Speedtoys

No, the damper is separate from the pulleys. GB has a 928 specific designed product for this.

Here is what a lot of 928 dampers look like, at this time. Lots of barely there hums and buzzes coming from crankshafts out there..this was an 87 with 112k miles, October 2017.

928S MN

Very excited to learn of this relaunch effort!

But I have a specific question/concern related to those of us with the 5 spd transmissions. I currently have an ‘85 US 5spd with LSD.

At what boost/power levels does the power potential then mandate an upgraded clutch above OEM specs? I’m going to assume the Level 1 will be ok but the Level 2 will be questionable? Level 3 would be a definite upgrade necessary?

And what is the safe upper power level for the standard 5 spd transmission before it grenades? 😳

Petza914

At 350 HP and 350 TQ at the crank, the so k friction discs slipped on my first 3rd gear pull and I had to go back to the sintered metal spec ones I hate. Greg has a really good single plate clutch that will have no issues holding this and way more, and Hans is coming out with something new that has interchangeable friction discs and components based on what it's going into.

hacker-pschorr

That depends a lot on the tires, driving style.......

My 81 was putting down 350 at the wheels and the stock clutch never gave me issues with 265's on the back.
The stock double disc can hold more than the 87+ single disc. A well tuned supercharged 85/86 should easily make 400-500 at the wheels depending on the boost level.

Strictly a street car or some track duty? Even in bone stock form, these transmissions need at minimum a cooler for track use.

On the street it really depends on how your driving style is. 500rwhp you get up to 150mph so damn fast you're not really "on it" for that long.

But again, a lot depends on the tires and how sticky a compound you go with. The better your tires stick off the line, the more stress you're putting on the trans.

Petza914

Good point on the tires. My supercharged car has 295 Nitto Invos on the back so I've moved the weak link from breaking the rear end loose to breaking the clutch loose

I run those same tires on my 84 Euro S but in a 275 width but that one is an Auto

Speedtoys

Kinda..depends...??

There's someone on here with huge tires, that drives a 5spd with a binary clutch and a lead foot, busts stuff all the time.

928S MN

I’m running 285/18’s Michelin Pilot Sport 4S’s on the rears. So pretty good grip with those.

I’m looking to liven up my weekend driver. I don’t track this car at all with the known oiling issues on the ‘85/86 engines when they’ve not been addressed/fixed.

What’s caught my attention here is the Stage 1 offering but with the added ignition/harness upgrade. Hopefully the Stage 2 added features can be purchased separately at a later date as more budget becomes available. Hence the reason for my original posting. What, if any, additional clutch items need to be added to the “budget” to realistically make my smiles per mile increase above what they already are? Kind of looking forward to my cheeks starting to hurt every weekend! 😆

hacker-pschorr

IMO the big issue with the double disc clutch is parts. I've been hording double disc clutch parts for close to 30 years and thankfully so since I currently have two (78 and 80) up in the air getting clutch work after getting the clutch in my 79 sorted (my first 928 with a modified intermediate disc with set screws).

If it were me, I'd wait and see what Hans is cooking up and switch to that if not for any other reason but peace of mind you'll be able to service it down the road.

If (or when) Porsche brings back some of the parts like the intermediate disc, I'm sure it will be $2,000 or more just for that one piece.

After that, longevity of the trans will really depends on your driving style. Some kind of a cooler sure wouldn't hurt.

Speedtoys

You can get kids through a nice school with a closet full of double disc clutch plates...

928S MN

Back to Rasant Products.

Will be very interested in your upcoming development work to see where the Stage 1 & 2 power numbers settle in at.

Just for clarification, my “butt dyno” can’t tell the difference of +/- 15 hp so those discussions go right in one ear and out the other. Now 40+ hp will get my attention. Hopefully the above 5 spd manual discussions will allow those owners to make a more informed decision on which of your product offerings to go with.

Rasant Products

Thanks! Yeah, this is the downside to driving this many different initiatives simultaneously - it takes much longer to get any one single development completed expeditiously.

