Backdating '76 930 to original non-intercooled setup, what should I change?

[G60SuperCharger]

I have a German market '76 930 in Copper Bronze Metallic with plaid interior. It is mostly original with only 62,000km. It was upgraded about 8 years ago to GHL headers, K27 turbo, Garretson long neck intercooler, and Tial wastegate.

Thank goodness the previous owner kept all of the original non-intercooler charge pipes and parts, and I have the early Turbo tail in the right color. I plan to keep the headers, K27, and Tial. I thought it would be fairly simple to just remove the intercooler and put the original parts back in, but nothing is ever that easy.

Questions:

1. Will the k27 and Tial wastegate work OK with the original charge pipe (non-intercooled) system?

2. The Garretson intercooler has an overboost cutoff switch (that cuts off the fuel pumps), but there is no bung for it that I can see in the original system. Does the original system have a different way of overboost protection?

3. The blowoff valve was external with the Garretson, but it is inside the aluminum housing in the original system. I don't understand how that one works...it doesn't appear to need any hoses connected to it to operate unlike the current external one. When I remove the external blowoff, do I just cap off the plumbing for it or does it somehow need to be re-routed?

Thanks for your help!

[1100sport]

Pics please;-) and some showing the interior too!

[jsveb]

I know it is not what you are asking, but unless you want to sell the car, I would keep it on there, IC etc., that is. It won't do your engine any good to remove, on the contrary. One day if you decide to sell re-install the original parts.

[G60SuperCharger]

Originally Posted by jsveb

I know it is not what you are asking, but unless you want to sell the car, I would keep it on there, IC etc., that is. It won't do your engine any good to remove, on the contrary. One day if you decide to sell re-install the original parts.

You guessed it, I plan to sell. My '66 911 is up on ebay now and I plan to list my 930 on there soon too. To be frank we could use the money and it seems like a great time to sell.

I'll be doing a photo shoot for it very soon similar to what I did for my '66: https://picasaweb.google.com/107462596126098920364/1966Porsche911SlateGrayRedInterior#

[TurboKraft]

The stock charge pipe to the throttle body does get a vacuum signal to operate the recirculation valve, pull the piston open. Vacuum from the top of the intake manifold, to the left of the throttle body.

Someone who drives his 1976-77 930 will enjoy that Garretson IC and factory 1978-89 wing.

[G60SuperCharger]

Thanks Chris.

What about overboost? Do I just eliminate the overboost cutoff system entirely?

All original cars fetch the most money at auction, but will provide the Intercooler and '78-89 tail with the car for the new owner to enjoy.

[infraredcalvin]

There is an overboost switch, it's number 24

[Ronnie's.930]

Regarding what you should change, well first and foremost, your mind (unless you like going way backwards with performance, that is)!!!!

[G60SuperCharger]

Originally Posted by infraredcalvin

There is an overboost switch, it's number 24

Got it...thanks. Looking closely, my car had an adapter/splitter with a boost guage sending unit on it, and there is an empty bung for the overboost switch.

Do I attach the vacuum line to the waste gate (which used to attach to the intercooler) to this port? It's hose 42 in the parts diagram above.



What is this port on the back of the bypass valve supposed to connect to? It's hose 43 in the parts diagram above.



Thanks again.

[michaeljeller]

a workshop manual might be useful--check the links at Porsche 930 Turbo Carrera 3,0-liter

[G60SuperCharger]

Thanks...I did look there but there's no vacuum line diagram to go by and the instructions for removing and replacing those parts don't mention where the lines go.

[stevie 77 930]

Here is a picture of an early intake manifold. I tried to mark vacuum hoses, its not great, but here you go.

Hose #1 large diameter hose for brake booster

Fitting # 2 Hose attachment to BOV hose is about 8'' long and is routed under
the manifold

Fitting #3 short hose to Vacuum limiter goldish canister

Hose # 4 vacuum to distributor pod

Hose # 5 to wastegate

Fitting # 6 vacuum line to vacuum limter nipple on the front

[G60SuperCharger]

*perfect* Extremely helpful...thank you so much Stevie...that solved all my problems! The collective knowledge on Pelican never fails to blow my mind!

[G60SuperCharger]

Having some cold start issues. The auxiliary air regulator (#44 on the parts chart above) connected to the inter cooler before, bit now it has nowhere to go. Where does hose #48 connect on the 3.0 cars?
I've seen the hose go back by the throttle body in the pics online, but I can't see where exactly.

Does it connect to the large nipple on the back of the intake manifold to the right of the throttle body? You can see it in Stevie's photo but a vacuum line kinda blocks he view.

Thanks again for your help.

[infraredcalvin]

I don't quite remember where it goes by the throttle body, but that nipple you mention seems too much of an angle the wrong direction, this photo is from a very dirty disassembly... I'll be at it this weekend, maybe I'll post a link of all the photos I have on a share so you can peruse through...

[TurboKraft]

There is a intermediate block with a hose nipple, the block is between the manifold and the cold start valve. AAR hose attaches to it.

[T77911S]

i would sell it as is with original parts.
coming from someone that was looking for an original 930 within the past few years, having the extra "goodies" on there would not be a negative. in fact more of a positive. that would just save me having to take the original parts off and put the go fast stuff on there.
the key is that it CAN easily be made original.
i have done some wiring changes on my car but you cant see it and it can easily be put back.

[G60SuperCharger]

Thanks Chris, I will look for it there.

T77911S, that was my original plan, but with the stratospheric prices these 3.0 Turbos fetch lately, they are likely to end up as garage queens rather than drivers, and original appearance is what that crowd wants.

I hope that's not the case with my car as it's a blast to drive, but that's the reality IMHO.

[stevie 77 930]

You are testing my lack of skills using paint......
Here you go.....(but remeber this is for a 77 with a Aux Air Valve that is used for cold start) This what mine looked after i pulled it duriing an engine rebuild I too removed a intercooler from my 77

A line to Aux Air Regualtor # 44 in parts diagram
B Vacumm control for WUR on the top of WUR (assuming you are using a 022
or 050 WUR
C boost enrichment line to WUR
D Cost start valve (blue device)
E used for Aux Air Valve on my 77
F vacuum line to Decel Valve (see previos post)
G vacuum line to EGR Valve




This is what my manifold looked like after a good cleaning and neww lines

[G60SuperCharger]

Thanks again Stevie...just what I needed. This will be a great thread for others who want to backdate later on...I won't be the only one.