924Board.org

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Just came across this and thought I'd share:

http://www.034efi.com/index.php?cPath=21&osCsid=925eb68abdef2b80508aa16af3c4f8c5

If my turbine housing was in better shape, I'd send it directly out to these guys...

nick

cleethorpes · Posted: Thu Jun 02, 2005 12:50 am Post subject:

this part of the site interest me.

http://www.034efi.com/featured_users.php?featured_user_id=30

Comments anyone?
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'24 turbo with dodgy gt bodykit......needs a new home

numbbers · Posted: Thu Jun 02, 2005 8:28 am Post subject:

Well, as I have stated before, if you want more fuel, all you need to do is energize the cold start valve. That what it is, a supplementary injector.
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1980 924 Turbo

u63af · Posted: Thu Jun 02, 2005 9:22 pm Post subject:

How would you get the cold start injector to come on when running higher boost? Do any companies make uprated fuel pumps or is there no point?

Paul · Posted: Fri Jun 03, 2005 7:15 am Post subject:

A simple pressure switch could be installed to turn it on. The stock fuel pump can more than handle the extra load.

I believe the problem will be that #3 and 4 will get most of the extra gas, while the other 2 will run lean.

Maybe the charge tube is a better spot?

macBdog · Posted: Fri Jun 03, 2005 9:22 am Post subject:

Crunchie57 has a K26 Garret T04 hybrid. He does! He showed me! He will show you if you ask him nicely. I want one now.
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1979 931 with a 350 chev
1973 911E with EFI

cleethorpes · Posted: Mon Jun 06, 2005 3:01 am Post subject:

Am I correct in thinking that the cold start valve runs at the equivalent of full throttle? and that all you need to do is disconnect it from the thermo switch to keep it running constantly?

It might mean a constant fast idle, but surely would let you up the boost a little bit?? maybe from 1.0bar to 1.2??

I agree that it may not be in an ideal location, but surely you could blank off the current location and having connected to just before the intake manifold.

Or am I very wrong
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'24 turbo with dodgy gt bodykit......needs a new home

cleethorpes · Posted: Mon Jun 06, 2005 3:02 am Post subject:

Am I correct in thinking that the cold start valve runs at the equivalent of full throttle? and that all you need to do is disconnect it from the thermo switch to keep it running constantly?

It might mean a constant fast idle, but surely would let you up the boost a little bit?? maybe from 1.0bar to 1.2??

I agree that it may not be in an ideal location, but surely you could blank off the current location and havie it connected just before the intake manifold.

Or am I very wrong
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'24 turbo with dodgy gt bodykit......needs a new home

Paul · Posted: Mon Jun 06, 2005 4:15 am Post subject:

I have no idea how much the cold start injector sprays, but the way it's wired, it is either on or off, nothing in between.

In it's stock setup, it receives power from the starter solenoid only when the starter is cranking. It receives it's ground from the thermotime switch.

This means in order to make it work, you would need a pressure activated switch (set at maybe 12 psi) that would provide a ground and a new source of 12V since you can not use the existing one. (would backfeed the starter solenoid.) As a matter of fact, you would have to unhook the thermotime switch also.

I could design a circuit for this using some relays that would allow the CS injector to function in both modes. But I'd need a few beers and a bar napkin for paper.

Might be all around better to just install another injector and a pressure switch set at 12 psi.

Paul · Posted: Mon Jun 06, 2005 4:23 am Post subject:

Wonder if the Megasquirt system could be set up to control a single injector using only an O2 sensor and a pressure switch for inputs. (no crank sensor, no MAP, etc).

We could leave the CIS in place, but have the Megasquirt monitor the mixture for lean conditions any time the boost switch is tripped (12 PSI?) and automatically add fuel when needed.

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

It would work, but it would also be very unaccurate fuel dosing. I think it would be easier and better to install MAP sensor and 2 additional injectors.
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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

numbbers · Posted: Tue Jun 07, 2005 8:57 am Post subject:

The easy way to control the cold start valve is through the full throttle enrichment switch. I already have the switch wired to a relay, that shuts off the AC compressor during full throttle. I can just wire the normally open contacts of the relay to the cold start injector and it will come on during full throttle application. You could make sure that all of the cylinders get equal fuel, by just making a small fuel rail out of aluminum tubing that runs the length of the inside of the intake manifold. Drill a few holes in it for each cylinder.

The car might run a little rich under full throttle, until the boost comes up.

Anyway, these ideas are just food for thought.
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1980 924 Turbo