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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Wed Apr 30, 2008 10:26 pm Post subject: Cooling System Upgrades for Ideola's Ultra Wide Body 931 |
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Here is what I have planned so far:
- Craig Davies Electric Water Pump (continuous mode)*
- Craig Davies Electric Booster Pump for the turbo**
- Craig Davies Thermatic Fan(s)
- Custom/modified bypass pipe***
- Heater delete
- Aluminum 951 racing radiator from Wizard Cooling
- New OEM 951 expansion tank
The radiator really has me in a quandary right now. I know I can order the Ron Davis version like Rasta's at a cost of ~$625. However, in my situation, I don't need a drop-in replacement because I will be completely reworking the front mounting points with custom fabricated brackets and such. That said, I also have a brand new in box 924S radiator.
- What other options should I consider for the radiator?
- Can I get a less expensive alternative to the RD rad since I don't need stock replacement?
- If I went completely custom, what would be the "ultimate" specs, in terms of # of passes, frontal area / dimensions, construction, etc.?
- Also, should I get a stock replacement 931 expansion tank, a stock replaceent 944/951 tank, or an aftermarket universal tank (again, considering I'm not constrained by stock replacement & mounting)?
- How many and what size fans should I use? (The CD fans cost less than Spal and have similar specs)
* Note: I'm planning to gut the stock water pump & remove the thermostat. The primary pump will run in continuous mode, as I've read several reports of the CD controller failing, and besides, this is a race car.
** Note: It's looking very good that my hybrid K26/27 turbo will have a water-cooled bearing housing, so I am planning to run a booster pump for it.
*** Note: I like what Roger did to his bypass pipe:
_________________ erstwhile owner of just about every 924 variant ever made
Last edited by ideola on Sat May 09, 2009 4:39 am; edited 2 times in total |
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Rasta Monsta
Joined: 12 Jul 2006 Posts: 11723 Location: PacNW
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Posted: Thu May 01, 2008 1:16 am Post subject: |
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If you're ditching CIS, thus creating a bunch of space up front, I would have Davis fab up the thickest core that will fit. _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Thu May 01, 2008 1:26 am Post subject: |
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Not ditching CIS initially, but slightly relocating the dizzy. Also, the entire front of the car will be reworked, so thickness won't be a concern.
I'm at work right now, so I can't go out and measure. Do you happen to know the dimensions of the RD unit you used??? _________________ erstwhile owner of just about every 924 variant ever made |
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Rasta Monsta
Joined: 12 Jul 2006 Posts: 11723 Location: PacNW
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Posted: Thu May 01, 2008 1:37 am Post subject: |
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The core was two rows of 1' tubing. _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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bass gt
Joined: 02 Dec 2004 Posts: 971 Location: Johannesburg for now!!
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Posted: Thu May 01, 2008 1:50 am Post subject: |
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Dan,
As you know, those are the pumps myself and Simon are using. Concerning the rad, i would say that a 951 unit wold be ideal. The rad is not an issue, rather balancing the teperatures between the front and rear of the head. If you upsize the piping from the back of the head, it all works beautifully. I have measured the temps and have a difference of 2 deg. C front to rear!! As you know, cyl #4 was prone to destruction due to detonation caused by high temps. This mod cures this nicely!!
Steve _________________ Front Wheel Drive is the Devil's work. |
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Thu May 01, 2008 2:12 am Post subject: |
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Steve
Duly noted on the size of the piping. That's certainly something I can address when I fab up my version of Roger's pipe pictured above...
Regarding the 951 rad, brand new they are ~$400, which is less than the Ron Davis drop-in replacement, but I thought they had the plastic end tanks, which are less than desirable. For that kind of money or not much more, I think I might be able to get a fully aluminum unit.
OTOH, in this post, Gohim indicates that the 924S rad is the same as the late 944. He (unfortunately) doesn't indicate if it is the same as the same era 951, but if it were, I already have an 87-88 924S rad, so that could be very cost-effective route!
