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Modified 944 turbo - taking in too much hot air?

I've just been reading your other threads about (a) taking the 964 to Donington and (b) the GRP front bumper from EMC and ducting and it suddenly struck me that there is another option open to you. Occasionally you will see turbocharged cars that have an intercooler spray setup. Very simply you install fine spray nozzles that spray water over the intercooler when you are on full throttle. Water is a much better coolant than air and so it lowers the charge temperature of the air leaving your intercooler and you gain more power. Obviously you have to keep topping up a water tank, but as a last resort it could give you the extra cooling you need.

Failing all that just stuff a load of dry ice down the front of your intercooler before each session :ROFLMAO:
 
Reminds me of the lorries that are raced where they have to spray water onto the brakes to cool them! Interesting thought but I would prefer the more perminent and tested route of the turbo front end. I'd probably get black flagged for leaking fluid knowing my luck [:D]

Cheers
Mick
 
You can use CO2 instead, there used to be a kit in the states with a switch on throttle and a rectangular (ish) discharge pipe in front of the IC. not sure what size cylinder you would need for a full trackday though.
 
Theyre all gimmicks! If you need to cool beyond the capacity of your inter/chargecooler then Id suggest water injection and even then you need to ensure that you have made provision for retarding the ignition when you run out of water or if the system fails.

C02 is a comical in this application unless youre going to pull a BOC triler behind you and water intercooler sprays are only slightly effective at best. Ive never owned an Impreza with an intercooler spray that made a real difference and even the New Age cars revisions arent a great deal better (and theyre a 'peak' application, not a permanently operating one).
 
Maybe the solution is staring us in the face. The 951 intercooler works well on standard engines despite its small inlet but that is to slow the air down sufficiently to allow it to expand as it passes over the intercooler, effectively providing net thrust. Now the 931 front vents collectively have probably more cross-sectional area than the 951 inlet so to prove if we are along the right lines, and with no offence intended, instead of all this conjecture and guess work, why not make up some ducting from artists board, this can be bought quite cheaply and is available in 1/8 thickness. I would suggest a steeply tapering front part that encompasses the 931 front grills,down to the same approximate shape as the 951 front duct then back out to enclose the dimensions of the intercooler. You can join it all up with, oh I don't know, duct tape! Wrap the entire area with cling film and fill the voids up with fix and fill expanding foam for support. This would give you the chance to test the effectiveness of the installation. That way if this proves the theory of insufficient airflow through the intercooler, you can lift out the cardboard template without leaving polyeurathane foam stuck to everything, and make the duct from aluminium, or paint the whole thing in your favourite shade of hammerite smooth. I know the cling film trick works because the liner of my socket set fell apart after 34 years so I filled the bottom part with foam and laid cling film over it before pressing the sockets into place and closing the lid. Net result nearly perfectly nestled sockets that at least stay in order.
 
Having had a further think maybe just duct the air straight in, I have no idea what effect haviing the inlets on the oblique surface of the panel is compared to having the 951 duct bolt upright. Any way as a sheet of artists board is about £3.95 you can do a lot of experimenting for 20 quid.
 
It's a good suggestion but as discussed earlier in this thread, those vents may not be in a high pressure area so might not be as effective (I remember some reprinted tech articles in Porsche Post I think, showing the pressure levels across the 924/944 bodywork)
 
Re my second post, yes that though did ocur to me hence the suggestion of ducting straight in without the taper, after all the vents are effective in sending a supply of cool air for the 931 engine for which they were designed
 
Im under the impression that air from badge panel mounted ducts interfere with the high pressure air routed from the intake on the PU.

The badge oanels look pretty but they impair performance, rather than enhance it, in my opinion.
 
There are a couple of considerations in my mind:

1. The issue has only occurred on track days when running at full throttle for significant periods. This heat build up cannot be generated on the road without driving everywhere in second gear. To test fabrications therefore requires booking a track day.
2. Any fabrication must withstand 130mph wind resistance - I assume this is quite high.

Based on the observations/experience of others, having gained better insight through their comments and good old Google searches and having discussed with EMC, I am satisfied that there is a strong consensus that the intercooler is most likely not working effectively. Others have used a GRP Turbo replica bumper with success so whilst I love cheap options the balance of booking track days to test a fabrication, fun though it is, looks outweighed by a tested but more expensive route.

The CO2 idea does rather defy logic since it will significantly add to weight, will cost a bit to refill and I certainly wouldn't like to crash with a highly pressurised bottle of CO2 next to the intercooler (I have an awful feeling there is some counter to the safety concern involving fire extinguishers but I'll overlook that!).

Cheers
Mick
 
Just looked up 931 and 951 (sorry, new here). Behind the badge panel vents (931 air intake?) there is a 1" to 3" gap before the face of the intercooler. Not enough room to make any meaningful ducting I wouldn't think.
Regards
Mike
 
The badge panel vents are definitely in a low pressure zone. I though. About buying a vented panel for mine but a bit of RL reading convinced me otherwise. I believe that the Lindsey one works to an extent as its big ugly snout pokes into the high pressure zone.
 
ORIGINAL: Masher

There are a couple of considerations in my mind:

1. The issue has only occurred on track days when running at full throttle for significant periods. This heat build up cannot be generated on the road without driving everywhere in second gear. To test fabrications therefore requires booking a track day.
2. Any fabrication must withstand 130mph wind resistance - I assume this is quite high.

Based on the observations/experience of others, having gained better insight through their comments and good old Google searches and having discussed with EMC, I am satisfied that there is a strong consensus that the intercooler is most likely not working effectively. Others have used a GRP Turbo replica bumper with success so whilst I love cheap options the balance of booking track days to test a fabrication, fun though it is, looks outweighed by a tested but more expensive route.

The CO2 idea does rather defy logic since it will significantly add to weight, will cost a bit to refill and I certainly wouldn't like to crash with a highly pressurised bottle of CO2 next to the intercooler (I have an awful feeling there is some counter to the safety concern involving fire extinguishers but I'll overlook that!).

Cheers
Mick
Click to expand...


The cylinder would be remotely mounted, nice and low ideally - However I was suggesting it as an alternative to water spray making the track wet, not as serious solution to your problem! I would worry about stress cracks in the IC if it was repeatedly cooled that aggressively hot to frozen / frozen to hot

http://www.designengineering.com/category/catalog/cryo2-system-components/cryo2-intercooler-sprayer-kit

It is also more expensive than I imagined! and I am not certain the one linked to would fit a 951 IC

 
EMC are working on the solution but this topic does strike me as one where a variety of weird and wonderful ideas can be thrown up most of which are complicated and expensive! I have considered hiring a small child to strap to the front bumper and throw dry ice at the intercooler every now and again but I expect someone will have an objection [:D]

That kit is certainly not cheap! Possibly because they don't sell many?

Cheers
Mick
 
Car being dropped off at EMC on Saturday for GRP turbo bumper, IC ducting and moving of air filter. Ten we'll have a chat about the bill and maybe tackle the suspension too. If it all gets done... Roll on Donington in August [:D][:D]

Thanks for the help,
Mick
 
Good move Mick. I am sure you will see a noticeable improvement on long straights on hot days - BOOOOOOST! [8D]
 
Got to watch EMC now - they seen to be playing with all sorts of SIX cylinder cars, including a hairdressers one......[:)]
 
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