Water injected vs dry headers

[Fire Water]

Does anybody have any dyno information on comparing water injected headers to dry? All the whitewater race boats are running dry headers. Just curious how much of an increase in horsepower they're getting.

[Squirtcha?]

No dyno, but gps'd it back to back several times. No difference in speed. Just a lot louder. It might be different if you have a behemoth mountain of a motor. On 500 hp + a 150 shot it was a big fat goose egg.

[SmokinLowriderSS]

I haven't done it but this Q was asked on here maybe 6 mos ago, and the several people who responded with results had no change like Squirtcha had. At least that's my memory of the thread. I followed it some from interest but wasn't looking to go from Thru-Transom to either.

[beerjet]

I had asked the same question a while ago because a dude told me the water messes with the exhaust pulses , it's not like your pumpin a ton of water through your over tansomes anyways like you would on through transomes . I cant imagine the mist screwin anything up to where it would be noticeable.
-beerjet-

[396_WAYS_TO_SPIT]

I gain alot more HEAT :crossx: :crossx:

[FASTRAT]

Does anybody have any dyno information on comparing water injected headers to dry? All the whitewater race boats are running dry headers. Just curious how much of an increase in horsepower they're getting.
also...keep in mind, that with water inj headers, u get less blueing over time!!
fastrat

[dragboat]

I went out last weekend just to get gps information on some changes I made. I found that it actually gained 1.4 mph when I turned the water ON! I was surprised by that so I repeated the run, same result. Mild 454 twisty ceramic coated Rewarders. What does that mean ? Are the tubes to big?..... or do I need MORE ENGINE!

[Ken F]

Could just mean that your engine likes a llitte back-pressure.
Why not try borrowing a set of mufflers & try it that way?
Ken F

[Some Kind Of Monster]

Right,
Pros to not running water:
Very slight increase in Hp if at all.
Louder
No problems with reversion and sucking water into the motor. Every time I go to the lake someone is about to hydro lock a motor because they are running too much water in their headers. Last time out was no exception. I've done it myself (never will again).
Cons to not running water:
Louder
Hotter
Headers discolor
Watch your spark plug wires and transom because they will burn.
Like I said, I will never run water again unless it's water jacketed or with a banderlog system.

[dragboat]

I'm running the bassett "high perf" mufflers? Not the auger style. Im running the water with a gate valve and stainless lines, tired of the spring setup messing up. Went with the swept back twistys to get them further away from the passengers. 4900 rpm bronze agressor a.

[Fire Water]

Just ordered a set of ceramic coated headers from Jim at Rewarder. 1 7/8" tubes to 4" belled collecters (wanted the 4" collecters so I could use my silencers). I will be able to run wet or dry. I might make a support brackett for the collectors if I start running dry all the time so I can keep them from sagging.
I was just curious what the difference would be. I know that you would increase back pressure quite a bit because of the thermal expansion that takes place when the water vaporizes to steam. Same principle except in reverse with a steam turbine.

[Glencoe MiniDay]

Might camshaft profile and duration and other various engine combos react differently to the amount of back pressure that you would create with the water injection??

[Squirtcha?]

Right,
Pros to not running water:
Very slight increase in Hp if at all.
Louder
No problems with reversion and sucking water into the motor. Every time I go to the lake someone is about to hydro lock a motor because they are running too much water in their headers. Last time out was no exception. I've done it myself (never will again).
Cons to not running water:
Louder
Hotter
Headers discolor
Watch your spark plug wires and transom because they will burn.
Like I said, I will never run water again unless it's water jacketed or with a banderlog system.
If what you're saying is true and you hear about that many cases of reversion/hydrolocking, I'd be nervous too.
I've run the standard Bassett T valve setup on mine for 10 years and never had any problems with the setup at all. No thermostat or any of that other stuff. Most everyone I boat with runs the same setup (also without problems). Guess we've just been lucky? K.I.S.S.
Might camshaft profile and duration and other various engine combos react differently to the amount of back pressure that you would create with the water injection??
No expert by any means, but from all I've read over the years.............yes. This topic is covered in great detail on other areas of this forum. Do a search on cam profile/reversion. Don't specify any particular forum in the search criteria so's it'll check all areas. Grab a cold one, and prepare to do quite a bit of reading.
I went out last weekend just to get gps information on some changes I made. I found that it actually gained 1.4 mph when I turned the water ON! I was surprised by that so I repeated the run, same result. Mild 454 twisty ceramic coated Rewarders. What does that mean ? Are the tubes to big?..... or do I need MORE ENGINE!
You always need more engine!
Dan

[79centurion]

On my picklefork with just me in it, it makes no difference wet or dry, but with a 200 lb passenger, I lose 200 rpms running them dry.
Dan