924Board.org

[john h]

Zuffen,

The way I've doen my boost controller is the same as jazz guys (or he doen it the same as me). As he mentioned is if there is a failure on any of the pieces the system reverts back to standard. It also controls the flutter that a wastegate can have a bit more - if you take the wastegate off and feed air to the control side the wastegate will start to open at a boost pressure a few pounds below the proper opening value. This acts as a bit of a safety valve but can affect the performance.
If you pressurise the spring side it's the same as putting in a heavier spring, allows you to alter boost depending upon fuel available, atmospheric condiitons - of a cold foggy day you can turn the boost upa bit higher due to the slightly higher density of the air.
If you put the controller in the control you can have the problem that if the regulator fails you might end up with no control to the wastegate.
The electronic controlers you can get now are very good but you still need to understand what happens when the unit fails so you don't end up with no safety margin.
I've run my controller since 1986 and have had not problems with over boosting on the road or even on the track. What I have noticed is that if I run the boost at around the 1.1/ 1.2 bar mark when I change up a gear from 2nd to 3rd (or sometime 3rd to 4th) the boost will flick up to over the 1.4 mark but as its not there long enough it doesn't shut the fuel off. You either have to be looking directly at the guage when you change gear or have the video camera picking up the gauge and seeing it on playback (which is how I first found out it was doing this)
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Remember a Porsche is not just for Christmas,

if you take it to pieces slowly it can provide anguish all year long!

[numbbers]

Z, you can do it simple, or you can spend a lot of money making it complex. If you just put the $5.00 air regulator and put it in series with the input to the wastegate. By the way, I am the one who posted the kit for the hot start problem in the tech section, and I thought about making a kit up for the boost controller. But everyone seems bound and convinced that you need to regulate the output side of the wastegate, so I didn't bother. I have pics available if you want to go the simple route.
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1980 924 Turbo

[Zuffen]

My plan was to change the spring to 1 bar and still add a controller to work the upper end of the fuel limit switch. Variable control from 1 bar on up to the switch limit or spike , which ever comes first.

With an intercooler and Air fuel gauge I'm thinking that the car can handle the extra boost on most days.

I'm going to fit a GT intercooler as stock. I'll still be cutting the nose apart to add the 951 intercooler, as I think that is the best method. It should buy me some time and be able to test both intercoolers. In the meantime I'm hoping someone works out a eays to convert EFI.

Since my car isn't pristine I'm not worried about cutting further into the nose.

I'm selling my other 931, the silver one in registry, if the deal falls through
I'll do a GT intercooler conversion and keep it stock. And do a side by side test.

Anyone have controller pics or diagrams please add them.
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Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

[81turbo]

Here is how my controller is installed. I considered doing it the way John H has his, But I have no desire to remove the wastegate now, and this simple way is working for me.

[924RACR]

Yeah, I can hear what you're saying about removing the wastegate. In my case, with the 82, I had to take it all apart anyway, so it was no big deal to pop that cap off and put on a rubber hose while I was in there. I also took the liberty of testing the wastegate with compressed air, make sure it worked!

Still haven't worked up a regulator, even though I have a few regulators sitting in my toolbox, because I haven't yet got the car running correctly or reliably.

BTW, I think the adapters that are used on the fuel filters are the same type of thread/fitting as used on the boost pressure port; this might be used to install a tee for a pressure tap, if you remove and save them when you change your filters!!!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Geddy T]

I'm surprised nobody has mentioned an electronic boost controller--or maybe I just missed it. Bob D., from other posts it seems that this will go on a car that has been converted to EFI? You've already got the computer, just wire up a pair of knock sensors and an electronic boost controller. Infinitely adjustable and very discreet. Doesn't Haltech sell one as an option to their kit? I don't know, it's been a while since I've had them on the phone. I guess it's expensive though...
Jazz Guy... wow... it seems everyone is in agreement with you in that the way to go is to regulate on the output side of the wastegate. I've never even heard of it being done that way, where've I been? Wouldn't it be simpler just to vary the input pressure to the wastegate by bleedoff through an electronic valve? It would be simple to install for one and seems pretty foolproof.
Here's a pretty informative site that looks like it was updated recently:
http://johnmonnin.netfirms.com/Boostcontrol.html
maybe check that out

[Geddy T]

What about a Flux Capcitor? I mean, we've gotta explore all of the options to make this a legitimate query.

