Dyno results Underdrive pulleys

JTGrant

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Aug 2, 2005

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Jan 6, 2007

#1

• Jan 6, 2007

• #1

Anyone have just results from a dyon with the only change being underdrive pulleys? I am about moded out as far as bolts-ons are concerned. I would like to add a cam but the prices are to high right now. Thanks

 

bigcat

start with the upper hole, and if more traction is

May 1, 2005

3,015

1

79

7200 feet

Jan 7, 2007

#2

• Jan 7, 2007

• #2

no dyno sheet, but the engine revs MUCH faster now. very noticable gain on my car. even my wife noticed the difference the first time she got in.

 

JTGrant

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Aug 2, 2005

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Jan 7, 2007

#3

• Jan 7, 2007

• #3

Have you experienced any negative effects?

 

bigcat

start with the upper hole, and if more traction is

May 1, 2005

3,015

1

79

7200 feet

Jan 7, 2007

#4

• Jan 7, 2007

• #4

nothing yet...

 

JTGrant

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Aug 2, 2005

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Jan 7, 2007

#5

• Jan 7, 2007

• #5

how many miles to you have on your car since the install?

 

bigcat

start with the upper hole, and if more traction is

May 1, 2005

3,015

1

79

7200 feet

Jan 7, 2007

#6

• Jan 7, 2007

• #6

i didnt look at the mileage, but i think only about 1000. give the thread a few days and others will chime in with more miles on the clock.

 

X

XStanger

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Sep 1, 2002

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Jan 8, 2007

#7

• Jan 8, 2007

• #7

Get the pulleys!!! I was worried about the negative effect on the water pump, but since I am running the 4.10s that turns her a little faster to compensate.

+1 on the faster reving.

 

JTGrant

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Jan 8, 2007

#8

• Jan 8, 2007

• #8

Any change in coolant temp or alternator output that you notice?

 

0

07gtfolife

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Oct 31, 2006

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Jan 8, 2007

#9

• Jan 8, 2007

• #9

Do you need to tune for the pullies? I had to on my 05 f150.

 

JTGrant

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Jan 8, 2007

#10

• Jan 8, 2007

• #10

Why would you need a tune for pullies?

 

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07gtfolife

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Oct 31, 2006

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Jan 8, 2007

#11

• Jan 8, 2007

• #11

JTGrant said:

Why would you need a tune for pullies?

Click to expand...

They said they had to bump up the timing and also it helped had idle with the a/c running Thats what they told me when I had it done.

 

S

seattlegt

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May 3, 2006

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Jan 8, 2007

#12

• Jan 8, 2007

• #12

No timing adjustment needed. Dyno's have been from around 5-10hp and around 10lbs of tourqe if you google it and hunt for a while. I noticed a differance when I had Steeda's installed about 6 months ago. MM & FF's most recent magazine comes with a DVD on a 05 GT piece by piece install and dyno per part. They got 10hp on the dyno with BBK UDPs.

 

8

8850

Founding Member

Jun 3, 2000

464

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TX

Jan 8, 2007

#13

• Jan 8, 2007

• #13

07gtfolife said:

They said they had to bump up the timing and also it helped had idle with the a/c running Thats what they told me when I had it done.

Click to expand...

I don't think your mechanic knew what he was talking about.

 

red05bullitgt

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Aug 15, 2005

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Pittsburgh, PA.

Jan 8, 2007

#14

• Jan 8, 2007

• #14

Besides, U/D pulleys don't increase HP ? they free it up by slowing down your belt driven accessories such as your water pump and A/C which have nothing to do with the computer's stock tuning files... therefore no computer re-flashing is necessary.

 

M

MBDiagMan

Member

Sep 22, 2006

171

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Lamar County, Texas

Jan 9, 2007

#15

• Jan 9, 2007

• #15

I have had underdrive pullies on my 88 Vette for over 100,000 miles with no negative effect. They will be going on my GT in the near future.

There is absolutely NO tuning necessary when changing to underdrive pullies.

 

0

07gtfolife

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Oct 31, 2006

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Jan 9, 2007

#16

• Jan 9, 2007

• #16

8850 said:

I don't think your mechanic knew what he was talking about.

Click to expand...

maybe its different for f150's cause the guy is a pretty big online programer on f150online.com

 

metroplex

Member

Sep 7, 2003

405

1

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SE MI

Jan 9, 2007

#17

• Jan 9, 2007

• #17

A bump in idle speed is generally required to maintain alternator charging levels. Side effects of going with underdrive pulleys include:

Reduced A/C output in low speed driving
Reduced power steering assist in low speed driving
Reduced alternator charging at idle

Bumping the idle speed UP will only reduce these side-effects. I've used the Steedas on my 4.6 2V for about 20,000 miles and eventually just went back to the stock pulleys.

 

Marine One

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Jan 28, 2004

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North Topsail Beach, NC

Jan 9, 2007

#18

• Jan 9, 2007

• #18

JTGrant said:

Have you experienced any negative effects?

Click to expand...

I did experience some negatives with them on a 95 Mustang GT. They caused my headlights to brown at idle and significantly contrbiuted to an overheating problem that I had when stuck in traffic. I realize that our cars are completely different than that Mustang, but can definitely see why someone would ask the question before purchasing & installing this mod.

 

metroplex

Member

Sep 7, 2003

405

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SE MI

Jan 9, 2007

#19

• Jan 9, 2007

• #19

Marine One:

You brought up an excellent point. On my 00 Vic (4.6 2V V8), the headlights did dim at idle and got worse when I had more accessories on at the time (HVAC blower, Air Conditioning, stereo, and turn signals).

I'm never going to try underdrives again in any vehicle, but that is just me. :SNSign:

 

Marine One

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Jan 28, 2004

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North Topsail Beach, NC

Jan 9, 2007

#20

• Jan 9, 2007

• #20

metroplex said:

Marine One:

You brought up an excellent point. On my 00 Vic (4.6 2V V8), the headlights did dim at idle and got worse when I had more accessories on at the time (HVAC blower, Air Conditioning, stereo, and turn signals).

I'm never going to try underdrives again in any vehicle, but that is just me. :SNSign:

Click to expand...

I share your viewpoint.