For starters heres the fresh combo set up for a supercharger but running N/A:

496 bbc
8.7:1 comp
brodix race rite oval ports
performer RPM ( for N/A)
800 holley DP
crane blower cam:
236 deg @.050 .553 lift (intake)
246 deg @.050 .571 lift (exhaust)
114 lsa
1 3/4 primary ceramic coated headers thru little dual exhaust, generic mufflers (2 inch) (I know, I know)
ST-10 4sp
2.73 (I know, I know)
pizza cutter tires.
3800 lbs w/o me (add 230)

First night out netted

2.43 60 foot
9.15 @84.8 1/8th
13.83@ 105.98 graemlins/boring.gif

I realize my 60 ft is horrendous, and my exhaust is too small, but I was looking for more MPH.
According to my Air/fuel gauge I was at 12.3 on going through the traps.
Timing was @ 15 intial 36 total

The engine doesnt seem to want to pull above
5000 rpm. It isnt starving for fuel (according to the AF gauge) and my jetting is in the ball park because I tried jetting up and down and this was my best MPH, although my best ET was 13.67 @ 104.67.
Is my exhaust hurting me that much?
it is a planned upgrade.
Is the lower compression and supercharger type cam hurting me this much? Is it one great big culmination? or am I an idiot and cant drive :confused:
fire away with the constructive critism ;)

what times were you hoping for? the trap speed you have is good for 12's but maybe change the tires to at least pizza cutter slicks and chip away at your sweet 60 foot.

the cam does look a bit small?

Your exhaust is very restrictive for a 496..its good for a stock 350 though :D
order up a nice 3" system
FYI..when I switched from manifolds,stock lead pipes and 2" tailpipes to headers and a full 2.5" exhaust,I picked a half second and 6 MPH,so get rid of that silly 2" exhaust!
Your 60 ft. times need major improvement..get some drag radials or DOT slicks,but don't get anything over 26" tall with 2.73 gears.
Between upgrading the exhaust,getting some bite and reducing your 60 ft. times,you will see a dramatic drop/increase in your ET/MPH
Looks like afun combo to me,even w/o the supercharger graemlins/thumbsup.gif

greasefire, I agree with Chris, the exhaust is the culprit. A good "3" exhaust with Borla XR-1 mufflers and you won't think your in the same car. Actually your times aren't that bad for the lack of gear, tire and no compression. A 3.73 or 4.10 gear would help and why are you running a motor designed for a blower without it? Also, like he said, get a set of small diameter slicks to help with gearing.

Small exhaust as had been stated and a lack of cylinder pressure, which I believe is the primary reason. Combined is why the motor is falling off quite early. The cylinder pressure is why the 60' is weak, the motor can't build the torque it should be.

thanks for the advice guys. I thought the exhaust was the culprit, but didnt realize the severity of the restriction.

Its proably not going to rev very hight,I shifted at 5700 in my 468 with a lot more cam. The blower with some good exhaust should bring it to life alone with a better gear.

I am not running the supercharger right now because of a lack of adequate fuel system. Also i just wanted to see how this combo would do N/A on 87 octane. I will monkey with this combo for awhile before installing the blower and until a fuel system is constructed.

another exhaust story if you will..................i built a very very mild 396 8.8 to 1 compression,stock low rise intake, 750 carb,284 crane cam with 3.42 gears single spinner, 3800 lbs car, was half azz tuned down to 14.40's at 92 mph......i unhooked the 2" full exhaust with glass packs of the headers and it ran on the next pass 14.001 at 98 mph......so yes your exhaust is a big problem for that big motor.........

hey greasefire want to run them i think i would give ya a good run in my zzzzzzz graemlins/boring.gif 28 with 2.73 gears......lol....just playing

thanks, keep the exhaust wonder storys coming. I need encoragement. It also allows me to gauge the performence increase. graemlins/clonk.gif

I saw a very restictve exhaust cost over 100 RWHP on the chassis dyno a few weeks ago on a 450 RWHP BBC. No joke.

Jegs sells a mandrel bent 3" system w/o mufflers for less than $200..I hear it fits good (some pipe trimming will be involved),and just add your choice of offset inlet/offset outlet mufflers.