924Board.org

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

I've finally got around to putting the car on the dyno and achieved 140.8hp at the back wheels. There's more available if I can find a way to get some more fuel in at higher revs as it's running lean at the top.

The specs are:
euro pistons
port matched intake manifold
Piper Cam
small intercooler
BAE turbo with external waste gate
boost activated cold start injector
points ignition!

I'll keep you all updated over the next few months as I sort it all out.
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Andrew
1977 RX924 race car
12a bridgeport supercharged
www.race4-dcup.co.nz

leadfoot · Posted: Thu Mar 08, 2007 12:17 pm Post subject:

Nice one, you could always bolt on another CSV onto the other side of the manifold and trigger it at a higher psi level...
leadfoot
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

is it stilll CIS? what about that vaccuum controlled audi WUR i read about around here somewhere?
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Just a thought, if you switched your points ignition to MegaJoltLiteJr You could control your spark better plus you could use one or two of the four auxilery outputs to control extra injectors based on either rpm or load. It would be rather rudementry but I think it would work plus you would have a hotter spark to boot. It wouldn't cost much more than a shift light setup.

Todd

BTW, nice dyno numbers!!
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

leadfoot · Posted: Thu Mar 08, 2007 2:48 pm Post subject:

I think the main problem is activating it based solely on RPM...
Basically this is not load dependant, and it would be operating constantly above 3000rpm.
The article below talks about a trigger sensitive relay that can work this function, what I would do is add a pressure switch in-line with the earth connection, probably at the injector ground, this would serve to break the injector operation when boost is not present.
I have searched other sites that also sell pressure switches that vary in their triggering values to, so you could even fine tune a little more with a higher/lower psi value.
If you can't be bothered building electronic components then I have seen autometer gauges that have external triggering capabilities, and you could just wire in your pressure switch to that signal... BTW I have no idea what the current draw of an injector is so you would need to make sure it could drive the injector current...
http://autospeed.drive.com.au/A_2810/hDg34uLtp_1/cms/article.html
http://autospeed.drive.com.au/cms/A_1034/article.html
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

Thanks guys - keep the great ideas coming through!

_________________
Andrew
1977 RX924 race car
12a bridgeport supercharged
www.race4-dcup.co.nz

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

Endwrench did hit the nail with that idea. Or you can go EFI anytime, it's really taking two days maximum to complete if you have all the gear needed (MS, injectors, fuel rail from endwrench

) and make your car really shine.

Good luck with your car Andrew!
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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

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

leadfoot · Posted: Thu Mar 08, 2007 10:19 pm Post subject:

Another option also on the autospeed site was a fuel regulator that can recieve an electronic trigger
http://autospeed.drive.com.au/cms/A_2619/article.html
Theory is if you can increase fuel system pressure and decrease control pressure you can increase overall fuel levels...
Firstly if you aren't using a turbo WUR use one as it will lower control pressure via boost sensing... which is what you want, load dependant.
Then you can use this little fella, or go old school and shim the system pressure... the advantage of this little fella is that you can do it above the 3000rpm reference where it was rich and starting to go lean, therefore no creating excessive rich levels below 3000RPM.
According to the 928 guys you can can run system pressure up to 80 psi, but control pressure needs to be watched as it can cause leakages if made to low. As system pressure would only be increased above 3000rpm this scenario would possibly be avoided.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

Min · Posted: Fri Mar 09, 2007 4:59 am Post subject:

simsport · Joined: 06 Nov 2002 Posts: 573 Location: UK Warrington

There is a device available over here called an MFI. I think its made by Aquamist the water injection people and it will run a 5th injector for you based on load/boost and I think rpm.

Look up AQUAMIST OR ERL?

Cheers
Simon
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Blown is always best!