ZZP Downpipes

I was saving towards an intercooler, but i've decided to finally ditch the stock downpipe. I've got around 200 bones towards it, and i'm probably going to save a little bit more and just go for downpipe+cat. I was looking at this from ZZP

http://www.zzperformance.com/grand_prix/products1.php?id=551&catid=110

If I got the 3 inch bolt in with cat, would I need to get that cat to bolt up to our factory 2 1/4 Inch?

I was also looking at the hogan 3 inch downpipe+cat, but that runs $269 and some change, zzp's is alot cheaper but i'm not sure if theirs is designed to work on our setup or only on grand prixs. Any thoughts, or should I email zzp and ask?

just go with the hogan , and bolt to converter ..... there nice , and well made too
ya gotta get the one made for a bonneville the gtp one is different

Could I buy the hogan DP, and buy a magnaflow cat seperate, it would be much cheaper that way.. or would it just be easier to buy the hogan dp with the cat already on it?

Ryan, I got my DP and magnaflow cat from Hogan. I actually bought them separately. The DP is a bolt on, to the exh manifold and to the stock cat. It also bolts directly to the Magnaflow hi flow cat if replacing the stock cat. The new cat needs to be either welded or clamped in to the stock resonator. Mine is clamped.

Hogan has nice parts, no complaints here. I took the easy way out and had a local shop do the install though.

the zzp shorty will weld up to the car with some modification. The 96 rivs i believe have a different flange from the manifold to the downpipe so you'd have to get it welded to the existing flange , but it may be different for other models. I was impressed with how clean the stock downpipe and cat were. 77k miles and hardly any carbon...

1998 Riv wrote:

Ryan, I got my DP and magnaflow cat from Hogan. I actually bought them separately. The DP is a bolt on, to the exh manifold and to the stock cat. It also bolts directly to the Magnaflow hi flow cat if replacing the stock cat. The new cat needs to be either welded or clamped in to the stock resonator. Mine is clamped.

Hogan has nice parts, no complaints here. I took the easy way out and had a local shop do the install though.

Awesome, that ran you what around $269?

my 321 slp knock-off stainless headers had a 3" downpipe and ran me a whopping 220$ shipped to my door. I think you can still find some for around 300$.

what's the brand name? that's tempting..

the brand name is nothing as far as I know.
I think ss auto chrome still has some? The people who sell them inevitably lose their ebay privileges for copyright infringement. A search will turn up the link to the vendor that carries them

RhinoFLA wrote:

Awesome, that ran you what around $269?

Don't recall the total, will have to dig that up.

The Hogan 1-piece unit is $270, DP and cat complete. Bolt to manifold, clamp or weld to resonator. Got mine in 2 pieces, as I decided after the fact to also get the Magnaflow cat.

If I was single and the only driver of my Riv, I'd probably be doing headers and more engine work, either cam or rockers. I do that to my 68 instead.


http://www.hoganperformance.com/HBodyGM.htm

Jason wrote:

the brand name is nothing as far as I know.
I think ss auto chrome still has some? The people who sell them inevitably lose their ebay privileges for copyright infringement. A search will turn up the link to the vendor that carries them

Nothing really turned up on ebay.

http://www.ssautochrome.com/level.itml/icOid/1886

I like what Hogan did making a piece that bolts up and fits without hassle. I think more Riviera owners should support their business, even if it costs a little more.

I wish Hogan would list it for our Rivs though. It is still listed only for the Bonnevilles.

1998 Riv wrote:

I wish Hogan would list it for our Rivs though. It is still listed only for the Bonnevilles.

Hey new to the board does Hogan have a website?I have a 98 riv stock want to put a new dp and cat whats the best way to go Thanks Steve

Welcome, 71stagegs. Check out this link:

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

71stagegs wrote:

Hey new to the board does Hogan have a website?I have a 98 riv stock want to put a new dp and cat whats the best way to go Thanks Steve

Hey Steve, welcome to the board. Hogan's H body link is posted on page one of this thread. Post up some pics of both your cars when you get a chance.

How far performance wise could I take my car with a downpipe rather than headers, I plan on getting rockers, would a downpipe be suitable?

theres one guy on regalgs.org that runs a SS intercooler , 1.9s a 3.2" pulley on a plog+downpipe.

I'd think if you are planning on higher ratio rockers, headers might be advisable first. Rockers will move more air, you'll need to be able to get it thru your exhaust more efficiently. Maybe a Plog and ported rear manifold would suffice, guess I can't answer that for sure.

yea i called to make sure it would fit a Riv , got to talk to curt him self
seemess as i recall curt drove a Riv at one time , cause he said on mine ...
either way there prices are great and customer service are great beacuse when it arrived it looked offset an inch or so , after another call curt assured me that alls well there designed that way.
and after a couple more questions about noise from the flex pipe , i was satisfied ... its on no probs....
wish it did more for my 4* though

Pat, I had the same concerns about my Hogan DP when it arrived, and Curt was very quick to address my inquiries. BTW, I've noticed absolutely no noise issues from the flex.

I planned on running 1.9 rockers, same as Aarons, maybe the yella terra, i'm not sure on that yet. The ssautochrome setup is only about $30.00 more than the hogan dp+racing cat, so I suppose i'll hold out and spring for that. Have any of you installed headers yourself? They have to be welded to your cat right? I think I might just delete the cat.

Nevermind, I found Aaron's write-up on installing headers. I've never read that before, excellt job Aaron, very detailed. That being said, headers it is. I can't wait until work picks up and overtime resumes..