BlkSS1755

had my car dynoed over the week.. the car seems to fall everytime it reaches ~5300 RPMS all 3 pulls for just a bit. same time, same drop same RPM.. mainly in 4th gear.. on the highway, if i stand on it in 4th, when i reaches ~5300 RPMS, it feels like i took my foot off the gas..bogs pretty bad...but 1st, 2nd, 3rd pull to 6000 RPMS with no problem. no check engine lights. car runs 26 spark.. and about 2.7 knock retard at that RPM..





it's a 2000 FRC w/ 30K miles

mods:
-halltech stinger
-Z06 intake maifold
-Z06 ti's
-Kooks 1 3/4" w/ 3x3 cats
- NGK TR55 gapped @ .045 w/ Z06 wires

the car has NO tune as of now. is this more of a tuning problem, or should i start looking at somewhere else? valve float? other than that problem, the car runs fine.

thanks in advance,
vinnie

Gman2002Z06

Looks exactly the same as the graph of my 00 FRC...Ended up being spring surge...

Where the spring vibrates out of control at a certain frequency, then starts working properly again a fraction of a second later...

I changed the springs to LS6 springs and the graph smoothed out perfectly...

Peace...Gman

WS6FirebirdTA00

iTrader: (33)

isnt that a tight gap on those plugs? getting a tune and fixing that knock would be a good idea as well, knock isnt good on the internals.

BlkSS1755

i have a set that am going to swap out this week.. hopefully it'll work.. it sounds like we have the same problem.

thanks

BlkSS1755

what should it be gapped to? out of the box they were .055

WS6FirebirdTA00

iTrader: (33)

on n/a car i gap them at 0.050-0.055, i would stick close to 0.055, i have never had trouble there. not saying that would cause the problem. lots of n/a guys run plugs gapped tight for spray