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FFP Underdrive Pully Good or bad?


sonyman87

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What type of hp difference is there on a 3.1 with a underdrive pulley vs regular pulley. When my a/c went out on my car I bought a shorter serpentine belt to bypass my a/c all together and could tell a little bit of difference in HP. Is it about the same?

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What type of hp difference is there on a 3.1 with a underdrive pulley vs regular pulley. When my a/c went out on my car I bought a shorter serpentine belt to bypass my a/c all together and could tell a little bit of difference in HP. Is it about the same?

 

At http://www.fastfwdperformance.com they have a dyno sheet for a 3.1L with and without the pulley. The biggest gains were on top end

 

Robby

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With a 5 speed you should be able to knock em off in 2 hours. Its so much easier with the smaller tranny.

 

do you mean the alternator or the UD pulley? with the pulley, tranny will make no difference. as for alternators, it is a lot faster with the 5-speed, but 4 hours is still a respectable time. and i take it you have a 3.1 so not like youd know anyway. if you do have a 3.4, ever done the alt?

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Guest Anonymous

Why does every response from you make it sound like you're god? I have 3 3.1's and I know how to change the alt on a 3.4. Since you have a 3.4, you must not know how to work on a 3.1 then. :roll:

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Why does every response from you make it sound like you're god? I have 3 3.1's and I know how to change the alt on a 3.4. Since you have a 3.4, you must not know how to work on a 3.1 then. :roll:

 

actually ive never been into a 3.1 below its upper plenum, but i did get that off. what a bitch it was. my god, way harder than the 3.4. that hose on the bottom, i finally cut it with bolt cutters i got so pissed at it :evil:

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Its not impossible to reroute around the a/c all you have to do is buy a shorter belt. My brother measured mine bypassing the a/c and then told the parts store what size serpentine belt I needed. For you guys who have 2.8s and 3.1s and want to get the smaller belt to bypass the a/c heres where I got mine and the part#. Carquest Micro-V Belt Part# K060696. Heres the belt size 21mm x 1785mm.

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check this! it cannot be done like that. buying a shorter belt only works on the 4cyl gms. on the 2.8L and 3.1L you absolutely must have an idler sitting in the place of the a/c (thats why they sale the part!!!). what will happen is the engine will spin the pulleys in the wrong direction. Man we (at least 50+ j-body.org members) had a huge discussion on this and everyone who tried it came to same conclusion. I leaned over my motor for hours trying to reroute with a shorter belt and it won't work.

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the water pump is turned by the back side of the belt, not the toothed side. so i cant see how it would be possible to apply any pressure to it unless the ac is there, a pulley was in its place, or a water pump with a toothed/ridged (whatever u call it) pulley was in place

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okay this is for your viewing pleasure. If you notice in the provided pick that if you remove your a/c and not have the idler pulley then your vehicle you will absolutely not run your water pump. This is for 2.8 and 3.1L. There is not acception and running a shorter belt won't do it.

 

scan---1.jpg?bcBQFa_Az2CTS_s2 If the pic doesn't show up just look at the last picture in my WWW :D

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thats amazing because franz of FDP is running his belt without the AC and it runs the waterpump just fine. You have to modify the timing chain cover so it doesn't rub. I had the belt and was modifying my cover when I said screw it and left it alone. Unplug the AC and its instantly an idler pulley.

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hey does anybody have the mantapart pulley set, it comes with the crank pulley and a bigger alt. pulley and a belt and seems to be priced ok for all that and wouldn't that fix the alt. problems. I am seriously wanting to make this upgrade and just want to get the best, so far mantapart looks #1 on this, what do you guys think of this.

 

and that sux everything ffp has for the 3100 is the most expensive stuff they have

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you mean franz peters with the cavalier? If so does he have pics. I don't doubt it if he had to modify but I want to see it. If i can figure a way to do it without the idler I will. If you can post his sight or ask him if he has pics ty!

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hey does anybody have the mantapart pulley set, it comes with the crank pulley and a bigger alt. pulley and a belt and seems to be priced ok for all that and wouldn't that fix the alt. problems. I am seriously wanting to make this upgrade and just want to get the best, so far mantapart looks #1 on this, what do you guys think of this.

 

and that sux everything ffp has for the 3100 is the most expensive stuff they have

 

how would adding a BIGGER alt pulley help anything? that is going to slow it down even more than the standard alt pulley. You will have MORE problems with underdriving the alt more than the FFP pulley does. There is a reason FFP doesnt include a bigger alt pulley (you WILL have charging problems if you slow it down even more). And even if you wanted a lartger pulley, mantacrap is still a rip off. You can go to any alt. shop and pick up a larger (or smaller) pulley for $25. add another $25 for the belt an that would brind the total to $160 (including shipping) if you got the FFP pulley. Manta part sells theirs for $225.... unless of course you have a 3x00 motor in which case the price jumps up to $250. How is that a good deal?

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anyone have the belt# for the 3.1 with the ud pulley from FFP? I'm too lazy to maesure or go fuck with the morons a the loacl parts store THanks Jay

 

ask michael....he shoulda told ya....ah well....

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