Performance Boats Forum banner

1 - 20 of 63 Posts

·
Registered
Joined
·
1,676 Posts
Discussion Starter #1
I know the old drawthru banks system used logs. I am getting ready to plumb up my single turbo. Is there any reason I can't use a center rise exhaust? The ones I'm looking at are cast aluminum. The plan is to use the center riser and make the elbows out of stainless tube then Y into a t4 flange. Main reason is I don't want glowing headers in the boat.
 

·
Premium Member
Joined
·
3,360 Posts
I know the old drawthru banks system used logs. I am getting ready to plumb up my single turbo. Is there any reason I can't use a center rise exhaust? The ones I'm looking at are cast aluminum. The plan is to use the center riser and make the elbows out of stainless tube then Y into a t4 flange. Main reason is I don't want glowing headers in the boat.
The Race Aero and Gentry systems are based on center rise manifolds. I am building my 622 twin turbo deal based around some old Drake manifolds with 21/4" equal length runners.
 

·
Registered
Joined
·
123 Posts
I was advised against using the Indmar style manifolds that I have on the shelf now. I ended up building my own stainless headers. The manifolds I have are not water jacketed near the port and arent really that thick between the exhaust and water. Temps in the back seat are okay. Im going to modify the heat shields more, but as they are, they are so so. With a little work, the heat is not a big deal IMO.
 

·
Registered
Joined
·
1,676 Posts
Discussion Starter #5
Well I dug a little deeper and it turns out the center risers I planned to use are cast steel so that's even better.
 

·
Registered
Joined
·
1,138 Posts
I have center rise Drakes also (aluminum). The premis is that the water cooled manifolds will pull heat from the exhaust stream. Which they lm sure they will, how much l think is marginal. The heat also drives the turbin along with the flow.
But having the turbin wheel 18-20 inches from the exhaust valve, how much heat
can be disapated at 3-7k rpm? I think the amount of flow and speed threw the exhaust mainfold will be too fast to have an impact.
In an race only application, this would not be the direction l would choose. But, a lake hot rod, l woukd rather not have the heat in the boat.
Just my .02. Be safe, schick
 

·
Or Seth, either one
Joined
·
3,270 Posts
I know the old drawthru banks system used logs. I am getting ready to plumb up my single turbo. Is there any reason I can't use a center rise exhaust? The ones I'm looking at are cast aluminum. The plan is to use the center riser and make the elbows out of stainless tube then Y into a t4 flange. Main reason is I don't want glowing headers in the boat.
Can't think of any reason you can't use center rise manifolds. The design is perfect for twins, but there's no reason you can't plumb them together for a single. The crossover will get hot as hell, you might consider water jacketing it too. A little more complex, but a lot cooler if you're worried about people getting burns.
 

·
Registered
Joined
·
1,676 Posts
Discussion Starter #9
Yeah it's a lake only deal, who knows I may run it on the clocks after it's together. I'll probably double wall the crossover and jacket it as well, depends how well it runs.
 

·
Registered
Joined
·
1,138 Posts
Yeah it's a lake only deal, who knows I may run it on the clocks after it's together. I'll probably double wall the crossover and jacket it as well, depends how well it runs.
Maybe wrap it in 3/8 copper tubeing, then wrap that in exhaust wrap (the crossover). Run water threw the tube. Prob wont cool the crossover, but would keep the heat out of the engine area. Would be pretty easy to try.
 

·
Half a bubble off
Joined
·
2,467 Posts
Kevin, I sure hope you pull this off. I was extremely close to pulling the trigger on going twin turbo but the heat issues really worried me. With your talent, I'm sure you can do it. :))THumbsUp
 

·
mo balls than $cents$
Joined
·
11,734 Posts
Better do what u can to keep some heat and velocity in the crossover pipe.been there done that and with a big single on a 5.3, better have the ability to bring up egts fast if you plan to race it. put twins on it now and dont bullshit.pm me if ya wanna turbo recommend.ive gta hookup
 

·
Highaboosta
Joined
·
3,431 Posts
The biggest challenge to the center riser exhaust manifolds is going to be the time when you want to pull the valve covers off.
 

