Exhaust Cut out

Shintsu wrote:

Oh okay, I see it now. To get their $50 off coupon do I have to send just the downpipe back or the downpipe and the catalytic converter too? Also, do I need to order any gaskets?

per zzp site "Returned units can be cut up but the OEM converter must be intact."
so i'm guessing they are reusing the cats to make high flow's, or they are selling the metal inside. to get the $50 i would send in the old cat.

that manual cutout sucks ballz, I had one on my 81 riv, and it didnt do shit but leak. I would go electric all the way or a 3" downpipe.

I've heard good things about the Hogan downpipe:

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/hogan-downpipe-t1142.htm

hogans are good for 97+ riv's but the 96's dont have the bottom flange to bolt up. it must be welded to the cat.
zzp is the only supplier that i can think of that offers a "shorty" pipe with a open bottom to weld stuff up to.

Shintsu, what you will probably have to do is cut out your high flow cat, expand the end of it to fit the 3" pipe or get a 3" reducer to w/e the cat pipe is.
you shouldn't need a gasket but there is one at the top where the DP bolts to the collector. if yours breaks or is old and crushed, then you may leak there. keep in mind too, that the 96's have a slightly different collector gasket than other 3800's. we use a doughnut gasket, not the flat kind that zzp sells. and you may need to ream out the bolt holes to allow the bolts to fit right. any competent exhaust shop can see what needs to be modified and accommodate. just know that a DP on a 96 riv is not just a bolt up, DIY mod. that being said, i would get a DP and cat delete long before getting an electric cutout. both would probably cost the same at the shop to have installed. (~$100 labor, or 1.5hrs if they dont know abut the upper part being different )

Oh wow. Damn. Well, there's another mod with too damn much work to do. I give up, I'm just going to cut out the resonator...

Found the link. You need a dump pipe and then this:

http://www.buickgn.com/electricexhaustcutout.htm


It's a very nice cutout. Basically it replaces the flange block-off plate at the end of your dump pipe (which can be very short)

Thanks, I'll look at that one if I ever go with a cutout but I'm not sure if I will or not now.

I'm trying to determine which of the two would be louder: Leaving the resonator on and replacing my stock mufflers with two miniturbo mufflers (My dad had them on his car for awhile and he said it was too loud and I think it would be for the Riv but he didn't have the big resonator and when he put resonator tips on it it was quite a bit quieter). The other option would be what I was already going to do and just cut out the resonator and leave the stock mufflers. I know someone on here put glasspacks on and they weren't that loud but I think they left the resonator.

Considering all I need to do with the mufflers is cut the old ones out and get them to weld in the new ones which of the two options do you all think would make more noise and by about how much?

cut out would be the loudest possible. do you have tips to go on the new mufflers?

Well I know a cutout would be but it's looking like an electric one is the only way to go and that's going to be pricey. All I need to do with the exhaust is just pay the labor to get it done, whether it be the resonator delete or the muffler swap. I don't have any tips to go on to the mufflers currently, I was going to carry over the stockers until I found a nice pair I liked (None so far).

I don't see why you think the downpipe requires work? you just tell them what you want and they'll do it. you don't really have to do anything except convice them its a good idea. i think you'd see more of a performance gain with the downpipe than mufflers.

i wasnt trying to discourage you from getting mods. i was only trying say few things are as "easy, cheap, or simple" as it appears to be online. do some research and know things may arise that were not planned.

i am installing a plog on Tuesday (i know, FINALY ) and i know something will either break, not come off, or go wrong. just part of modding a car with no support other than fourms.

Shintsu wrote:

I know someone on here put glasspacks on and they weren't that loud but I think they left the resonator.

yea the resonator and cat and stuff were left stock and it was definitely not uncomfortably loud. As far as sound goes, I think anything but open pipes is gonna be alright to live with with otherwise stock exhaust.

I agree with the others who have said the performance gain is all in the downpipe and primaries. The mufflers alone may help but nothing you are likely to notice. In contrast, I lost 3lbs of boost (a good thing jic) and gained noticable top end when I got the DP and 3in mandrel to technically more restrictive mufflers than the glasspacks. (no cat or resonator) and its louder with the superturbo mufflers and that than with glasspacks and stock exhaust. And yes resonated tips pretty much saved my life on this exhuast too. They eliminated a lot of cabin drone. id say get the mufflers or whatever first and then decide what tips you need.

Well Mr. Riviera, is the shop going to do all that work for me? I'm not that techincally inclined nor feel like putting that much work in to it. There's other mods I'd be doing if I did. I want to leave my cat all I want is that bigger DP and that's it. I have no idea at all what I would need to order.

On the other discussion, so would that be a yay or nay on keeping the resonator and changing the mufflers?

Quote :

On the other discussion, so would that be a yay or nay on keeping the resonator and changing the mufflers?

Again, it depends on if you are after noise, or horsepower. If you just want more noise, delete the res, the cat, the mufflers, or all three. I believe that these components flow pretty well, so replacing or deleting them won't make the car that much faster, imo.

If you want more horsepower, do the downpipe, and maybe the cat (I hear the cat doesn't give much HP gain, but I think it helps a little). Doing these two will not make your car much louder at all. Might sound a little deeper.

I want a little of both. I don't want to be illegal so I'm not taking the cat off. I don't care if they don't do VET testing here or not, I don't want to risk a huge fine if I was caught without one.

I'd still like to do the downpipe, but it might take me awhile to warm up to the idea since it sounds like a bit of work. I don't want drone and I don't want full on noise so I'm trying to determine which is the better choice. I'm not sure how similar the GTP's exhaust is but when we swapped the factory mufflers with the miniturbo mufflers and the stock tips, it was very loud. Louder than I'd want the Riv to be. Even with the resonator tips it was still pretty loud, muffled just a tad more and it would've been fine to me.

What I'm thinking will make the most increase in noise without getting too loud will be leaving the resonator and swapping my mufflers with the miniturbos and possibly using resonator tips if it's too loud.

Shintsu, for the cost of a nice cutout, you can get yourself set up with a 3" DP.

In my opinion, which was assembled from everyone else's opinions, the DP is one of the best bang-for-your-buck mods. Yeah, you can slap a 3.6 or 3.5 on the car with a stock DP, but trust me... you don't notice how much HP you're making until you have the 3" DP on there.

The labor does suck. You really can't do it yourself if your car has seen winters. I don't know how your high-flow cat is connected to your DP, but my stock DP was bolted to my stock cat. The 3" DP from Hogan Performance was literally a "bolt-on" but the nuts were so rusted that they didn't even resemble bolts anymore, and the exhaust shop had to take the studs off the cat and put new studs and bolts in. You might experience a similar situation. The nuts that bolted the DP to the rear manifold were fine, but locked on there, and the guy had to torch them to get them to loosen up.

However, it really depends on how far you want to go with your car. Even if you're running the stock 3.8" pulley and never intend on messing with that, this mod should give you a little extra gas mileage and a LOT better topend, plus I think it will kill any KR you would see with a stock pulley on WOT. Either way, this is entirely SAFE mod for your car, and will make it a hell of a lot more fun to drive. Plus, it will be a nice little addition to your gutted box. The next step after this, IMO, would be the 180 t-stat which you SHOULD do yourself, and don't worry, nobody will disgaree with me on that one. I would do plugs if you ever drop the pulley to a 3.6 or 3.5.

I think plugs and t-stat should be among the first mods you do to a stock Riviera.