Hello all, i am about to purchase my new exhaust and i was wondering something. Should i go with a cut out before the muffler? I am ordering an adjustable Borla Cat-Back. I was thinking of either the one in Thunder Racing or an electric cut out. What do you think? Should i just stick with the cat-back or should i add a cut out? I believe the Borla system has four plates to adjust the flow. Should i get a cut out anyway? All opinions are welcome. I am open to constructive critism! lol Thanks for your time-Bryan

 

My understanding is..

If you get a cutout (ie after the catback), you'll be bypassing your muffler totally, which means that expensive Borla system won't even be used..

Of course, this also depends if you're going to leave the cutout open all the time? If not, when you close it up, then you'll be able to enjoy your Borla system..

You will see better performance and louder sound with the open cutout, because basically you'll have an open exhaust setup (ie no muffler)..

Hope that answers your question?

-LJ

 

I believe that adjustable Borla system has a setting for "straight thru", ie it goes straight out and doesn't enter the muffler or anything, so I think that would suffice and don't see why you'd need a cutout too... just turn it on the full open setting when you want to.

 

Welllllll its not overkill, but it is pointless.

With the full open plate, you basically have a cutout, its a little quieter that a full cutout, but its still sweet.

Hows this for an idea, I should have mine this weekend, The Quicktime Electronic cutout, they make one to replace the plates on the borla kit so you can open close it with a button/switch from inside the car.




Quick Time Electronic Cutout

 

Thanks for the link 86FyrBrd. I was under the impression, for some reason, that the adjustable system on the Borla cat back was to control the flow through the Muffler itself!? If that made any sense! So on the Borla system, you can run it straight through, with out the use of the muffler? Thats where i am confused. If thats the case, then why would i even bother to get a cut out, correct? And with that electric cut out in the link above, you can do it automatically instead of getting under the car to do it manually. For another $135, i'll have to think about that one though. I still have to get a cat also.

 

Get a high flow cat.

My Set-up is

Borla 3" adjustable cat-back
Edelbrock T.E.S Headers
Catco High Flow Cat
Quicktime Cutout on the way

and I love it

 

I've got the Edelbrock TES headers with the AIR capped off and am also ordering the Borla system. About the cat, looks like i am going to have to go with the Catco b/c i am going broke! lol I would like the Random Tech but i just can't buy it, especially since there is not a huge difference between the two. I checked out the web site for the cut out and it seems pretty good! Maybe i'll get one but its still another $135. Let me know how yours turns out. I am sure its a "trick" piece. Also, what did you do with the AIR tube from the Cat? Did you not hook it up? Thanks for the info-Later

 

See the flange after the passenger side Y connection? That is where the plates go. A solid plate diverts all gases through the muffler=quietest, the open plate allows virtually all the gases to go straight out=loudest. So a cutout after the cat on this system would only eliminate a few feet of 3" pipe. A cutout BEFORE the cat might be worth it. Then you could open the cutout at the track, and close it for the street (or at least emissions testing).

I am in the process of installing this system on my 91 formula. I have been told that the only difference in the plates would be sound. But is seems to me with the open plate you would have less back pressure than if you put in one of the smaller plates or the solid one. Also, Im not crazy about the dual tips. What does anyone think about cutting them off and putting a nice chrome 3" tip on each side?

 

If you get the Borla Set Up....I wouldn't get the cut out. Like everyone is saying, it comes with the adjustable plates so you can change the tone of the exhaust system. Somebody was saying that a cut out "bypasses the muffler" well.....that's not true. I have a 3 inch 80 series flowmaster cat back system with both cat's removed, a 3 inch exhaust cut out and a McCord Power Plate II on order (I'll be able to adjust the volume of the cut out electronically from inside my car). The exhaust still totally comes through the muffler and still has the flowmaster tone. The cutout (the way I have it set up) just adds ALOT more volume to it.......but still has that aggressive flowmaster tone....so it doesn't bypass the muffler much at all......

 

yeah, the plates on the borla make virtually no performance difference, I think somone dyno'd it and it make maybe 1 hp, if that.


THe "cutout" I am getting isnt really for performance, I just want it to be able to change the plates quickly, Otherwise I have to get down there, undo 3 bolts, change the plates, but them back in.

Pushing a button is so much easier.

 

Thanks for that picture Larry. It helped a lot. I have seen pictures of Borla systems before but i am almost positive they were not for our cars, so now i am sure of what its like. If you did put a cut out before the cat i am sure there would be a difference in performance. On another board someone had gotten consistant .3 gains in the quarter with it done before the cat. I am sure it would be loud as hell and i would probally only use it at the track though. The electric one seems better and better everytime i look at it. We'll see, i can always go back and add one! Well, thanks for your help guys. Later-Bryan

 

Does anyone know if its possible to run a 4" bullet after one of those or do you have to run open? Also last time I checked I didn't think there would be enough room to run one before the cat... How much of straight pipe does a cutout need to be welded in?