·
Registered
Joined
·
123 Posts
Kevin, I sure hope you pull this off. I was extremely close to pulling the trigger on going twin turbo but the heat issues really worried me. With your talent, I'm sure you can do it. :))THumbsUp
Dont you have a 21' Daytona? I too was worried about the heat, but there is enough room in a 21' that its not a huge ordeal. The girls in the back said it got warm if I was in boost for an extended period of time, but not totally unbearable. My heat shields leave #1 and 2 cylinder header tubes somewhat exposed and that is where the heat is coming from. My shields pretty much only cover the outboard side and I have painted valve covers with no problems.
 

·
Registered
Joined
·
123 Posts
The biggest challenge to the center riser exhaust manifolds is going to be the time when you want to pull the valve covers off.
Good point. With logs, be careful where you mount the turbo so it doesnt damage gel/paint on the transom. Thats what let me to do more of a center style, that, and I ran my exhaust back through the transom instead of over it.
 

·
Registered
Joined
·
1,676 Posts
Discussion Starter #16
I have saddle tanks in my southwind, they sit really close to the headers I have now. That along with just having a kid makes me not want the potential for something bad to happen. Center riser to a crossover that Y's right above the flywheel cover is my plan. I'm thinking of different ideas for the crossover, either jacketed or using custom aluminum heat shields that bolt on like a dirt bike. The crossover sits up high out of the boat so the only heat issue I have with that is bubbling my paint. Hope to have the whole project done by this summer. I already have a 76mm Gt45 turbo I'll be using. I'm doing the whole deal with cheap parts. I'm tuning it and fabbing everything myself. I couldn't see myself buying a high dollar turbo to just send parts through it when I blow it up.
 

·
Highaboosta
Joined
·
3,431 Posts
The heat is certainly a concern with a turbo setup but it's not insurmountable.
If you have a hatch over the engine then certainly you will need everything water jacketed.

With an open engine compartment dry headers work fine with heat shields.
Huge weight difference between jacketed manifolds and single wall headers.
As I recall my turbo headers weigh about 14# each.
It doesn't take much to block radiant heat. Aluminum foil will block it.
I have single wall stainless tubing with .030 heat shields that cover the entire header and it blocks the heat real well.
I stow a plastic tool box about 2" from the header that is covered with a .030 aluminum heat shield and it has never shown signs of melting.



As you can see I am not a very skilled sheet metal fabricator but it works :)sphss
 

·
Or Seth, either one
Joined
·
3,270 Posts
I have saddle tanks in my southwind, they sit really close to the headers I have now. That along with just having a kid makes me not want the potential for something bad to happen. Center riser to a crossover that Y's right above the flywheel cover is my plan. I'm thinking of different ideas for the crossover, either jacketed or using custom aluminum heat shields that bolt on like a dirt bike. The crossover sits up high out of the boat so the only heat issue I have with that is bubbling my paint. Hope to have the whole project done by this summer. I already have a 76mm Gt45 turbo I'll be using. I'm doing the whole deal with cheap parts. I'm tuning it and fabbing everything myself. I couldn't see myself buying a high dollar turbo to just send parts through it when I blow it up.
I'd really appreciate a build thread, if you're up to the extra time it takes to document and photograph your progress.

As you can see I am not a very skilled sheet metal fabricator but it works :)sphss
Kinda like wrapping an odd shaped Christmas present, not pretty but it works. :))THumbsUp

How is the temperature of the heat shield after a hard run? If it doesn't immediately sear skin on contact... :))THumbsUp

Ever put an IR thermometer on it?
 

·
Registered
Joined
·
1,676 Posts
Discussion Starter #19
I've done build threads for both the jetboats I've redone, I'll document the turbo build as well. I'm sure I'll have questions somewhere along the way.
 

·
Premium Member
Joined
·
3,360 Posts
I don't think a single 76 is a big enough Turbo. Now 2 76's would be sweet!!!!!!!
 
1 - 20 of 63 Posts
Top