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 Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rating: Thread Rating: 10 votes, 4.80 average.
Author
Thread Post New Thread    Reply
Registered User
Quote: "How do people feel about having to drill a hole in the pipe just before the muffler?"

Would it be more accurate if you tapped in before the cat?
__________________
Warren & Ron, may you rest in Peace.
Old 12-15-2003, 12:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #41 (permalink)
Registered User
 
1fastredsc's Avatar
 
Join Date: Apr 2003
Location: Las Cruces, NM
Posts: 2,459
Send a message via AIM to 1fastredsc
Actually, 30lbs should be plenty, that isn't all that big. Stock 951's have 33lb injectors and handle just under 300 hp before needing replacement.
__________________
2007 Mazda 3 hatch
1972 Porsche 914 roller with plenty of holes to fix
Old 12-15-2003, 12:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #42 (permalink)
Registered User
 
tbitz's Avatar
 
Join Date: Feb 2001
Location: Ottawa
Posts: 769
Would it be more accurate if you tapped in before the cat?

Absolutely. O2 must be placed on the intake side of the pipe (CAT)before the muffler.

With SSI or backdated headers there is no CAT, so no problem. In turbo applications, the O2 sensor must be after the turbo, cause readings are affected by both temperature and pressure.

Stock 951's have 33lb injectors and handle just under 300 hp before needing replacement

Are you sure they are 33lbs? If you do the math 4 injectors at 33lb/hr at 100% duty cycle only give 240Hp. Is the fuel pressure at the 3bar standard, or is it bumped up to get more flow?

Cheers,

Tony
__________________
Tony
'78 911SC with BITZRACING EFI conversion kit

Last edited by tbitz; 12-15-2003 at 02:11 PM..
Old 12-15-2003, 12:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #43 (permalink)
Registered Loser
 
Join Date: May 2001
Location: Worcester, MA
Posts: 2,392
Tony, I'm excited to see you are "weaponizing" your EFI conversion. I wish you great success. I think it's gonna be a killer app (as we say in the software biz) which could be serious competition to PMO. I'd gladly buy one from you but my 911SC...ummm...blew up...so she is no more. So I'll have to live vicariously through you !!
__________________
Owner of a wrecked 944

Last edited by Wrecked944; 12-15-2003 at 01:10 PM..
Old 12-15-2003, 12:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #44 (permalink)
Registered User
 
Join Date: Sep 2002
Posts: 3,580
Quote:
Originally posted by tbitz
In turbo applications, the O2 sensor must be after the turbo, cause readings are affected by both temperature and pressure.
Tony, can you clarify this? I am running an O2 sensor directly to an AFM gauge on my K-basic 930 engine (no cat). The sensor is mounted on the wastegate pipe, between the exchangers and the turbo. I think this is the factory location on later cars that use lambda.

Would be more accurate if mounted after the turbo, at the muffler, and why is this so?

Thanks,
Colin
__________________
993
Old 12-15-2003, 12:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #45 (permalink)
Registered User
 
tbitz's Avatar
 
Join Date: Feb 2001
Location: Ottawa
Posts: 769
Quote:
Originally posted by cowtown
Tony, can you clarify this? I am running an O2 sensor directly to an AFM gauge on my K-basic 930 engine (no cat). The sensor is mounted on the wastegate pipe, between the exchangers and the turbo. I think this is the factory location on later cars that use lambda.

Would be more accurate if mounted after the turbo, at the muffler, and why is this so?

Thanks,
Colin
Don't want this thread to become a debate on where to put O2 sensor, but, if you have it on the wastegate pipe (which is before the turbo) the O2 sensor is exposed to the back pressure caused by the turbine. This increase in pressure causes O2 readings to be off. How much? I dunno. I can't remember if higher pressure reads leaner or richer. I'd have to look it up.

