Upgrade I/C only?
 

I have a bone stock 930 from 1986. I don't want to upgrade the turbo since I will need to modify the stock sheet metal (k27). Therefore, if I only upgrade the I/C to say a kokeln, would I see a noticeable increase in power i.e., quicker turbo spool time to get on boost sooner?

I can't bring myself to altering the stock sheet metal since the car is so pristine. With that said, I/C technology has vastly improved since 1986. I like the Kokeln because it is a true bolt on and does not require any modifications. I know they are expensive but this will probably be the only change I make. Is it worth the time and money to only change an I/C?

Waste of money unless you will be tracking the car - which it does not sound like you will.

You don't have to modify the stock sheet metal to add a K27. I've done it many times.
You do need to modify the stock 3LDZ turbo bracket. For pristine or bone stock cars I buy a new bracket to modify and stick the stock bracket and turbo in a box for storage. Same with the intercooler and muffler.
A K27-7200 will reduce your lag by nearly 1000rpm. You also need a free flowing muffler for optimal results. These are the two mods that give the best bang/buck on a stock engine and remain 100% reversible.

Thanks. If I choose to do this I think I know where to get that exhaust :)

I am going to take a different stance. I recommend upgrading the stock intercooler to a newer more efficient core and more efficiently designed intercooler, even if you leave everything else alone (stock turbo, exhaust, muffler etc).

The stock intercooler was "marginal" even from the get-go in '78 / '79 when they first came out. Porsche should be embarrased to put those $hit things on one of the most expensive cars that money could buy (I have run oil coolers that large on some of my cars!!). Those stock intercoolers were made by a German \ Austrian fridge manufacturer that is now defunct, there is some cool dinner trivia for you!

My stock intercooler was "OK" if it was cold outside and I was not beating up on the car. In the summer really working the motor through the gears and rpms it would get very hot to touch, which is an indication how undersized \ inefficient it is for a large 6 cylinder. In addition its placement on top of a hot air cooled motor right at the very back of the car is not optimum, so there are alot of negative factors working against the intercooler from the get go.

To prevent detonation and keep your hp from dropping in the heat, is where a newer intercooler would be a great benefit. You will not necessarily see an increase in hp as you asked, but rather sustained power and sustained engine health.

I have test 4 intercoolers on my car to date.
Hope that helps.
Yasin

P.S: As already mentioned, there is no cutting of anything to upgrade to a K27 turbo, turbo housings can be easily re-clocked in a few minutes so you do not have to worry about trimming anything on your car's engine tin.

Isnt it about doing one change at a time and seeing the differences, fine tune for improvement and move on. Sounds like great upgrade.

Regards,

I want to do it right and make sure I can reverse the changes I make since the car is in new condition with only 11,885 miles. With that said, I recognize that technology has improved immensely over the past 22 years. Therefore, a new turbo, intercooler and SS exhaust would be the best improvement. The car will NEVER be tracked. It is a 2,000 miles/year car do to work and other obligations. It has been my desire to own one of these vehicles and now I do. Thanks for the feedback.

Once you do the above things, bring up the boost to .8 bar too -

Yes a bigger more efficient inter-cooler will make more HP. It better cools the air making it more dense packing more into the cylinder. I believe a good inter-cooler is often good for 20-30 hp all by its self over the stock style.

+1 on the K27.7200 and lowest restriction muffler you can run.

+1 on making sure you are getting .8.

Now you are making 320-330hp.

With the bigger IC if you are so inclined you can to to .9 bar boost for an added 15hp which is very safe even under the track conditions. 1 bar is good for about a total of 30 more HP (set the CO to 3%). Thus, 245 - 360hp or there abouts.

You might be supprized how well it will run just putting a good muffler on it and making sure every thing is in spec.

Installing a bigger intercooler is a great idea. Anything you can do to take thermal stress off the engine is an improvement. First thing I did was to install a larger B&B intercooler on my 1979 930 and then a Carrera oil cooler in place of the trombone in the passenger fender.
Also, this allows later improvements like more boost and k27 turbo which will need the safety of the larger intercooler. You can always go back to stock too as it uses stock intercooler up pipe and o-rings.
The B&B is another option to the Kolken and it fit well except for some machining on the attachement boss to the fan housing bracket which was way off center. You will need to make sure you get the intercooler shrouding to the tail done properly to seal the intercooler to the tail so all the air gets pulled thru the cooler and not arround the edges of it.
Seeing that you live in Oakland county in Michigan, you will likely see hp dropping off while hammering on the I-696 "autobahn" with the stock intercooler. With the bigger B&B cooler I can run flat out all day on that road. Though I did not recommend speeding in writing.

Can I give a shout out to all the Southeastern Michigan 930 Pilots, we need to get together in the spring, I volunteer to host and my beer fridge is open.

Schnele, just heard that shout out and I'm game. Saw the post a while ago about you getting your car back and was wondering how I could see it in person. Man that car is really something. I live in Ann Arbor and meet up with a couple of 965 guys from your area for drives west of Ann Arbor. Anyways standing by for spring driving.

Andy

My wife went to Law School at Ann Arbor so we are up there for football games and I sometimes bring the car I have a choice spot on the golf course. You are welcome to come see the car at any time.

BTW I know Paul who has been on a couple runs with you guys.

Yep Paul is one of them, thought you might know him. I sent you a pm so I would not steel this thread.

I'm in for a spring run.

Alright NOH20, I'm sending you a pm.

I am in for a spring run too.
Lets make it some twisty roads with no troopers.

Great Fred, we need to get WCC (Bill) in on this I think we should start a new thread.

Fredmeister, your in too. I can tell you the roads are twisty and we have yet to see a trooper, knock wood on the troopers though. I think at this point I'm going to put up my e-mail address for people to shoot me a message I'll lock them in my address book and send out a e-mail to all who have shown interest this spring. That's assuming spring will come to Michigan this year. Oh I think I have about 7 or 8 so far so keep them coming.

Here is my e-mail athompson@inlandpress.com