ZZP Downpipes

find my post regarding the knock off headers to see what else you need to buy. You'll have to grind down the slag on the inside. Someone reported problems with the crossover not sealing properly with torca style clamps, and I just noticed I have the same problem. It's fixable, but you have to fiddle with it.

Aaron's write-up is great, but expect MUCH swearing and throwing of tools when doing the back bolts They are hard to reach.

Like Jason, I also bought the knock-offs. Installation needed a few extra clamps and gaskets purchased, but only took a day. I had to open up some of the pipes and cut some of the slots with a dremel to make it fit right, but overall I am still very happy with my cheesy headers.

Will it be noticable where I need to trim?

if you mean where the slag needs to be ground off, then yes, it will be quite noticeable. Look inside the primaries, where they are welded to the flange.

Good deal. Thank you all for the insight. I'll probably be ordering them here within the next 3 weeks, when I start putting them on i'll take pictures maybe we can throw a write up together on the ssauto headers.

You'll be glad after it's done. I don't think a write up is necessary. It really is exactly the same as the SLPs. I didn't make a write-up because it would have been identical to Aaron's. Take note of the little extras you need to purchase and that's it.

btw I have a spare gtp trans dipstick.

Jason wrote:

You'll be glad after it's done. I don't think a write up is necessary. It really is exactly the same as the SLPs I didn't make a write-up because it would have been identical to Aaron's. Take note of the little extras you need to purchase and that's it.

btw I have a spare gtp trans dipstick.

Alright good deal. I'll pm you when I order them and we'll work something out.

Guys, anything you notice that's missing from the header write-up, please post it in the write-up thread. I will edit it to include necessary details. My write-up is far from perfect. Feel free to give feedback.

Good luck, Ryan. Please carefully read the beginning of my write-up, the part about whether or not you really want headers. I tried to make it clear that the car's character changes quite a bit with them installed. Rivs have gone into the 12s with 3" down pipes. Just so you know...

AA wrote:

Guys, anything you notice that's missing from the header write-up, please post it in the write-up thread. I will edit it to include necessary details. My write-up is far from perfect. Feel free to give feedback.

Good luck, Ryan. Please carefully read the beginning of my write-up, the part about whether or not you really want headers. I tried to make it clear that the car's character changes quite a bit with them installed. Rivs have gone into the 12s with 3" down pipes. Just so you know...

Hmm. I plan on running the same rockers as you, and right now i'm running a 3.6" mps. I plan on getting an intercooler and porting my blower, so if I scan and my kr is low enough, i'll want to drop down to lower pulley sizes, maybe just 3.4" for everyday driving, but i'll want to be able to run smaller. Would it be a good idea to just spring for the headers now so I don't have to spend twice as much going with a DP now and then replacing it later?

It really depends on what you want. There are different ways of approaching it. Doing an IC will let you run higher boost with no KR, so for you the headers really aren't a KR reducer as much as a flow mod for more power. You could run a 3" down pipe with stock manis and probably be into the 13s with ease - and your car would still sound and feel stock, just a lot quicker. You'd have a real torque monster on your hands. It's not a bad way to go.

The way I approached it, I used headers as a way to push more air out of the engine, lowering boost, and ridding KR. That let me use a slightly smaller SC pulley to gain back some boost and pick up HP. The drawback is, headers don't sound stock, and once I reach a certain boost level, I will see KR.

If you ran IC, rockers, and headers all at the same time... holy hell. You'd really be in the fast Riv category. That's a dream set-up, imo.

Good luck finding Gen III INTENSE rockers. I thought they were discontinued long ago. If you find used ones, be sure to check them for wear.

AA wrote:

It really depends on what you want. There are different ways of approaching it. Doing an IC will let you run higher boost with no KR, so for you the headers really aren't a KR reducer as much as a flow mod for more power. You could run a 3" down pipe with stock manis and probably be into the 13s with ease - and your car would still sound and feel stock, just a lot quicker. You'd have a real torque monster on your hands. It's not a bad way to go.

The way I approached it, I used headers as a way to push more air out of the engine, lowering boost, and ridding KR. That let me use a slightly smaller SC pulley to gain back some boost and pick up HP. The drawback is, headers don't sound stock, and once I reach a certain boost level, I will see KR.

If you ran IC, rockers, and headers all at the same time... holy hell. You'd really be in the fast Riv category. That's a dream set-up, imo.

Good luck finding Gen III INTENSE rockers. I thought they were discontinued long ago. If you find used ones, be sure to check them for wear.

Maybe i'll give the hogan dp a shot. Headers would be excessive with an IC huh? I just won't be able to drop pulley sizes until I see where i'm at on my KR, and then pick up an IC right?

