Olli

Great place I lived and worked in the Durban area for 6 months in the latter half of 1976. Managed to live in 2 houses in that short time too in Winston Park near Hillcrest and in Kloof. I put that down to be part of my reckless youth (early 20's) for moving around a lot in those years. Used to work mainly at 320 West Street. I remember the great fruit juices and sandwiches at Juicy Lucy's there at the bottom floor (street level) of 320 West St. Most of my time in SA was around Cape Town (mainly Somerset West) though with 3+ years in the Johannesburg area.

Anyhow, thanks for your reply again since I thought afterwards that I should have asked about the air filter in your car and the melting of it. Can you remember what circumstances led to this issue in your car? Was it during track days or just regular driving? Do you think a turbo blanket would help?

Mo Mia

i noticed the problem over track days and not street use. the first was at the A1 this year in Durban.

Extremely hot and the filter was new (Drove the car straight from the shop to track). By the end of the weekend, approx. 160kms later the filter was stuffed. All it needed was 1 track day, my filter edges (plasticky stuff) melted (top and bottom) which casued a tear at the bottom. Under boost the filter would collapse down muffling the turbo (causing varaible boost and stress on turbo) and the tear allowed little stope chips (altho they were big enough to stuff up the impela) through. I have never used a turbo blanket so .. not sure ... but from what i saw happen to 2 of my filters, i would hesitate.

For normal street use ... just make a point of checking it regularly

PS ... i think what you doing with the tranny is awesome ... have you tested it yet .. how does it feel.

Olli

Geez...thanks for the info! I will keep checking the filter regularly. So far there has only been spirited bursts done with this car during street driving and the filter has held up without any visible damage to it. The reason I know this is because the filter has been on and off quite a bit while we were chasing an oil leak that had to be the last place we checked (some sealant around the chain cover studs had cracked). In between the various checks there was also some real hammering, but just for short distances, and the air filter had remained looking the same. But I'll try the turbo blanket as well until the permanent changes are made. I guess it couldn't hurt.

Thanks for the tranny comment. The transmission feels really smooth when shifting so I am very pleased with the gearbox itself. The one thing I did that did not work out as nice as I had hoped was the lightweight flywheel/ race clutch/ PP combo with an expensive release bearing ($795) that I had to buy (from Smart Racing I think) to make everything work.

Before I go any further I need to state that the installation of this package was due to my own ignorance and there is absolutely nothing wrong with the parts themselves. I am sure that they are perfect for a car that is primarily being tracked. Being a newbie in this Porsche world I just had to learn a lesson about being careful what I wished for and everything that sounds great might not be good for the application that I am using the car for.

The LWFW/Race Clutch/PP is from AP Racing and I discovered that the LWFW allows a lot of noise to come through that the old heavier and bigger FW had probably masked. Also the LWFW made me do a lot of revving to keep the car from stalling and the idle was affected as well. The one piece clutch being a real race clutch is very grabby and I discovered that most likely any amount of skill would not be enough for a smooth take off. All this combined made street driving somewhat conspicuous and hazardous. At least for me.

I have now taken the car back to the shop with the old FW/Clutch (spring centered Sachs)/PP and they will put those back on next week. I will use use the racing clutch package for a future track project as I am sure it will be perfect for that.

Jean

Olli

Here is what a blanket looks like, they work very well, at least by the time you decide to change the configuration of your setup if you end up doing it.



Sorry to hear that the clutch did not work our for you, I am sure you will be happy with a normal clutch setup.

Olli

Thanks Jean, that looks good.

Regarding the clutch, it was just my own foolishness to think that there would be more advantages/benefits to having this setup for my street car. I know it will be perfect for a track car setup in which those characteristics could be capitalized on. But in a street car there is not much opportunity and the environment and conditions we drive in are not friendly for the behavior that results from the LWFW and race clutch. Hindsight is always 20/20 and of course now I think I should have asked for and relied on advice from more experienced people who have gone through this already, like yourself, instead of just asking the shop on a whim to put this package on for yet some more performance gains. Oh well, live and learn.....

I am looking forward to having these components in a track project when I can afford one.

A930Rocket

Olli,

How much power are you making? You may want to think about a KEP stage one or two PP. They have a disc that is supposed to be better and it's the same price as a stock one if you want to add that (~$175). I went with a stage two and the disc and I'm happy so far.

