I'm under the impression that all of the Mopar orange ECU have a built in rev limiter of 6000 RPM in them, all of them

I assume rear jet extensions, what pump is on it now?

Cab, I have never read that "rev limiter" thing. I bought my orange DC box in 1984. I think it has more to do with a slightly faulty memory and the Direct Connection/MP catalog wording that says it's best used up to 6000rpm. I don't think there's enough electronics in the box to include a rev limiter, unless the transistor speed isn't fast enough for more than 6000rpm.

OP, there are two reasons why your cam is acting like it's too big. First of all you closed up the lash and that has the effect of increasing duration. Then you are running 1.6 rockers and they have the effect of increasing duration. BTW your lifts with the 1.6 rockers are 0.657 and 0.661.

Also, your rear gear is really slowing you down off the line. Those are highway gears with the big tires. I think you need 4.30s. Now it seems you're crossing the line at 5000 rpm.

AndyF was right, the cam is too big for the car and gears. 4200+ lb and 3.54s don't work with that cam. If you want to keep the car and gears the way they are, then the cam has to change.
If you change the gears and stop making the cam act larger than its measurements, the cam can stay. I'd run the test with 0.022" lash. Most sources say that 0.004 more lash won't hurt and the stock lash is 0.018. I'd be in favor of keeping the cam as you've got it broken in.

One more thing: If you are showing no vacuum under the carb as you cross the line, the carb doesn't need to be any larger. As you change the gearing and start going faster, it may happen that you need more carb. But that's for later.

R.

Cab- I never had it break up on the street, one of my runs though it acted like it was a rev limiter. That's ok though, I wanted the rev limiter in the FBO box.

FurryStump- I'm running a Carter Mechanical 120 GPH and a full 3/8 line and sending unit. No jet extensions.

https://www.ebay.com/itm/Carter-Muscle-Car-Mech-Fuel-Pump-Dodge-BB-413-440-120-GPH-5-5-to-6-5-PSI-M3672/331399778792?epid=76996104&hash=item4d28f751e8:g:0Y8AAOSwLVZVy4wY&vxp=mtr

dogdays- Wow lots of helpful info

I wasn't thinking that increasing the lash would increase the duration. I can sure open the lash up.
When I was looking at cams, I wanted to get a high lift to take advantage of the .700 lift number the intake would flow.

I had 26" tires on the car but just put on the 28s. You can tell the difference. I got the 28s because I was originally planning to drive the car about 800 miles to go to the Moonshine Fest north of Atlanta, but will throw the 26s back on.

I'll be pulling the rear seat and wiper motor and hood. That should drop me back to 4000 lbs race weight.

I can't wait to see what the improvements net me.

Thanks again for all the help.

Based on you mph, it does seem that you need to find some missing hp, IMO.

Even though your A/F looks okay going down the track, I would still put a pressure gauge on it to verify it.

If the A/F is right, I would try fattening it up until it loses mph.

I also like the idea of opening the lash. I would not be afraid of 0.024 for a trial.

Yea, that is kinda why I started this thread, seems like I'm missing some power.

What kind of pressure gauge do you mean? fuel pressure?

The car has a clutch fan with a mechanical water pump, so that's like what, 30ish hp?

I have no idea what an orange box pulling 8* of timing might drop hp.

Kept my 3" exhaust corked.

I took off the air cleaner, using NGK heat range 6 plugs.
The gas I used was 90 octane with a bottle of booster.

I was thinking the engine should be up closer to 600 than 500 hp.

Maybe it is ,and it just isn't coming on fast enough, like Andy said, to make up for the big bog off the line.

According to Wallace, Im 525-540 HP

Opening up the lash fools the motor into thinking that the cams is smaller, tightening it does the opposite
Test, test, test and then test some more until your happy with the car

Yes, fuel pressure.