Headers would not be excessive , but you would see an enourmous power increase with the two is what hes saying.so i guess depending on your power goals , then yes they are excessive. but they arent as important if you get an intercooler IMO as the headers are usually used to an extent as a KR reducing mod. With an intercooler you could keep the riv nice and quet. With 1.9s , headers and an intercooler you would have probably around 340-350 hp at the crank. and run mid thirteens at least.

Alright, so if I went with the 3 in. hogan DP, I would most likely just delete my cat all together. Intense sells the race pipe, but it says it's for headers. What size/length tubing would be needed to replace the cat with a 3" dp? Also, zzp sells the ported manifolds, what would be recommended if I got those, front/rear powerlog?

I think most vendors sell downpipes with an extra section for a cat delete. The rear powerlog is only for turbo applications , The powerlog w/3in downpipe felt pretty good while i had the plog on there , and ive read the rear manifold is a decent design so its not too restrictive to begin with. the biggest gains come fromt he front , or so zzp says. The powerlog seems like a decent product ,even if i only drove it around my neighborhood with it on , when compared to the factory manifold it definitely is an improvement.

$119.00 For the front powerlog, that's not too bad at all. I'm thinking the 3 in. dp and the front plog would be a decent gain and it'll run me about the same as the ssautochrome headers would shipped. I don't see a cat replacement with the DP on the hogan website.

Yay, nay?

Well what i did is just ordered the zzp shorty , and welded it to the stock cat , bought a used plog and cleaned it up and sprayed it with some high temp paint ( not the best paint...will probably pick up some VHT as ive heard thats good). If i had to buy one new , i'd spring for the extra 40 bucks and go with stainless. as the one i bought had some surface rust. If you appreciate quietness and dont feel like hassling with the money and install time on headers ,than plog+downpipe would be the way to go. i was happy with it , minus the exhaust leak. hopefully the gaskets will fix that.

Good deal. So the zzp shortys fit our cars? If I got the 3 inch bolt on offroad, that would replace my cat and clamp onto my resonator?

I had to have mine welded to the factory flange , idk if the H-bodies have the same flange as the W-bodies , or if the 96 rivs got a different flange for some reason. But i had to hassle the guy to put it in. And he also had to cut the shorty as it wouldve been too long to connect to the cat , but its worked perfectly with no leaks .

RhinoFLA wrote:

$119.00 For the front powerlog, that's not too bad at all. I'm thinking the 3 in. dp and the front plog would be a decent gain and it'll run me about the same as the ssautochrome headers would shipped. I don't see a cat replacement with the DP on the hogan website.

Hogan has the H-body 3" DP and the H-body magnaflow hi flo cat listed on the same page. What year is your Riv? This is not a direct bolt on for all 95-99, I think it's 97-99 Riv, listed as 97-03 Bonneville.

1998 Riv wrote:

RhinoFLA wrote:

$119.00 For the front powerlog, that's not too bad at all. I'm thinking the 3 in. dp and the front plog would be a decent gain and it'll run me about the same as the ssautochrome headers would shipped. I don't see a cat replacement with the DP on the hogan website.

Hogan has the H-body 3" DP and the H-body magnaflow hi flo cat listed on the same page. What year is your Riv? This is not a direct bolt on for all 95-99, I think it's 97-99 Riv, listed as 97-03 Bonneville.

My riv is a 97. I'm just looking to run a straight pipe similar to the intense race pipes instead of using a cat, but if I can't track one down, I might just have to spring the extra 100 bucks or so and get the DP+cat.

It was a tough choice, to keep the stock cat, go Magnaflow, or delete it. I decided the Magnaflow was a better choice than cat delete, in the event I needed to resell, the lack of a cat could detract. And I wanted the stock cat to go. The Magnaflow really looks like it flows well.

I bought the INTENSE Race Pipe, and it aint cheap. I ended up cutting a lot of it off, because I also had to squeeze in a tapered section to mate up with the stock resonator. I still have the 7" piece of it I would sell if you need it. Could be enough depending on whatever else you are doing.

https://rivperformance.editboard.com/for-sale-f22/intense-3-od-stainless-steel-race-pipe-15-shipped-t871.htm#9160

AA wrote:

I bought the INTENSE Race Pipe, and it aint cheap. I ended up cutting a lot of it off, because I also had to squeeze in a tapered section to mate up with the stock resonator. I still have the 7" piece of it I would sell if you need it. Could be enough depending on whatever else you are doing.

https://rivperformance.editboard.com/for-sale-f22/intense-3-od-stainless-steel-race-pipe-15-shipped-t871.htm#9160

On that end, just a downpipe+cat delete. It's a 3" inlet right so it would fit on a hogan 3" dp? And then clamp onto the stock resonator?

Don't know, but you might be able to use a pipe expander to make it work.