I'm going to try 1 3/4" Supercomps next week so I had to make an exhaust that would work with both sets of headers. 4' of 3" pipe w/2.5" Mac Flowpath mufflers, no crossover and no tails. I liked the real deep tone they have but man they are loud. I also tried a Holley 750dp, it is pretty much out of the box but I cleaned up some casting flash at the bottom of the main body and lined up the baseplate a little better. I haven't checked it with the LM-1 yet.

Car was running perfect before I left the house with the 650, of course on the drive to the track it wouldn’t idle and had a slight miss at cruise, full throttle was fine. The 650 wouldn’t idle the entire time at the track. When I put the 750 on it idled fine.

New bests in bold. I had my buddies weather station with me.

650 carb, mufflers, kind of a dead spot before 60ft
1.73, 7.67@ 91.32, 12.00@ 112.94- DA 3600- when Paul smoked me
same
1.70, 7.64@ 91.32, 11.96@ 113.26- DA 3450
same
1.69, 7.62@ 91.43, 11.96@ 112.67- DA 3260
Remove mufflers, dead spot went away
1.66, 7.55@ 91.58, 11.86@ 113.64- DA 3050
750 carb, still no mufflers:
1.655, 4.863, 7.536@ 91.81, 9.850, 11.835@ 113.84- DA 2900-
same
1.661, 7.54@ 91.72, 11.84@ 113.83- DA 2820

Video of 3 best passes:
http://s213.photobucket.com/albums/cc31/lonphotobucket/New383vids/?action=view&current=Lonbest1017.flv
http://s213.photobucket.com/albums/cc31/lonphotobucket/New383vids/?action=view&current=Lon21017.flv
http://s213.photobucket.com/albums/cc31/lonphotobucket/New383vids/?action=view&current=Lon1017.flv
Timeslips:
http://i213.photobucket.com/albums/cc31/lonphotobucket/Timeslips/slips1008002.jpg

Congrats Lonnie. :thumbsup: Damn, mine and your car would make a hell of a race. Look at my time slip in my signature.

Very cool videos!! We'll see if we are faster next Friday!

Good job Lonnie! Good luck with the header swap....I will keep my fingers crossed!

Well, I blew it on the header comparison.
I hadn't checked my afr with the 750 before I ran last week, I didn't know if I would even have time to try it. It was stock jetting 71/80. I was going to check it before I took the old headers out but I forgot until I was almost done :clonk:

I had it running with the new headers. Friday morning I was going to take it out and check the afr at full throttle. I got 1 block from my house and it burned my battery cable on the header and shorted. I got the car back home, pushed it, and found and fixed the problem. It drained the battery so I had to charge it, I never did check the afr.

The DA was 1000ft lower than last week.
1st run, DA 2500, with mufflers, no traction, 1.90, 12.12@ 113.59mph
2nd run-DA 2200, with mufflers, 1.672, 7.549@ 91.82. 11.86@ 113.15- slight dead spot right after launch.
3rd run- DA 1850, no mufflers, 1.660, 7.541@ 91.6, 11.86@ 112.88- still had the dead spot.
It took 4 1/2 hours to make the 3 runs. I had more gas and crap in my trunk this time too so I probably weighed 35-40lbs more.

The better the air got the slower it ran.
This morning I hooked up the LM-1, DA 2500ft, idle 16-17afr, cruise 14.3+/-, full throttle 1st 13.4, 2nd 13.6, 3rd 13.7. Leaner than I thought it would be with the jets it has. When I punch it from a 10-15mph roll afr spikes to about 16 so I'll need to play with squirters at the track too.

With the 650 I always hit my best ET's when afr is 12.5-12.7 on my meter so that's where it was last week.

I'll try to go again next week with a better tune and maybe try both carbs again if I can get more than 3 runs.

So far, the 750vs650 seems to go to the 750 by a small margin and the 1 5/8vs1 3/4 might be a wash.

Here is a sound clip of the car going down the track. http://s213.photobucket.com/albums/cc31/lonphotobucket/New383vids/?action=view&current=incarsound.flv

Lonnie, glad to see it picked up and awaiting final verdict on the 1 3/4 headers.

I'm following along keeping notes :yes:

Congrats on the new times.

I like those supercomp headers Lonnie, I vote to keep them!

Boy what a frustrating night last Friday, huh? My girls liked seeing the funny cars but that forced us to have to stand around for loooong periods of time, LOL!


P.S. Update, "technically" Lonnie beat me this week...I crossed the line first but red lighted, ooops!

I crossed the line first but red lighted, ooops!

automatic lose :beers:
You'll get him straight up soon.... keep at it :yes:

Nice best! Looks like she is dead consistent....you'll be dangerous if you bracket race :yes:

Get that baby jetted up and bring her back Lonnie!

Nice best! Looks like she is dead consistent....you'll be dangerous if you bracket race :yes:

I do bracket race some, been doing it for years. Lately though my reactions are very inconsistent, I've been going out in the 1st or 2nd rounds.

Ron, I will. No drags on Halloween. I have something going on on the 7th but I'm gonna try to make it. The 14th for sure... The bigger headers didn't hurt anything but I don't think they are going to help either. At least they look fast. Bigger headers will probably work better for you now that you are going to cheat. :D

I do bracket race some, been doing it for years. Lately though my reactions are very inconsistent, I've been going out in the 1st or 2nd rounds.

Ron, I will. No drags on Halloween. I have something going on on the 7th but I'm gonna try to make it. The 14th for sure... The bigger headers didn't hurt anything but I don't think they are going to help either. At least they look fast. Bigger headers will probably work better for you now that you are going to cheat. :D

Haha.....I think I am going 1 3/4-1 7/8 stepped.