UD pulley (lights flickering)

[Strykerviper2014]

Had an under drive pulley installed along with my headers, noticed the cab lights flickers when I rev up the car, that normal?

[Voice of Reason]

That didn't happen on either my '13 or '14. It takes no time at all to swap the pulley, you could try putting the stock one back to see if that's the real issue.

My only problem ever was on my '13 when taking off from a stop if rpms dropped too low the belt would chirp. But that has never happened on my '14 so it makes me think the tensioner pulley on the '13 was weaker.

[Strykerviper2014]

That didn't happen on either my '13 or '14. It takes no time at all to swap the pulley, you could try putting the stock one back to see if that's the real issue.

My only problem ever was on my '13 when taking off from a stop if rpms dropped too low the belt would chirp. But that has never happened on my '14 so it makes me think the tensioner pulley on the '13 was weaker.

It don't happen every time, just every now and then I noticed and it's only at idle

[One Viper Bite]

I am currently experiencing this problem with my 2013 GTS and I do not have an upgraded ud pulley.

The dash display flickers at least once a day when I'm cruising at or below 2,000 RPM. Also happens at idle occasionally.

[Strykerviper2014]

I am currently experiencing this problem with my 2013 GTS and I do not have an upgraded ud pulley.

The dash display flickers at least once a day when I'm cruising at or below 2,000 RPM. Also happens at idle occasionally.

It never use to happen before only since I added headers/exhaust and pulley

[GTR>Viper]

mine did this too, check your battery connections, mine were so loose you could take em off without a wrench. Once I got them clamped down, no longer an issue

[Strykerviper2014]

mine did this too, check your battery connections, mine were so loose you could take em off without a wrench. Once I got them clamped down, no longer an issue

Checked all the connections, everything's tight

[Steve M]

If you are comfortable using HPTuners, you can bump up your idle speed to 925 or 950 RPMs...the alternator has to spin fast enough to be able to charge, and the underdrive pulley reduces that speed. Stock idle is 700 RPMs, and bumping it up is as simple as putting in the new number.

[Strykerviper2014]

If you are comfortable using HPTuners, you can bump up your idle speed to 925 or 950 RPMs...the alternator has to spin fast enough to be able to charge, and the underdrive pulley reduces that speed. Stock idle is 700 RPMs, and bumping it up is as simple as putting in the new number.

Yea I cleared the o2 sensors last night with hp tuners,I can do that but doing that I don't have a clue, torrie he is going to remote tune it via team viewer soon from the headers/exhaust , he already got a tune in it from last year this is a re tune I'll bring that up to him thanks

[Steve M]

Under Engine -> Idle:

http://i305.photobucket.com/albums/nn227/meentss02/HPTuners%20Viper/Write_zps8825ff2d.jpg

See the two boxes that say 850? That's where you change the idle speed...it's as simple as typing in the new number and reflashing the PCM.

[KB Viper]

I have the IPSCO pulley and have not had any issues. did you upgrade the belt?

[donk_316]

Supposed to run an upgraded, 1" shorter belt with the pulley. Yeah you can get away with the stock one but its at the limit of the tensioner. IPSCO will even give you the part number so you can buy it locally.

[Strykerviper2014]

Under Engine -> Idle:

http://i305.photobucket.com/albums/nn227/meentss02/HPTuners%20Viper/Write_zps8825ff2d.jpg

See the two boxes that say 850? That's where you change the idle speed...it's as simple as typing in the new number and reflashing the PCM.

I'll check it out when I get home from work, yes I upgraded to the 1" shorter belt

[Strykerviper2014]

Under Engine -> Idle:

http://i305.photobucket.com/albums/nn227/meentss02/HPTuners%20Viper/Write_zps8825ff2d.jpg

See the two boxes that say 850? That's where you change the idle speed...it's as simple as typing in the new number and reflashing the PCM.
Checked how the car was running, it's idling around 750-800, the lights wasn't flickering like it was before I cleared the Engine light by flashing the DTC's and the o2 sensors, the car is working fine

[Steve M]

Well, if it does it again, setting the idle speed higher is a very easy thing to do to see if that's the issue. I'm guessing if it does happen, it is likely where there's a fair amount of electrical load on the system, like headlights on, A/C on, and radio turned up. I know there are some guys with Gen 4s that have that issue. Actually, come to think of it, if you just manually bump the idle up by giving it a little gas and it clears it up, you know that it is an alternator charging issue. No mods are without drawbacks, and this is something to be expected from an underdrive pulley.

[Strykerviper2014]

Well, if it does it again, setting the idle speed higher is a very easy thing to do to see if that's the issue. I'm guessing if it does happen, it is likely where there's a fair amount of electrical load on the system, like headlights on, A/C on, and radio turned up. I know there are some guys with Gen 4s that have that issue. Actually, come to think of it, if you just manually bump the idle up by giving it a little gas and it clears it up, you know that it is an alternator charging issue. No mods are without drawbacks, and this is something to be expected from an underdrive pulley.

I might just set it higher anyways maybe 900-950, It doesn't hurt I guess

[Dr.Ron]

Any issues doing this mod? Is anything effected?
I plan to do 1-3 HPDE days/year. Will doing this mod effect that in any way?

Ron

[ViperPete]

My SRT10 does the same thing when i installed the UDP. The Alt is spinning slower. Nothing to do other than increase idle- or maybe have the alternator rebuilt to make more amps at a slower speed.

[XSnake]

mine did this too, check your battery connections, mine were so loose you could take em off without a wrench. Once I got them clamped down, no longer an issue

^^^ this

[Colo08]

If you are running the stock belt, it is slipping, change out your belt for a 1" shorter belt DAYCO #5070685 for GEN 4 & 5 cars, and #5070675 for GEN 3.

[cplabaunza]

I have no issues with my UDP...bought mine from JTSVP and includes the proper belt size.

[cashcorn]

If there is no real hp gain & you are 90% street driven, whats the benefit?

[Steve M]

If there is no real hp gain & you are 90% street driven, whats the benefit?

My understanding is that it was used on the ACR-X cars to prevent water pump cavitation at high RPMs, something you'd likely encounter on a road course. It would free up some HP, but how much is usually hard to quantify.

[Dr.Ron]

I've seen around 8-10hp

[cashcorn]

Do the Gen V ACR's & Extremes come with a UDP or do all Gen V's have the same pully?

[ACR]

All have same pulley

[XSnake]

My understanding is that it was used on the ACR-X cars to prevent water pump cavitation at high RPMs, something you'd likely encounter on a road course. It would free up some HP, but how much is usually hard to quantify.
Correct, we also don't have an AC pulley to deal with.