man i hope you guys get some thing to work out that you can sell cheap so i can buy it!! LOL

 

I have no reason to go with a cog setup really, F1C F1R maybe but this SDCE is working just fine for the F1A and down.

Same belt for over a year now, I dont replace them because I need to, I replace them because I feel guilty about leaving one on so long.

A properly set up cog works great though, I have never had one on a street car (except for a 8-71 blower) so I'm not sure how well they are suited for street use. At this point if I wanted an F2+ I would whip out the sawzall and hang a gear drive unit on the car - problem 100% solved.

Or just use a turbo

 

man that gear drive thing would be bad *** some one should make us something like that

 

They do, except it puts the blower 7" directly in front of the balancer, going to take some major cutting to get one to fit.

Well that and they cost like 3000.00

 

wow no thanks

 

So I assume a fixed drive isnt a problem due to the fact its fixed ? and could potentially damage the blower ?

The problem is purely down to the risk of a cog belt breaking, as opposed to anything blower related ?
Otherwise a gear drive, could be a threat to the blower itself ?


How much wrap does the SDCE have on the blower pulley ?

My 12 rib belts can easily last a year, they dont shred, they dont do dust etc.....But for some damn reason, they still dont grip how I'd like. Hence Im seriously contemplating cogs.

As things stand, my setup would look a little like this, with this much wrap ( give or take due to a crappy pic ).
Cog setup would be the same obviously.



I could add idlers right at either side of the blower pulley to force wrap, then try and make a different tensioner closer to the crank, on the top side. ( tensioner is top blue one, closest to blower )
Crank/blower rotation is clockwise as viewed on pic

The lower idler I added eliminated all belt throwing/shredding problems I ever had.

 

Crank drives are supposedly easier on the blower than big cog belts, no tension on the bearings and no harmonics.

One of the PROBLEMS with cogs is hey dont slip, when you dump the throttle (or hit a rev limiter) that slams everything the other way and thats when a lot of cars throw a belt. ATI makes a sprag blower pulley that combats that, along with using a couple large bypasses. is a good way to but I think thats a procharger only pulley.

But the death of any belt is long, unsupported runs and small diameter pulleys. From what I gather (there is no real published data) the YSi takes less power to turn than a F1A like I use. But i'm not sure what size pullets you are using, mosy YS blowers I see have a smallish pulley on them. I can see a 12 rib not being enough, since you have no signs of slipping maybe it isnt, valve float and restricted intake can sure look like slipping belts, maybe you are just maxing the thing out as well. But before I invested in cogs I would spend a couple hundred and have reichard make an ultra grip blower pulley in the size you need and see if that cures your problems. They will cut belt life a bit but if you put one of those on a 12 rib and it appears to be slipping you most likely have some other issues.

This is a pic of whats on mine, red pulley is the spring tensioner, works well because of good wrap and short runs, it has almost no tension on the belt as well since the tensioner is on the non-drive side it doesnt take much, its just taking up the slack more or less. When you nail the throttle and the belt stretches for an instant is what causes a lot of problems, like tires once they start slipping its hard to stop unless you really tighten the belt.

 

So the rapid acceleration/deceleration of the blower itself isnt a huge concern with a fixed type drive ???

I tried to get pulleys from Reichard...total waste of time. I emailed them, spoke to them, and they said no problem...then never bothered their **** making anything, or responding to any further emails.

I had a local company make some 12 rib pulleys to try. A 2.95 and a 2.90" with slits across them similar to the Reichard as best I could tell from photos, albeit with only 4 cuts on them.
Anodized black finish.

With the 8.25" crank, and 2.90" blower, there was definate slip above 6000rpm when I blew it up. Previously a normal 8.25" and 3.0" by ASP were gripping fine.
Even tightening the crap out of it didnt help.
No dust.....but also no grip. The current belt has only been on since June, so not a huge pile of miles or passes.
I also have an 8.5" crank I can try, but it leaves the belt very tight in terms of length, so less wrap again.
I had actually been using the 8.5/3.0 combo from mid 2006 until the end of 2007 when I rebuilt a 383 for this year, when I reverted back to 8.25/30.
When using the 8.5/3.0, I am now sure my BOV's had been leaking.

Whether the new pulley wasnt as grippy due to finish, the slits, or size...I dont know. Cant really put the old 3.0" back on to find out lol.


If the cog belt is strong enough, and well controlled in terms of idlers.....then surely it could last a very long time ?

 

The fixed type drives are supposedly easier on the blower, less backlash the better I suppose plus no belt harmonics and no side loading of the bearings.

I cant say really say since I never ran a cog blower drive on a street car, it depends on the belt and tension I would imagine, more than one type of cog belt out there.