[924RACR]

I'd thought that I was voting for an EBC when I voted... not a bleed valve.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[jazz guy]

Well from the poll, I think it is safe to say that the majority of the posters to this topic think that a boost controller delivers the biggest bang for the buck. I know of no other mod. that produces such an increase in horsepower for such a small outlay of cash. What has not been determined, however, is what kind controller works the best and why.

There may or may not be a definite answer to this question. If you read my previous posts, you see that I don't have the answer and I hope that I haven't advanced my views as the most reasonable or "best" way to control boost. It is just another way. I am surely not the originator of the system as John H., and I'm sure others, were using the same setup several years before I owned my 931. I got the info for my setup from another 931 owner and am passing it along. I was hoping others might have ideas that I could learn from.

I think what Bob D. is trying to accomplish is ultimately the way to go to achieve the highest boost (hp.) levels. With his design goals in mind, one could expect a large power increase. Incorporating an intercooler, EFI, and knock sensors would also increase reliability and safety margins beyond what we could hope for with our present systems. I would love to talk more about that. Keep us informed on what you are thinking, Zuffen!

I am also intrigued with the idea Geddy T. brought to the table. He advanced the idea of looking at using a Flux Capacitor, saying that we should explore all of the options. I am in total agreement. Along those lines, I am going to investigate the rumor that you can control boost by raising or lowering the coefficient of friction in the muffler bearing. I've heard accounts of 28 psi. boost levels and 300+ hp. with no other modifications! I'll report back.

[Zuffen]

I'm thinking about actually water cooling the intake and turbo with this product called liquid ice.

You basically get a storage device called a beer cooler (I hope that is the terminolgy for it) and stick wet ice not dry ice and water and a small pump and spray the the areas with super cooled fluid, i.e. the term liquid ice.

If you use dry ice you actually can either pump the gas to the outside of the car so it looks like you

either blew a head gasket

blew an oil ring

or have jet pack on your car

Or you pump into the inside and play reggae music while using the word Dude frequently, you can do this while driving or parked. Even if your not speeding I promise the cops will pull you over and give you ticket.

Disclaimer

(I'm totally kidding about pumping any coolant on to the turbo,the rest is up to your discretion)
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Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

[924RACR]

Awright, let's get this thread really outta hand... When expanded rapidly, a gas will experience a substantial drop in temp... basic thermodynamics... so just take your air tank, fill it as much as possible, equalize the temps, and then vent it directly on the intake charge tube as required when you need the extra boost for charge intake cooling!!! LOL

Better yet, get a CoolShirt, wrap it around your charge tube w/ zipties, plumb it into the AC system, and use as required to control the charge temps... instant water/air intercooler!!!

Somebody shut me up...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[dwak]

Can somebody repost that wastegate blowup. I can't get it to show on the previous thread.
dwak

[wdb]

I recently learned about THE TRIPLE POINT OF WATER .where water will be in a gas, liquid, and solid form at the same time. basically if you have a vessel of water and use a vacuum pump to lower the pressure in the vessel , the water will boil and freeze at the same time, because of the very low pressure . maybe a propane bottle and a small electric vacuum pump (old refrigerator compressor ) might make for a steady supply of cold . with 2 heat exchangers , 1 in the propane tank, 1 in the intake and a small pump that circulates a water alchohol mixture from 1 heat exchanger to the other to cool the air charge . I wonder how many BTU's a small setup can muster . anybody know about the triple point of water .

[wdb]

triple point of water refrigeration unit .

http://www.ide-tech.com/code/eco_chil.html

[CarreraGTSCS]

What is the collective thought on the way that 81Turbo has plumbed his manual boost controller as shown in the photo? Is it safe for the motor? If there's a breach in the line somewhere will the overboost be controlled?

I like it. It's so simple. But is it right? If it is then I'm going shopping tonight!
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1988 951
1982 931
1975 Caldwell D-13 Formula Vee
1969 911T
1967 Austin Healey Sprite
1961 wife