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AFM744 AFM744 is offline
Cynical Misanthrope
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Join Date: Dec 2001
Location: Campbell, CA
Posts: 382
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Originally Posted by spjuvern View Post
are there any parts that i can modify for better power if I leave the heads untouched on the engine, i thinking mabye the stock inlet manifold?
The airflow bottleneck on our engine is the 32mm intakes. This is a contiguous size from the intake manifold to the intake valve bowls. You can hog out your intake ports (in the head) as big as you want (Ted Robinson showed me some 935 heads with 43mm), but you have to pull the heads to do that. You can open up the intake manifold and injector stacks (like I've pictured above) but there's no sense in it if your intake ports are still 32mm.
The stock injector blocks are 40.5mm OD, and they're phenolic fiberglass. 35.5mm bore-out leaves me 2.5mm walls to withstand boost and vacuum, that's as big as I'll take these (and I still half-expect them to fail).
The 993TT had the same 43mm intake ports as the 935, and used these successfully because of Motronic sequential electronic injection. 935 used CIS and huge intakes because it didn't have to pass smog, didn't have to make torque below 4,000rpm, and ran on liquid crack.
X-1, AFM744, Jon, '92 C2 Turbo
JE 8:1 pistons, 964 cams, 38mm intakes ported/polished/twinplugged, ARP hardware, B&B headers/exhaust, 355whp. Full-blown GT35R 3.2 intake EFI pending...
Where my misspent time and money is currently going.

Last edited by AFM744; 12-12-2008 at 08:47 AM..
Old 12-12-2008, 08:23 AM
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