loop, it uses the MAF reading and will utilize the ECU maps.. Since its basically a grid of sorts, the load cells are referred to by engine load (based on MAF frequency) and RPM..

Closed loop fueling does not use maps, it is biased by fuel trims, and utilizes O2 sensor readings to maintain a particular AFR..

My TPS reading is considered WOT at aroudn 3/4 throttle though.. in my case it reads 100% TPS at about 3/4 throttle.. Some cars are a little different.

 

Hmmm... Thanks for everyone's input... As far as my 2G Talon and EVO, I'm the second owner both vehicles and it's evident that the previous owners of both cars had aftermarket goodies. But when I bought the EVO it was completely stock minus a few plastic clips and an added rear strut tower bar and an abandoned (still connected) greddy turbo timer harness tucked behind center console just below the head unit. Also, the heat shield that connects to the turbo outlet is also missing. I'm guessing he had a full turbo back exhaust. Not to mention the fact that I had to re-route MAF sensor wires and discovered the bracket missing for the solenoid/sensor which has two vacuum hoses connected which one runs to the wastegate diaphram, hinting that previous owner had an intake as well. I honestly don't know what all of my findings add up to. In comparison to my friend's stock EVO that he bought brand new, after he rode in my car, says that my turbo starts spooling a bit quicker than his car. Could any of that be a contributing factor to the partial throttle symptom described in my first post? Another thought that popped into mind is the possibility of a flashed ECU. Is there any way to detect for that?

 

I want to resurrect this thread because I am experiencing the same thing...

If I floor it, then back off slightly, the car pulls NOTICABLY harder.

Also, In logging today, I did one WOT all the way to 7200RPM, then I did a WOT to about 6500RPM and let off slightly... According to Evo Scan, my torque and HP shot up when this happened.

In his graph, the darker is the 2nd run in which I started to lift off at the end.

 

I've noticed this on a number of different cars I've driven. Particularly my grandpa's 92 GMC sierra. It had the old throttle body injection("electronic carb"), I'd notice the same phenomena you guys are talking about. I thought it might be the butterfly choking off excess airflow, improving velocity and volumetric effeciency.

I notice it on my evo at low speeds before the turbo can spool, and with a 35R that gives me several thousand RPM to play with. Looking at my boost gauge, the engine seems to run best when the throttle is depressed enough to be at 0 in of vaccum, but much more and the car sputters and runs very poorly, and rich..

 

I wonder it there isn't some software code that reduces load allowed at wot as a means of protecting the motor.
The reason I suggest this is I happened on a part throttle log where the knock is way higher than I've ever seen at wot.
I also recall feeling what felt like great power during the warm up lap (something less than full throttle)which I was disappointed to not feel during the regular session (where I would have used full throttle)

But once I try to figure how they would accomplish this I realize its more likely a different timing position between part throttle and full throttle. That part throttle timing is not mapped like the full throttle or has some other factor involved.

 

I noticed this way back with the 2g. The conclusion I came to at the time is that car just seems to run better/faster because of the leaner AFR and increased timing. The motor sounds crisper, throttle response is excellent. I'm sure there is also some psychological assclownery going on since your brain knows you are only at partial throtttle, etc. Testing it at the track though, it was indeed faster at WOT, as would be expected. The closer to stock the ECU is, the more pronounced this is. As I tuned the full load map for typical 11:1 AFR and more appropriate timing values, it went away entirely.

 

Anyone else have insight?

Is it just because you're running too lean?

 

Everytime that happened to me in my DSM or EVO it was because I had a boost leak.