Honda D Series Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
0 Posts
Discussion Starter #1
So recently I went through a real weird issue with my crank snapping during commute, while going a merely 65mph on the highway, as I was slowing down for the exit, it just snap and the car went dead. Took about a whole month to get the engine back together with some high compression builds, pushed the cr up to 12:1, it needed a new exhaust, so I went to see some fabricators to get this done :)
not sure if its good looking, but it works, custom mid pipe, and muffler, specifically lifted higher for better ground clearance, for shitty roads here in Taiwan.. and custom valve controlled by vacuum with an on and off remote switch, basically I can manually set it open or close, while its open its completely straight thru the tail pipe, while closed it will circle back to go thru a smaller exit with lots of silencing, hence increase back pressure.

I'm not quite a exhaust guru, but that was what the shop explained to me while it was getting done, and it seem to make a difference driving in stop and go traffic with better low end torque, definitely super quiet too,and when its opened, it sounds super loud and mean at WOT.. however, I still get this metal clinging sound at 3-4k rpm range, everything goes away pass 4k.. checked the heat shield, it wasnt it, can a header make that noise?
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,543 Posts
sounds like its just vibrating against something
 

·
Registered
Joined
·
5,885 Posts
my exhaust has a super nasty rattle/buzz at certain rpms.

its caused by hitting the inside corner of the "s" tunnel.

push your foot against the exhaust tip and have someone rev it and see if the nosie goes away.

if it does, its a matter of tracking down what its touching or close enough to make resonate with the sound
 
  • Like
Reactions: slo_eg8

·
Registered
Joined
·
0 Posts
Discussion Starter #5
my exhaust has a super nasty rattle/buzz at certain rpms.

its caused by hitting the inside corner of the "s" tunnel.

push your foot against the exhaust tip and have someone rev it and see if the nosie goes away.

if it does, its a matter of tracking down what its touching or close enough to make resonate with the sound
I see, let me try that later tonight and see if i can track down anything :D
 

·
Never finishes (TWSS)
91 Civic SI hb/ 01 GSR
Joined
·
1,918 Posts
^^ right
You may have knock going on man. 12:1 with 91 or less and no tune/ shitty tune is asking for trouble.
 

·
Registered
Joined
·
2,003 Posts
It also might be the cutout valve itself, those things are not known for being super stable.
 
  • Like
Reactions: slo_eg8

·
Registered
del Sol si '94
Joined
·
2,539 Posts
Def sounds like it is hitting some where while under load. You said the muffler is tucked up higher for clearance, like Matt suggested, move the exhaust side to side and see if its contacting. I had a custom exhaust do that, but it fixed itself eventually lol

The others made a good point about the valve as well, some are known to rattle.
 
  • Like
Reactions: slo_eg8

·
Registered
Joined
·
0 Posts
Discussion Starter #10
did you retune or use higher octane fuel after installing the high compression engine?
Hey, the car is running on 98 octane in Asia, probably equivalent to the 94 in the states. knocking is still happening but only when i engage the clutch too roughly which brings rpm too low. I'm getting the car tuned very soon.

^^ right
You may have knock going on man. 12:1 with 91 or less and no tune/ shitty tune is asking for trouble.
yeah, I do experience it a bit, but the sound coming from the exhaust is definitely not knock, since if I really hammer the pedal the sound seem to go away ==

It also might be the cutout valve itself, those things are not known for being super stable.
right, I was suspecting the valve as well, its designed kinda like the throttle body style valve, and it sits right after the straight through muffler, I can only imagine the flow of the exhaust hitting it

Def sounds like it is hitting some where while under load. You said the muffler is tucked up higher for clearance, like Matt suggested, move the exhaust side to side and see if its contacting. I had a custom exhaust do that, but it fixed itself eventually lol

The others made a good point about the valve as well, some are known to rattle.
I will check it out tonight and see if its actually the exhaust hitting, or the valve itself :( hope its something simple tho
 

·
Tape-R taper/driver
EC3, ED8, ED9, EE5
Joined
·
574 Posts
Hey, the car is running on 98 octane in Asia, probably equivalent to the 94 in the states. knocking is still happening but only when i engage the clutch too roughly which brings rpm too low. I'm getting the car tuned very soon.
98 RON is likely similar to our US 91 OCT. I would look into the possibility of knock if it doesn't turn out to be the exhaust physically contacting another part of the car.
 

·
Registered
Joined
·
0 Posts
Discussion Starter #12
98 RON is likely similar to our US 91 OCT. I would look into the possibility of knock if it doesn't turn out to be the exhaust physically contacting another part of the car.
oh dear, I will take a closer look at it then, maybe get that fuel comp in there first
 

·
Registered
del Sol si '94
Joined
·
2,539 Posts
A simple hammer will fix most interference issues lol
 
1 - 13 of 13 Posts
Top