Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Speed Density

Thread Tools
 
Search this Thread
 
Old May 10, 2009 | 10:54 PM
  #1  
nolls's Avatar
nolls
Thread Starter
|
New User
Joined: Apr 2009
Posts: 2
Likes: 0
Speed Density

How come speed density limits the mods you can make to your motor (ex. supercharger, turbo)? If you are essentially putting more air into the cylinders, won't the manifold pressure increase, and therefore the fuel injected will increase?
 
Reply
Old May 11, 2009 | 12:59 AM
  #2  
BucksTrucks's Avatar
BucksTrucks
Senior User
Joined: Jul 2005
Posts: 347
Likes: 0
From: USCGC Never Home
I read somewhere that you can run forced induction with S/D, you only run in to problems with cams with to much overlap. And you dont want a lot of overlap with forced induction anyways.
 
Reply
Old May 11, 2009 | 02:09 AM
  #3  
86F150302's Avatar
86F150302
Postmaster
Joined: Dec 2007
Posts: 3,052
Likes: 1
From: Jacksonville FL
Yes you can run a supercharger on SD. Im getting one soon and running it on SD. Alot of Lightning guys still run SD but with a tune from a Tweecer.
 
Reply
Old May 11, 2009 | 05:49 AM
  #4  
frederic's Avatar
frederic
Post Fiend
Joined: Oct 2003
Posts: 6,214
Likes: 13
From: New Jersey
The problem is not speed density EFI. The problem is Ford speed density EFI isn't very hacked and difficult to work with because most of the Ford EEC editors (freeware and commercial) really do not support these EEC's very well, if at all.

Of course if you're familiar with the Intel 8051 processor and have countless hours to reverse engineer a particular ford EEC down to the source code level, you can make that EEC do anything you want - even control Christmas lights.

See, things like Tweecer and similar products focus on Lightenings and Mustangs, because those are the vehicles typically used as the foundation for high performance "street toys" that will have forced induction.
 
Reply
Old May 11, 2009 | 09:17 AM
  #5  
Conanski's Avatar
Conanski
FTE Legend
15 Year Member
Photogenic
Photoriffic
Community Builder
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
As stated the Ford SD system is compatable with forced induction because these kits include an FMU to boost fuel pressure so no extra tuning is necessary. SD is only restrictive when it comes to naturally aspirated mods like cams and heads because the computer is programmed for a stock motor and has no way to recalibrate itself to these high flow components, and in general isn't supported by aftermarket tuning systems.
 
Reply
Old May 12, 2009 | 08:13 PM
  #6  
EPNCSU2006's Avatar
EPNCSU2006
Lead Driver
20 Year Member
Joined: Nov 2002
Posts: 9,557
Likes: 44
From: Concord, NC
Manifold pressure can't measure air flow, so if the airflow for a given manifold pressure changes (i.e. big heads or cam upgrades), the fuel calibration will be incorrect.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Sixtone
1987 - 1996 F150 & Larger F-Series Trucks
11
Mar 19, 2015 05:26 PM
390Highboy
Computer Chips & Tuners
7
Jul 17, 2007 09:06 PM
cowboy4x4
1987 - 1996 F150 & Larger F-Series Trucks
7
Apr 7, 2007 11:54 PM
LxMan1
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
4
Dec 24, 2002 07:19 PM




All times are GMT -5. The time now is 02:58 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE