Kokeln Intercooler issues
 

Good Evening All,
I am having a bit of an issue with my Kokeln intercooler as the title suggests. This car is new to me so forgive my ignorance, here goes.

I took the car for it's initial shake down and on over-run from a high boost situation the car backfired (shooting flame in the process). After the backfire I experienced a surging problem when under full-ish or partial boost. I got home and did an inspection and found that the intercooler had apparently lifted out of the housing at the rear of the car, in so doing it cut the O-ring, part of which was still hanging out of the junction.

I removed the intercooler to find that some of the hardware which holds down the IC was missing. I went out purchased some new hardware and O-Ring, and set about re-installing the IC. No surprises, everything went back together well...

Took another little drive and all seemed well, problem solved I thought...
Well fast-forward to today... New shift bushings installed (thanks for the upgrade ideas by the way) and clutch adjustment completed. time for a little spin to check the work. Clutch and shifter, working like a charm! Then I did a second gear pull... BOOST is SO much fun! I needed to do it again... This time back to the same surging problem!

Got home for a little inspection... You guessed it the IC had decided to lift again! What the heck is happening! I did some searching... but could not find an answer. I may just be looking in the wrong place. Can you Gents give me a bit of direction? Either a link to another thread that I missed or... Just help!

How about a picture of the installation.

Absolutely! Will these suffice?

http://forums.pelicanparts.com/uploa...1205555353.jpg

http://forums.pelicanparts.com/uploa...1205555438.jpg

http://forums.pelicanparts.com/uploa...1205555515.jpg

Is there one more mounting bolt to the left of the intercooler? Should be a total of 3 holding it down. The gap showing between the intercooler & pipe, is that always there? You may need to get a hose & clamp that gap off.

There is the third mounting point, it just didn't photo well. The gap is the problem in question. I loosened the mounting hardware reset the IC and we are back to the original starting point.
This is the "normal" gap. It is much smaller, than the first pictures, granted, but it is not completely uniform about the entire circumference. This is about as close as I could get to getting everything to sit flush. Should I give it another try to get the lip on the IC neck to sit evenly on the pipe below?

http://forums.pelicanparts.com/uploa...1205559588.jpg

http://forums.pelicanparts.com/uploa...1205559623.jpg

http://forums.pelicanparts.com/uploa...1205559643.jpg

In regards to the hose clamp idea, the neck of the IC and what it slips into are both alloy, so no dice there.
It there a pressure release valve which might be sticking?

The ignition coil mounting braket which is also part of the intercooler mount looks like it's flexing upward under boost.
Also the left side mount is no longer there when the intermediate manifold has been removed for a long neck intercooler like it looks like you have.

There should be a mount in the back of the intercooler that goes down and bolts to the intake manifold. Look and see if the bolt is still there and snug.

If your running higher than stock boost that can also help lift the intercooler up off the up pipe from the turbo if the brackets are not fitted just right.
If the coil bracket isn't strong enough to hold it down you can fabricate a turnbuckle or rod ends and threaded tube to make an adjustable length bracket that goes from the coil bracket mounting point down to the engine mount cross bar.
If you do that the turbo's air pressure won't lift the intercooler off the up pipe anymore.

Mine was doing the same thing just not as bad, so I took a $7 turnbuckle and made this bracket from stuff I had around.
First is a pic of it on the car right after I made it a few weeks ago, and then a pic of it on a table from a few minutes ago.
I've sanded and polished it a little to try and make it look better. The bottom end of it uses a shouldered seatbelt bolt and a castellated nut from an old BMW 2002 tie rod end sprayed black, and hooks onto the bottom of the engine cross bar.
I've seen other people make up a similar bracket with rod ends and that looks alot better but costs alot more to make too.
http://forums.pelicanparts.com/uploa...1205560384.jpg
http://forums.pelicanparts.com/uploa...1205560884.jpg

JFairman,
You are a crazy night owl, or a very early riser with great priorities! I am using a 1bar WG spring... So I am going to fab a bracket and give it a try! Phenomenal! Thank You!

lol... you were right the first time :)

Sean, the factory installation had the inlet tube captive between the turbo and intercooler with o-rings at both ends. Since you have a K27 conversion, you may have a thin wall 2" hose making the lower connection, and it could be bulging under boost. This bulge will shorten the hose length pulling the tube away from the intercooler. May need a couple extra hose clamps along the hose connection to stop it from bulging.

Edit, see the right inlet tube which is modified for a hose connection. Note the really thick wall orange and blue hose which was needed to avoid bulging.
http://www.members.shaw.ca/jddyck/boostpipe.JPG

Nice to see the night owls are out and about tonight! SmileWavy
Does owning a 930 cause insomnia? Or just Porsche's in general?

Jim2,
She does have a K27... I will check there as well. Thank you ever so much for your advise!

Update
 

Jim2
Directly off the Turbo I have a 1.5-ish inch section of hose which acts as a connector to a, what looks like plastic could be alloy, 90 degree fitting which travels up to section of hose (3/8" wall thickness) 3-4" long connecting to the alloy pipe the neck of the IC settles into.
Think I will have a problem with bulging?

EDIT: just saw your edit! Aprox. wall thickness on that orange hose?

Do you have the stock turbo bracket installed? Some on here have removed... while under boost the turbo will pull down which may be causing the inlet to the intercooler to pull out. Just my .02

The orange hose in the picture is about 5/16" wall. I really don't understand your description of "90 degree fitting". Can you get a picture like this one:

Example of a thin hose which resulted in similar issure to yours:
http://www.members.shaw.ca/jddyck/hosebulge.JPG

Tomorrow...

Infraredcalvin is talking about this braket which sandwhiches between the turbine outlet and muffler flange. It's visible between the muffler and engine.

http://www.members.shaw.ca/jddyck/turbobracket.JPG

Yes I can! Here it is:

http://forums.pelicanparts.com/uploa...1205567838.jpg

RE: Turbo Flange, I will check that out tomorrow morning and report!
Thank you all very much!

You could have a leak at that connection under high boost. Might be worth using better t bolt hose clamps there.

I think there is supposed to be a visible sealing ring between the intercooler and connector pipe as seen on this stock motor. Also, note the same issue with this install

http://members.rennlist.com/magisterc/kokeln.html


http://forums.pelicanparts.com/uploa...1205591659.jpg

Is the C2 bypass valve fitted? They are black and made by Bosch.

Sean, checking back in. I think I recognize the type of hose you have as an industrial product from Gates. It is very, very stiff. Will not bulge under boost.

Did you get a chance to look for the turbo support bracket which infraredcalvin mentioned. He has a very good point that without this bracket the boost pressure will force the against the turbo inlet pipe deflecting your headers, potentially enough to cause the upper O-ring to squeeze out.

You might loosening off the upper hose clamp and try pulling the pipe out of the hose, forcing it against the intercooler, then re-tighten the hose clamp.

i have the exact same i/c and a kokeln turbo and i started having similiar issues, so i called kokeln. by the way the guy who installed items cut the up-pipe and added about 3 in of blue hose to make it fit. the guy at kokeln told me that on their newer i/c's they extend the neck just enough to make it a snug fit...cost about 100 bucks labor plus extension unknown exact price maybe 150 total not inc shipping