Nitrous Oxide Installation | Tuning | Products
Sponsored by:
Sponsored by:

Detonating in Third Gear

Thread Tools
 
Search this Thread
 
Old 09-06-2006 | 02:35 AM
  #1  
NXZ28's Avatar
Thread Starter
10 Second Club
iTrader: (45)
 
Joined: Sep 2004
Posts: 611
Likes: 0
From: Richmond Hill, GA
Default Detonating in Third Gear

I am using a NX Direct port setup. I am running 20N and 12F for jets. I have made 10 passes with the 150hp jets. I have the Ramchargers timing tuner and a custom nitrous tune from Jeff Creech. I have pulled up to 5 degrees at WOT with the TT and I am still getting detonation in third gear only. I have a 255lph fuel pump and 98 octane fuel. It does not detonate at all in first and second. I have the TR6 plugs gapped at 35. Should I go with a one step colder plug? I am baffled on this one. Anyone have any suggestions? I am trying to get in the 10s in Germany. My best pass is 11.22. This car has a 10 in it but I can't get a full throttle run out of it.
Old 09-06-2006 | 08:50 AM
  #2  
CAT3's Avatar
Restricted User
iTrader: (9)
 
Joined: Sep 2002
Posts: 7,603
Likes: 0
From: Sierra Vista, AZ
Default

I know your chasing your tail on this one, but I cant see the need to pull 5* AND use 98octane, unless your running 12+ cr. How many miles on the car, whats its history? My guess, you have oil being sucked thru the intake stream, which hits the combustion chamber and makes your detonation OR you have false KR reported from banging Y pipe/Headers etc... What do the plugs tell you? Is this audible KR or result of a scan?
Old 09-06-2006 | 09:05 AM
  #3  
NXZ28's Avatar
Thread Starter
10 Second Club
iTrader: (45)
 
Joined: Sep 2004
Posts: 611
Likes: 0
From: Richmond Hill, GA
Default

The engine only has about 3K on it. It only detonates in third gear. I am leaning towards a fuel pressure issue or I need a colder plug. I can't pull a plug right after a run because of the stupid tracks we race on in Germany. You have to turn around at the end and line up. Then they close the track for a few minutes so we can drive back down it. It is stupid. All of our racing is on old air fields with no traction compound. Just concrete or asphalt.
Old 09-06-2006 | 03:16 PM
  #4  
CHRISPY's Avatar
TECH Senior Member
 
Joined: Nov 2001
Posts: 10,341
Likes: 0
Default

What pump are you running? Do you have a FPSS?
Old 09-06-2006 | 09:37 PM
  #5  
CAT3's Avatar
Restricted User
iTrader: (9)
 
Joined: Sep 2002
Posts: 7,603
Likes: 0
From: Sierra Vista, AZ
Default

You can check plugs for detonation after getting back to the pits, look for deposits on the porcelain/facing of the plug.
Old 09-06-2006 | 11:26 PM
  #6  
Nitro Dave's Nitrous Outlet's Avatar
FormerVendor
iTrader: (25)
 
Joined: Jun 2002
Posts: 12,284
Likes: 4
From: Waco, TX
Default

Do you have a fuel pressure gauge on the car. Check and see if the fuel pressure is droping on the top end. The walboro intank will be good for about 450- maybe 500. I bet between the directport and the motor you are running out of fuel.. If this is the case adding ahot wire kit may help.

THe TR6s are fine.
Dave
Old 09-06-2006 | 11:32 PM
  #7  
CAT3's Avatar
Restricted User
iTrader: (9)
 
Joined: Sep 2002
Posts: 7,603
Likes: 0
From: Sierra Vista, AZ
Default

Oh snap, I thought he was running your fuel cell for the DP there Dave...ouch, sorry I missed that. If your taping off the rail I would suggest getting a dedicated fuel cell. Can you run without one? YES. Will it be safer and more flexible to run one? DEFINATELY.
Old 09-06-2006 | 11:39 PM
  #8  
NXZ28's Avatar
Thread Starter
10 Second Club
iTrader: (45)
 
Joined: Sep 2004
Posts: 611
Likes: 0
From: Richmond Hill, GA
Default

I do not have a FPSS. I am running a Granatelli 255 lph fuel pump. I was going to buy a dedicated fuel system from Nitro Dave's this winter. I have a race this weekend and was trying to get a full pass out of this car. It has gone 11.22 with the nitrous shut off in third gear. Thanks for all the input.
Old 09-08-2006 | 02:38 AM
  #9  
NXZ28's Avatar
Thread Starter
10 Second Club
iTrader: (45)
 
Joined: Sep 2004
Posts: 611
Likes: 0
From: Richmond Hill, GA
Default

I checked the fuel pressure last night. It was 62 psi at idle and dropped down to 60psi at WOT. This is without a load on the motor though. It is a universal mechanical gauge so I can't drive down the road and see it. I did notice that my timing was at 26-28 degrees at WOT. Do I need to bring it down to around 22 degrees?




All times are GMT -5. The time now is 06:14 AM.