F150 Ecoboost question

[bamsho]

I need knowledge here.  I met a very nice man at the local dragstrip.  His GT500 is down cause he is on his 3rd clutch.  That's another story.  In the mean time he has been running his latest F150 4x4 supercrew truck at the strip.  We got talking about it and this is his 3rd truck.  All 4x4, supercrews.  He is puzzled cause his first truck has 3.31 gears in it and put up decent times.  Next truck has 3.55's and current one has 3.73's.  He cant figure out why the 3.31 geared truck ran faster than the other two trucks.  I said I would ask here, you guys might have a better idea, than me.

 

[ecoboostsho]

Boy there are a lot of variables right there.  Every vehicle is different...were any of them tuned etc...?  One possible reason could be the 3.73's and 3.55's require an extra shift to get through the quarter which would add a significant amount of time especially if it isn't tuned for quick shifts...just a thought though.

 

[panther427]

Was he launching with 4 wheel drive?? All same motor.

 

[Brucelinc]

Yes, lots of variables for sure.  If all else was equal, I would expect the 3.73s to be quicker - especially on the low end.  I wonder if traction issues come into play with those trucks.  The deeper geared trucks might have more wheelspin than the one with the 3.31 gear.  Do guys who race these trucks use 4WD at the strip?

I have also heard that there is quite a bit of variability between stock ecoboost engines.  I think Livernois has mentioned that.  Once tuned, presumably there is less variation.

 

[bamsho]

None of the trucks where tuned, all stock programming.  No, launched in 2wd with all trucks.  Trucks were all 3.5 EB, 4x4 Supercrews, same bed.  Yeah, he figured the 3.55, 3.73 trucks would be faster.  He is a very good racer, leading the points in True Street. Yeah seem weird to me too, but seen weirder things too.

 

[Brucelinc]

Wow!  I don't know how he hooks up in 2wd. 

 

[bamsho]

Well he is used to ALOT more power, since he usually runs his '13 GT500.  I've gotten to be able to watch him, there is no spin, I think there is traction control too on the trucks.  Thanks guys.