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 944 Turbo and Turbo S


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
951 v 3.2 Carrera Motronics differance?

Can anyone here tell me the differences between the 944T injection system and the 3.2 Carrera?

Dose the 951 have a TPS or a WOT switch like the 911?

Dose the 951 have any vacuum sensing ability?

Dose the 951 pull air through the AFM and then into the turbo?

About what are the dimensions of the 951 air filter? What HP limit dose this create?

What is the HP limit of the AFM?

Is the fuel pressure regulator mostly fixed or dose the boost level increase fuel pressure dramatically for more fuel?

Are there any other significant systems differences as to the injection or plumbing?

I am asking so I can better understand the feasibility of converting a 911 to a such through turbo?

Thank you in advance for any help.


Old 03-03-2009, 06:43 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Is the Cycling Valve used by the DME to control boost?

Is this basically a frequency valve? That is dose it use something like a 50mhz signal and the changes in duty cycle control how much boost is delivered?

Plumbing: http://www.oz951.com/public/images/gallery/vac4.jpg

Thx?
Old 03-03-2009, 07:09 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
I am new to the KLR.

Is its sole purpose to control the boost amount?
Is it pretty much stand alone?
How hard is it to get access to reprogram it and or are there those that will do this?
Old 03-03-2009, 07:21 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
winter-hater club member
 
nynor's Avatar
 
Join Date: Oct 2003
Location: salt lake city, utah
Posts: 24,705
Quote:
Originally Posted by 911st View Post
Can anyone here tell me the differences between the 944T injection system and the 3.2 Carrera?

Dose the 951 have a TPS or a WOT switch like the 911?

yes

Dose the 951 have any vacuum sensing ability?

i don't know.

Dose the 951 pull air through the AFM and then into the turbo?

yes.

About what are the dimensions of the 951 air filter? What HP limit dose this create?

couldn't say offhand. 8x12 inches? its good for over 300HP.

What is the HP limit of the AFM?

see above.

Is the fuel pressure regulator mostly fixed or dose the boost level increase fuel pressure dramatically for more fuel?

fixed. but you can get variable rate regulators.

Are there any other significant systems differences as to the injection or plumbing?

no.

I am asking so I can better understand the feasibility of converting a 911 to a such through turbo?

sounds like a bad idea. there are surely easier and less costly ways to go about it.

Thank you in advance for any help.

sounds like a major project.
__________________
2000 Corvette - ????, 2007 Buell XB9R - Astrid, 1996 Discovery - Piglet, 2000 Forester

"COOL PRIUS!" - Nobody Ever
Old 03-03-2009, 01:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
winter-hater club member
 
nynor's Avatar
 
Join Date: Oct 2003
Location: salt lake city, utah
Posts: 24,705
Quote:
Originally Posted by 911st View Post
Is the Cycling Valve used by the DME to control boost?

sort of. it opens at certain boost levels to open the wastegate.

Is this basically a frequency valve? That is dose it use something like a 50mhz signal and the changes in duty cycle control how much boost is delivered?

it gets a signal from the KLR.

Plumbing: http://www.oz951.com/public/images/gallery/vac4.jpg

Thx?
again.
__________________
2000 Corvette - ????, 2007 Buell XB9R - Astrid, 1996 Discovery - Piglet, 2000 Forester

"COOL PRIUS!" - Nobody Ever
Old 03-03-2009, 01:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
winter-hater club member
 
nynor's Avatar
 
Join Date: Oct 2003
Location: salt lake city, utah
Posts: 24,705
Quote:
Originally Posted by 911st View Post
I am new to the KLR.

Is its sole purpose to control the boost amount?

no, its main function is to retard timing in case of detonation.

Is it pretty much stand alone?

no


How hard is it to get access to reprogram it and or are there those that will do this?

impossible, as far as i know. its been tried.
last one.
__________________
2000 Corvette - ????, 2007 Buell XB9R - Astrid, 1996 Discovery - Piglet, 2000 Forester

"COOL PRIUS!" - Nobody Ever
Old 03-03-2009, 01:02 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: Jan 2003
Location: Atlanta
Posts: 184
The 911 3.2L, 944NA and 951 all use the same version/family of the Motronic system. The 944NA (MY1986+) is much closer in functionality to the 3.2L than the 951. The 951 uses a DME and a KLR, both boxes communicate. The DME handles the engine management functions, the KLR handles boost control, knock control and drives the factory boost gauge in the cluster.

