Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: May 2015
Posts: 713
Anyone running 3.5L 964 cams with CIS

Gents

I'm considering some slight tweaking and wanted to see if anyone is running a similar setup AS A STREET CAR and wanted to get driving impressions. This is 1986 US 930 stock fuel head, lines, injectors, CIS with FrankenCIS managing the mixture via the lambda valve.

-3.5L 8:1 compression
-964 cams
-Lightweight clutch
-ported intake possibly as much as 40mm
-1.2 bar w/g
-twin plug w/ distributorless ign, COP in a wasted spark config
-Stock exhaust port
-RarlyL8 headers + hooligan

If anyone has done anything similar I'd like to head impressions on driveability, and gotchas you ran into, or would-do-it-differently-next-time's.

Thanks
Old 01-24-2018, 06:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
prschmn's Avatar
 
Join Date: Feb 2007
Location: Northeast
Posts: 379
I'd talk to maybe DC or Web about the cam choice-964 is not ideal for force fed engines.
And I would NOT used wasted spark with COP-the spark at overlap causes reversion that prevents the turbo from spooling efficiently.
Course ther's a million possible combinations to ponder!
__________________
Mark
www.exotechpower.com
1981 Targa-messed with. 91 C2 supercharged track rat
97 Van dieman F2000-gone but not forgotten
30 plus years of rebuilding services
Old 02-01-2018, 05:55 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Jul 2001
Location: Portland Oregon
Posts: 6,898
FWIW,.....

I've used 964 cams in a Turbo motor quite a few times over the past 25 years and its based on how the car will be used. For street cars, I prefer SC cams in these things.

You may have more experience than I do, but I've never, ever gotten sufficient fuel flow into a CIS Turbo motor to safely run 1.2 bar. There is far more to this, however I'd certainly re-think that much boost without running Engine Management to accurately (safely) control AFR's and timing.
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 02-01-2018, 08:50 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Jeff Alton's Avatar
 
Join Date: Jan 2003
Location: Langley,B.C.
Posts: 10,091
The 965 S2 was a 3.3 with 964 NA cams (I had them mapped) and a few other bits. It didn't run 1.2 bar mind you, but made for a very good engine. The cam choice you made will be fine in a 3.5. Not sure about 1.2 bar with CIS, I will defer to Steve here as we don't try to run more than 1.0 bar CIS.
__________________
Turn3 Autosport- Full Service and Race Prep
jeff@turn3autosport.com
997 S 4.0, Cayman S 3.8, Boxster 2.7, Boxster S race car, 996, 955 Cayenne TT, 958 Cayenne TT

Last edited by Jeff Alton; 02-01-2018 at 09:06 PM..
Old 02-01-2018, 08:50 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Chain fence eating turbo
 
Join Date: Dec 2008
Location: Austin, TX
Posts: 8,382
Quote:
Originally Posted by prschmn View Post
And I would NOT used wasted spark with COP-the spark at overlap causes reversion that prevents the turbo from spooling efficiently.
I have never heard about this?? I'm wasted spark, but a 3.2 platform (higher flowing heads and intake over a 930). Spooling a fairly large 66mm turbo just fine (Borg-Warner S300-S366). As long as it's slightly rich on the punch, it lights pretty quick.

Curious if running sequential would enhance?
__________________
Cory - turbo'd '87 C3.2 Guards/Blk, 3.4, 7.5:1 CR P & C's, soon to be 993SS cams and GSXR 750 ITB's fed by 964 intake, Borg-Warner S366 turbo @ 1.4 bar, Treadstone full bay IC, TiAL F46 WG, HKS 1 1/2" BOV, twin 044 pumps, MegaSquirt 2 (v3.57 board) w/EDIS, Tramont wheels (285's rr, 225's frt), Big Reds frt, 993 rr., tower brace, MOMO wheel
Old 02-02-2018, 04:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
prschmn's Avatar
 
Join Date: Feb 2007
Location: Northeast
Posts: 379
Tippy, Dont be getting too worried here since turbos aren't as sensitive as blowers.
But, I watched a supercharged engine break belts on a dyno clearly due to the wasted spark setup. But it was a clear indicator for sure.
COP is great but I'd strongly advise not using wasted spark if it can be avoided.
Gains from sequential vs semi are not a ton-doubt it will help much since at higher RPM events are happening too fast.
Stay rich-fats where its at but lean is mean-----
__________________
Mark
www.exotechpower.com
1981 Targa-messed with. 91 C2 supercharged track rat
97 Van dieman F2000-gone but not forgotten
30 plus years of rebuilding services
Old 02-05-2018, 05:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 04:44 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.