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Anybody have thoughts on WATER INJECTION?

 
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Wtchypoo22  



Joined: 30 Aug 2005
Posts: 3
Location: New England, USA

PostPosted: Tue Aug 30, 2005 9:52 am    Post subject: Anybody have thoughts on WATER INJECTION? Reply with quote

Hey everybody!
Bought a 80' 924T in the spring, good sound engine, however the car was killing me with all the "little things" it needed. Just recently purchased another in much better shape and I am in the final stages of installing the old engine into the "new car". (It's been a long week...) My husband tells me I can boost my horse power by running water injection. Has anybody tried this? ALSO, what's this I hear about synthetic oil not being the best bet for late model Porsches? Thanks
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Lizard  



Joined: 03 Nov 2002
Posts: 9364
Location: Abbotsford BC. Canada

PostPosted: Tue Aug 30, 2005 11:04 am    Post subject: Reply with quote

first off welcome to the board,
and I must say I wish I had a gf who was willing to give a hand in the shop

as per the Oil, no synthetic is good no matter what year the engine and ESP in a turbo, HOWEVER if you dont replace the seals in the engine it may spring up new leaks that is the only risk.

in regards to the water/alchy injection, it may boost horse a TINY bit due to the fact it will lower the intake temp slightly,
the main reason water/alchy injection is used is for higher boost applications (if you install a boost controller and UP the boost) and it is mainly then on a boost switch which activates it once a certain boost is obtained.
the reason it is used is because it does slightly lower the intake temp, but it also increases the detonation threshold, and detonation is what will kill the engine.

good luck and again welcome,
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Wtchypoo22  



Joined: 30 Aug 2005
Posts: 3
Location: New England, USA

PostPosted: Tue Aug 30, 2005 10:54 pm    Post subject: Reply with quote

Thanks for the welcome Lizard!
Everything you said is pretty much what I'm hearing from other people, There are a couple of websites I go to that claim the water injection system will boost my HP 50, (I don't know if I buy that..)
Today I start her up, I'm at the final stages, just need to put the exhaust on....Can't wait to see where the wastegate is set! It's off of the car I just purchased, which I feel was driven very hard...(let's just say this, I pulled the pan and there were piston ring pieces in my oil pickup..pulled piston, cracked, didn't bother checking others, too busy sobbing.....see, chicks aren't made to be mechanics, we can't take the let downs....HA HA, I'm kidding, I didn't sob but boy, did I swear...) I have to be careful with the engine I just dropped in, there was some play in my KKK,(according to my book, "it should be replaced") although out of the 2, this was the better, will rebuild the other over the winter. SO, I'm thinking water injection is not the best bet for me right now, I don't know if she can take it. I'll keep ya posted. Thanks again! PS. years ago I bought a 1980 Camaro, 265, auto....my husband had a 350 laying around, dropped that in, picked up a T5, dropped that in, threw a posi rear end in and that was all it took to get me down the garage. My parts were so cheap and it was such a "user friendly" car to work on, I couldn't keep myself away..that was 2 broken fingers, 127 busted knuckles and 10 years ago!
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Wed Aug 31, 2005 1:50 am    Post subject: Reply with quote

I've about 13 pics of my water injection system starting here - http://www.flickr.com/photos/9754161@N02/739687612/in/set-72157600685471748/
-And 6 more including an improved nozzle - http://www.flickr.com/photos/9754161@N02/738834727/in/set-72157600685471748/
It uses a Porsche OE (Hella) headlight washer pump to pump fluid from the windshield washer reservoir to a nozzle that's mounted in the airbox. It's switched on by a pressure switch that's Tee'd in to the intake manifold. A somewhat preferred approach would be to use a higher pressure pump and place the nozzle downstream of the turbo, but my upstream setup hasn't caused any apparent problems.
There shouldn't be any issue with your engine being able to handle water injection. By itself it doesn't increase stress on the engine, but rather decreases it by cooling the intake air and more importantly in effect raising the fuel mixtures' octane which lessens the engines' tendency to knock, detonate, whatever you want to call it. As you're suspecting, it won't have a great effect on HP by itself, but instead allows you to make other changes (namely up the boost level) while providing the engine a level of protection.
A bit more on H2O (and methanol) injection - http://www.924board.org/viewtopic.php?t=14981
Lizard wrote:
as per the Oil, no synthetic is good no matter what year the engine and ESP in a turbo,

Lizard - did you leave out a comma there between "no" and "synthetic"? -I'm assuming you meant to say that synthetic is good, but as written, that line is saying the opposite.

As far as synthetic oil, I've got nothing but praise for the stuff. I've been running Mobil 1 ever since 1996 when I installed my current turbo. From what I've read, a 924T's turbo should be toast by 50k miles, but mine's somewhere up over 60k at this point. -And maybe I'm just lucky, but I've had no oil leaks and have never changed a seal on the engine. In fact, the deepest I've been into the engine is just under the valve cover to adjust the valves and replace the head bolts with Raceware studs.
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"..it's made in Germany. You know the Germans always make good stuff."


