open header
05-24-2006, 10:26 AM
#1
Junior Member
Thread Starter
Join Date: Mar 2006
Posts: 22
ok my friend has a 87 rx-7 dunno the model but it does not say it anywere on the outer body if that helps but he wants to take the down pipe off and run open and wants to know how long untell it will hurt thae car or if it will at all thanks
05-24-2006, 11:47 AM
#5
Senior Member
Join Date: Mar 2002
Location: Ky
Posts: 2,723
as far as i know theres no way it can damage the engine. The ports wont open though and because of the sound waves bouncing off the bottom of the car and around it will be LOUD. I ran my car like that for 5 minutes when i was doing exhuast work and needed it out the way real quick. the car shook at 5k from the exhuast. Someone yelling 5 feet away you couldnt even hear. At idle its not bad anything after wont work. If you plan on driving the car anywhere you wont be able to so hope its not planned for street.
05-24-2006, 12:56 PM
#6
Super Moderator
Join Date: Apr 2002
Location: VA
Posts: 2,532
Right before I put my exhaust on I drove my car (T2) a few miles with just the HKS downpipe and a 45-degree downturn. It was pretty loud. Okay, it was RFL, especially when I opened it up. At cruise it really wasn't all that loud inside the car. I was pretty near back home when it occurred to me that the cops might not like it that way. Johnny Law is pretty laid back around here. 
My street setup is just a hiflow cat and a 3" Borla XR-1. Some people would say it's loud, but it's just right as far as I'm concerned. Passes VA state inspection just fine.
My street setup is just a hiflow cat and a 3" Borla XR-1. Some people would say it's loud, but it's just right as far as I'm concerned. Passes VA state inspection just fine.
05-24-2006, 04:24 PM
#8
Senior Member
Join Date: May 2005
Posts: 959
I believe the general thought is loud. Back in my NA days, I ran an open manifold for a few seconds...that was fun.
But seriously, don't use open headers unless the car is track only and the engine is ported to match that kind of exhaust...
But seriously, don't use open headers unless the car is track only and the engine is ported to match that kind of exhaust...
05-24-2006, 10:08 PM
#9
Junior Member
Join Date: May 2006
Posts: 29
let them do it, they'll find out
run it open header, you wont even get out of the driveway before deciding it cant stay that way. and yes, i would be more worried about a fire under the car than anything else. its likely that it will shoot flames, not to mention the EXTREME heat all across the bottom of the car, right onto the undercoating.
i started my car with just the manifold on it when i was putting the transmission in it, revved it a few times and was done with it. i had a look at the sheet of plywood that was about 18" from the manifold and there was a small amount of gas and moisture that had collected on it. i know i wouldnt want that across the bottom of my car.
you CAN, but in my opinion, it would be dangerous. i could be wrong though.
run it open header, you wont even get out of the driveway before deciding it cant stay that way. and yes, i would be more worried about a fire under the car than anything else. its likely that it will shoot flames, not to mention the EXTREME heat all across the bottom of the car, right onto the undercoating.
i started my car with just the manifold on it when i was putting the transmission in it, revved it a few times and was done with it. i had a look at the sheet of plywood that was about 18" from the manifold and there was a small amount of gas and moisture that had collected on it. i know i wouldnt want that across the bottom of my car.
you CAN, but in my opinion, it would be dangerous. i could be wrong though.
