924Board.org

[ideola]

No, I think he means it's to be located where the plastic grill normally goes in the opening above the chin spoiler. So the IC will be installed in front of the AC condenser and the radiator. The RHS end tank points straight up, and will need an exit hole plumbed near the hood latch. The LHS end tank curls around the condenser / radiator, and requires both to be moved toward the RHS of the car as noted above.
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erstwhile owner of just about every 924 variant ever made

[tuurbo]

Ok I think I getcha thanks Dan. Yeah ok. Hmm.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[Raceboy]

On stock 931's it would work better if you rotate the intercooler and to have everything opposite.
BTW, the intercooler won't protrude much out of the chin spoiler, but it will be hard to use the stock plastic grille. I plan using something better anyway because I don't like the idea of getting some stones in the core.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Shurick]

We're just fitting an Mitsubishi EVO VIII IC into my 931. I hope I'll be able to take some pictures later this weekend. The idea is to move the rad backwards and fit a blow-through fan in front of IC and rad.
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WBR, Shurick
'79 931 -- intercooled K26-3060-6.10 turbo @ 1.2 bar, EFI+EDIS, 951S brakes, stripped interior, 951 look.
'86 924S -- R.I.P.
https://www.instagram.com/ru_pacecar/

[Raceboy]

Ok, installed the modified 951 intercooler to the car today.

Since the head is still in machine shop I couldn't start the car yet, but you'll get the idea.

Here it is on the brick for test and measurements:


Already installed and behind the cooling rad that was moved 40mm's to the passenger side. Note that hole for the intercooler outlet is not yet drilled.


Front view:


And just for reference, the engine:

_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[ideola]

Not to squelch the creativity (because this definitely looks easier than removing the badge panel), but I'd be concerned about putting the 5"-thick 951 FMIC in front of the rad...and I also assume that this requires removal of the A/C condenser...

Otherwise, it's a very cool idea (pardon the pun)...
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erstwhile owner of just about every 924 variant ever made

[Raceboy]

99% of the Euro 924's don't have AC.

And I left 60mm space between front cross-bar and IC, additionally there's a gap between IC and rad. That eliminates any cooling issues both on IC and rad.
Remember, all heat echangers (intercoolers, rads, oil coolers etc) work better with having low pressure behind it than high pressure in front of it
Important is to have just about enough room in front for the air flow to get to rad, it doesn't have to ram it.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[ideola]

Except that the air it's getting is now preheated by the intercooler. I think this is of particular concern because the IC is 5" thick, unlike the thin 1" or less condenser typically stacked in front of a rad. Your air flow is going to be MUCH less coming out of that FMIC than a condener, and it's going to be much hotter than ambient (if it's doing it's job).

The other important factor for heat exchangers is temp differential between the mediums, and preheating the air that's supposed to cool your coolant is not a good idea. The other concern on this location as well is that you've essentially blocked the most open area to ram air that the radiator gets. Above that opening is bumper and badge panel, so unless you intend to open up some airflow through the baffling behind the badge panel, your rad is going to get significantly less airflow than it was designed for.

The other problem I see is that I think 60mm is too large of a gap. If you look at most stacked heat exchangers on production cars, they are almost always an inch or less apart. From what I've read and discussed elsewhere, more than an inch or so tends to cause turbulence coming out of the front heat exchanger, and the air doesn't want to go thru the second exchanger. OTOH, too little distance and there's too much resistance, so the air is like hitting a brick wall and would rather go around than through. I would try to get them closer together, like an inch apart.

Don't get me wrong...I'm not "dissing" your design...but there are some considerations that have to be addressed before stacking exchangers like this. It will be very interesting to see what type of performance you get from your cooling system when you get the car on the road.
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erstwhile owner of just about every 924 variant ever made

[Raceboy]

You are missing my point here, Dan.

60mm gap is between 951 IC and cross-member that connects main rails. It means that cool air will get to rad bypassing the intercooler.

There's a 40mm gap between IC and rad.

Besides, I can throw some logs that shows CLT and IAT during runs and perhaps on the track also when done, it shows that this is enough for modest power levels of this car.

BTW, have you seen cooling system of 20v turbo Audis? These have rad inside the engine compartment and without any significant airflow to them. There's aux rad in front but many builders remove it but these cars doesn't overheat anyway. It's much worse solution than mine, yet works successfully even on 600+hp cars. Not for 24h races obviously, but for fast street car it's more than enough.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Min]

Nice work raceboy, sometimes we just need to remember that if we sit around nitpicking the details, we won't ever end up getting things done(I've got a few projects laying around because of that problem). I would be very interested in seeing your datalogs when your motor is back together.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

[ideola]

Raceboy...ah, OK, understood regarding the 60mm...but I think 40mm is still not optimum (i.e. too far apart). Bear in mind, I'm simply basing that on my own observations plus the conversations I've had with guys in my town that are doing intercooler installs on supercharged modern vehicles...may not be applicable, but it's worth noting.

My comments are general observations, since I don't know the power levels you're planning for this car, nor its intended usage. I tend to look at things from an "optimum / maximum" design perspective, rather than a "just enough" design perspective. Sometimes to my detriment, I will admit. You may be right that this will work fine for a modestly boosted street car.

I don't mean to nitpick or squelch innovation (I think I said that already, but it probably bears repeating). Please share the results once you're able to get some track time and data logs. It will be very interesting to see.
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erstwhile owner of just about every 924 variant ever made

[Raceboy]

Doing my best, I'm building three 924's right now (white, this red and Gulf), plus I stepped into the dark side of Porsche ownership and acquired a 911
It's 1978 Euro Carrera roller and 1970 2.2S engine, taken apart and waiting for rebuild. Will be lightweight fun car.
I wouldn't have bought it, but I got it for free. Well, almost, I had to do electrics in friends 1967 911 RSR replica racecar, so no money involved, just time.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Rasta Monsta]

FWIW, badge panel is easy to remove. However, transplanting a 951 rad/IC mount to accomodate the plumbing is another story.

2.2 rebuild? Better start saving up your pennies.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Raceboy]

[Rasta Monsta]

Awesome, man, enjoy!
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3