The upshot to embarking on several new product developments at once, is that some of the problems to resolve, are often shared across the different products; a solution for one, means a solution for all. Then when you reach the goal line, you have several things rolling off at the same time! For example; finding a new source for cadmium and yellow zinc chromate plating - those types of business have been driven out of the city (and even out of State.)

What was left was either taken out by the scamdemic, or this sheity economy, so we had to find a new small-batch resource for the hardware on the air-cooled ITB kits, as well as for the 928 Rotrex brackets (which are currently steel) and for some of the other classic model projects (like the Alfas.) A small example, but you get my point.

Anyway, been busy.

Between building out a new showroom and ten other things, we've actually made forward progress on this Rotrex kit for the 87+ 928 models. We have installed the neat Hans SerVaas crank-case oil splash / vapor baffle over the crank-case opening at the front-center of the block (where the OEM oil-filler neck used to bolt down.) Funny how closely the capped top part resembles the crankcase ventilation plates on air-cooled 911 cases! (We modify those to be the pivot points for the 6-ITB throttle-pulls!)

Anyway, now we're working on a new 3-D printed vented filler-neck and catch-can solution that will replace the stock 928 oil filler neck and to bring that all together for proper crank-case ventilation!

Rasant Products

Another example perhaps are the 5-cylinder 07K engine conversions (also with Rotrex superchargers), for the 924 / 944 / 968 models. This requires a bit of rapid prototyping of the brackets and now we have several resources assisting with the design aspects of those systems, transferring designs to CAD and 3-D printing of mock-ups. Those resources apply those skills to work on the 928 challenges and so on...

We're hunting for custom inter-cooler solutions, heat-exchanger solutions - on and on and some of the same resources can help with parts for several different products! Years ago, we sourced some classic finish (cloth-wrapped) stainless-steel braided lines with more muted tones for the AN fittings (in base colors like gray and black, as apposed to the usual red and blue anodized crap.) This was on a Turbo 2002 project - now that groundwork has aesthetic application on these projects!

For the 928 installations, we've have been experimenting with various slot-MAF tube solutions as an alternative to the stock MAF. I know that Victor "ran fine" on the stock MAF, but what if the MAFs are different, or off, or out of spec, or vary from one car to the another - given age and wear and miles!? We want a consistent part, but it will only be for the initial stage stage kits. By the time were on to the third stage kits, we're running speed density based (manifold absolute pressure) tuning without the MAFs anyway.

Rasant Products

Anyway, we have relocated the horns in the passenger-side front wheel-well area and made room for the new heat-exchanger there. We have mounted the Rotrex oil cooler in the driver's-side front wheel-well area on the other side of the car. Lots of problem-solving along the way.

We also played with Hans' custom billet fuel rails and fuel pulse dampers, but unfortunately those were still too long and interfered with the Rotrex inlet pipe, so we're back to modifying the stock fuel rail on the passenger-side. I don't like deadhead fuel rail systems though, so we are working on creating a flow loop with return (even after that one rail is modified.)

Rasant Products

Lots of wonderful little curve-***** - we thought that we had the right fuel injectors ready, but we went to install them and discovered that they were missing the top groove for the locking clips. Back to the drawing board. Easy enough though, but it's just lots and lots of little things to consider (and none of it exists independently in a bubble.)

Each decision impacts ten other prior choices that you thought was put to bed...

Mrmerlin

NOTE the lower tan O ring is a special size for the S4 intake,
you would be smart to use the factory size O ring .
NOTE the black O rings are not exactly the same size,
usually its the ID that slightly bigger,
this will lead to intake leaks and worse if your pressurizing the intake.

NOTE also keep in mind that the powder coating layer is a part of the how the O ring seals in its bore.
If you have any injector bores with missing PC,
then the intake should be removed and freshly powder coated to restore this bore diameter.

NOTE injector O ring kits are available from Bosch ,
and they also contain new pintle caps and the correct size spacer.


NOTE I also suggest you use DC111 on all of the O rings,
this will keep them soft and flexible and make them not stick when they are installed.