B15 Sentra Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
542 Posts
Discussion Starter #1
I got the idea from a fellow auto-xer, who runs a Neon in GS. He removes his muffler at events and replaces it with a short pipe that just bolts right up to the muffler flange. Since the dyno shows a 3WHp and 6Wftlb gain just from removing the muffler, would this be wrth trying? (I run a Spec V in DS) I figure I could get something welded up for like $20, and just swap it at the event or the night before. I don't really want to go full catback as I don't want to deal with the increased loudness on a day-to-day basis, I just want the (small) gain on auto-x day. After all, in the nationals, it could make that .001 seconds difference that I need to go up an additional spot.

I will be putting Koni Yellows on the car in the spring , as the stock Spec dampers will probably be pretty close to shot by then anyway (24k miles right now) and I already run race rubber.

I figure that this setup will be stupid loud, and I'm not sure if it will be legal at SCCA events. The Neon I mentioned earlier is legal, though not by much. I have an SPL meter, so I guess it's not too hard to find out.. ;)
 

·
Registered
Joined
·
181 Posts
It is still DS legal, provided it is not too loud (in which case it would not be legal in ANY class). No one has dynoed it. Many have thought about it. The biggest cost would be in dynioing it to see if its worthwhile.

Sean
 

·
Registered
Joined
·
542 Posts
Discussion Starter #4
The dyno for muffler removal is here:

http://www.b15sentra.net/sections.php?op=viewarticle&artid=32

I can't see a 12" straight section of pipe effecting the dyno much, if at all.

As zozo points out, I can do this and stay in DS. As long as it isn't too loud. Any catback exhaust is legal in stock classes. I just don't want to drop that kind of money into a leased car. It's different with the shocks, as they will be worn out and need replacing anyway. I expect the stock exhaust will last the duration of the lease.
 

·
Registered
Joined
·
542 Posts
Discussion Starter #5
Well, today I went looking for an appropriate flange so I could get this ish welded up. I ended up finding something even better, an 18" pipe with the flange and hanger bracket already welded on. Total price of that and a decent hanger was $15.

Then I tried to install it. Well, it's only two bolts, and I knew they'd be a ***** to get loose the first time, but I always seem to underestimate the difficulty of these things. I managed to get both of them to break free (thanks to liberal application of PB Blaster) but one of the captive nuts on the exhaust flange came loose, and being a square nut (with rounded corners :mad: ) I haven't got a good way to grip it with enough force that I can turn the semi-seized bolt. Running out of daylight, I gave up instead of breaking out the hacksaw which is probably my next move.

:idea: Might be time to buy that dremel with some cutoff wheels...
 
1 - 5 of 5 Posts
Top