I think even on TurboBricks most folks have found that spiffy exhausts on NA B230's is moot. More noise than benefit.

If you do get rid of your old cat, try selling it as scrap on fleaBay. Lots of catalyst in these things. I got a *pile* of money for my original 1990 cat. Though that was about a year ago, and I think scrap platinum values have plummeted.

-Ryan

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Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars

I have a B cam advanced 2* in my 89, and there was a noticeable different when I added a 2.5 exhaust, but I also lost the catalytic converter too. I used a moroso spiral flow in place of the cat. I'm still working out if I want to still run a stock turbo muffler like I am, or something a little better.

2.25' will increase the flow while maintaining a good amount of gas speed. The stock turbo exhausts were 63mm, almost 2.5"

Losing the first muffler or replacing both with higher performing units will give you more flow too if you wanted to stick to the stock diameter.

Another place to look for more flow would be the y-joint on the header pipe. My stock header has one that isn't a smooth transition, decreasing at the joints and bulging in the middle. I have thought about cutting it out and welding in a better y-pipe, I just never find the time to measure the diameters...

It does help, if you have done the standard airbox mod too.

I've got the IPD kit and an A cam, all on a lowered sedan. The sound is good, the car has a little more pep too. I mostly did it because the IPD kit was about the same price as the Volvo stock replacement. The overaxle is not really needed, on my lowered 91 I have no issues with contact.

I did have to modify the last muffler hanger in the system to get it to work around my OEM trailer hitch, but that was just a 5$ extension from autozone.

Having the exhaust already will help when I +t this spring.
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1968 P220 Kombi (122S Estate); 1991 244, 2003 S60

The engine only generates high volume exhaust at full throttle and max RPM. It also does no good to increase exhaust capacity unless intake capacity is also increased. Therefore, unless you have a turbo or supercharger larger exhaust is just for looks and sound. It may even be detrimental at normal driving speeds since the whole system must be designed and tuned for a given range of operation. Volvo rightly designed the engine for max low-end torque because it is a small engine driving a heavy car. If Volvo could have got more power with a larger exhaust, why would they not have done so? Beware of retailers selling “performance” or “mileage” products without dyno and durability data for your exact model and range of operation.

I'm at the same point as you, ready to start over. I've decided to order the stock exhaust but delete the front muffler. If it's too loud I'll pop it back on.

One of the most effecient exhaust systems ever designed and used on a production vehicle did not use a muffler as we know them at all. In the late 60's Chevrolet made a, "Chambered exhaust," for their high output Camaros. This was a piece of 3" exhaust tubing that was partially collapsed on both sides, and then the pipe was rotated 90 degrees and the collaplsed area was repeated, and then the pipe was rotated 90 degrees again and the process repeated, and on and on. It was labor intensive to manufacture, and so it went by the wayside. Also the police departments did not recognize this as a muffler, since it did not look like a common muffler, and so the Chambered exhaust system was discontinued. You could make one of these fairly easily, and it is/was reasonably quiet, and made bunches of horsepower.

Just please don't go with 3" or bigger with GRedyy exhaust or the like.
Neither the Turbo or N/A pushes enough volume to move the static volume within the over-sized system. Expect a substancial loss of back-pressure and an over-worked O2 sensor.

2cents
Tim
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'92 244 NOW w/ M47 (Hydra, turbo bars, bilstein, urethane bushings)

Sean,

If you get 2HP gain out of it, your doing well with a turbo exhaust on an A cam N/A engine.

jorrell
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92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!