IMO, this is the time to kinda let go of trying to reconcile all the calculator hp numbers and "what should it be" engine dyno #s. Otherwise you'll make yourself crazy trying to rationalize stuff.

I'm simply comparing mine to yours.

If you are blowing 175 on the gauge, you'll be fine, you just need to find it. Could be in the tune or a few small things. You'll find it.

Not my orange box. I shift about 6200 and trap about 6400 and it never misses a beat with my orange ECU. And when we had it on my sons Dart with his 400 he would push it over 6500 and still it worked good. He ran no faster when we put MSD on his car. Ron

You need some gear with the 4 speed to get it off the line. Are you shifting at 7g? If you are that’s not helping et either. That thing should probably be shifted around 6-6200 with standard port window.

Hello,
I didn't get many runs down but it has TF heads opened up to MW ports with a matched 337 intake.
I wish I knew where the HP/TQ peak was.

Its funny to hear that and I mean it in a nice way. Thats because my brother always used to ask me what I shift at as years ago we raced each others cars. And he would get mad at me sometimes as I told him I dont look at the tach when I shift. We had 4-speed cars when we first started racing. I am just the kind of hotrodder that shifts by the feel of how the car is pulling to me. To me as soon as I feel like its peaking I shift. I shift my 63 the same way as I just dont use the tach much when I shift. And I must get it pretty good as I ran 10.76 three passes in a row before and never looked at the tach when shifting. My brother always uses the tach when he shifts but back when we had 340 four speed cars I was always faster then him in the stick cars shifting by how the eng feels. I dont know why but I have always felt I can jump in any car and with just a few passes know about where it feels right to shift. I am sure other hotrodders must feel the same way. Course for wanting to be very consisdent when bracket racing it has to help shifting at the same rpm every run. Ron

Need bigger carb, and in the video looks like your front end is tight.

if your dead hooking on radials what RPM are you launching at?
Dead hooking that car may end up breaking a lot of drive line parts in time
Stick shift cars are full of drive train eating demons, you have to feed them AKA, you can feed them tires or clutches or U joints or axles or so on and on

The funny thing was, I couldn't hear my car because I had a full exhaust. The guys beside me were running open headers.

Car feels like it's still pulling strong past 7k, but, I'm putting my FBO box with the 7k limiter in to keep the engine together for a while.

I'm going to try next time out making the changes you guys have suggested, can't wait!

I keep getting conflicting advise on the carb. It doesn't pull a vacuum even to redline, although there's no doubt a Dominator would make more power.

Good call on my KYB gas charged shocks.

The tires turn maybe a time or two, just enough to make them smoke a tiny bit.

I tried launching at 3000,3500,and 4500 rpm.
At 4500 I could smell the clutch (McLeod RST twin disc).

Going out next time with all the changes you guys suggested, smaller tires, increased valve lash, about 200lbs less weight, so I guess the whole testing process needs to start over to see where it's at.

FWIW: I’ve found the most important factor in moving a big heavy car is effectively utilizing your “torque peak”. For instance, my car FEELS like it’s pulling through 6700. But when I short shift it at 6200, car goes faster. It isn’t always whether or not it’s pulling at the upper RPM, it’s balancing that pull against the torque you’re shifting back into. In order to use your torque effectively, you want to land right on your torque peak with your shift, if you land beyond it, you may be losing ET by letting the engine wind too long even though it still is making power at that upper RPM.

As I see it....the only way your going to get the best out of the car with the hp you have is if you can trap at nearer 7k, as you say it still pulls well there. Best way of doing that is to use the 28" tyre with a 4.56 gear, but thats probably not going to happen, so the only other way it can be done is with say a 29" tyre and try and run it out in 3rd. A 26" tyre will still only see you trapping at around 5400, not enough, and I don't think lash changes etc, will do much to help hp but it'll be fun trying I guess......my2c's

Sorry I missed this response-
I actually have a MW ports,but you are correct, it seems to go as fast or faster shifting 65-6700.