Mark Tsai's Web page: RX-7 Borla Systems

Borla Stainless Exhaust system

These are some notes on the Borla System I purchased for my 2nd generation car after my stock system rotted off from exposure to New England weather, and the hot rotary exhaust.

Originally, the majority of this text was written to a fellow RX-7 owner who had questions about the Borla system. I thought I'd neaten it up a bit, and include it as a page in the my ever-expanding web page collection.

With the cracked pre-cat, and the Borla system, the system had a decidedly throatier and slightly raspy sound. (The raspiness is almost certainly due to the leak in the pre-cat.)

Borla on a 2nd generation RX-7 The Borla system's fit is pretty good. The joint between the stock Cat and the Borla system required some finessing (read: forcing) to get the cat-bolts to go into the Borla's flange. Otherwise, it uses all the stock mounting points, except for the two immediately aft of the cat. The Borla system is significantly lighter than stock, so the omission of these two points should not be critical.

The Borla system itself comes as two sections. One is an arm of the Y-pipe, and a can, while the other is a single can. One exhaust clamp is necessary to secure the system.

The Borla's finish is generally pretty good. Both cans are polished, and bear the Borla logo (but you can't really see 'em once installed on the car.) The tips are 'intercooled,' that is, there's a outer chromed pipe, which is attached via fins to the inner steel pipe. There's holes drilled in the fore section of the pipe to allow cooling air through the chambers (to prevent tip-bluing).

The Y-pipe itself is a much more 'natural' unfinished steel look, as nobody will ever see it without the car being on a lift. There is significant bluing around the welds. The welds themselves look quite substantial.

The tips are slightly larger in diameter than stock (probably 2.5"), but hardly obnoxious (or noticeable to the untrained eye. Of course, the intercooling itself gives away that the system's not stock). (I dislike large tips).

Overall, I've been quite pleased with the performance and the appearance of the Borla system.

Borla on a 3rd generation RX-7 As a side note, sometime after I purchased the Borla system for my 2nd generation car, a 3rd generation Borla exhaust (with dual tips) came up for sale on the national RX-7 list. Brooks Weisblat had 'outgrown' this exhaust for his heavily modified car, but it made a fine addition to my car. Again, this has a much deeper tone than stock, but looks very similar to the standard system (although the tips stick out significantly farther on this system.) As an added bonus, the Borla system is much lighter than the standard Mazda can (which is huge!)

Comments? Questions?Mail me!