6.4 cam questions//help

krasselt21 · Dec 10, 2018

I have a 2.6 smooth bore 6.4 pull truck. No matter what gear ratio: 4.88,4.56,4.30, or 4.10 truck will only turn 3600 rpm. Stage 4 rcd cam. Ported heads. 100 over injectors. Ported intake manifold. Looking for some help. Tried different tuning already. Is it head flow would overdose valves help?

powerstroked08 · Dec 10, 2018

Really? I'm running 5,500 with a zf6 in high range second (labeled 1 on the shifter) with 3.73's on 35's.

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krasselt21 · Dec 10, 2018

Running 4 lo direct 35 tires.

krasselt21 · Dec 10, 2018

Also zf6 here

powerstroked08 · Dec 10, 2018

Wow. Something is off then. I mean I was able to hold 4300-4400 down the track with stock fuel on 76/59 chargers. That was before I bumped my build up to what it is now.

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powerstroked08 · Dec 10, 2018

Are you maintaining rail?

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krasselt21 · Dec 10, 2018

Yeah it’s holding rail. Also only 2.6 smooth bore single. Wondering if stage 4 rcd is to much and if it’ll perform better on less of cam

sootie · Dec 10, 2018

Something's wrong that's for sure

powerstroked08 · Dec 11, 2018

Just out of curiosity what all is done to it?

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krasselt21 · Dec 11, 2018

Ported heads, ported intake manifold, dual fuelers, 1000% over injectors, cut coated delipped pistons, bd manifold, bd up pipes, Midwest s400 turbo pedestal, RCD stage 4 cam

powerstroked08 · Dec 11, 2018

It's the 1000% over injectors....

just kidding I know what you meant!

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powerstroked08 · Dec 11, 2018

I really doubt it is head flow issues. And by running oversized valves it can actually hurt you a little bit. Because of it shrouding the valves. The porting helps out for sure, not like a gas job but it helps none the less. What does it do? Will it free rev to 4k? Or is it more of a load thing that it won't come up to the top end? Are you able to data log? Sorry for all the questions, but we need to know a little bit about what it's doing.

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krasselt21 · Dec 12, 2018

no matter the gear ratio on the track, it will only turn 3600 rpm. it will free rev past no problem, it will go past on a dyno, just doesn't do it on the track. so I wondering with the load and the bigger cam if that is hurting it or not. trying to get it figured out for the spring.

sootie · Dec 12, 2018

Have you tried pulling back pulsewidth and seeing if anything changes? What if you drive it down the track with no sled behind, will it pass 3600?

powerstroked08 · Dec 12, 2018

Hmmm seems strange. Have you played with the timing in the upper rpms to compensate for the cam and bigger piston bowl? Because that cam should move your power band up higher in the rpm range, And sacrifice some low end. And like sootie said, try pulling some fuel back and se3 if you're choking the charger out some.

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krasselt21 · Dec 12, 2018

itll turn 5000 rpm just drive down track. its as soon as its loaded on track it seems. as on dyno I can run it up to 4500. but the power band on the came maxes out at like 3500 and doesn't make sense to me.