924Board.org

AppleBit · Joined: 16 Nov 2002 Posts: 1516 Location: Minneapolis, MN

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=1809178642

awilson40 · Guest

Bummer man...you let the cat out of the bag...I was hoping to pick it up cheap

dwak · Guest

They talk about these in the current 911 & Porsche World mag.
dwak

Richard · Guest

Aside from the cheap price, this is not such a big deal. I just put a brand new one on my 924 two days ago. It cost $85 and i got it at a Audi dealer in Seattle. Fits all 8 valve VW's and 924. Was excellent quality. E-bay discription is also not accurate. You don't change duration, but simply retard or advance the cam relative to piston position. Retard helps top end, advance helps low end. I'm still experimenting, but it seems like a couple degrees retard helps all around, with a peak around 4000rpm.

Joes924 · Guest

Yea jon i bid on it about 3 hrs ago and had high bid of 35.00 wonder what its up to now..
that guy

_________________
924porsche1979Joe

[ This Message was edited by: Joes924 on 2002-03-21 17:12 ]

awilson40 · Guest

Richard...
Does it make much difference??
If so, in what way?
Thanks

Richard · Guest

Yes, it most certainly makes a difference. The power feels "crisper" at higher rpms. Low end not so bad either. Before I bought this I retarded the cam by skipping back one belt tooth. Top end was great but low end was flat as Kansas. One belt tooth is worth about 8 cam degrees. This is fun stuff because you can so easily change the power curve. Just loosen the allen screws and turn the crank pulley untill whatever marks you want line up, readjust the ignition timing and go! What is even more cool is the Franco automatic cam gear as seen on Apple Bits web site. This baby starts out advanced and as rpms climb, switchs over to retarded. It is on my wish list...cost $300. I must be honest though, it does not produce "OH MY GOD" power. But in a NA, everything helps.

Rick MacLaren · Guest

Bah! :grin:

[ This Message was edited by: Rick MacLaren on 2002-03-04 05:29 ]

Richard · Guest

Rick, Is that bah like in bah humbug! in which case you do not believe that changing the timing of the cam can effect performance?

Joes924 · Guest

Well I won the auction.

AppleBit · Joined: 16 Nov 2002 Posts: 1516 Location: Minneapolis, MN

Rick - your wrong -- it does deliver on it's promises

- Jon

Joes924 · Guest

Richard or any one where does low end turn into top ens considering max rpm is 6000
It seems Im gonna start at advanced since
low end performance is what I want but not so as to have no high end performance ..

Id there any danger from running so far advanced or retarded.

Joes924 · Guest

Im kind of pissed off I won the auction cause I had better use for the 38.51

Any one want to buy it from me.

_________________
924porsche1979Joe

[ This Message was edited by: Joes924 on 2002-03-21 17:17 ]

dwak · Guest

Ain't it just like the stock market, so easy to buy (high) and so damn hard to sell.
dwak

Richard · Guest

Yeah, e-bay can really suck 'cause you get stuck with things just 'cause you didn't want anyone else to have it worse than you not needing it in the first place. But now that you have it, at least have some fun with it before you sell it! It's also good education to how different parts of an engine affect power and their relationships to one another.
Now looking at a power curve in a '78 owner's manual for a standard engine I immediately see that H.P. drops off at about 5750 rpm, so let's call that the upper limit of top range. We already know that 0 rpm is the beggining of low range. Now all we need is two more values for defining the ranges, and these are the killers because everyone who reads this post will have a different take on it...but since I opened my trap I'll take a stab at it. Looking at this same graph I see that max torque occurs at 3000 rpm and is pretty flat untill around 4500 where it starts to fall off. This is where the car is the most "driveable" This is the range, when you think about it, that most street/hwy driving happens. I would call this mid-range. 4500 to 5750 (maybe 4000) would then be top range. Another way to look at it is low range is what gets you going, mid range is where you spend most of the time driving, and high range is for alluding the police.
No, as far as I can tell you can't do any damge with advancing or retarding the cam gear within its range of adjustment. Also, a good way to get the cam bolt off is with an air impact wrench. Or maybe loosen it before you take the timing belt off, otherwise the cam just turns. I wish I had better things to do than talk about cars. I need a life!