top end hesitation issue

SickboySS

Amateur Racer
Oct 7, 2006
224
0
0
auburn ma
ok, this has been driving me insane the past few weeks. my car has a top end hesitation at about 5500rpm. at the track it feels like it hits a wall in 1st gear and the suspension comes right down, shift 2nd and i feel it again, but it will power through and rev to 6400, shift 3rd and it holds itself at 5500-ish...same thing on the highway, 3rd gear, 5500, doesn't want to give anymore. its not leaning out, i have a wideband 02 and the a/f is 12.2-12.4 wide open when it does it. fuel pressure is rock steady at 6psi. new plugs too. if i put the car in neutral and rev it on the highway you can hear it breaking up and feel a slight vibration like an imbalanced tire when it hits 5500. below that rpm the car is an animal. the cam is new this season, lunati recommends the same valve springs at the old cam that was in there, so its not a spring issue. junk wires mabey? 1 year old superconductors, or valve lash a little too tight? i went 1/2 turn past 0 lash cold

car specs - 355, holley aluminum heads, lunati voodoo .525/.546 241*/249*@.050, holley street dominator dual plane, hvh supersucker spacer, 650dp, msd distributer & 6AL
 

bowtie81

Moderator
Mar 28, 2008
5,008
0
36
sarnia, ontario canada
what kind of ignition do you have? when i was using the stock HEI the 4 pin module was breaking down on me, till i put the msd module in.
 

bowtie81

Moderator
Mar 28, 2008
5,008
0
36
sarnia, ontario canada
try taking the pill out of the box, try changing the gap on the plugs.
 

bowtie81

Moderator
Mar 28, 2008
5,008
0
36
sarnia, ontario canada
fire it up at night and to see if there is any arching from the wires.
 

slimbo

Moderator
May 21, 2007
4,223
0
0
www.yellowbullet.com
valve springs. and that intake is probably done by 6k
 

SickboySS

Amateur Racer
Thread starter
Oct 7, 2006
224
0
0
auburn ma
i'd rather have the intake be out of power by 300rpm on the top end then to have it start making power 1500rpm later down low
 

joemalibu78

Dragway Regular
Sep 8, 2004
851
0
0
flint mi.
new plugs, to much timming, need a 750 dp
 

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