Unfortunately where you live I'm sure you see a lot of unreturned e-mails and phone calls from American companies, thats too bad really. But its not much different with a lot of these places if you live in America, I have had some places not returning phone calls when I wanted to buy something also..

I use a 7.25 crank and 4" blower pulley, its a lot easier to keep a 4" pulley from slipping naturally. Have you tried bead blasting the pulley? That doesnt last a long time but you may have to keep one pulley for street driving and one just for making blasts.

Honestly my biggest fear of a cog drive is the belt coming off and tearing stuff up under the hood (or the hood itself). I have fuel and brake lines near the belt, plus power steering lines, wiring etc. When those kevlar belts let go they can seriously tear some stuff up, another thing to consider..

 

Ive had several ribbed belts shred until I got the drive sorted.

Worst was when it took out some wiring, and trailed it into the pulley and shorted out. I was very very fortunate to avoid a serious fire. Even more considering it was the main feed to the alternator !! Still managed to effect a repair and drive home lol
I removed all wiring from anywhere in the belts path so it couldnt happen again. Later that year, it took out my PAS cooler after a failure. I had thought it would be strong enough to take a hit....guess not.

So I also removed the cooler altogether. It does cause some fluid issues when in warm weather, and using the car hard ( not in straight lines ), but that isnt very often.

So at present, the only concern from a broken belt...is that it could potentially take the radiator out too.. Nothing I can do about that though. I dont think there is anything else thats vulnerable in its path.

So again.....if the cogs do fail in such a fashion....why do they fail ? Is it a lack of belt strength to cope ?
I'd only be using Gates belts.

Bead blasting is one idea....and swapping pulleys. But my entire goal with this, is a car I can drive, anywhere and everywhere, without having to resort to changing anything other than tyres, for racing.

Cogs are looking ever more tempting. Although Ive made up a few brackets to force wrap around the existing setup.
I'll maybe have a go at that first....need to get another engine built and in the car first though !!

 

If I retain the 12 rib...this would be my intended plan. Move the tensioner ( pink ) further way from the blower, and place two fixed idlers ( blue ) either side of the blower pulley, forcing wrap.

Even with a cog setup, I would probably do this, although to a lesser extent with the wrap. Mostly to remove any chance of belt vibrations going onto, and off the blower pulley itself.

 

The ATI ProCharger 350Z and G35 kits work quite well with their cog drive assemblies, with a little luck we'll get our Camaro working with one as well. Bob

 

Getting more wrap never hurts.

Ever think of doing a strut between the crank and blower and really cranking the belt?

 

I did......It was working great, and then the upper mount at the blower broke lol and I never got around to fixing it.

It would ideally need me to make a new pulley, with much deeper recess to hold the strut mount fixing, and take some or all of the loading off the bolt itself. The bolt sheared when I was in Denmark in June, the brace walked off, and damaged the upper bearing in the brace. I took it off, got the broken bolt out and was able to continue though without it. Luckily it broke when I was queuing to race, as opposed to actually racing.....which would have been nastier

It's also a very very tight squeeze, and a PITA to fit on the crank.

All of this would be much easier if I had a small all lathe to make stuff. When trying to pay people etc to do it, or rely on machinists, waiting on them etc......its a f'in nightmare.
Unfortunately the friend that used to do all that sort of stuff for me, was killed on his motorbike just over a year ago. He was the only person I could simply tell him what to do, and it would be done right !

 

We added a strut similar to SD concepts peice, and we still had 3/8s to 1/2in movement when revving up the car. We added a peice from the top of the blower, to the driver cylinder head. It only moves 1/8" or so now.

Still looking into other venues.

For the price of R&D and materials, it adds up to a nice crank drive setup. We have one setup for a f3 mounting and it looks pretty good.

 

I was talking about a strut that uses bearings and goes between the crank and blower pulley, lets you tighten the belt like crazy wothout tearing up the blower or front main bearing.

I use a tubular brace between the blower and oil pan, plus use an extra bolt in the bracket by the idler. Without that extra bolt its amazing how much the J bracket moved, now its pretty solid with a steel J bracket + the brace.

 

My brace before it broke....It was intended for the cog setup which had a deeper pulley.
FWIW, my blower bracket is a simple steel item. Secured with only 3 bolts. Pretty damn strong though.

Although with the bearing supports bearing made of alloy...I guess they are inherently weak, especially at the blower end due to its faster rotation etc

 

I hear you, I used to have access to a complete machine job shop with 40 years of odds and end raw materials laying around plus an engine machine shop where I used to live. I used to have a lot of fun building parts.

Around here everything I have had made by local machine shops I have been overcharged and it never was what I wanted.

 

Ah, im famillar with the term crank support lol.

We are going to try the steel bracket out. Since we have a iron block, we do lose one boss for the alt mounting.

 

You can have a crank support without a strut, just words

I would think that missing bolt on the iron block is going to hurt some.