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

If it is non-turbo, it most likely won't hurt the car at all (unless something catches fire from the exhaust), but it will be deafening loud.

why would you want to do that? it will be VERY loud and not make any more power (probably less as the 5th &6th ports wont work) and could **** the engine up

How could it **** the engine up?

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.

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. https://www.nopistons.com/forums/pub...IR#>/bigok.gif



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.

I drove my NA to the exhaust shop open RB header, it was ******* loud as hell though.

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...

let them do it, they'll find out https://www.nopistons.com/forums/pub...IR#>/smile.png

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.

I drove with just a downpipe around the block one time and I got the biggest headache. Its not a cool loud but a painful loud. Have fun kid.