another emisions question..

[guitarfreak235]

i'm looking to take as much emissions crap off as possible and i've looked on other posts here but am still a bit confused... kinda new to all of this. but what all could i or should i take off that hurts performance in any way or is just not necessary to keep?? any help would be appreciated. also how would i keep any modifications from messing with the computer?

 

[Jims86]

i'm looking to take as much emissions crap off as possible and i've looked on other posts here but am still a bit confused... kinda new to all of this. but what all could i or should i take off that hurts performance in any way or is just not necessary to keep?? any help would be appreciated. also how would i keep any modifications from messing with the computer?

Assuming your truck is stock, You are better off leaving it the way it is...you will gain nothing for all the work on a stock engine.
If you still have the air cleaner with the flame arrestor, you may get a little from removing that, and a high flow muffler, like a Magnaflow. You may also want to try a carburetor spacer that is open to both sides of the intake, instead of separated barrels.
Can you post a picture of your engine with the air cleaner off...close up? If we can see what you have, we may be able to help you a little better.

 

[guitarfreak235]

ok i'll get a pic of it

 

[bucket]

I removed a bunch of stuff from my '84 305. There was never any performance gain (well except replacing the tired carb), but that wasn't the point in removing any of it. First it was the smog pump, it was tossed when the headers were installed. More recently, I replaced the stock carb with a basic electric choke Holley carb... which necessitated removing all the little vacuum lines, valves, solenoids, EGR valve, etc. All that's left is a brake booster hose, vacuum advance line, and a PCV hose/valve.

I'll repeat, there was no performance gain, but I was not expecting one. I did gain a simpler, less cluttered engine compartment, as well as an engine that's easier to work on. There's also much less items to cause problems now.

 

[guitarfreak235]

oh i have been under the impression removing the smog pump would increase power

 

[bucket]

oh i have been under the impression removing the smog pump would increase power

It will, but not enough of a difference to tell with the butt dyno.

 

[Jims86]

It doesnt make a difference period...unless its siezed up. smog pumps spin pretty easily by hand.

 

[guitarfreak235]

makes sense

 

[bucket]

It doesnt make a difference period...unless its siezed up. smog pumps spin pretty easily by hand.

It does make a difference. Sure it spins easily by hand, but at 5000 rpm, it's going to suck up some power. Not to mention the stupid thing trying to force more air into an exhaust that's probably already a bit on the restrictive side.

 

[guitarfreak235]

im definitely going to rework the exhaust though

 

[Jims86]

It does make a difference. Sure it spins easily by hand, but at 5000 rpm, it's going to suck up some power. Not to mention the stupid thing trying to force more air into an exhaust that's probably already a bit on the restrictive side.

How many trucks do you see spinning 5 grand for any length of time? That is, if they reach it at all.

 

[Jims86]

im definitely going to rework the exhaust though

What carburetor do you have? is it the Computer controlled Quadrajet?

 

[bucket]

How many trucks do you see spinning 5 grand for any length of time? That is, if they reach it at all.

Mine see it. The wimpy 305 likes to rev and it often sees high rpm on the freeway on ramps, as well as a hill I pull on my way home from work. The Blazer was a screamer too, it too often saw a lot of time at the top end. Even surprised a C4 Vette once.

Just because it's a truck doesn't mean you can't have fun with it

 

[Jims86]

Mine see it. The wimpy 305 likes to rev and it often sees high rpm on the freeway on ramps, as well as a hill I pull on my way home from work. The Blazer was a screamer too, it too often saw a lot of time at the top end. Even surprised a C4 Vette once.

Just because it's a truck doesn't mean you can't have fun with it

Damn bro! Mine shifts at about 4200 at WOT.

 

[smurph20]

Mine see it. The wimpy 305 likes to rev and it often sees high rpm on the freeway on ramps, as well as a hill I pull on my way home from work. The Blazer was a screamer too, it too often saw a lot of time at the top end. Even surprised a C4 Vette once.

Just because it's a truck doesn't mean you can't have fun with it

THANKYOU for that last comment. My 92 S10 with the 2.8 and 5 speed get shifted most of the time at 5500 on the rev limiter. Itll top out at over 130. I took my smog pump off of it because with 260000 miles on the motor it didnt spin freely even the new one i thought about putting on it did not spin freely. Anything a belt is turning will cause drag. MIght not be more then 1 horse but thats power lost.