Also note, stock O2 sensors only tell you your above or below stoic mixture. Don't try and interpret AFR from a stock (narrow band) O2 sensor.
__________________
Tony
'78 911SC with BITZRACING EFI conversion kit
Old 12-15-2003, 01:11 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #46 (permalink)
 
Registered User
 
Join Date: Apr 2003
Posts: 12
Tony,If you can sell as a kit for 1400.00 I buy one in a second. thanks JB




79 911 sc
__________________
jkb157
Old 12-15-2003, 01:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #47 (permalink)
Registered User
 
Join Date: Sep 2002
Posts: 3,580
Quote:
Originally posted by tbitz
Don't want this thread to become a debate on where to put O2 sensor, but, if you have it on the wastegate pipe (which is before the turbo) the O2 sensor is exposed to the back pressure caused by the turbine. This increase in pressure causes O2 readings to be off. How much? I dunno. I can't remember if higher pressure reads leaner or richer. I'd have to look it up.

Also note, stock O2 sensors only tell you your above or below stoic mixture. Don't try and interpret AFR from a stock (narrow band) O2 sensor.
Thanks for the reply Tony. I'm aware of the limitations of the narrowband sensor.

Just wanted to know why the placement was critical, and what you say makes sense. I'll take this into a new thread after I dig around a little.
Colin
__________________
993
Old 12-15-2003, 03:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #48 (permalink)
Registered User
 
1fastredsc's Avatar
 
Join Date: Apr 2003
Location: Las Cruces, NM
Posts: 2,459
Send a message via AIM to 1fastredsc
To tell you the truth dude, i don't remember although 3 bar (45psi) sounds low.
__________________
2007 Mazda 3 hatch
1972 Porsche 914 roller with plenty of holes to fix
Old 12-15-2003, 04:56 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #49 (permalink)
Registered User
 
Join Date: Sep 2002
Location: Cedar Falls, IA
Posts: 212
Toney,

I too am interested in your kit. I have been reading the MS sites and am very intrigued. I am planning a turbo conversion on my 82SC. Since I have installed a C2 electric tail I have no room for a intercooler so am considering two small turbo's off of my SSI's and then running compressor output to intercoolers in rear wheel wells (will install 73 oil tank).

I will want to get rid of airbox and pick up ambient air nearer to the turbo's. My question is, can you do your MS installation with no air box? or do some kind of workaround??

Guy Chiattello
82SC Black Coupe
Old 12-15-2003, 04:59 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #50 (permalink)
Registered User
 
Join Date: Sep 1999
Location: Featherston, New Zealand
Posts: 963
Tony , good luck with the project--I followed it eagerly,as you published http://www.geocities.com/tbitz/cis_to_efi.html
Questions--did you publish anything after Feb?-- How has the car performed since you got it running.- In other words, how about an update.
Regards Bob
Old 12-15-2003, 05:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #51 (permalink)
Registered User
 
diy83sc's Avatar
 
Join Date: Jun 2002
Posts: 862
Tony,

I have an 80SC that want's to show me what a 3.0 can really put out! Keep me in the loop as your beta kits develop. I have another car to drive...

Tony
Old 12-15-2003, 06:36 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #52 (permalink)
Registered User
 
tbitz's Avatar
 
Join Date: Feb 2001
Location: Ottawa
Posts: 769
will want to get rid of airbox and pick up ambient air nearer to the turbo's. My question is, can you do your MS installation with no air box? or do some kind of workaround??

With the CIS gone, the air no longer must flow through the CIS airflow metering plate. You can just put air filters directly on the turbos intake and feed the turbo output directly to the throttle body. You still use the stock airbox, with CIS parts removed.

How has the car performed since you got it running.- In other words, how about an update.

Car has been running all summer and fall. Runs great.

Would your system supply adequate fuel for a twin-plug setup? What about larger displacement with twin-plugging?

Based on my calculations above with 30lb/hr injectors, the system would be good to supply enough fuel for 280Hp with injectors running at 85% duty cycle. You can always go with bigger injectors if you want more power. There is a limit though, then the fuel pump, regulator, fuel lines can't cope. Also large injectors cause problems at idle.
__________________
Tony
'78 911SC with BITZRACING EFI conversion kit
Old 12-15-2003, 07:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #53 (permalink)
Senior Member
 
Zendalar's Avatar
 
Join Date: Apr 2001
Location: Finland
Posts: 1,206
I am building MegaSquirt currently. 60mm throttle body, intake runners from 2.7 CIS. The megasquirt will be with MegaSpark software, so the fuel injection box will also handle the ignition advance/retard. After i get this running I will install a turbo.

