Underdrive Pulleys Installed - Dyno'd Before/After

iceguyb14

Mustang Fanatic
Joined
Jun 7, 2010
Posts
1,367
Reaction score
0
Location
Fredericksburg, VA
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!

thanks!

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...

lol yeah i bet! and the tune was the same before and after.

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.

the afr change .2. that isnt much at all. what contributed to the gains was the UDP. nothing else was changed. maybe making the 3% increase in power was enough to lean it out by that minuscule amount. lol.

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.

i just informed them of everything i had installed when i got the tunes. and i told them UDP even though they werent installed yet. i wouldnt think it woudl change things, but hey, maybei t does just a lil bit.

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?

no sorry. but all i had installed before was intake, tune, xpipe, and axle back. stock our cars make around 270whp. so thats about 28whp from intake, xpipe, and axle back. on a 92 octane, not 93, performance tune, not the race tune. not bad. especially with 3.90 gears.
 

Riptide

Will work for Mustang.
Joined
Oct 27, 2009
Posts
5,248
Reaction score
17
Location
Montucky
I barely felt any difference at all after I put mine in. Removed them recently and also couldn't feel a change.

I wish I had a sensitive enough "butt" dyno to feel a 2% power differential.
 

fdjizm

Drag Queen
Joined
Nov 29, 2009
Posts
19,534
Reaction score
343
Location
NY/NJ
Just put in mine on saturday, I could tell a difference in how fast the car revved up and taking off slow wasnt as much of a struggle, that's about it, hopefully it gained a little something as they are known to, but it's not that dramatic but a gain is a gain :)
 

Scord

Member
Joined
Jun 17, 2009
Posts
182
Reaction score
3
Location
Palo Alto
I felt zero difference with UDP... but I did see +1 average MPG which in turn will pay for itself theoretically...
 

fdjizm

Drag Queen
Joined
Nov 29, 2009
Posts
19,534
Reaction score
343
Location
NY/NJ
It makes mathmatical sense that UDP's would free up some horsepower.
Why are people reacting surprised? UDP's and their gains have been around for years, this is not a new mod.
 

Riptide

Will work for Mustang.
Joined
Oct 27, 2009
Posts
5,248
Reaction score
17
Location
Montucky
Removing my steeda crank pulley was a bitch. I had a hard time finding a three jaw puller that would fit the inside edges on that thing.
 

Noclutch

Member
Joined
Jul 31, 2010
Posts
287
Reaction score
3
Location
Niagara Falls
I liked the added hp to the wheels, I had the cmdp and the cams added without the UDPs and gained a tenth and 1mph at the 1/4 13.344 @ 104mph. Added the udps and with the same tune it ran hard. Got my PB in my sig.

UDPs with the CMDP are the best combo after the CAI and tunes and with cams makes it all that better so I hear.

Modding these cars are fun.
 

Steedman07

Classified's Moderator:)
Joined
Feb 4, 2008
Posts
9,246
Reaction score
113
Location
Connecticut
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.

Yes it will. More air means more power..grats on the gains, but the A/F is a little higher on the pull with the pulleys. Not that it matters..Still a decent gain for a cheap $$ mod..
 

Ken04

gm troll basher
Joined
Sep 14, 2009
Posts
2,503
Reaction score
40
Location
Santa Rosa Ca.
I liked the added hp to the wheels, I had the cmdp and the cams added without the UDPs and gained a tenth and 1mph at the 1/4 13.344 @ 104mph. Added the udps and with the same tune it ran hard. Got my PB in my sig.

UDPs with the CMDP are the best combo after the CAI and tunes and with cams makes it all that better so I hear.

Modding these cars are fun.

great quote right there; "Modding these cars are fun", 1 hp gain, 30 hp gain, 200 hp gain, it's all good.
 

RetroGT2006

06 S197 Member
Joined
Aug 15, 2007
Posts
2,486
Reaction score
15
Location
Florida
I liked the added hp to the wheels, I had the cmdp and the cams added without the UDPs and gained a tenth and 1mph at the 1/4 13.344 @ 104mph. Added the udps and with the same tune it ran hard. Got my PB in my sig.

UDPs with the CMDP are the best combo after the CAI and tunes and with cams makes it all that better so I hear.

Modding these cars are fun.

Damn dude, your car has more in it i would say.. I don't have cams, but when i installed my UDPs an CMCVs i gained 3 tenths, and 2+ mph.. I am looking now days to install cams and see what it gets me.
 

Jeffs FRC

Senior Member
Joined
Jul 17, 2009
Posts
1,210
Reaction score
9
Location
Bartlett IL
Removing my steeda crank pulley was a bitch. I had a hard time finding a three jaw puller that would fit the inside edges on that thing.
Thats because you should have used the bolt on type puller. The factory crank pulley is removed with a 3 jaw...
 

iceguyb14

Mustang Fanatic
Joined
Jun 7, 2010
Posts
1,367
Reaction score
0
Location
Fredericksburg, VA
thanks guys! went to the track last night and with only the addition of UDP went from 8.751 @ 81.49mph to 8.627 @ 83.47mph on stock tires

not bad :)
 

Rubrignitz

Member
Joined
Jan 10, 2009
Posts
218
Reaction score
0
Location
Austin
Goddamnit I told myself I wasn't going to mess around with stupid pulleys and you have me considering it! You sure the nice fall air wasn't just better? lol
 
Last edited:

iceguyb14

Mustang Fanatic
Joined
Jun 7, 2010
Posts
1,367
Reaction score
0
Location
Fredericksburg, VA
Goddamnit I told myself I wasn't going to mess around with stupid pulleys! You sure the nice fall air wasn't just better? lol

actually when i ran before it was about 65 degrees and last night it was about 60-65 degrees when i ran those times. very comparable. one run i also trapped 83.81mph. im getting pretty close to 8.50s and 84mph at a notoriously slow track (its slightly uphill).
 

Rubrignitz

Member
Joined
Jan 10, 2009
Posts
218
Reaction score
0
Location
Austin
It does look like you picked up a nice couple of trap mph which is understandable with the lower accessory drag at higher rpm. Cant dispute that.
 

AMChrisRose

AmericanMuscle.com
Joined
Apr 23, 2010
Posts
443
Reaction score
0
Location
Malvern, PA
The first run, oil temp was probably still colder. I've seen cars dyno slightly rich, the second run perfect, third run perfect, fourth run perfect, etc.

It looks like the first run was 12.3-12.4, and the second run was 12.6-12.7. That's only going to account for 3-4 RWHP. So if he gained 10 altogether (to make it easy), you can say he picked up 6-7RWHP from the UDP's. Something along those lines.

We could lean it out about 1% total, and maybe see another 3-4RWHP maximum. I'm happy with 12.7 if he is. :) (unless this wasn't before the cats, and it was taken from the tailpipe, then I'd like to pull out maybe 2-3% instead of 1%)
 

Latest posts

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Back
Top