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Last edited by Smoothie on Fri Mar 27, 2009 11:24 am; edited 1 time in total
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Lizard  



Joined: 03 Nov 2002
Posts: 9364
Location: Abbotsford BC. Canada

PostPosted: Wed Aug 31, 2005 10:39 am    Post subject: Reply with quote

yah you got me smoothie I did,

as per the water injection the amount of HP boost you will see depends on displacement, boost PSI, boost CFM, and a multitude of other things as well as per 50HP on this engine, NOPE, guarenteed.

as per the sounds of the other engine I would say that he must have had some trouble there and would NOT be suprised to see that the wastegate he had in there has a blown diaphram, so I would either install yours as you know it worked, or INSPECT the otherone before you install it.

in regards to the turbo, if the shaft has play in it then yes it should be replaced, however all that will happen is that it will blow oil into the intake and out the exhaust,
when you have the other turbo rebuilt keep in mind that you WILL need to have the exhaust housing of the turbo replaced with a new unit, as well if you inspect your exhaust manifolds then you will probably find that they both have cracks, while you have 1 out you should consider before installing them to have the crack in the manifold fixed (professionally) and STRONGLY consider having the manifold and exhaust housing of the turbo ceramic coated, and then upon installing them, wrap both with an exhaust header wrap this will keep more heat in the exhaust and will also prevent the manifold and housing from cooling off too quick which is the main cause to them cracking. keep in mind this MAY not prevent it entirely, but I do believe it will definetly help, and you can run water injection without any worry in the car, and will gain a couple of hp, but it is not really needed.
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Raceboy  



Joined: 01 Mar 2004
Posts: 2321
Location: Estonia, Europe

PostPosted: Wed Aug 31, 2005 3:35 pm    Post subject: Reply with quote

Lizard, what concernes turbo shaft play.... There shouldn't be ANY longitudal play, or the thrust bearing needs replacement, however radial play IS necessary, but it shouldn't exceed 0.3mm when dried out from oil leftovers. Why it is needed? Because shaft expands by a considerable margin due to the extreme heat from the turbine size.
If radial shaft play exceeds 0.3mm, the bushings need replacement.
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'67 911 2.4S hotrod
'90 944 S2 Cabriolet
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'84 928 S
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
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Wtchypoo22  



Joined: 30 Aug 2005
Posts: 3
Location: New England, USA

PostPosted: Thu Sep 01, 2005 12:04 am    Post subject: Reply with quote

Wow Lizard,
Your right as far as the crack in the exhaust manifold! We did weld that up before putting it back on, I never thought to wrap it up, darn it, wish I had done that a few days ago. Thanks for all the info, we're soaking it up guys....keep it coming....also, car started right up yesterday, no problems,first time I've had the power hooked up in the new car, was happy to see everything worked! (windows, lights...etc) will be putting exhaust from first car on it for now, which comes with the factory wastegate...so 7 is my lucky number ...for now...thanks again guys, I'll post some pics this weekend of the old car (don't laugh, the body is still solid) and the new one...Thanks again B
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Thu Sep 01, 2005 1:26 am    Post subject: Reply with quote

Here's an interesting detail about water injection -

(Fuel enrichment shown preventing detonation up to 240psi BMEP. H2O injection extends the limit to 290+psi BMEP.)
Turbochargers by Hugh MacInnes wrote:
"In Chapter 5, I discussed enriching the fuel/air ratio as a way to prevent detonation when the engine is supercharged. Fuel enrichment will work up to a certain limit; what that limit is depends on the engine and installation. Beyond this limit the engine will detonate regardless of how rich the mixture is. At this point, either water or water/alcohol injection is required to prevent detonation."

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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox


Last edited by Smoothie on Fri Mar 27, 2009 11:31 am; edited 1 time in total
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WEASEL149  



Joined: 19 Aug 2005
Posts: 595
Location: UK, Sheffield

PostPosted: Fri Sep 02, 2005 10:19 am    Post subject: Reply with quote

Lizard wrote:
as per the Oil, no, synthetic is good no matter what year the engine and ESP in a turbo, HOWEVER if you dont replace the seals in the engine it may spring up new leaks that is the only risk.


Just to add to the discussion, it's normally the viscosity of synthetic oil and also detergents that can cause leaks. I would not advise using the typical 0 - 40 grade of synthetic. I personally use the 15 - 50 Mobil 1 synthetic and I've not had any problems with it.
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WEASEL149  



Joined: 19 Aug 2005
Posts: 595
Location: UK, Sheffield

PostPosted: Fri Sep 02, 2005 10:32 am    Post subject: Reply with quote

Your water injection system looks nice Smoothie. How much boost are you running? I've just got hold of an Aquamist 1s system but haven't fitted it yet - I'm in the process of fitting a Blitz dual solenoid boost controller, in the hope of eliminating some lag caused by fitting a 951 intercooler and plumbing. Hopefully then I shall also be running slightly more boost than standard.
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