Major Lag Spike

[D'darrio]

I've been working with servers for along time. But there has always been one problem that I have not seem to figure out. When ever the 6th player joins a game, people start to experience FPS problems. Then they experience their characters arms fly to different positions than the camera, they will lag for about 30 seconds to over 300-600 ping. After that, it seems fine. All my other friends have the same problem. Here is my server.cfg:
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//Server Hosting Settings
hostname "-=LAG-WARS=- (Potential Lag)"
rcon_password "xxxxxxx"

//Executed files
exec "mani_server.cfg"

//Server Configuration
sv_accelerate "6"
sv_airaccelerate "360"
sv_allowupload "1"
sv_allowdownload "1"
sv_alltalk "1"
sv_cheats "0"
sv_consistency "0"
sv_filterban "0"
sv_friction "4"
sv_gravity "220"
sv_lan "0"
sv_logbans "1"
sv_maxrate "0"
sv_minrate "0"
sv_maxupdaterate "80"
sv_maxupdaterate "33"
sv_password " "
sv_pausable "0"
sv_timeout "55"
sv_voicecodec "vaudio_miles"
sv_voiceenable "1"
sv_region "North America"

//Multiplayer Configuration
mp_limitteams "3"
mp_flashlight "0"
mp_autoteambalance "1"
mp_allowspectators "1"
mp_autokick "0"
mp_buytime "999"
mp_c4timer "30"
mp_chattime "10"
mp_disable_autokick "1"
mp_footsteps "1"
mp_freezetime "0"
mp_roundtime "9"
mp_tkpunish "0"
mp_friendlyfire "0"
mp_hostagepenalty "0"
mp_startmoney "16000"

//Multiplayer Physics/Other Physics
phys_pushscale "-400"
phys_timescale "-1"