Cool, good job. Now get that bumper on and drive it.

Have you tried to adjust it richer it at the fuel distribuitor?

At what rpm and boost pressure does it go lean?

I would try and keep it simple and just swap out the WUR as you mention. This way you won't mess up any adjustments and it is easy to go back.

I say this assuming you have a 930 WUR at hand. Which I believe to mentioned earlier.

Make sure you monitor those AFRs while having fun.

Just my 2c

I suspect changing to a 930 WUR will not be "simple".

Might want to check to see if the SC and 930 WUR warm base control pressures are even close before trying.

If not, it may not run on a 930 WUR without major modification.

There have been turbo and blower kits for SC's for years and I believe they got them to work with the stock fuel system.

Another converted CIS to turbo trick is to put a pressure sensing fuel pressure reg on the fuel distributor return line. This jacks the system pressure with boost for more fuel.

Gavin, I hope this is ok as you can apply it in your project.

911st, I am stil learning, A LOT. Please tell me why switching the WUR is not a simple task.
They physically are almost the same, and he has the plumbing squared away already.
I am not including adjusting/tuning in this statement. Just the swap of components to see the effect?

Gavin, congratulations!! Sounds great on the video.

Sounds mean! Good work...

Sounds really good! Really good!

Swiching is, getting it to work may not be.

The WUR is basically a pressure regulator. As such they operate at a given pressure that works to offset the forces of air flow about the metering plate and how far and fast it opens.

If the 930 WUR operates at the same basic control pressures (except on boost) as the SC's it will run correctly. If not it may not run at all. This would require it to be made adjustable such that it could operate in the needed pressure ranges. Cold, hot, and on boost.

Someone needs to look up the specs of the SC and 930 WUR being used to see if they are even close. I forget but I think the 930's are significantly higher.

Another way to get enrichment with the SC WUR would be to bleed off control pressure using a frequency valve and an additional injector controller. It works quite well and makes the CIS very tunable by rpm and load. Or, there is an aftermarket tunable electronic WUR that sould be a great / best soulition.

I would really like to install a digital WUR like the one from UnwiredTools, but its not cheap :(
I will first of all just try plugging in the 930 WUR and see what happens and post the results.
I can also make the 930 WUR adjustable, so should then be able to adjust it to more suit the SC/turbo setup.

The car is currently at Canford Classic where they have helped with the engine remove/install and a few other bits. (Canford Classics - Classic Porsche Restoration & Parts Refurbishment) Couldn't of done the install without them, thanks guys.

I hope to get the car running enough to just get it home then I can send more time on it instead of just Saturdays.

Thanks for all the positive feedback :)

Started to tidy things up and took it for a small drive to the gas station.
All went OK, but monitoring the AFR I didn't push it past 3K as the AFR was at 15 by then.

Cold idel - 10.2
Warm idle - 12.1
Warm cruise - 13.5

As the revs rise towards 3K the AFR hits 15 so I defiantly need to try the 930 WUR.

I can hear the turbo start to whistle at about 2500 to 2800rpm and a little extra push, so it appears to be starting to spool quite low down, although once the AFR is sorted i'll get a better idea of things.

One problem is the draining turbo oil back the the top of the oil tank.
I have noticed oil dribbling from the small filter I installed as a tank vent.
It appears the oil is not flowing back into the tank quick enough and is backing up.
I need to explore a better solution. Maybe use the same solution but make it better.


http://forums.pelicanparts.com/uploa...1365705722.jpg


http://forums.pelicanparts.com/uploa...1365705758.jpg


http://forums.pelicanparts.com/uploa...1365705787.jpg

I know the OEM drip tank had a vent but most aftermarket applications I have seen do not. If the vent is too low, it may be below the oil level in the engine case at times. I have run my turbo oil drain direct to sump, electric scavenge to chain box, and now cam driven mechanical scavenge pump to breather cover all without venting and so far no issues.

Wow, the car looks great!

I apologize if you already know this stuff.

I believe CIS on SC's usually run a very flat AFR curve from idle to peak rpm so it is surprising you are getting leaner with increased RPM. (not under boost)

I suspect your WUR warm control pressure is a bit high which keeps the metering plat from advancing as fast as it should with increased in air flow. Or you could have an intake leak after the metering plate.

If control pressure was low you would naturally get richer with increases in RPM.

If you are going to tune this beast you have to have a set of CIS gauges.

If you are going to try the 930 WUR it might be worth checking your present control pressure as a reference point. Also should look up stock control pressures for the SC and the 930 for reference. This will give you and idea how far you need to be able to adjust the 930 before it will work.

Once you make your 930 adjustable I would think you could hot wire the CIS system (safety & to get 12v to the heat on the WUR) and test the pressure in place before you try to start it.

There is a guy here somwhere that has run an SC turbo for some time. If me I would get with him. No need to reinvent the wheel.

;)

To find the other SC turbo'd threads:

Search: Keyword(s): turbo ; Threads Started By: patkeefe

Not sure it this link will get you there:

Pelican Parts Technical BBS - Search Results

This might come in handy.

Here is the WUR specs for the SC:

Sorry for all the stuff.

It looks like the SC and 930 control pressure's are a match at close to 3.6 bar warm.

Thus, you might get lucky just bolting the turbo WUR on.

I think you may be short on fueling. If you can't get sufficient volume of fuel to the fuel head, a different WUR won't help much. Are you running a stock SC fuel pump? What is the fuel pressure at the fuel head?

Oil return and fuel are the two biggest issues you will face.

I will be picking up the car this Saturday to return it home. I should then get more time to sort th last issues out.

I have a set of CIS gauges so will test the pressures asap.
The fuel pump is standard, I did consider swapping it for a Bosch 044 but read in several posts the standard pump should be able to cope.
I have read the US and Euro car's differ in area's such as the fuel heads with the euro being able to flow more fuel, although I'm not sure if that is just for 930 models and not SC's.
With any luck I should get some more work done on Sunday.

Thanks for the above info, it's certainly given me some hope that the 930 WUR may work in either standard form or made adjustable.
As for the fuel pump and fuel head I guess i'll have to see what happens with the 930 WUR on and go from there.

Went to check the stock SC and 930 WUR pressures only I can't find my gauge now!!

So whilst I was there I finished off a new oil feed to the main oil tank.
I've made a pipe that goes down into the main refill neck and also has a small air filter as a breather.
So far so good. it seems to work OK. I'll get some images soon and post them.

As for the WUR issue.
I plugged in the 930 WUR and it started, although it did'nt seem to go through the warm up cycle and the AFR at idle was 14.4 even after several minutes. When I revved the car a little the AFR went into the 18's so I turned it off and plugged the SC WUR back in.

With the oil return issues hopefully fixed I went for a drive and very gradually pushed further into the rev range.
The AFR stayed at mid to high 14's as the turbo spooled, then just as you can feel the power come in the AFR dropped into the 9's and power instantly dropped away and the car hesitates.
I'm assuming the issue is the WUR over fuelling as other threads say turbo AFR on boost should be between 11 and 12 AFR.

So the SC WUR does seem to be reading the extra air flow and trying to compensate with extra fuel but if the AFR reading to correct, to much fuel.

Is far as I know the only read adjustment I have is the the 3mm hex fuel head screw. I've read this adjusts the idle and the midrange some.
My current warm idle is 12 AFR and cruise is AFR 14

I'll have a go at leaning it out with the 3mm hex and see what happens. Hopefully it will lean out the on boost also.


If anyone has any idea's I love to hear them :)