Just a few days ago i had straight pipe put on my car (no muffler, only cats) and now my car really runs like crap, i have terrible acceleration especially when i mash it, like it wont drop down into 1st gear. It's cold here so when i look at my exhaust it only comes out of one pipe and feels hotter on one side than the other. It runs really rich, or so says my autometer air/fuel, do i not have anough backpressure, is somthing else wrong ? how can i fix this ? If i put a set of hedders on, will this help or hurt me ? Do i need more horsepower ?

 

Hmmm, good questions. The only answere I can think of, is that my dad had this same problem on his 73 chevell. Now his was fixed up without cats and had a true duel exaust system. When he went to a bigger exaust he was experienceing the same problems you mentioned, and the only thing he could figure was that he didnt have enough back pressure. After changing to a smaller tailpipe,to provide more back pressure, the proplem was solved. Now about one tail pipe getting hotter and stuff like that. Again on the same chevell as mentioned above, and since it was a true dual exaust, my dad said you could always tell when something was going wrong on one side of the engine due to the way the exaust was being let out thourgh the tail pipes. but remember this was only so because he actually had one exaust pipe for each side of the engine.

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1983 all original Z28 with 5.0L HO L69. One of only a very few.

 

Can anybody else help ?????????????

 

yea, why would you run no mufflers but run cats. That makes no sense. Also, straight pipes will only hurt your car unless you have ALOT of horsepower. Different of course with turbo applications where more efficiency equals higher boost.

Why don't you just stop ghetto rigging and lay down some cash for a catback system. There is some crap on this board. From V6s running true duals (???), to cars with cats but no mufflers. What's next guys. Are you going to run right off the heads?

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91 Formula
305 TPI 5speed
1LE/G92/WS6

Paxton SN92 polished kit, SLP airfoil, ported/polished plenum, March pulleys, Crane AFPR(43psi),Crane Gold 1.6rrs,MSD coil,MSD6AL (5200rpm limit),Holley 9mm wires,Ac delco R43ts plugs,stock chip,Ford SVO 24# injectors,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,170* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.



[This message has been edited by theformula (edited March 12, 2001).]

 

Like theFormula said, get a cat-back. I was runnig a getto set-up. Straight pipe, no cat and a cheap-o summit muffler. But, ya know what, it run stronger than when I put a new Catco cat and Dynomax system on it. Now it is better on the low RPM's but no way is it strong as it was @ 3000 RPMs or above. But ya gotta have a cat and you may as well get a good system. I do recommend Dynomax. Cheap, well built and when on in an hour, yes AN hour. 1 hour. It was pretty painless. $154 from Summit Racing. There are others, like Flowmastr blah blah blah everyone knows...

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1987 GTA 350,rebuilt in 1998. new heads, Heddman headers w/y-pipe, Dynomax cat-back system, 45,000 coil, accel plug wires and cap&rotor, k&n, b&m shift kit and trans cooler, modified mass airflow sensor, manual fans switch. MSD 6A yet to be installed. No time slip.

1993 Bonneville SSE ALL STOCK. 98,xxx miles and stil counting...plan to install K&N and Flowmaster 80 series

 

I run the same set up,no cat no mufflers on my '88 Formula 350.
It runs great,no problems at all,apart from a lot of noise when driving in small streets,with full throtle!
It even passes emissions over here in the Netherlands........!
So something else is wrong with your car.

 

Me again, I wasnt trying to tell you something wrong, the chevell does have a true dual system and could easily run over and out run any third gen camaro or firebird, and thats someting hard for me to admit since I own one. And it was a V8 not v6. If you still want to run it with out a muffler you can tie the exauhst pipe into one 3" from the cat back and split and bend it into two tail pipes. My dads got an 86 Iroc set up this way and it runs and sounds great. Just though I would let you know and clarify that the chevell was not a V6 and has such a system.

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1983 all original Z28 with 5.0L HO L69. One of only a very few.

 

About the hotter pipe than the other thing; since i don't think anyone said anything yet.
If you have a crossflow muffler like the stock dual out one, more exhaust might come out one side du to the inner passages being different- they're not the same length and are routed differently through the muffler. More exhaust=more heat. (go to flowmaster website, they have a cross section shot of their muffler- you'll see what i mean.)
On my edelbrock system, more comes out the passenger side.
I don't think your muffler is damaged.
I'm no expert, just my thought.

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'88 RS (originally 2.8)
New 350, .040 over, ported vette L98s, ported stock tpi.
Old 305 injectors & chip
TES headers, 3.73 gears, 700r4.
Best with 2.8-17.4@77mph
Best with 305-15.0@93mph
Best with 356-13.7@101mph
(Damn the 2.8!)

 

87FakeIrocz I didnt really read what you wrote but im pretty sure you didnt read what anyone else wrote. The guy doesnt have a muffler.

 

Z28, what engine do u have??

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

 

In regards to the exhaust running hotter on one side. Some exhaust setups had a heat sensative damper in the manifold that would be closed when cold and open up after it got hot (used a coil spring i believe) It was to help the car warmup faster in cold conditions. This may just be on older cars though... anyone???

-Rich

[This message has been edited by rhawki (edited March 15, 2001).]

 

Damn, I've been breathing exhaust too long.
Thanks for the catch 89 Iroc.

 

Lol that reply didnt come out how i wanted it too. I wasnt tryin to be an ahole but no problem.