86 Iroc HOTROD

I went from a .630 .630 .252/.258@.50 on a 106ls to a
.660 .660 .264/.272@.50 on a 110ls with a 4-7swap

Before I usually ran low to mid 7.30's @94-95 with a 2800-3200 stall and 26" slicks and 6.7's @100 on a 100shot
Now with this I run low to mid 7.30's @94-95 but I had to move to a 4000 stall because of the dur. and I couldnt get it to hook on 26's so I got some 28's and it hooks to 1.55-1.60 60fts on motor on a 175shot it ran 6.77 @ 102 with a 1.4760ft. what gives I have been that fast with the smaller cam on a smaller shot when i ordered the cam I was told it would be a better juice cam but it seems to be worse

Could the problem be in fuel, is the new cam wanting more fuel? I checked the plugs driving around town they are black and smell like gas but at the strip after a pass they are white and seem to be a little lean I have a Holley 950HP with 84's in the front and 86's in the back i'm afraid if i go up on the jets it will flood around town, i've been told to mess with the air bleeds but i dont know how they woork and am afraid to mess with them.
Has anyone run into this before any help is appreciated.

86 Iroc HOTROD

TTT... Come on guys, has anyone ever run into this before?

WS Sick

I wonder how much the taller tire has come into play. Is the larger converter possibly eating more power?

I wonder how much better a full 1/4 would be with it?

86 Iroc HOTROD

I tried the new cam with the old 2800 to 3200 converter with the 26 in tires. It ran 7 high 40s-low 50s at 93 mph w/ a 170 60ft. The new converter put it back in the 30s with a 28 in tire. The 26s wouldn't hold it. The 28s and the new converter had the best 155 60ft. This is where I am puzzled.

The reason I wonder if its fuel is also in the mornings, it spits back through the carb. Usually this means lean condition or excessive timing. The old cam did not spit back with the same timing and smaller jets in the carb.

WS Sick

It may be spitting back through the car because of the extra overlap, that would cool the engine a little making it need more warm-up time.

Maybe if you add more gear or carry each gear higher?

86 Iroc HOTROD

It may be different with this cam but I tried a 4.86 gear w/28" tires with the other cam and the 3.70 i have now was faster w/26" tires plus i got a huge amount of drivability over the 4.86

86 Iroc HOTROD

Someone suggested that I am running too much timing and too much fuel. I am running 84's in the front and 86's in the rear (jets) @ 40deg. total timing. He said 36 deg usually works better but I told him I have tried going up on the jets and it gets faster, I have also tried 32, 34, 36, 38, and 40 deg. total with 40 being the fastest, He said that the reason for that is I have so much fuel I have to get the fire there faster. He said I should go back to the original 78's in front and back and try 36 total. Does this sound right to anyone else? This person owns a local shop that builds racing engines and has their own chassis dyno, I'm inclined to believe him because he is around this stuff all the time but I would like any other opinions thanks

greezemonkey

Might not be a bad idea to let`em tune it and see, chassis dyno`s give up a lot of info you can`t get on the 1/8 or 1/4 without data logging..just a thought

86 Iroc HOTROD

In case anyone is wondering I tried less fuel and less timing killed it .02 60ft. and .1 E.T.