2001 Sapphire Blue
Enthusiast
Let's say you have the rain baffle removed or you get one of Heffner's air boxes and you hit a sudden rain storm. Is there possible damage to the engine or does your K&Ns just soak it up?? Anybody have this happen?
Remove rain baffle question...
- Thread starter 2001 Sapphire Blue
- Start date
Don,
If you keep your filters well oiled, and the rain is drizzley, you have no problem. At a minimum, go to 5th or 6th and slow down. Keep your throttle demands / RPMs low, and DONT race to get out of the rain. Slow down. If you have sheeting-waves of thunderboomer rain, like you and Dorothy get there in KS-MO, I would pull under an overpass and wait it out.
You can literally pour a 5-gal bucket thru the NACA and it will drain, engine running.....but the STRAIGHT-IN Downpour while driving fast can ram water into and THRU the dry / dirty filter. It would take a lot to damage the motor.
"In My Opinion, but my lawyer says I could be wrong"
If you keep your filters well oiled, and the rain is drizzley, you have no problem. At a minimum, go to 5th or 6th and slow down. Keep your throttle demands / RPMs low, and DONT race to get out of the rain. Slow down. If you have sheeting-waves of thunderboomer rain, like you and Dorothy get there in KS-MO, I would pull under an overpass and wait it out.
You can literally pour a 5-gal bucket thru the NACA and it will drain, engine running.....but the STRAIGHT-IN Downpour while driving fast can ram water into and THRU the dry / dirty filter. It would take a lot to damage the motor.
"In My Opinion, but my lawyer says I could be wrong"
Fiorano
Enthusiast
I once got caught in a huge downpour with my Viper (Factory 10 airbox). The filters were wet once I got home and checked. However, no problems from what I could tell. I just let the car run for about 15 min to hopefully have the heat dry them faster.
Ron
Enthusiast
Rain baffle removal provide zero horsepower. Why, because the NACA scoop provide zero RAM AIR. No RAM AIR no HP improvement. Go one step further. Entirely remove the front of the airbox... bare naked K&N's.... Horsepower improvement... zero.
The airbox is not the limiting factor. Why risk hydrolock for a poser mod?
The airbox is not the limiting factor. Why risk hydrolock for a poser mod?
Toby
Enthusiast
I think I did...I asked this question over at the alley and the water issue came into play when I was asking about HP gains.
The front of the airbox is about twice as much area as the NACA duct opening. Cut a piece of (black?) sponge or foam rubber that's large enough to compress a bit when it's in the NACA duct hole and keep it under your seat. Stuff it in the hole if it starts to rain, the engine should be able to breath well enough through the non-duct fed openings to keep you running well and dry.
Bad02ViperGTS
Viper Owner
I belive this mod is worth some power......Its beem proven for 5 hp at the dyno....
Matt M PA
Enthusiast
Better air-flow must certainly be worth something. Is it like bolting a blower on? No.
Straightening airflow can only help and that is what this mod does. It's true that the NACA duct will provide ZERO ram-air as a NACA is designed expressly to create to no drag. No drag---no ram-air effect. That said, ram-air is worthless on a fuel injected car anyway. With a carb, you will see an increase, but at the expense of a big-time drag making scoop.
Id' bet than in a gentle rain, there would be no problem, but in a storm, you might have issues. (My GTS is not going out in the rain, so it;s no problem for me.)
Straightening airflow can only help and that is what this mod does. It's true that the NACA duct will provide ZERO ram-air as a NACA is designed expressly to create to no drag. No drag---no ram-air effect. That said, ram-air is worthless on a fuel injected car anyway. With a carb, you will see an increase, but at the expense of a big-time drag making scoop.
Id' bet than in a gentle rain, there would be no problem, but in a storm, you might have issues. (My GTS is not going out in the rain, so it;s no problem for me.)
