924Board.org

Pascal924 · Joined: 24 Dec 2014 Posts: 29 Location: Vlissingen

Hello Porsche friends.

Iam new on This form, but u follow your post already for Many years.
I am a Porsche enthousiast from the netherlands, and i
restored Porsches for my hobby.
For the moment my collection consistent 4 classic 911 and 2 924 turbo's with gt kit.

For my latest project i have questions about the ignition of an 924 turbo s1.
I have a gt carrera intercooler, so u want to upgrade the engine ril 1.0 bar turbo pressure.
I want to use the mittelmotor or 123 ignition option...
I have read that some of you tried This, but it is not clear for me if it was succesfull...
Thanks for your feedback.

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

You don't really need other ignition if you run 1bar with an intercooler.
its a good way to upgrade but in my opinion not really necessary.
_________________
Supercharger and EFI kits
https://www.the924.com

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

The advance/retard of the stock dizzy isn't optimized for IC and 1.0 bar. It can be recalibrated but still not too effective in avoiding knock. I had knock at 0.9-1.0bar.

The CGT top mounted IC may not cool the intake enough to reliably run 1.0bar without knock. I'd recommend a knock sensor/warning

Take a look at my thread below as I'm running the Mittelmotor dizzy successfully. But I'm struggling to go too far north of 1.0 bar even with CGT turbo and front mounted 944 IC but more mods are on their way to help.
_________________
1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

Pascal924 · Joined: 24 Dec 2014 Posts: 29 Location: Vlissingen

So what turbo pressure do you have?
I think i need a other dizzy because the vacuümbox is in the way.
Perhaps a normal turbo curve in the 123 ignition be perfect...
I want to have a bit more hosepower, but it must be reliable, and i want to have some advantage from the intercooler.

How much hp do you make.
I have seen, you strugle with the head gasked...

Tanks for your reply...

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

So the S1 is much more agressive in advance to make up for lower compression?
_________________
Supercharger and EFI kits
https://www.the924.com

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

924-76 · Joined: 05 Jun 2006 Posts: 1489 Location: Ontario, Canada

Welcome to the board
The 924 Carrera GT is running at 12lbs boost.
I also have a GT intercooler and currently set at 10lbs and still running stock distributor and ignition.
I'm planning on increasing to 12lbs when everything else is sorted.
_________________
1976 924 N/A ROW SOLD
1980 931S
1981 931 Part car RIP

Pascal924 · Joined: 24 Dec 2014 Posts: 29 Location: Vlissingen

I Spoke to mittlemotor and they could give a good and reliable solution.
I think if you want a more efficiënt engine with more hp, you need to have an other curve. 1 bar is more les the limit with the top mounted intercooler. Probably somewere between 0.85-0.9 should be perfect with the mittlemotor dissy.

I dont know if it worth to invest in a special/sharper camshaft?

.