Detonating in Third Gear
#1
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From: Richmond Hill, GA
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.
#2
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?
#3
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From: Richmond Hill, GA
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.
#6
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
THe TR6s are fine.
Dave
#7
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.
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#8
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From: Richmond Hill, GA
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.
#9
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From: Richmond Hill, GA
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?