The 951 in std form does not reference vacuum nor boost. However we converted it to reference boost. We also converted a 944NA system to reference boost as it was used on a 914 Supercharged application. Using the knock control on the 911 will not be a simple task as the knock signature between the 4-cyl and the six varies greatly. The knock filtering in the KLR is based on a 4-cyl application. The 944NA DME can be converted to be used on the 6-cyl..

Converting 3.2L for forced induction is not a big deal, we have done it on a 930 CIS to EFI conversion. For high HP applications (as with any forced induction 3.2L engine), a MAF replaces the AFM (with the associated software as well).


The 951 AFM flows approx. 900kg/hr so it'll support in the 300s hp range. Using the AFM between the various systems (951 to 944 or 3.2L) is doable, however the software must be modified as the calibration of the various AFM sensors is different between them.. There are other variables to deal with, but it can and has been done.

There are many details that I'm not going over.. Hope this helps!
Old 03-03-2009, 07:04 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Thanks guys.

Is the sensor at the throttle a TPS, or is it a WOT switch, or is it both?

I am suspecting that using the AFM in a draw through will create more of a restriction than a blow through. I am thinking a lot more preserized air is going to flow through a given size opening and such a restriction is better on the pressureised side of the turbo but not sure??? Some seem to be getting 425 hp or more with a 3.2 blow through.

Anyone know what the Boost Cycling Valve signel looks like (a frequency valve, a steper motor, or ?.)

Again, all help is appricated.
Old 03-03-2009, 09:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
Join Date: Jan 2003
Location: Atlanta
Posts: 184
The 3.2L, 944NA both use a switch type TPS (Idle, WOT). The 951 uses a more complex TPS where you get the Idle, WOT and you get the 0-5V output. The 951 TPS is sent to the KLR not the DME. The 0-5V signal is used by the KLR for various functions.. The KLR sends load signals to the DME (based on the 0-5V TPS input)..

The AFM is calibrated to handle a certain flow. Once you reach the flow, the AFM will generate the Max signal (close to 5Vdc) (AFM Maxed out). It does not matter if you have the AFM as a blow or draw through.
People do various things to get a bit more out of the AFM, they modify the scraper to alter the output curve. In my opinion, this is a band-aid solution! Which is why we convert to a MAF where we can support high HP engines (high flow) and not max out the sensor. (note: a badly selected MAF can be maxed out as well, in the same manner as the AFM maxes out).

The CV receives a PWM signal from the KLR.

Good luck with your project.
Old 03-04-2009, 04:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Thx Fast,

Very helpful.

What is a PWM signal please. Is it similar to what an injector or frequency valve receives?

Even on a NA 3.2 the AFM stalls out and it becomes more of a reference system. I did not think this was a big concern so long as the RPM cells past that point are set correctly. However there migh be something here I am missing. If I am at 5500rpm and the AFM door is stales I suspect I am on full boost & WOT. How much fuel I need should be pretty straight forward and accommodated by simple RPM reference and a fuel pressure regulator that increases fuel pressure with boost.

The KLR intrigues me. It looks like an add on boost controler to deal with monitor and controll boost and feed a gage. I do not see it doing much of anything else.

I am wondering if there is actually anything being fed to the DME from the KLR or could it just be sharing inputs with the DME like RPM, head temp, air temp... The norma DME is capable of calculating acceleration based on the rate of change in AFM angle.

There seems to be a lot of work done on adapting 944T's to MAF or even MAP but little support for doing this on a 911. Some are working on it for NA 911 function but not for Turbo function where the output voltage is extended over a wider air flow range. What I have read makes it seems there is a lot of mapping time needed to get it close to Right and the help of a chip jockey.

I know just enough to be dangerous.

Thanks for your help.
Old 03-04-2009, 07:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered
 
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
I wonder if the KLR feeds an on/off sighel to the DME in place of the tradational WOT switch feed?

Will the 944T DME box plug into a 911 wire harnes with most of the pins being the same?

Fun.

Old 03-04-2009, 07:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Reply


 


All times are GMT -8. The time now is 05:58 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 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.