Exhaust System Question

[Scott Elgas]

It's weekends like this last one that make me not want to sell my boat! Weather wasn't great, but water conditions were. Anyway, I have read a lot of posts on this site since I have joined and there are definately a lot of knowledgeable people on this site! So I need some honest opinions. If I don't sell my boat I would like to give it a little more power. I'm looking into exhaust systems.

I have a 1995 22'Classic, stock 502 with blackhawk drive. Being involved in snowmobiling I know there are a lot of "blown-up" horsepower claims from exhaust manufacturers out there. So my question is this. What kind of honest horsepower and torque gain can I expect from an aftermarket exhaust system? And "real world" performance gains? By this I mean that I know that "peak" horsepower isn't everything. Do you have to give a little to get a little? What can I expect to the low-end, mid-range and top-end. Also, from experience, what brand(s) would you recommend.

I guess that's more than one question. http://www.donzi.net/ubb/smile.gif Any feedback would be appreciated.

Thanks

[BigGrizzly]

Scott, for my money the best ehaust system is the C.M.I. sport tube the long runners make the system work. Their elbow tops with the short runners are better then others of the same design, but not the sport tubes. the reason is they are stress releived befor being polished. These guys work closly with engine builders to get their results, tapered tubes, etc. they worked with me for mine. the people they have are so good that they built my clevland headders, with out seeing the boat, just drawing and masurements from me. The pipes fit exactly. Never saw anything like it. Horse power---well don't know just that they added 700 RPMs to my top end and noticable snap when accelerating and from the bottom up, and weight savings. One added feature- to us motor heads- is the sound- grrrreat. Kind like having your own Nascar on the tralier. They also a larger selection of cams available. My Criterion will have them some day.
Randy


[This message has been edited by BigGrizzly (edited 09-05-2000).]

[Emmo]

Hey Randy, are those the $10,000 headers you didn't want Barb to know about? http://www.donzi.net/ubb/biggrin.gif

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Emmo mailto:emmette@emmette.comemmette@emmette.com</A>

[This message has been edited by Emmo (edited 09-05-2000).]

[wbateman]

You got it Emmo!!!!

[GEOO]

Scot, I run Stainless Marine Exhaust on my small block. When I first put them on my 300hp 350ci small block I did not notice a speed gain over my stock Volvo transom exhaust. I have them on my 434 ci which was able to build over 600hp on the dyno with a carb, so they can flow air.
Hot Boat did an article on the 22 Donzi with a big block a few years back. They added Stainless Marine Exhaust and cross over housing which replaces the water pump. They gained 3 to 6 mph. Call Stainless Marine
ask for Brownie. He may have a copy of the article. (305)681-7893

I think Stainless Marine Exhaust is the best exhaust for a reasonable price. I would love a set of CMI's but at twice the cost, I wanted to put the monies elsewhere. GEOO

[CDMA]

Geoo,

How much were the Stainless marine manifolds and risers?

Chris

[GEOO]

Chris, Stainless Marine Exhaust Systems cost About; $ 1,500.00 for Alum. Manifold & standard SS riser, (use rubber tubes & through hull fittings).
OR like I have; $ 2,100.00 Alum. Manifold & SS riser that is one piece through the transom; custom made to your specs for the lenght and bend in tube. Exhaust water can enter exhaust where ever you like. GEOO

[Scott Elgas]

GEOO,

Thanks for the input. I have heard good things about stainless marine and cost is an issue.(I like a decent dollar vs. horsepower investment when possible) I have spoken to Brownie on a couple of occasions on other products. I have done some research into exhaust systems but I like to get input from people who have actually tried the products. Anyone else?

[Riley]

Hey Scott, are you considering selling your boat? I get to Cadillac a couple times a month on business, and I'd love a chance to see one of those Blackhawk drives up close! Let's try to hook up sometime for coffee or lunch....or maybe a beer. Thanks, Chris Riley.

[Scott Elgas]

Chris,

Actually my boat is for sale. I have it listed in the "Boats for Sale" part of this site. But if I don't sell it no big deal. I do love the boat and if I don't sell it I'll probably do a few upgrades next year. Give me an e-mail next time you'll be in Cadillac. If I remember correctly, didn't I see a post that stated you worked as a rep for a snowmobile company. Parts Unlimited I thought. If that's the case it will be a long lunch cause I to talk snowmobiles. Just ask my ex-girlfriends!

[Riley]

Hi Scott, yes, I do work for Parts Unlimited. I used to have a few customers in Cadillac, but with Pro Am and a couple of other stores closing the only really active dealer in the area is Team Highland over in Marion. If you know anybody looking to get into the sled, atv,and motorcycle business, Cadillac is in need of a store!

I'd love to sit down and talk sleds with you. I used to drag race out in Wellston, and I still like to run as many MSDRA events as possible. I've kind put driving on the back burner for now, as I have been doing quite a bit of writing for Snow-Week the past couple of years.

I hope you don't sell your boat! We are going to try to have a Donzi meet up here in the Les Cheneaux Islands next summer, so the more the merrier.

I should be in the Cadillac area sometime in the next week to ten days, I'll email you and we can set up a time and place to meet....Chris.

[MattM]

When I upgraded the 454 in my 22' to 530Hp I went from 4900 RPM to the 5500 RPM I was looking for by switching the stock iron manifolds to Stellings "green" SS headers. The jump was tremendous. This is an extreme example of a change from what was a very inadiquate exhaust to the best possible. In your case the 502 doesn't have nearly as much cam and the factory exhaust is better than what I have. If you have a decent exhaust already and a carburated engine your money may be better spent on a cam. I agree with biggrizzly though, even if I saw no performance increase, the exhaust note alone probably would have been worth it.