tonydepo1

I have a 2000 trans am and I am planning on getting KOOKS headers with their y-pipe, not sure if I am getting catted or not. Should I rip out the EGR stuff and if so, is their a handheld programmer to delete the information from not having the EGR.

Thanks

steve2001sh

I believe removing the EGR will set off a warning light. You probably wouldn't pass emissions if you have them, but if you don't get cats you wouldn't pass anyway. HPtuner sells software that will remove the EGR check as well as about everything else you can imagine. I plan to remove mine eventually.

Reasons to remove the EGR:
Cheaper headers
More HP (not much, but exhaust in your intake can't be good)
Less crap under your hood

The HPtuner software is about $500 I think. Its not worth it unless you plan to use the software for other things too. If you don't have to pass emissions and don't care about the warning light, you could just rip the EGR out and be done with it.

conan

iTrader: (5)

Wait untill you get your headers and then remove the egr and air system. You will get the ses light for removing those systems. I dont think there is a hand held that can turn off the ses, like said ubove hp tuner can do it. I have hp tuner and it has been worth the $$ but I am always doing some thing to the car that usually needs scaning.

tonydepo1

how much hp difference between catted y and ory

300bhp/ton

TOTALLY wrong, removing EGR will yeild ZERO bhp.

The aim of EGR is to intorduce an inert gas which reduces PEAK combustion temps and thus reduces NOX emissions.

At WOT (Wide open throttle) EGR does NOT activate so you will not yield power what so ever.

If you plan on getting cats then IMO it's probably worth keeping EGR as without it you will still run the risk of failing a sniffer test due to the fact that CATS to not address NOX emissions in the exhaust gas.

If you plan on an ORY then you might as well ditch the EGR as it will offer no real gain.

tonydepo1

Thanks for the replies. I will plan on ripping my egr out, because in the future I would like to get the lsx intake and I am pretty sure they dont have an egr setup. Also, how do the 2001+ deal with nox emissions if they dont have an egr?

Also, what is the horsepower difference between cats and non cats? I might just get cats in case I move to a state that test for emissions. What do you think?

Thanks

300bhp/ton

SLP and TSP both sell Ls6 intakes with EGR provision they cost about $50 more though.

They run a lesser profile cam which I think helps also on a milder setup a degree of internal EGR can be acheived (this is what the Jaguar AJV8 does). However I'm not sure specifically what the differences are or how the 97-00 Corvettes didn't have EGR either, there must be some subtle difference but I've never researched it. If the Corvette didn't need EGR then I can't see why GM would have gone to the cost/hassel of having it on 98-00 Fbody's so there must be something different somewhere.

This largly depends on how much power you are making and what cats you are running.

Simple answer = 10bhp +- 5bhp

More complex anser=

David Vizard tells us we need 2.2cfm of exhaust flow for every 1bhp. So a 500bhp engine would require 1100cfm of flow for zero restriction. Half the number for each bank of cylinders, so each cat needs to flow a minimum of 550cfm to be zero restriction on a 500bhp engine.

Most cats do not flow this well.

However Random Technolgy Metal Matrix cats flow at about 598cfm so will be good for zero loss on a 550bhp (flywheel) motor. But these cats are expensive. Magnaflow Carsound cats (used in TSP's catted Y) are a lot cheaper and flow in the 430-450cfm range. So they will be slightly restrictive on a 500bhp motor.

However if you don't think you will have that much bhp then it's not much of an issue.

Also a slight restriction isn't going to make a massive difference. Personally I feel that the Carsound cats are fine on most cammed LS1's (~400rwhp) without any real loss of power, probably 5-15rwhp at most but more than likely towards the lower end of the scale.

If you plan on FI and ~500rwhp+ then Metal Matrix ones like the Random Technology 7000 Series are the way to go.

Hope that helps

steve2001sh

I stand corrected. If EGR doesn't even turn on at WOT, then max HP would not change.

steve2001sh

Where did you get these cfm numbers for Random Tech? I have seen them before, but Random Tech's own website advertises 502cfm, which would still be a slight restriction.

300bhp/ton

I believe from an email from RT, I haven't looked at their website for a while but I'm not certain which CATS are listed as they offer the same series cats in different inlet/outlet diameters which of course will affect flow.

Anyhow a small restriction really isn't going to make any real odds.

Think about when you add a catback to a stock car, it doesn't really improve HP, maybe 5bhp at most. Even replacing the Y pipe with an ORY (stock manifolds) won't really make much odds. The biggest gains with the exhaust are with LT's but that's due to scavenging mostly and not flow so it's a whole nother ball game.

I really doubt good cats like the Carsound ones will sap any more than 15-20rwhp on a 500bhp motor. But at that level of performance can you live with that sort of reduction to remian emissions legal?

I know I can as running an ORY in the UK is not an option, the same as most people in CA.

Many people running FI and cats thru a 3" catback have acheived 600+rwhp without any issues.