I know this has been addressed about a million times....but. Has anyone ever actually tested the power increase associated with the addition of the RT Cat, in isolation? (assuming that intake & y-pipe measurements on the same car have already been taken) I'm considering getting the RT, but I'm only interested in the ponies it brings to the party. Since putting the header wrap on my Stillen Y, noise is no longer a concern. But I don't want to drop $200 on a .5 hp mod.

I've heard very different stories on what the RT will do. Most say not to expect much, if anything. Others, like Shing, say that the addition of the RT dropped their quarter mile times by over half a second. And of course RT says to expect anywhere from 8-20 more hp, or some other crazy @$$ number. So what's the REAL DEAL. Anyone ever do before & after dyno's on a car, with the only difference being the RT? Robert, you & George ever do this??

 

The only good reason I got one was:

1) I gutted the stock one (BAD MISTAKE)

2) The outlet of the catman Y is larger than the inlet of the stock cat. So the RT is slightly larger. So the two match up much better.

The power/$$ ratio is pretty low on this one. IMHO

 

Jeff: On Billy's 97SE, the ~2.25" diameter of his Cattman Y is smaller than the 2.5" diameter of his stock cat. Go figure.

I'm not sure anyone has done conclusive testing on this. Booker, want to be the first? The main reason the SoCal guys seem to have for the RT cat upgrade is to kill the droning noise that results from the aftermarket y-pipe + aftermarket exhaust setup.

 

Check this post.....

<a href=http://forums.maxima.org/showthread.phtml?threadid=2043>Here</a>

 

But we want to stay emissions legal.

 

The RT cat was developed for the Maxima on Justin Gadlage's car. I think he has a dyno chart for it.

 

Is the RT CAT Carb cert?

 

Yes the RT Cat is CARB certified & 100% legal. I believe it actually does a better job of removing certain contaminants from the exhaust gases than the stocker does.
If the general consensus on this is right, Random Technology should be open to a false advertising suit for all the claims that they make about the increase in power production from this thing! You ever take a look at the dyno charts they used to have on their site??? (don't know if they're still there or not) Considering how popular a modification this is, I can't believe that no one has ever done this dyno testing. hmmmmmm....Brian, you may be onto something. You up for leaving a little more skin off your knuckles underneath my Max? I REALLY want to do the fog rewire & paint my calipers!

 

I was the one that prototyped the RT cat for the 4th Gen Maxima and got it to production. I gained 6hp and 17ft-lbs of torque with the 3" cat over stock. I would reccomend going with a 2.5 cat for your application. You can see my <A HREF="http://www.geocities.com/jgadlage/dyno.html">dyno results</A> on my website. Let me know if you have any questions.

[Edited by jgadlage on 09-13-2000 at 07:34 PM]

 

But I must say, I'm nearly as corn-fused now as ever. 17 ft-lb improvement in torque output?! At the wheels? I've been asking around for some time now, & have been told by no fewer than a dozen people on this board that its not a mod which will produce much in the way of increased power. How someone could NOT notice another 17 ft-lbs of torque & 6 horses is beyond me. This is on par with, if not better than, a UDP.
I'm going to go look over your dyno results now & I'm sure I'll have questions. For now, is the increase you've cited with the RT being the ONLY change in the exhaust equation? (ie:200 lb. ft. with stock cat, swap cats, no other changes. 217 lb. ft. with RT) Same atmospheric conditions? Were you running a y-pipe, w/stock b-pipe & muffler? If not, what other aftermarket exhaust parts may have contributed to the number?

(sorry about the 40 questions)

 

I should have read your dyno page before I dropped the question bomb on you. I see that your increase was attained with the CAI/GReddy cat back set up. 6&17 is nice. VERY respectable. I'm running Stillen/K&N cone, w/stock muffler. Do you have any opinion on what sort of improvement the 2.5 RT should yeild w/my set up? thx

 

How much does an RT CAT go for?

 

but I tend to think that sometimes I went for the "bigger is better" theory and might have gone a bit overboard. I think that the 2.5" cat might produce better hp b/c there isn't a big amount of difference is diameter before and after that cat, although this is just a guess. I can only assume that the 2.5" cat will make around the same numbers that the 3" cat did. I might try a 2.5" cat on the setup I have now when some more capital comes in.

I think that the RT cat goes for something like $225

 

Anyone want to contact Dalton at lightning motorsports and see if we can get another one going, it only took 10 members to respond and it looks like we have plenty of people interested, I know I will order 2 (my cousin needs a cat for his 3rd gen) so we only need 8 more according to the details of the last group buy.

 

increase was attained with the CAI/GReddy cat back set up....

Ok, I confess to being a skeptic.

But how much of your gains would you attribute to the fact that the RT cat flange openings are now matched to the GReedy cat-back opening?? Smoother flow = more HP, ya know.

DSM guys have gained 5 HP by port matching their O2 sensor housings to their 2.5" DP, and this is w/ simple bell porting.

I remember someone at the 2K Sentra board posting the fact that Nissan's Primera BTCC race car used the OE cat. (Admittedly, I never bothered to research this further)

I also have a book around here somewhere written by Corky Bell, who also claims that replacing the stock cat wouldn't lend to that much more HP gained.

But, FWIW, there ar a couple of DSM guys who have gained 10 dyno-proven HP by using the 3" RT cat. But, then again the question arises if it was due to the fact that the RT cat beter mated to their full 3" exhaust.

 

*How much of your gains would you attribute to the fact that the RT cat flange openings are now matched to the GReedy cat-back opening?? Smoother flow = more HP, ya know.

Hmm.. The only thing I changed in between tests was going from a stock cat to a RT cat. I gained 6hp and 17ft-lbs of torque. I would attribute this gain 100% to the addition of the RT cat. Whether or not it has to do with the flanges or whatever else about the cat I don't know- it's all in the cat.

*I also have a book around here somewhere written by Corky Bell, who also claims that replacing the stock cat wouldn't lend to that much more HP gained.

True this modification hasn't given the power increase of say a supercharger or NOS but it is still a noticeable gain.

The 2 1/5" cat might have been a better selection for the car, maybe I went overboard with the 3" but it did show gains. I think that if we could go to a 2 1/2 full exhaust from the y-pipe back we could find some more gains instead of going from different diameters from each part. This is just my guess though maybe that backpressure going between parts is needed somehow.

[Edited by jgadlage on 09-14-2000 at 10:05 AM]