Loooooong dyno pull?

[fiveoh2go]

Seriously, a 20+ second dyno pull complete with the W/B blowing out of the tailpipe on the top end of the tach? :nonono: Just found this on YouTube while browsing through random Cobra vids.

Whomever owns this car, run away from this shop and find a new one..... NOW.


[youtube_browser]D7QRgiqSEME[/youtube_browser]

 

[Nick_B95GT]

was that a 5th gear dyno pull?

 

[Red Turtle]

Wow....

 

[03cobraaa]

:nonono:

 

[MICLO50]

poor car

 

[Quicktime_GT]

maybe they aren't at WOT?

 

[fiveoh2go]

was that a 5th gear dyno pull?

Pretty sure it was 4th gear.

 

[Paulinator]

slow 4th gear pull is smarter than a fast one if your tuning it.

 

[Slightly Motivated]

Exposing my very little knowledge on dyno/dyno tuning, do you regularly make pulls in 6th? I always assumed it was the top gear. Why is a slow 4th gear pull better then a fast 6th gear/fast 4th?

 

[bb97gt]

Exposing my very little knowledge on dyno/dyno tuning, do you regularly make pulls in 6th? I always assumed it was the top gear. Why is a slow 4th gear pull better then a fast 6th gear/fast 4th?

For the sake of accuracy, you want the drive ratio to be as close the 1:1 as possible, which on these cars happens to be 4th gear

 

[Slightly Motivated]

For the sake of accuracy, you want the drive ratio to be as close the 1:1 as possible, which on these cars happens to be 4th gear

So when/if i ever dyno my own car (which id never do without somebody who knew how to dyno a car obviously lol) i would want to do a 4th gear pull? Slowly drive through up to forth then WOT till redline? Or i guess as stated before a slow pull/not WOT which is more accurate.

 

[D's01Snake]

slow 4th gear pull is smarter than a fast one if your tuning it.

:idea:

 

[DSGWhippedSnake]

Either 5th or a stupid high load placed on the roller preset

 

[gray 5.0]

shop looks familiar and judging by the pa plates i know the place. indeed stay away

 

[bb97gt]

shop looks familiar and judging by the pa plates i know the place. indeed stay away

Interested in what shop that is!

 

[thomas91169]

4th is 1:1 which is best for pulls.

However, if the customer is a freeway racer, a 5th gear pull with that duration at WOT would really tell the tuner if the tune is correct or if it will start to heatsoak up top. Going from 3rd-4th-5th on the road will not be as long of a pull as a 5th gear low to high pull would do.

If I had a proper stretch of road id do 4th gear pulls in my GST to ensure tune accuracy (3rd is my 1:1, but its over very quick when modded).

 

[frequency101]

Checking the partial throttle tune? You don't drive 100% throttle all the damn time, so you shouldn't tune your car as such.

How-ever all tuners I've used have always done the partial throttle on the street.

 

[Paulinator]

:idea:

if you do a slow pull it gives you a chance to lift if there is any knock, being that cobras and lightnings do not have knock sensors to cut the timing back and you cant always trust the IAT2 sensor to pull enough timing out to remove the detonation. thus a slow pull is smarter than just stomping the throttle.

 

[Paulinator]

Checking the partial throttle tune? You don't drive 100% throttle all the damn time, so you shouldn't tune your car as such.

How-ever all tuners I've used have always done the partial throttle on the street.

yeah not many streets is it safe to do a part throttle 4th gear pull on lol thats why a mustang loaded dyno is best for tuning.

 

[thomas91169]

Checking the partial throttle tune? You don't drive 100% throttle all the damn time, so you shouldn't tune your car as such.

How-ever all tuners I've used have always done the partial throttle on the street.

yeah but you can tell the engine is under load in the vid.

hes not doing a partial throttle check, hes doing a long duration WOT run to simulate, IMO, a freeway pull, doing worstcase scenario by starting in low 5th and going to redline. I think the video is misleading and it starts off in 2nd.

been a while since I read into how mustangs ecu's work but in the dsm world, the ecu uses compensation factoring to compute proper fuel/spark delivery per a given load, throttle position, rpm, airflow value, etc that it sees. You tune at WOT to get the most out of WOT performance but the ecu will use those factors and draw up a proper fuel/spark delivery curve from there against a stock (or modified) base fuel/spark table.

partial throttle checks are done at consistent rpm to check short term and long term fuel trims, and thats pretty much it.

damn I need to get back into tuning.