I wanna get my shitty exhaust replaced. I plan on just sending it to a muffler shop and running straight pipe. cant i just not get a cat back and have them run the pipes all the way to the back and just throw on some mufflers? I have an 88 Vert..... should i keep the cat? <~ Im an idiot sorry

 

you can toss the cat, be carefull about the muffler you get, they're loud cars.

 

Yes loud cars indeed i have mine street ported with the stock exhuast system n some restrictors taken off and its just as loud as 7 with aftermarket exhausts. the only problem is my mom complains every time i come home, she says its way too loud.
but hey what can i do, im 16 and i drive a 7 with street port and clean *** original paint. what can be better??

 

but tossing tyhe cat makes the 5th and 6th port not work...... what kinda resitrictions would i get because of this

 

No, that's not true. If you were to get a racing beat presilencer, it will have a nipple for pressure that attaches via hose to the LIM, making your aux ports open up.

 

yeah but i don't want a silencer :\ alternative?

 

Um, drill a hole in the straight pipe, weld a nipple bung on there?

 

You're in miami... are there no emissions laws there?

Federally speaking you may not get the "cat back". The shop may be legally obligated to throw it away when removed and may also be legally obligated to replace it meaning: they may not do a straight pipe. This is regardless of state or local emissions laws. ~rich

 

well my dads a mechanic and he can pretty much tell these guys(friends) to just do it.... ;\ will that nipple thing work? i was actually thinkin about that last night and yes there are no emission laws

 

I do NOT think the bung in a straight pipe would work. If it did, everyone would do it.

The only reason it works in the presilencer is because the air is not just shooting right thru, it's getting stuck inside for a little bit (backpressure) obviously long enough for the pickup tube to do it's thang.

You're gonna have to have some sort of restriction (presilencer, cat) to get the aux ports to function mechanically.

OR, you can use an RPM switch and an electronic air-pump to open them. This is both more reliable when done correctly, and will ensure that they open in all gears. Ex: In first gear, you're not under a lot of load, you may not get them to open all the way, if at all.

 

Actually, there is a pipe in the rb presilencer that picks up the exhaust regardless of backpressure. I'll get a pic of it in a bit. It also uses the split air pipe in the stock location. Only the road race header just has a nipple for a tube.

 

You can do this, but if you eliminate the cat you may find that the car is very loud with only a single muffler and you will have to figure out a way to actuate you 5th and 6th ports (check Archives for both air pump and electronics methods). Turbo cars can get away with only mufflers since the turbo quiets the exhaust down a lot.

Just welding a bung onto the mid-pipe for the aux ports generally doesn't work as most flow through mufflers don't have enough restriction. You may actually end up having to insert a curved tube through that hole with a bellmouth on it's end and pointing it towards the exhaust flow. Or jus use the air pump...

 

how can i use the air pump? <~ im a newb people sorry

 

Check the Archives as I mentioned.

 

yeah i just did that thanx.... doesn't look to difficult, all i gotta do is find the parts.

 

Heres the pic of how the RB presilencer works - notice the tube in the middle.

 

Hey Aaron, the rotating valves are connected by a linkage right? Could you flip the linkages 180 degrees and use variable vacuum to operate the valves in reverse? Would make it easier... ~rich

 

if you were 16 with a turbo 7 and clean *** paint. (check my Vb garage) and yes i'm 16.