I will propably use 30-33lb/h injectors.

Total cost so far has been under 200$. Already have the MS box and the intake manifolds. The sensors are not very expensive.

Oh yeah, the engine is 2.4T


I think the MS is the best/cheapest way to go, it is cheap and very versatile.
__________________
Projects:
911 -72T EFI "964-look" "Smoky"
914 -71 1.7 D-JET "Rusty"
Old 12-16-2003, 03:47 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #54 (permalink)
Stahlwerks.com
 
jhelgesen's Avatar
 
Join Date: Dec 2001
Location: Charlotte, NC
Posts: 4,256
Send a message via Yahoo to jhelgesen
Would the stock 3.0 injectors be capable of working with the system, if the plumbing were changed? Do they have the capacity?
__________________
John Helgesen
Stahlwerks.com restoration and cage design

"Honest men know that revenge does not taste sweet"
Old 12-16-2003, 03:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #55 (permalink)
Registered User
 
Tim Walsh's Avatar
 
Join Date: Sep 2002
Location: Green-Salem, NC
Posts: 3,914
Garage
Send a message via AIM to Tim Walsh
John.
From what I've seen CIS injectors work on the same principal that MFI injectors use. THey open at a certian pressure and close at that same pressure. So by varying the pressure you know when your injectors are firing. The EFI injectors are electromechanical, not opened by pressure.

I'm not 100% on that but That's my impression.
__________________
Tim
1973 911T
2005 VW GTI
"Dave, hit the brakes, but don't look like your htting the brakes...what? I DON'T KNOW, BRAKE CASUAL!!!" dtw's thoughts after nearly rear ending a SHP officer
Old 12-16-2003, 04:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #56 (permalink)
Registered User
 
1fastredsc's Avatar
 
Join Date: Apr 2003
Location: Las Cruces, NM
Posts: 2,459
Send a message via AIM to 1fastredsc
That's true, they open when the coil in them are given current, kind of like a relay closing a connection. And as already stated, cis injectors respond to fuel pressure, not electrical pulse.
__________________
2007 Mazda 3 hatch
1972 Porsche 914 roller with plenty of holes to fix
Old 12-16-2003, 05:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #57 (permalink)
Stahlwerks.com
 
jhelgesen's Avatar
 
Join Date: Dec 2001
Location: Charlotte, NC
Posts: 4,256
Send a message via Yahoo to jhelgesen
Okay, learn something new every day
__________________
John Helgesen
Stahlwerks.com restoration and cage design

"Honest men know that revenge does not taste sweet"
Old 12-16-2003, 05:48 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #58 (permalink)
Registered User
 
911ctS's Avatar
 
Join Date: Jul 2003
Location: morro bay, california
Posts: 895
Send a message via Yahoo to 911ctS
Zendalar------Please keep me posted on your progress with that 2.4T motor. I also have a 2.4 in my car and i am curious how yours turns out with the FI setup, 2.7 CIS manifold, and then the turbo. Good Luck!!
Clint
__________________
_____________________________
Clint Smith
www.RebelRacingProducts.com
1970 911T ----> RGruppe RS/R (mexico blue)
1995 993 becoming an RS (gran prix white)
Old 12-16-2003, 08:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #59 (permalink)
Registered User
 
tbitz's Avatar
 
Join Date: Feb 2001
Location: Ottawa
Posts: 769
Cool Update

Guess what I've been doing over the holidays





The above parts are one of the key pieces in the CIS to EFI conversion puzzle. They allow you to simply remove the existing CIS injectors and bung and pop these in place. Then fit a standard Bosch type EFI injector in the stock CIS intake runners.

I have redesigned these parts from my original ones. These parts now feature O rings to perfectly seal the bung in the intake runner. No need to weld, or epoxy these in place. Just push them in and your done.

I'm still working on the other parts. Subscribe to this thread to stay upto date with the kit.

Cheers,

Tony
__________________
Tony
'78 911SC with BITZRACING EFI conversion kit

Last edited by tbitz; 01-02-2004 at 09:42 PM..
Old 01-02-2004, 09:27 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #60 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 02:20 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, 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.