5.7L OF JUSTICE

I live in Colorado and they will soon be removing emissions testing. What emissions equipment can I remove that will add HP and not affect how well it runs. Any info will be helpful.

five7kid

iTrader: (14)

Really? Where did you hear that? Some counties don't have it, but the front range metro area (Fort Collins to Colorado Springs) is pretty much stuck with it from what I hear.

There isn't much you can remove. A.I.R. and cat are about it. And, A.I.R. removal may affect PROM calibration (not sure if that affects an '87 MAF system).

5.7L OF JUSTICE

I read it in the paper about a month ago. Its supposed to happen next year sometime but I'm not sure when.

five7kid

iTrader: (14)

If you can find an on-line version of that article, post a link here.

cryptic

I've never really liked emissions hardware, having said that however, a point to remember is that the engine was built or "tuned" with the emissions in mind. So removing some components may have an adverse effect even though you may gain a slight increase in HP. A better route may be to install compatible after market gear. The only thing I could think of to remove without adversly affecting other engine systems (fuel, ignition, etc.) would be the cat. conv. But I would look elsewhere first to increase HP.

5.7L OF JUSTICE

I couldnt seem to find that article online. It was in The Gazette newspaper though if you want to try.

Coult_91

you also take off your smog pump...i have emissions where i live only three counties in Indiana have em and i live one darn it.

Black Bomber

I never understood the reasoning behind removing that stuff. Really isn't costing you horsepower, and some of it actually helps the longevity (sp?) of the engine.

5.7L OF JUSTICE

Based on everything I've heard the more emissions equipment you take off the more HP you gain. Cats, smogpumps and all the air filtration tubing that is on there is robbing Hp I thought. I guess thats why I started this thread to get all the info possible.

five7kid

iTrader: (14)

There's very little truth to that. In the 2000 racing season, I started off with a basically stock LG4 (larger L98 cat-back about the only mod). After I fixed a bad fuel pump, I was able to start collecting data on what changes improved performance and what didn't. Emptying the trunk made a difference, removing the non-functional AC equipment made a difference - both of those because of weight. An open element air cleaner helped, because the stock single-snorkel LG4 air cleaner is very restrictive - that's an emissions item because of the thermovac. The open element actually ran worse on the street, especially when the engine was cold or hot.

One week I thought I'd take the belt off the A.I.R. pump and see what happened. No difference in times (run to run variation greater than w/ or w/o the pump). Well, there was one difference - when I went to put the belt back on a couple of weeks later, the pump was seized up. Removing all of the A.I.R. equipment will save a few pounds, but not make as much difference as a 10 degree air temp swing.

Removing the cat doesn't make much difference, because the real restrictions are before and after the cat (on a stock exhaust).

All in all, the real differences come when you make real changes: Exhaust upgrades (headers, especially), cam upgrade, head porting, cool air inlet, converter stall increase, gear ratio change, traction improvements, etc.

5.7L OF JUSTICE

Very helpful info, thanks to all that replied. I guess I have another question as far at the cat goes. Even if removing it doesnt make much difference performance wise, does taking it off make it sound better?

sellmanb

if you dig the raspy, popping sounds, then sure it does