Underdrive Pulleys Installed - Dyno'd Before/After

[iceguyb14]

2010 Mustang GT Manual
JLT CAI
Bama 92 Octane Performance Tune
Pypes Cut and Clamp X-pipe
Pype Bomb Axle Back Exhaust
3.90 Gears (remember gears hurt dyno performance)

Steeda Underdrive Pulleys Before/After

Before 298.51whp 311.36wtq
After 307.55whp (308.24 run before) 319.69wtq

Thanks. AFR looks perfect too. Right at 12.4 before and 12.6 after

I'm very pleased

 

[Weou09]

Nice numbers!

 

[killr3v]

Nice.

 

[iceguyb14]

Nice numbers!

Nice.

thanks!!

 

[Greg Hazlett]

No other changes, right?

 

[JeremyH]

The a/f is leaner on the after pull, which is accounting for a good chunk of the gains. The before run 12.4 is a bit rich for a n/a car. I have always ran 13.0:1 n/a.

 

[3vs197]

yea i was going to mention that. not worth 9whp but a couple. still worth a gain though.

 

[Greg Hazlett]

If he did not load a different tune how does swapping out pullies lean out the a/f....?

 

[dsmx17]

Just wondering, what shop is that? doesn't look local?

Ps. Howdy Ive seen your SN on Drag I think.

 

[JeremyH]

If he did not load a different tune how does swapping out pullies lean out the a/f....?

It doesnt say he didnt load a different tune.

 

[Rubrignitz]

Wow, surprising. Nice little torque gain. I'd heard pulleys were good for like 3-5hp (at like 6200rpm ;-)) but word is the more mods you have the better they work.

 

[Rubrignitz]

The a/f is leaner on the after pull, which is accounting for a good chunk of the gains. The before run 12.4 is a bit rich for a n/a car. I have always ran 13.0:1 n/a.

Oh...yeah. That explains it.

 

[Greg Hazlett]

It doesnt say he didnt load a different tune.

My point exactly..how did the a/f lean out if another tune wasn't loaded as UD pullies can't alter a/f ratio's....?

 

[JeremyH]

My point exactly..how did the a/f lean out if another tune wasn't loaded as UD pullies can't alter a/f ratio's....?

Its not that big of a change in af, he didnt neccesary have to load a different tune. You can do mutliple dyno pulls with no changes and see .2-.4 differences in wot af as well as 5-10hp difference in peak hp. Even more so on a fi car.

 

[iceguyb14]

The a/f is leaner on the after pull, which is accounting for a good chunk of the gains. The before run 12.4 is a bit rich for a n/a car. I have always ran 13.0:1 n/a.

going from 12.4 to 12.6 AFR isnt going to make much of a difference in power or torque. going from 12.4-13.0 might net 3-4whp on my car, but only a .2 diff wouldnt provide any measurable change.

but yeah i had no other changes. ONLY change was the UDP install. im not sure why the AFR went from a consistent 12.4 to 12.6, but oh well. the tune im running i had told Bama to make based on UDP. im pretty familiar with tuning and i wouldnt think it would make a difference, but hey maybe it does make a .2 difference.

dynos were done within an hour of each other. car was never even unstrapped from the dyno. did 2 pulls before, each was within 1whp/wtq. then did 2 pulls after, with whp being within 1whp and wtq being within about 2.

 

[RedFire07GT]

Its good to see you got gains from these.. I threw a set on but never dyno'd the car to see in any gains were made..

Congrats buddy!

 

[RetroGT2006]

Nice gains, see i did pullies and delete plates at the same time and boy did it wake my car up! Seat of the pants feel was great and the improvement at the track was amazing!

Why is everyone talking about retuning? UDPs don't do anything on the tune...

 

[Greg Hazlett]

Read what everyone has talked about and you will understand why the tune was questioned; you posted your gains with the pullies alone but your a/f ratio changed as per your dyno sheet which raised the question what contributed to your gains, the UD pullies or the leaning out of the a/f ratio.

 

[fdjizm]

going from 12.4 to 12.6 AFR isnt going to make much of a difference in power or torque. going from 12.4-13.0 might net 3-4whp on my car, but only a .2 diff wouldnt provide any measurable change.

but yeah i had no other changes. ONLY change was the UDP install. im not sure why the AFR went from a consistent 12.4 to 12.6, but oh well. the tune im running i had told Bama to make based on UDP. im pretty familiar with tuning and i wouldnt think it would make a difference, but hey maybe it does make a .2 difference.

dynos were done within an hour of each other. car was never even unstrapped from the dyno. did 2 pulls before, each was within 1whp/wtq. then did 2 pulls after, with whp being within 1whp and wtq being within about 2.

He wrote a tune for UDP's? i'm not the most informed around but I don't think you need to alter a tune for UDP's.

 

[Ignatowski]

Thank you for posting the dyno. I have a 2010 as well and just installed a set of Steedas last week and felt a noticeable difference.

Did you by chance run a before and after dyno for the intake?