I would like to put some thru-haul on the nova I have....Its a twin 302 with log style manifolds. My question or problem is that I have heard that the log style manifolds are not suited to doing this. However, I haven't received a real reason for this. I understand that capping the y-pipe will cause some loss of aeration to the prop. Being that this is a resin bucket I'm not to worried about loss of speed. I also have a machine shop at my ready so if its a good Idea I will most likey be making the risers myself......you guys have any input I would love to hear it! Thanks everyone in advance

My 400 trs had the old 3" logs with through hull. Don't see any reason it wouldn't work.

That's what I'm figuring....at one point someone told me that the way the logs flow water it was not a good idea. But all I see as a diffrence is that the logs exterior get hot an center risers don't. Prostock85 do you have any photos of your 400 setup?

On a Baja I had years ago, I had a buddy make up some Y pipes so I could run the exhaust out the transom. I made up a mock Y pipe out of cardboard and had my buddy who is a welder, weld up some Y pipes out of 4" alluminun tube . I ran the exhaust out through the transom and through the outdrive at the same time. Worked great. It was a cheap way to make some noise.

These are from when I went to look at the boat, so the pics are kinda garbage but hopefully they work for you.

they make a straight out the back riser for log manifolds. i have seen them on older twin bbc set-ups. that being said, the only diff you will see is more exhaust noise. no change in perf at all...so you can't hear the old lady yell "slow down!!!" instead she will dig her fingernails in your arm...

Lol yeah I know I getting nothing in terms of performance. I just want the sound. I really just wanted to make sure this had been done before so there were no issues.

I assume you intended to say thru hull. Not haul
Not quite sure what a haul would be on a power boat

Allot of jet boats use log style exhaust with thru hull exhaust and never have any problems cant see why it would be any different for you

the main reason for the center riser manifolds is that you just don't have enough room between the inside of the transom and the riser outlet if you use end riser logs.

i converted a 302 ford/merc 1 drive to a through hull exhaust and i bought a center riser manifold/center riser exhaust and i still only have 16 inches of hose between the riser and the through hull fitting. i would not have had enough space to use the end riser logs.

i bought a "set" of manifolds and risers off ebay for 550 bucks or so. the tips were another 225 and the hose was 75 or so.

i made a block off plate and removed the factory "y" pipe.

good luck.

some pics: