Doing a engine back custom exhaust - few Q's

[tuner-automotive]

m doing a full header back custom exhaust in the very near future.

Just getting my parts and info together first.

Im going to have the exhaust shop build my headers.

Since the heads are single port , this should be easy and simple for them.

Is the current exhaust dia. on my 96 2.2L NA 2"?

Should I go 2.25" or 2.5" dia.

I have a cone filter on the car now so this should compliment it well.

Im using a Summit racing turbo muffler and a universal Catco cat , no resonator.

 

Any suggestions or tips.

[Kilroy]

I added a larger 2.5" exhaust and totally took out the cat on my '90 Legacy (180,000 km) and put on a 'racing' muffler. Other than it being louder, I didn't notice any power difference. Has anyone verified that doing this on a 2.2L NA makes any difference?

[tuner-automotive]

Well from your amount of gutting I can certainly expect there not to be any bottom end gain.

There is almost zero back pressure on your car now.

Im going w/2.25".

 

I had a 90 2.2L 5spd w/flowmaster 50 , no resonator , 2nd cat delete and it wasnt loud and had better throttle response and low end torque.

[Hodaka Rider]

There is almost zero back pressure on your car now.

 

That was probably the goal. Low backpressure = more power, as long as the pipe is not so big that it only creates a proper scavenging effect at higher RPM's. That being said, I would think a 2.5" exhaust would be a little big for a 2.2l to develop proper exhaust flow at lower RPM's. The cross-sectional area is just too big. I would think a 60mm exhaust would be good on the 2.2 (slightly larger than the 2.25"), based on the fact that most 1.8-2.0 litre N/A engines are happy with 2.25".

[subyfreak]

I just went from a 2.5in pipe with out converter or resonator to stock pipe with converter, resonator, and a free flowing muffler and noticed how much low end power I was missing. The 2.2 NA engines seem to like a little back pressure. But now I miss the wake the neibhors piss off old people rally car sound track! Just my 2cents.

[Kilroy]

Well from your amount of gutting I can certainly expect there not to be any bottom end gain.

There is almost zero back pressure on your car now.

Im going w/2.25".

 

I had a 90 2.2L 5spd w/flowmaster 50 , no resonator , 2nd cat delete and it wasnt loud and had better throttle response and low end torque.

 

 

2nd cat? Are there 2 catalytic converters on U.S. cars?

[Hodaka Rider]

I just went from a 2.5in pipe with out converter or resonator to stock pipe with converter, resonator, and a free flowing muffler and noticed how much low end power I was missing. The 2.2 NA engines seem to like a little back pressure. But now I miss the wake the neibhors piss off old people rally car sound track! Just my 2cents.

 

The 2.2 NA engine hates backpressure, just like any other 4 stroke engine. What it does like is having the exhaust pulses create a good scavenging effect in the pipe, which does not happen at lower RPM's in a 2.5" system.

[Hodaka Rider]

I might add that there's a Borla knock-of header on ebay that a lot of people like. Cheap, too.

[tuner-automotive]

Can you send me a link to one of those knock-offs?