HEADERS:- Are they a good idea on the NA or too expensive for what they deliver. More glamour than clout...:confused:

 

Racing Pulley:- again, good or bad. This I believe does give benefit.

 

Bearing in mind I may go ahead with one or the other, whats the best way of contacting Jeff at Zedworld.... I've sent emails and left messages... no reply.... need prices please. :)

Have heard that headers are the way to go, all about tuning lengths and direct paths, supposed to be good for reasonable gains. The one I have seen have been in the £600 ballpark.

 

Have heard the same about lightweight pulleys, but there is a school of thought that says the pulley is weighted for a reason and if you remove it you are putting serious strains on the engine. Its apparently ok for race cars as they get rebuilt regularly. Be interested to know what you go with and what it does for the NA.

 

Also polishing of intakes is supposed to do wonders for the power. I think anything that smooths the flow of air into and out of the engine is good, but you need to leave some rough in the intake as it creates turbulance which is supposedly good

Likely to go for both realy. Reading the yank forums say good things about the stillen headers as u state. Not as exp as 600 but still a good move I guess....

 

Will let u know about the pulley once I find someone to fit it or how to, ok with the headers but never done a pulley and cant find any info on the varying sites....

the pulley will be easier than the header , in my opinion. Having taken the pulley off to do the 60k sevice I would guess you could change it in a few hours with basic tools

What are these pulleys like then?The N/A has a VVT hub on the inlet cams,do these new pulleys incorporate a new VVT hub or are they some kind of settable vernier pulley?

Or ya mean the crank pulley??

I think Jock's talking about the crank pulley

 

Robin

yeah, i did, but I cant imagine the inlet outlet pulleys being any more difficult. Cant tell you what the new ones have, never seen a set close up, but would imagine they either come with the various gubbins fitted, or more likely with holes to fit the old stuff. If it doesnt have either, gotta reason they are not for the zed:D

yea,,non are hard to fit,,just time consuming really.You should be takin the cam covers off to hold the cams while you undo the bolts that hold ya pulleys on..thats a job in itself i suppose.I just never heard of a pulley set for them.Unless it was vernier timing gears i cant see it making any difference,theory yea,,real life,,no!!

Keep ya cash in ya pocket and get a nitrous kit!Think there only about £800 fitted.Plenty of fun then!!

Good luck.

This is the one I'm on about

 

http://conceptzperformance.com/Cart/description.php?II=129&UID=2003072419384381.77.161.144

Thats a crank pulley.

 

I reckon a couple of hours would see that on, if you are due a 60k service, you could do it as part of that.

Those quoted power figures for the UD pulley are in Shetland ponies not proper horses!

 

We already had a bit of debate on here about the 12bhp actually measured at some rpm on a RR for a TT with UD pulleys. Do a search.

 

Also why should the bhp savings be quoted different for a TT or NA on a pulley? This is BS.

 

If they have to do it in pretty colours then you know its for the guys and gals who have everything else.

 

The dosh is better spent on tyres and brakes!

 

imho of course

Originally posted by WillieO

 

Also why should the bhp savings be quoted different for a TT or NA on a pulley? This is BS.

 

 

cos its a %age figure i would say.

Sorry Paul its not a %age figure. The saving is supposed to come from the slower turning of ancilliaries like fan, water pump and alternator. i.e less hp per rev going to them due to the smaller pulley. That implies a fixed amount saved per rpm. So it doesnt matter whether NA or TT on a crank pulley. Its what the ancilliaries would have consumed and a bit for rotational inertia. Sure somebody will maybe say the pulleys are different sizes but I doubt if they are and if they are it wont be to that kind of extent.

 

Also if that same argument was true on the different bhp savings the NA would get a lot less benefit than a TT and the guys who measured it got a big fat 12bhp on a TT and 12bhp was the maximum at a short band of rpm. The numbers these con performance guys quote would risk the trade descriptions act in UK.

 

Big bhp improvement numbers seem to be bandied about everywhere without any objective substantiation. Even the Stillen mod staging chart looks a little bit suspect on some mods. They have a waffle get out clause about the state of your engine and wear, piston ring blow by etc if you dont see these sorts of gains when you do the mod. They are not stupid.

 

caveat emptor or somfin that sounds like that!

Don't forget that these UD pulleys also weigh about a tenth of the stock items weight.. Seriously, the stock pulley is about 11lb, and the UD pulley must be 2lb max..

 

Ok, it's very close to the crank, so the saving in rotational mass won't be as much as a lightweight flywheel - but it's the same principle.

 

Wish I'd been able to do a proper before & after comparison on my car, really.. but I never really ran it without one to be able to tell..

 

[edit]

Just thought I'd add that I'm not disagreeing that the stated gains are most likely numbers someone made up to look good.. I'm just saying there's more to consider than the underdriving of the anciliaries.

 

But lets face it - all the manufacturers quote, shall we say, 'optimistic' power gains.. I do believe even that well known South Eastern tuner used to say you got a 15bhp gain from a filter?

like aaron says - most of the gains are from the weight loss, underdriving only accounts for around 10% of the gains

 

i agree that the figures quoted seem a little optimistic tho ;)