Also, what are your thoughts regarding the expansion tank? Just looking at the system, it seems the best placement will be the battery tray, as this will be vacated by my rear-ward located battery. The next best alternative would seem to be the 944-style expansion tank. Just wondering if it's worthwhile to drop the extra $$ on a lightweight aluminum tank vs. the stock plastic version. The alum 944 tanks from Lindsey are VERY spendy. _________________ erstwhile owner of just about every 924 variant ever made |
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Rasta Monsta
Joined: 12 Jul 2006 Posts: 11723 Location: PacNW
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Posted: Thu May 01, 2008 2:21 am Post subject: |
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bass gt wrote: | If you upsize the piping from the back of the head, it all works beautifully. |
Hmm. . .got pics/specs? _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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tuurbo
Joined: 08 Aug 2007 Posts: 1446 Location: East Windsor, New Jersey
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Posted: Thu May 01, 2008 2:32 am Post subject: |
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Mind if I ask how much boost and power you're intending for this project?
I think, if you're into it, that weld or solder stuff that melts at 800 degrees and can be used with a blow torch would be ideal if you just wanted to fabricate one yourself out of the same stuff Lindsey uses. After all, there's a bleed from the cap, isn't there? Then you just have to deal with the cost of aluminum ($).
http://www.durafix.com/
If you're not into that scene and just want a tank try maybe JEGS?
Last edited by tuurbo on Thu May 01, 2008 2:49 am; edited 1 time in total |
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Raceboy
Joined: 01 Mar 2004 Posts: 2326 Location: Estonia, Europe
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Posted: Thu May 01, 2008 2:35 am Post subject: |
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924S/944 rad is almost the same as 951 unit, difference is IIRC 2 rows. I removed plastic end tanks and welded aluminium ones instead. _________________ '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 |
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Thu May 01, 2008 2:37 am Post subject: |
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tuurbo wrote: | Mind if I ask how much boost and power you're intending for this project? |
Hope you have some time on your hands for some light reading Start here. Liberally cross-referenced to various detailed threads on each of the major systems I'm developing for the car (hybrid turbo, intercooler, top end, bottom end, etc.). _________________ erstwhile owner of just about every 924 variant ever made |
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tuurbo
Joined: 08 Aug 2007 Posts: 1446 Location: East Windsor, New Jersey
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Posted: Thu May 01, 2008 2:52 am Post subject: |
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Ok so you're intending on somewhere around 9 or 10 PSI.
I did not know the car got that hot from that kind of boost, but I guess with the dollars you are investing you intend to drive it pretty hard and expect reliability. _________________ 1980 924 turbo, MSD, Meth. Inj, otherwise stock. |
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Thu May 01, 2008 2:55 am Post subject: |
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tuurbo wrote: | Ok so you're intending on somewhere around 9 or 10 PSI. |
Uhhh....read the whole thread...I'm targeting 350 BHP. Based on my hybrid turbo and other factors, I estimate I'll need a minimum of 15 psi boost to achieve my goals... _________________ erstwhile owner of just about every 924 variant ever made |
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tuurbo
Joined: 08 Aug 2007 Posts: 1446 Location: East Windsor, New Jersey
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Posted: Thu May 01, 2008 3:01 am Post subject: |
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Ahh ok I saw the part about leading up to 9 or 10. So if you are at 15 PSI it all makes sense. Thanks. |
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bass gt
Joined: 02 Dec 2004 Posts: 971 Location: Johannesburg for now!!
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Posted: Thu May 01, 2008 5:55 am Post subject: |
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Rasta Monsta wrote: | bass gt wrote: | If you upsize the piping from the back of the head, it all works beautifully. |
Hmm. . .got pics/specs? |
Rasta,
I have a 32mm pipe connected tothe rear of the head. This joins to the pipe from the front of the head. I machined an adapter to fit this pipe to the head, which replaces the stock temp sensor/heater output flange.
I don't have any pics at the moment, but will try to take some when i return home.
Steve _________________ Front Wheel Drive is the Devil's work. |
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emoore924
Joined: 13 Apr 2004 Posts: 2815
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Posted: Thu May 01, 2008 8:03 am Post subject: |
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I'd be interested in hearing more about the BOTH (back of the head) piping change, with how-to, and pics if they're handy. I sort of understand what you've done, but I can't quite visualise it without some more info.
THANKS! |
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