924Board.org

[Lizard]

on the 931 it will cause a vacuum leak(unmetered air)
on the 924 NA it will have no change as the hole is after the metering plate
_________________
3 928s,

[J1NX3D]

ideola do you have pics of your i/c setup?
_________________
'86 944

[ideola]

Well, it's *really* hard to see with all the body panels on, but I do have a couple of pix where you can kind of see it. Here is the thread I posted with a list of photos.

To elaborate, the intercooler is mounted in a vertical orientation with the inlet and outlet pipes directly behind the headlight bucket on the passenger side. You can see the foil-covered inlet pipe coming from the turbo on the left and the outlet pipe on the right, along with the top of the intercooler in this photo:


Here is another shot of the engine compartment where you can see the inlet and outlet along with the charge tube:


And is this image, it's hard to see, but there are two ducts that direct air over the intercooler: one on the inside of the turn indicator, and one at the bottom of the valance:


I'm going to do a complete rebuild, and we'll be taking the body panels off for prep and paint. When I do this project, I intend to meticulously document everything, so more photos will be upcoming...is there anything specifically that you're interested in re: my set up? Maybe I can take some more shots...
_________________
erstwhile owner of just about every 924 variant ever made

[J1NX3D]

wow!! just read the thread you linked, can't believe i missed it!!! that is quite a nice project you have! i love the front guards and spoiler!

i agree, the bumpers look like modified US ones, the vent in the front spoiler on the pax side would have been originally for the oil cooler.
re: the scoop that lizard is talking about its the flush NACA scoop on the stock 931 hood. you should be able to find one ( i mean the whole hood) at the wreckers or buy a new grp one from Gt-racing and the like.

can you see any extra ducting to your pod filter? when you pull aprt the lights i'd lu to see pics of them
_________________
'86 944

[-nick]

I would bet that accordian style rubber hose is blowing up like a balloon when the boost rolls on. I would suggest getting some real turbo hoses to replace it with. That hose is probably increasing your lag time a tad and is definitely not very efficient. Otherwise, pretty good looking IC placement! What boost level is it set to?

nick

[ideola]

Yeah, I was wondering about that whole charge tube set up...it's not very substantial, and I suspect that it is leaking like a seive. How "airtight" should it be?

Believe it or not, it's only running the stock 6PSI (according to the boost gauge), so I don't think the PO got around to doing any mods to the turbo unit. There's no boost controller that I can see, so I think it's just stock.
_________________
erstwhile owner of just about every 924 variant ever made

[-nick]

Or it could be leaking so much that it won't build any more than 6psi boost !

It should be 100% leak proof to at least 20hg vacuum and 10psi (absolute bare minimum!).

nick

[ideola]

Ahhh! Interesting! Maybe I'll look at doing something there in the short term because I'm pretty positive it's not airtight. Any suggestions or pointers to the correct materials I should be using?
_________________
erstwhile owner of just about every 924 variant ever made

[-nick]

If that's the case, you're probably getting a lot of turbo whine. Plus, it's making your turbo work much harder than it needs to; shortening it's life. Oh, and you'll be running really rich on boost (or really lean off-boost if the mix adjustment has been tinkered with) since the injectors are supplying an amount of fuel proportional to the amount of air that goes through the meter flap- this isn't taking into account the amount of air you're loosing out the intake leaks.

Search ebay for turbo hoses or intercooler hoses and you'll get an idea of what you need. They aren't cheap. But they're usually blue (cool - bling bling ). As much of the length as possible should be using metal/aluminum pipe (you'll probably see this come up too in your ebay search).

You definitely need to be air tight!

nick

[ideola]

Well, some more pieces of the puzzle fell into place. There's no question I'm running rich under boost...been struggling with that since I got the car. I think I know why now.

It will definitely be worth it for me to correct this problem now, particularly since I'll be putting it all back together the way it is now...the turbo hose will be directly reusable after the rebuild, so no harm in fixing it now. Thx a bunch for the tip!
_________________
erstwhile owner of just about every 924 variant ever made

[bass gt]

I had the same tubing used in my car when i got it. Nick is spot on. When my car was on the dyno, the concertina pipe was ballooning to about 2- 3 times its normal diameter. Once it had run out of expnsion, bang, the boost arrived at the TB. Bloody awful!! I would recommend using Samco type silicon pipes with as much solid metal tubingas you can use. Use the Silicon pipes only for bends ect.
As i keep promising, give me a couple of weeks and i will post my new set up.
Regards,

Steve

[ideola]

The only thing I see on eBay is silicone hose...any pointers to metal hose suppliers would be appreciated, although I'll look at Racer Parts Wholesale, EBR, etc.

Looking at the current setup, it's going to take a little ingenuity to route a metal hose. Now I'm *really* curious to see what is rigged up on the inlet side of the intercooler underneath all of that heat wrap! Guess I know what I'm working on this weekend!
_________________
erstwhile owner of just about every 924 variant ever made

[ideola]

Another question: there is a rubber-like boot between the charge tube and the intake itself ... you can sort of see it in this photo...


It appears to me that the angle of the charge tube was modified slightly to accomdate getting the intercooler outlet to attach properly. As a result, there is a gap on the front side of this boot where it is supposed to seal against the intake ... I'm assuming that this could also produce a "leak" contributing to my rich condition under boost...

When I was tweaking the "tuning", I had taken the charge tube off in order to better access and replace the plugs. I straighted the bracket a bit, so the fitment is a little better, but I still think not quite right. I'll add that to my todo list over the weekend.

...so basically, the entire airflow path needs to be as airtight as possible, correct?
_________________
erstwhile owner of just about every 924 variant ever made

[CMXXXI]