PCM Diagnostics & Tuning HP Tuners | Holley | Diablo
Sponsored by:
Sponsored by:

Does the rev limiter pull fuel or spark?

Thread Tools
 
Search this Thread
 
Old 12-14-2007, 09:40 AM
  #1  
Restricted User
Thread Starter
iTrader: (18)
 
socmguy's Avatar
 
Join Date: Apr 2007
Location: Fayetteville, NC
Posts: 1,515
Likes: 0
Received 0 Likes on 0 Posts
Default Does the rev limiter pull fuel or spark?

just as the title says.
Old 12-14-2007, 09:58 AM
  #2  
TECH Resident
iTrader: (7)
 
BackinBlack02SS's Avatar
 
Join Date: Feb 2004
Posts: 879
Likes: 0
Received 0 Likes on 0 Posts

Default

the stock rev limiter pulls fuel
Old 12-14-2007, 02:35 PM
  #3  
Restricted User
Thread Starter
iTrader: (18)
 
socmguy's Avatar
 
Join Date: Apr 2007
Location: Fayetteville, NC
Posts: 1,515
Likes: 0
Received 0 Likes on 0 Posts
Default

ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.
Old 12-14-2007, 02:49 PM
  #4  
12 Second Club
iTrader: (16)
 
LiT1_up's Avatar
 
Join Date: Sep 2006
Location: Topeka
Posts: 109
Likes: 0
Received 0 Likes on 0 Posts

Default

I'll bet it does.
Old 12-15-2007, 03:50 PM
  #5  
Kleeborp the Moderator™
iTrader: (11)
 
MeentSS02's Avatar
 
Join Date: Mar 2004
Location: Dayton, OH
Posts: 10,317
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by tblu92
Yes--That's exactly the reaon for a LOW PRESSURE safety switch on the NOS fuel line to shut down the entire NOS system when fuel drops below a minimum setting--(most set around 30 PSI)
A low pressure safety switch wouldn't work in this situation (where the PCM pulls fuel)...the fuel gets pulled by keeping the injectors from firing, so if anything, your fuel pressure would increase in the system since it isn't going anywhere. The PCM isn't shutting off the fuel pump, and as long as that's pumping, you'll have at least 50+ psi in the rails...
Old 12-15-2007, 10:38 PM
  #6  
TECH Veteran
iTrader: (1)
 
gametech's Avatar
 
Join Date: Sep 2004
Location: Stockbridge GA
Posts: 4,068
Likes: 0
Received 432 Likes on 307 Posts

Default

Originally Posted by socmguy
ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.
Actually, the problem would be if you were running a WET shot, not dry. There is no harm in pumping unfueled nitrous through the motor. There would be a lot of harm in pumping a fueled nitrous shot with normal engine intake air not being fueled. In any event, the proper way would be to set the factory PCM rev limit above the nitrous rev limit.
Old 12-16-2007, 03:13 PM
  #7  
TECH Senior Member
iTrader: (2)
 
Robert56's Avatar
 
Join Date: Aug 2003
Location: Tacoma, WA
Posts: 9,557
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by socmguy
ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.
I am living proof of this. I had a high rpm (7000rpm) lean backfire with a 300rwhp shot, because of hitting the limiter and resulting lose of fuel. Now with that said, it was my own damn fault and not the dry hit, or the kit. I had decided that shifting without a window switch would be a cake walk. Didn't happen that way. When you don't shut the spray down the rpms will keep raising and take a bit to come down, so shifting at 6800rpm caused it to go up past limiter. Outcome was a hole or two in the manifold and bellows blown apart. Glad is wasn't a wet hit otherwise likely it would have been much worse.
Robert



Quick Reply: Does the rev limiter pull fuel or spark?



All times are GMT -5. The time now is 06:47 PM.