Jim

Olli

Thanks Jim! I'm glad you told me that. I'll talk to Dave on Monday about that.

Regarding power, that's a tough one because we never did a final power pull all the way up to 6800 RPM or whatever the limit is. All of the pulls they did when they did the initial tuning were up to 6000RPM only.

The best pull that I saw was a nice and smooth 0.8 bar curve that peaked at 531hp. They did not save that graph (one of the first ones) and I no longer remember the torque number but seem to remember it was just over 500rwtq.

This is the 0.9 bar pull that I posted earlier on in this thread that peaks at 547.9hp and ~520tq:



Here's another 0.8bar pull that did not produce the highest numbers but you can still tell the power curve is still on its' way up:



Here's a series done later in the afternoon of a hot and muggy day when it was just about to start thundering. This is the one where you can tell how the throttle body starts choking. The hp numbers a bit lower even though higher boosts were used, but as you can see the top torque number here is 550lb-ft. This one seems to go to 6200RPM unlike the others. I no longer remember at which boost levels each run was done but I don't think the top one was more than 1.1 bar. I am speaking under correction though since I honestly don't remember, but they never went into any ridiculously high boost levels:



Here's one just for interests sake. You will notice that they had typed for the Run Id: First Dyno No Boost:



Anyhow, once again the bottom line: No final pull has been done so I can't really answer the question properly regarding how much power it makes. I would think that around 550rwhp and also around 550rwtq is where the limits would be due to the throttle body restriction.

Given the above, any impact on the choice of clutch?

911rudy

What is the purpose of a turbo blanket?

Olli

I would be using it for reducing heat in the immediate surroundings of the turbo to preserve the air filter. If it has any other benefits maybe someone else (more knowledgeable) can inform us about them.

Jean

Olli

the turbo blanket is also supposed to improve boost response by keeping the exhaust gases flowing at their maximum speed and avoiding boost pressure losses by keeping the heat in there... How much of that can be verified I am not sure

As for the PP/clutch, I have heard good things about the KEP setups, but I would personally stick with Sachs, which is what I am using on my car now, no slipping whatsoever with my 3.8TT engine ( I never run higher than 1.1 Bar though) and the pedal is as smooth as my stock 993TT. These are rather new setups, and have much stronger clamping force than the old ones.
Here is one who sells them:

http://www.cargraphic.de/index.php?/...,article,3671/

Closer to you, Kevin M. at UMW has access to some very good SACHS clutch assemblies as well that will fit your needs.

Cheers.

nathanUK '81 930 G50

It has been said on here that the Sachs pressure plates lose their clamping force over time & will eventually slip. That same person has now got a Kennedy PP and he says it has maintained pressure/clamping force over time perfectly.

Jean, I hope you are well. I did see that you said "These are rather new setups, and have much stronger clamping force than the old ones."

Are you saying they have improved their PP's?

Jean

Hi Nathan, all is well thanks

If people are drag racing their cars, this might not hold, I don't know. My clutch does not slip with the Sachs, nor do other high torque 993TTs that I know of and we have some decent acceleration times.

There is a certain degree of tolerance in the ratings of Sachs, these are rated 810NM which IMO is good for 900NM. I don't know of any aircooled turbo putting those sort of numbers in real life, I am not talking about dyno charts but rather real force as Sachs measures it.

Olli

Great info, thanks Jean I was talking to Lincoln (Schnele) last night on the phone and we were looking at these turbo blankets on the sites of a few vendors. They seem to go for around $150 and I will have one on by the time I get my car back this coming week.

Thank you all also for the good discussion regarding clutches/Pressure plates. I will take all this info and discuss it with David Brown on Monday.

I realize that real life HP and TQ is a completely different thing from the numbers that these dynos put out, but even if the 550lb-ft (~745Nm) was also true in real life, it would still be well within the ratings (810Nm) that you mentioned Jean so it is a good possibility. But as I said, I will discuss these options with my builder as well.

Once again, many thanks for the much appreciated input

Jean

Olli

My pleasure, just please double check all this with your builder as you rightly pointed since I am only an end user.

Excellent build

Mo Mia

Hi Jean,

If i read your e-mail correctly, you have a 993TT clutch in your 930. If yes, did you dump the clutch cable for a hydraulic system? the reason why I ask is that I have TT clutch but experience problems with the fork as well as setting (freeplay and clutch riding). I am told that it is better to go the hydraulic route.