10 feet of 2 and a half inch straight pipe

[OnlySonoma]

Hey Everybody!!

Recently I had a little trouble with the exhaust on my 1995 4.3L V6 TBI Sonoma.
The Factory muffler had rusted away and fallen off. The tail pipe was gone when I bought the truck, and the cat was completely hollow. I decided i had had enough of mending a broken pipe. I wend down to Home Depot an picked up a 10 foot 2.5 inch galvanized steel pipe for about 90 $. Mated it with a 3 inch coupler right to the Manifold Y and welded it in place. I can honestly say that My Sonoma has never performed better! The 2.5 inch straight pipe is the the same diameter at the flare on the manifold Y and provides the Perfect amount of vacuum pressure that makes the 4.3L v6 purr, bearing in mind i also have a CAI. Fingers crossed i dont have a vehicle inspection in the near future
Will post pictures soon

 

[OnlySonoma]

Pics

Here are some quick pics i snapped last night.
Exhaust manifold to the Y pipe welded to a 10 foot 2.5 inch diameter straight pipe connected to a 45 degree with an 8 inch Cherry bomb that I shined up

(i know, i know, leaky diff )

 

[OnlySonoma]

Pics

Couple more pics

 

[OnlySonoma]

Review

SO,

Its been a month since I put the straight pipe and cherry bomb on my Sonoma.

WHATS THE DIFFERENCE!

I've noticed that the acceleration has changed, for example:

If i'm going up hill and i feather the throttle the engine bogs down a little because its not got the back pressure at low speed to build up RPM.
Instead of feathering the throttle, if I give it a little off the line the engine performs phenomenally and you can really feel the cold air intake and exhaust doing the trick. The exhaust is an increase in power and acceleration.

The Cherry bomb at the end of the straight pipe adds for a nice humming exhaust sound. A gas engine with a straight pipe usually sound throaty and a little rough but the cherry bomb almost puts a honda buzz into it. The cherry bomb is attached by a 45 degree bend which i think is crucial because the diameter of the straight pipe does not provide enough back pressure by its self. The single 45 degree bend at the end creates just enough resistance.

The most important part of this mod is that the Intake also be improved.

A cold air intake mod goes hand in hand with an exhaust mod.
As you try to increase the intake volume, you also want to increase the exhaust volume. One mod without the other is almost pointless.

My trucks acceleration has definitely been improved there's no doubt about that, and the sound of the exhaust is like music to my ears. But at what cost?! I now have to put about 60 $ of 89 Gas in my truck a week, which is more than before. I use 89 because believe it or not, my truck runs better on 89 that is does on 87 even though its a 1995.
The 87 seems to make it shift later and not rev as high as quickly.
The 91 feels like it causes pre-ignition and the engine timing just sounds wrong.
89 is what I would recommend.