no offence but i think UAS is flogging their product. i reckon their product only has merit pushing upwards of 500hp at the wheels. i have searched many forums regarding super light flywheels, many of them have been running upwards of 400hp to 550hp with 1kg flywheels for YEARS without any problems. the only time i reckon it could become unbalanced is with mega power, high revs and constant track use. the rb26 is a much much longer motor and not as well balanced. after searching so many times on us forums i havnt seen an example of engine failure attributed to an underdrive pulley (and how many thousands of zeds, maybe 10's of thousands of zeds have underdrive pulleys in US) although in racing i can completely understand because the stresses are far and beyond even that of a high horsepower street car. John, from memory i recall you selling an underdrive pulley that weighed 1.3kg which is maybe a better option
I already have a GFB pulley, which I could go and get balanced with the rest of the engine + clutch, which is what I was looking at doing, but still kinda undecided on what to do now with all this being brought up. Your right i've found it hard to find people posting about zeds that have died or had bearing failure due to a UDP, its always been due to other reasons. Who is running a high HP zed with a UDP? Anyone, shifter or ports either of you running a UDP?
hey hey bro howz foxtel going? i would have thought that any inline 6 is much more ballanced than any v6.... when u talk... say.. the M motor BMW inline 6, the Jaguar 4.2L, the Hemi 265 and of course the 2j.. they are very well ballanced 6's...
Yer I think he means that the inline 6 has a higher chance of becomming unballenced because it has a longer crank shft wer as the v6 has a much shorter one thus less chance of becoming unbalenced. And can any one answer my question on the post i made before this one? Many thanks mike
More answers Swifty Devil I think you have flywheel and crank pulley mixed up. Both have been mentioned and if you read my posts I am saying better off spending money elsewhere unless big power. So on same page there. Let's not shoot the messenger. I am not saying there is a huge list of VG engines that have failed due to these non harmonic pulleys. I am saying it is not get but most get away with it. Some notice vibration even when pulley is torqued up correctly as some are not. Some are out of balance and some not or get balanced in engine build, but does not mean it is not doing bearings damage. As I said and don't take my word and experience for it talk to an engine shop. Also what basis do you say a 1.3kg one is better? Less rotating mass, indirectly yes and I have said there is better ways of lightening the drive train with NO disadvantages as mentioned. The factory one is not big and heavy for no reason. The RB Ross harmonic balancer is actually a bit heavier than the stock one now, in their latest version for big hp applications. The experts at Ross suggested not going any lighter than the one they made for us. Re balancing, they can be balanced neutral by themselves. Yes balance flywheel and pressure plate also. See pics of my motor which we used stock harmonic balancer prior to the Ross ones as I did not want any bearing problems. I get lots of things balanced on motors in my race car, including cam gears and engine pulleys, even turbo's to check and finner balance for over 100,000rpm. Not needed on road car realy. However road or race car these alloy pullies are at best a question mark and if and when we fit them we warn customers in advance. For the slight gain in response from less weight and a step forward there is often a potential step back in power robbing vibration. Some more plus than minus but some step back and wearing motor slowly. I know of one performance engine shop with balancing machine tested a lgiht alloy pulley on Commodore Race motor years ago, and the engine made less power than stock pulley. Possibly more response down low but top end making less power is easy to understand, as this is where most of the vibration would be happening. Lastly if a lighter pulley replacing harmonic balancer was better then I would have on my car. Link to motorsports section and UAS race car section videos of engine balancing and turbo balancing. Go to Motorsports section page 4 as I could not get the link thing working. http://www.nismo.com.au/
yes, regardless of balanced, a ud pulley does not provide harmonic damping.. whether this may lead to damage is an open question, though my guess is that nissan included a damper for a reason.. and indeed, perhaps moreso for chain driven cams, this twisting/vibration of the crank can lead to inaccuracies in valve/ignition timing, and performance can suffer.
Well after reading all this I will have a chat to a couple mechanics I now and I will go from there but at this satge I will forget about the ud pulley for now its a bummer i bought one but at least it hasent been installed. Manny thanks for all your helpfull replys much appreciated expecialy to unique zed thanks alot guys chers mike :biggrin:
If you getting seriously about power losses and the sorts. Forget under drive pulleys. Get a electric water pump. It will only run when it needs to, so the extra strain on the alternator IS NOT perporital to the old pump. Not saying under drive is unless, saying there are better more effective ways of removing power losses at you level.
mate you know nothing....just keep quite...you dont own a sr20 by any chance (im going off your other posts towards chilli)
