I'm thinking of getting an ASP underdrive pulley.

Are they easy to fit?

Anyone got one and know if it uses the standard belts?

 

Seen them for $99 and for about 18bhp on a stock Z, more on a modded one it seems pretty good.

 

http://www.aspracing.com

:eek: :D :eek:

 

Thats only $5.50 per 1BHP, is that right?! Where's the catch?

 

Pete

I got mine from SGP for $160 but that included all the belts. Im sure the belts will be smaller because the pulleys smaller. Its a job you want to do while changing your cambelt.

On the same note someone on TT net just done dyno testing before and after fitting a RPS lightened flywheel and got between 12 and 20 hp increase through the rev range and an extra 16 lbs of torque :o

Paul

Piece of cake to fit, but you'll have to get a very short puller, or take the rad out..

 

And they use shorter belts than standard, I think the TTnet article on cambelt replacement tells you what the 'universal' belts are that you need..

 

Down side - well, read TTnet and decide for yourself, or a massive debate will start ;) There are two camps, roughly defined as;

 

(and yes, the capitals are deliberate);

 

DON'T DO IT, YOUR ENGINE WILL DIE AND SHAKE ITSELF APART!

 

And

 

I've been running one for 30,000m and had zero problems that can be attributed to extra harmonic vibration/lack of dampening

 

Personally - I have one fitted. I haven't noticed any extra noise or problems, and I'll be able to check the bearing wear very soon when I pull the engine. Not worth it on an auto, IMHO, as you don't notice the freer revving (it's rather like fitting a lightweight flywheel), on a manual, yes..

 

The stock pulley weighs a ton (10-11lb!), literally, I couldn't believe how heavy it is.. The ally one weighs bugger all..

http://www.ttzd.com/tech/pulleytech.html

 

Some people think they may cause longterm engine damage but there doesn't seem to be much evidence and a lot of people use them.

 

Unorthodox Racing are probably the best known maker of them but more expensive:

 

http://www.unorthodoxracing.com

If my engine is out then should be a quick job if I get a puller?

Depends how much the belts are going to cost.

Everything I look at sounds cheap until you add all the belts, gaskets, tools etc LOL

Chris - it'll be an absolute piece of the proverbial if the engine is out.. And then space isn't an issue, so a standard two leg puller will work just fine (so long as it opens out big enough, try a 6" or 8" puller, you should pull on the thick divider on the large pulley half of the pulley, or you'll bend the pulley rather than removing it).

 

I have the Unorthodox Racing pulley set, by the way, including the alternator and PS pump pulleys (just there to look nice, really, lighter but don't do anything to reduce parasitic drag) - very well made.

 

The belts, you should be able to get them from a motor factors over here, really (or from Courtesy, just ask for the shorter UD pulley belts, they know which ones to send, or I can look up the part numbers tonight for you), so long as you know the length..

I've got one for a bargain price off Anders UK so lets hope the engine damage thing is untrue!

 

I PM'd you back mate.

Originally posted by aaronjb

Not worth it on an auto, IMHO, as you don't notice the freer revving (it's rather like fitting a lightweight flywheel), on a manual, yes..

I put one on my auto and it made a noticable difference.

Chris

 

I dont believe these underdrive pulleys are worth anything like 18bhp. And if you were to run a tuned / hot engine at full output and max rpm where you might just find a few bhp savings then one place it comes from is the water pump. This is now running slower than it should and therefore not shifting as much coolant as it should around an even hotter pair of cylinder heads and very expensive turbos. imho more to loose than win. Last thing you need is a costly rebuild again. Protect your investment not put it at risk.

 

Willie

Originally posted by WillieO

Chris

 

I dont believe these underdrive pulleys are worth anything like 18bhp. And if you were to run a tuned / hot engine at full output and max rpm where you might just find a few bhp savings then one place it comes from is the water pump. This is now running slower than it should and therefore not shifting as much coolant as it should around an even hotter pair of cylinder heads and very expensive turbos. imho more to loose than win. Last thing you need is a costly rebuild again. Protect your investment not put it at risk.

 

Willie

 

i believe with the kits that chris is talking about, most of the bhp gains is in weight reduction, they dont underdrive too much because of those problems.

I have a full set of underdrive pulleys and it makes a noticeable difference to the engine. Revs more freely. Definately more power with no bad effects like additional heat. Pete at SE has decided the crank on the Z is 'ard enuff to cope with any additional stress. One of the UStuners make the pulley upgrade their stage one upgrade before a filter/xorst.

 

And Willie, yes everyting is running a bit slower incl the water pump, which means the water circulates more slowly through the engine but also through the radiator. So you could argue that the engine might run cooler. The net effect either way is minor IMHO. Besides you should disconnect the water supply from your turbos as it superheats the engine and does b*gger all for cooling the turbos.

Guys,

 

What do you think between these two 60,000 mile service kits? One is just the normal stuff you would expect and the other comes with an Unorthodox Racing Pulley for about another £90! It's gotta be worth it surely?

 

http://conceptzperformance.com/specials.php

 

Would it cost me anymore labour to fit one of these though? Any ideas?

 

Cheers,

 

Justin:)

no extra labour involved, the crank pulley's gotta come off for the cam belt anyway :)

Shame, you just missed a group buy on these - check the traders forum - group buy section, there's loads of really useful conversation on there about all of this!

 

Mine is being fitted in a couple of weeks

Thanks for the replies guys,

 

It is a shame I missed the group buys but i guess I can still have one at a good price if I buy one all in with the service pack. Just a little worried about the potential engine damage.

 

Justin

Reading people's posts on TT.net and it seems it is the flywheel which acts as the balancer and not the pulley.

Yes, I did a lot of asking around before I took the plunge and I'd be lying if I said I'd concluded that there was no risk at all. But, the risks appear to be minimal and the effect seems to be fairly impressive (thanks to DaveW for the drive!)

 

But your best off doing your own research, check the threads with a search and speak to a few people who you think know what they're talking about.