Bigger Headers, Slower Car

[PRHeads]

My suggestion is a trip to the chassis dyno to sort out the jetting & timing.

 

[padam]

Got it done today, took the win in UMTR Street Stick.

Now

 

[33 IMP]

Congrats! Another stick shift win! Yeah!

 

[fourgearsavoy]

Wow another win for a Mopar in UMTR ! You might just be at the head of the table at the banquet this year. Are you leading the points so far?

 

[padam]

Wow another win for a Mopar in UMTR ! You might just be at the head of the table at the banquet this year. Are you leading the points so far?

Yes I’m leading now, but a lot of races to go.

 

[Budnicks]

Yes I’m leading now, but a lot of races to go.

What changes did you make ?
or did the track & weather just come to your set-up ?

 

[padam]

What changes did you make ?
or did the track & weather just come to your set-up ?

The car still seems to be at least .200 off my quickest times.
The last move I made was to increase jet sizes, but at the same time I had to install tubes in the rear tires.
That slowed the car by .05 60' and .100 1/8! The weather seemed similar.
Hopefully Friday I can pull a plug and check the reading again. I saved your diagram on my phone for reference.

Right now the car is dead hooking on launch and bogging the engine. Not good for max ETs but it does wonders in a bracket race.
My last three runs were 7.760, 7.756, 7.763, all on a 7.740 dial, not lifting at the stripe.

The ladder bar suspension is really paying off here. We were on a crappy track this weekend and the other stick cars were having all kinds of traction problems.

 

[496 polara]

What rpm are you launching at?

 

[padam]

What rpm are you launching at?

4k now.
I had launched up to 4500 and the car is quicker that way but consistency went out the window.

 

[66 Cornpicker]

Padam, Where did you get that car ? Is there any chance that Dave owned that car before you and it was Panther Pink ?

 

[padam]

Padam, Where did you get that car ? Is there any chance that Dave owned that car before you and it was Panther Pink ?

No, I bought in 82, it was green with black stripes from the factory, 318 auto.

 

[33 IMP]

No, I bought in 82, it was green with black stripes from the factory, 318 auto.

Weren't they all? LOL.

 

[padam]

So this is another plug I pulled after 1 run with the bigger jets. It’s a little blacker on the face of the threaded portion, but I still don’t see any color on the porcelain.

I know the gap looks small, I dropped it a couple times.

To me it looks like it’s still a little lean.

 

[HawkRod]

I know the gap looks small, I dropped it a couple times.

I agree the gap looks small. In general, you want more gap as compression (either static or due to superchargers/ turbos) increases.

 

[padam]

I agree the gap looks small. In general, you want more gap as compression (either static or due to superchargers/ turbos) increases.

I run them at .035”, but installed plug in staging lane and removed it on return road. A little hot down there and dropped the plug, probably closed the gap.

 

[dvw]

The color on the porcelain will only be about 2mm right at the base. You need to look deeper.
Doug

 

[RemCharger]

I agree the gap looks small. In general, you want more gap as compression (either static or due to superchargers/ turbos) increases.

I'll have to un- agree on that one.

 

[padam]

The color on the porcelain will only be about 2mm right at the base. You need to look deeper.
Doug

I’ll cut the threads off and have a look

 

[padam]

Same plug;

 

[dvw]

I would agree thats lean.
Doug