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#1
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Questions on an underdrive pulley
Hey, has anyone used the Motorsports Underdrive pulley set-up? I'm replacing my timing belt on my 94 LS and i thought now would be a great time to order the step up from something stock, plus it comes with belts, i think. Any inputy to the stuation would help.
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#2
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Works great. I have the underdrive on ne car and the standard size one peice on the other. Doesnt seem to have any effect on performance, though Id imagine if you combined it with other lightweight stuff, in theroy, it could make a slightly noticable diffrence to performance. More or less, it's shiney, and wont seperate like the factory ones sometimes do..plus it makes your mod list 1 longer
If it doesnt come with belts, make sure to get some. The stock size will be too big, I think you need something like 1 or 2 inches smaller
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R.I.P Cool Signature. You're gone but not forgotten. I mean, sure, I kindof don't remember some of the finer details..but I remember you were funny, and at one point you said spaghetti in Dutch....but definantly not forgotten |
#3
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Yes it will work and may look pretty and you may not have any problems.
However, your engine will no longer incorporate any means of torsional vibration dampening and this will impose unwanted stresses on the crankshaft. Accessories will run at a slower speed including the alternator, which could be important if you are running extra electrically powered gear.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
#4
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Quote:
Tom |
#5
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Quote:
It can nor be denied that the OEM pulley incorporates a means of, and is a torsional dampening device. The expense of incorporating same will have been taken into account by Subaru. I agree that the effects or affect can not be seen, are from obvious and lack of same may not directly cause a problem. But is dispensing with a known advantage warranted? A will disclose some very interesting facts and detail regarding the technology involved. All accessories driven via a flexible belt comprise an excellent means of absorbing torsional vibration and a supercharger will add to the affect. I would not suggest such a load should be imposed on the OEM pulley and you have no alternative option. As a matter of interest I ran up against the lengths designers go to in respect of torsional vibration when I built my first car for competition, over fifty years ago. The Fiat engine had the generator flexibly coupled directly to the front of the crankshaft. The fan was fitted directly to the overhead crankshaft, chain driven at the rear end, via cone clutch sort of slipping hub. This set up was beautifully neat and tidy, but belt drives are superior. Sincerely, I would love to have the opportunity to talk engine design, etc., etc., Tom/Tom/Trevor, over e beer or two. Cheers, Trevor.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
#6
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tehn come to the states and we can do this
Tom |
#7
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Thanks Tom.
Invitation much appreciated, noted, recorded and put on hold pending a windfall.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
#8
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I have emailed dayle about his pullys and he told the the best one to get for your money and proformance would be the stock size pully that is lightened if that helps anyone?
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Seth 94' Barcelona Red w/ Tricoat black 2-tone AWD Ls -Sold Mods:AWD conversion/4.44 swap by Budfreak, Custom red interior lights, Custom Satin black dash, Power mode switch, Cold air intake, Permecool tranny filter,Sony xplode 10" sub, Sony xplode 1000w amp, Blitz in-line driver, DDM Tuning 6000k HID's, New paint job/body work by me, 97' Grill, QC shift kit, 17'' MB Motoring rims, 15&20 min mod, front & rear urethane swaybar bushings, Custom fiberglass sub box, Custom red led a/c control unit, perrin lightweight crank pulley, Black wrinkle finish powdercoated intake manifold w/ clear hoses , 02' outback heated/power black leather seats Soon to come:Fiberglass hood, upholster ALL suede to black leather Past subies: 92' Pearl White/black top LS-L-SOLD 96' Legacy Outback-TOTALED 99' Legacy Outback Limited 30th anniversary edition-TOTALED 98' Forester L -Totaled Other toys: 99' Forester S -WRX brake upgrade, soon an 04 wrx motor swap 06' B9 Tribeca-Stock 1982' Yamaha xj650 Maxim Mods: work in progress |
#9
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i agree... the stock sized pulley is your best bet for aftermarket pulleys. You can also find them on ebay as they are the same as other subies for the most part. But they are of lesser quality than dayle's
Tom |
#10
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I have Dayle's lightweight stock pulley and I noticed that the engine cranks over a little easier. Other than that it's pretty much the same.
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bLAh
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#11
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wouldn't torsional vibration dampening be less important on a H6 than on some other cars like an I4 design, as its already a fairly well-balanced design?
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1992 Pearl White/Black Onyx Subaru Alcyone SVX LS-L Donating Forum Member In Good Standing JDM 4.11 Geared Transmission JDM 'ALCYONE' Rear Panel JDM 'BOXER' Eingngine Cover JDM 'SVX' Hood Badge L-Edition Suede Rear Seats |
#12
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Thanks for the advice
I'm not really expecting any more hp from the underdrive pulley, i just thought it would help with lowering the total recipricating mass by alittle. But you all pose so many good points its still hard to decide what to do. I have another question for you all. I've been told that not having enough back-pressure in your exhaust can make you lose power. Now i have always thought the other way, less back-pressure, more power. I know for a fact that i have 0 back-pressure as you can see in the pic i'm posting, but is there a certain amount i should have? there not in the pic, but i have a pair of Thrush glass-paks about 2/3's the way down the straight pipes.
Anywho thanks again. P.S. if my pic fails to show, check out my cardomain page. www.cardomain.com/ride/2488463 |
#13
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ooooooooops
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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin blk 92' LSL w/ average mods pics here http://s306.photobucket.com/albums/nn277/yourconfused/ Cash68: "Hmm, I wouldn't brag about beating Escorts. That's like saying you tricked a retarded person." |
#14
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2.5InchTrueDual
My puter didn't like your link.
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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin blk 92' LSL w/ average mods pics here http://s306.photobucket.com/albums/nn277/yourconfused/ Cash68: "Hmm, I wouldn't brag about beating Escorts. That's like saying you tricked a retarded person." |
#15
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TomSVX
"i agree... the stock sized pulley is your best bet for aftermarket pulleys. You can also find them on ebay as they are the same as other subies for the most part. But they are of lesser quality than dayle's
Tom" How is Dayle's of better quality? What is it made of? 7075, 6061, 6063? Is it hard anodized? Or does it come with a sticker? Seriously though, I am curious. What is it that make it better?
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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin blk 92' LSL w/ average mods pics here http://s306.photobucket.com/albums/nn277/yourconfused/ Cash68: "Hmm, I wouldn't brag about beating Escorts. That's like saying you tricked a retarded person." |
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