E Cut-Out on a NA B18C1

UMR Racer · Post by **UMR Racer** » Tue Feb 19, 2008 2:52 pm

So im doing research on exhaust tuning and trying to find info on cut outs and I can't find much. I know that a pipe thats to big such as a 3'' is to big and causes the exhaust to have less flow velocity and therefore robbing HP. So what I want to know is if a cutout after a 4-2-1 header will actualy decrease HP due to decreased flow velocity. The setup would be on a NA 2001 GSR that has no plans of being turbo. Thanks in advance for the advise.
Also an update on my car, the motor is ordered and I should have my bady back in two weeks.

Sean

Waffles · Post by **Waffles** » Tue Feb 19, 2008 2:55 pm

A cut out on a honda is not usually a good thing. What the people that have used them have fond is that the engines have a higher tendency to burn valves.

UMR Racer · Post by **UMR Racer** » Tue Feb 19, 2008 3:16 pm

Thats what I was afraid of and the cold air gets to the valves thru the cutout sooner after shutdown and quenches then causeing them to become britle.

Waffles · Post by **Waffles** » Tue Feb 19, 2008 3:17 pm

UMR Racer;98353 wrote:Thats what I was afraid of because the cold air gets to the valves thru the cutout sooner and quenches then causeing they to become britle.

I personally have no experience with it, but that is just what I read on the interweb.....check out honda-tech, there might be more info.

UMR Racer · Post by **UMR Racer** » Tue Feb 19, 2008 3:33 pm

btlfedgolf;98354 wrote:I personally have no experience with it, but that is just what I read on the interweb.....check out honda-tech, there might be more info.

Will do forgot about that.

Spork · Post by **Spork** » Tue Feb 19, 2008 3:49 pm

I can tell you from personal experience with running open header... you lose a lot of torque. How much? If I were to make an unscientific guess I would say... all of it.

Waffles · Post by **Waffles** » Tue Feb 19, 2008 3:51 pm

Spork;98358 wrote:I can tell you from personal experience with running open header... you lose a lot of torque. How much? If I were to make an unscientific guess I would say... all of it.

So what your saying is open the butterfly at half track

Spork · Post by **Spork** » Tue Feb 19, 2008 4:03 pm

I think its a waste of money just like the guy asking about ITBs on a stock b18a... but whatever, its not my money.

UMR Racer · Post by **UMR Racer** » Tue Feb 19, 2008 4:23 pm

Spork;98364 wrote:I think its a waste of money just like the guy asking about ITBs on a stock b18a... but whatever, its not my money.

I would like to think that this is not as stupid of a question as ITB on a stock B18a. Thanks for the advise it looks like a no for Cut out.

Spork · Post by **Spork** » Tue Feb 19, 2008 4:50 pm

UMR Racer;98368 wrote:I would like to think that this is not as stupid of a question as ITB on a stock B18a. Thanks for the advise it looks like a no for Cut out.

maybe not quite as pointless... but I still think it's silly. are you planning on putting an aftermarket exhaust on it anyway, or did you want to do a cutout and leave the factory exhaust on?