Catalytic converter removal, hp gains??

Joined
27 August 2001
Messages
153
Location
Rogers,Ar. 72758
I have a 93 with headers, exhaust, cold air intake and a dinan chip. Would I gain any hp by removing the converters...if so how much, and how much weight would I lose. Please spare me the green peace speeches!!! Also, how much louder could I expect the exhaust note to be?
 
Quoting from the FAQ:

"Does Removing Or Bypassing The Catalytic Converter Help?

Removing the cats on an NSX yields no practical performance benefits. I configured my Supertrapp muffler as a straight through with no silencer disks and the torque was miserable below 6000 rpm, less than stock, which proves that messing with the muffler alone will give you all the back pressure reduction that is beneficial."
 
About exactly how much weight will be saved? I'm thinking of doing the same with my car. I just recently took off all the heat shields for the cats and the exhaust hoping that it would save a little bit of weight.

[This message has been edited by NSX36 (edited 02 May 2002).]
 
Originally posted by Andrie Hartanto:
NSX36
becareful when removing the heat shield from the exhaust. This can mean the heat transfer better to your trunk. Check your tool foam, make sure it doesn't get cooked.

Thanks, I wasn't aware that might happen. I'm gonna check right now! BTW, I didn't remove the heat shield off of the muffler, just the ones on the cats and on the pipes leading to the muffler. It looked too hard to take off the shield for the muffler so I just left it like it was
smile.gif
 
For me, removing the cats makes the car more responsive when accelerating. I can feel the car pulling a little bit harder. So my theory is .... if I can feel the diff, there must be a little hp gain somewhere.

Just my 2 cents
 
I agree totally with NSXHK, I feel the same differences with my Comptech cat bypass pipes... and the exhaust's sound is louder too.

The weight's gain is 7 kg

David
 
I'm thinking about getting the Comptech bypass pipes for my '93 NSX. Is there anything I need to know before I install them? Or is it a true plug-and-play installation? I mean, do I just take off my cats and replace them with the pipes and off I go?
 
Just installed the Taitec by-pass Pipes for a track event this weekend and Holy Crap is this LOUD!!! I have DC Headers and the RM Racing DTM Exhaust I cant believe it Nasty sounding is all I can say.


Steven 91 Blk/Ivory
 
About exactly how much weight will be saved? I'm thinking of doing the same with my car. I just recently took off all the heat shields for the cats and the exhaust hoping that it would save a little bit of weight.
The cats with heat shields weigh 22 lbs. The heat shields probably make up less than 10% of this figure, so removing them is not worth the risk.

Cat bypass pipes weigh between 3 and 6 lbs, depending on material and model year.
 
Originally posted by nsxtasy:
Perhaps you bought your cat bypass pipes from Placebo Racing?
biggrin.gif

joker.gif



------------------
Andrew Henderson
The NSX Model List Page

"We have long acknowledged that enthusiasm for things automotive is a sure
sign of emotional instability if not outright dementia"
- Brock Yates
 
Yep, I agree with Placebo Ken on this one.Louder yes ,stinky yes ,faster not by my backside.
 
Originally posted by 4g62bt2c30a:
I got 15hp by taking out the cats.....but, that alone won't do it...I had to add fuel to make the power

If you've added fuel but you're claiming a gain from removing the cats, you really don't know that the cats had anything to do with the gain... Or did you measure after removing the cats but before adding fuel? What was the increase? Changing two things and attributing the increase to one or both without verification is fundamentally flawed.



------------------
Andrew Henderson
The NSX Model List Page

"We have long acknowledged that enthusiasm for things automotive is a sure
sign of emotional instability if not outright dementia"
- Brock Yates
 
To the person with the cryptic sig;If you added more fuel then by the gods of stoiciometry you must be adding more air too.That means you are talking about a forced induction motor and I would agree that in that instance you could make more power with cat removal but for an NA motor like mine it does ugatz for power.
 
Originally posted by 4g62bt2c30a:
I got 15hp by taking out the cats.....but, that alone won't do it...I had to add fuel to make the power

With the stock NSX, you may have to add fuel to make power, but doing so will give you 270 more hp than trying it without fuel.
biggrin.gif
 
Originally posted by docjohn:
To the person with the cryptic sig;If you added more fuel then by the gods of stoiciometry you must be adding more air too.That means you are talking about a forced induction motor and I would agree that in that instance you could make more power with cat removal but for an NA motor like mine it does ugatz for power.

whatever....
 
Originally posted by lemansnsx:
If you've added fuel but you're claiming a gain from removing the cats, you really don't know that the cats had anything to do with the gain... Or did you measure after removing the cats but before adding fuel? What was the increase? Changing two things and attributing the increase to one or both without verification is fundamentally flawed.


yea..ok...whatever
 
Back
Top