Ron
Enthusiast
I know of a Viper owner that went through a deep puddle, had water ride up the nose into the scoop and hydrolocked the engine. Result? New engine. Had rain deflector and it wasn't rain but the result of rain that caused it so not really relevant but stated just to prove the hydrolock isn't something hypothetical.
On the dyno question, a 5 horsepower variance is not measureable given the incosistancies of the equipment, temp changes in the engine, etc. Also, there is no RAM Air effect on a stationary car, (fan or not) even if the scoop was design to be in a high pressure area. The fan in front of a dyno car is to cool the engine rather than RAM Air.
The only way you could get horspower on the dyno out of an airbox mod is if the part you modified was a airflow inhibitor at normal engine intake velocity, for example if the airbox opening was smaller than the combined diameters of the throttle bodies. To validate that I ran my car on the dyno with a fan on in front, K&N's with smooth tubes, airbox complete and got 434.9 RW corrected out of it. Next run, a few minutes later to allow the engine temp to return to baseline with no changes except removal of front of airbox, maximizing any positive effect of no rain baffle, I ran 434.2, statistically no change.
Before this dyno run I bought a old airbox front and removed the rain baffle, so believe me I wanted the mod to work, but for me at least is doesn't. Add to that the risk that you'll be caught in the rain, someday somewhere (think VOI7 perhaps) and why do it? I'd rather spend money on mods that add proven power without downside.
On the dyno question, a 5 horsepower variance is not measureable given the incosistancies of the equipment, temp changes in the engine, etc. Also, there is no RAM Air effect on a stationary car, (fan or not) even if the scoop was design to be in a high pressure area. The fan in front of a dyno car is to cool the engine rather than RAM Air.
The only way you could get horspower on the dyno out of an airbox mod is if the part you modified was a airflow inhibitor at normal engine intake velocity, for example if the airbox opening was smaller than the combined diameters of the throttle bodies. To validate that I ran my car on the dyno with a fan on in front, K&N's with smooth tubes, airbox complete and got 434.9 RW corrected out of it. Next run, a few minutes later to allow the engine temp to return to baseline with no changes except removal of front of airbox, maximizing any positive effect of no rain baffle, I ran 434.2, statistically no change.
Before this dyno run I bought a old airbox front and removed the rain baffle, so believe me I wanted the mod to work, but for me at least is doesn't. Add to that the risk that you'll be caught in the rain, someday somewhere (think VOI7 perhaps) and why do it? I'd rather spend money on mods that add proven power without downside.
99 R/T 10
Enthusiast
Yeah, but Ron, when you add Vipair to the mix there is an easy 50 RWHP 
Ron
Enthusiast
That I would not dispute!
Craig 201 MPH
Enthusiast
I just don't get why people do this. You're not going to feel 5-10 horses anyway. It's less than a 2% gain!
BigCarrot
Enthusiast
5-10 hp for free? I'll take it any day of the week! It would be stupid not to! Every little bit counts! What do roller rockers give you? 10-20 hp, max? How many people pay a geezer for that?
Craig 201 MPH
Enthusiast
but putting on roller rockers doesn't involve the risk of hydrolocking your engine
BigCarrot
Enthusiast
I hydro-locked one of my Vettes, just after putting a new motor in my brother's hydro-locked car and making fun of him relentlessly, so I'm very familiar with the term. Like Jon B said, the chances of hydro-locking a Viper are pretty slim. A small amount of water won't hurt the engine. If it did, do you think Doug Levin would put water injection on his cars? You would almost have to submerse the nose of a Viper to hydro-lock it. Hard to do.
Craig 201 MPH
Enthusiast
I guess you're right. Bonkers tried to do it.
Matt M PA
Enthusiast
FE 065..here's a link to a post that describes it better than I might. I could not quickly find the info about carb-vs-fuel injection. (I'll try to find that and post it later.)
Obviously, colder air, or better flowing air is a benefit..but by and large ram-air is a non-issue.
Here's the link...
http://www.vetteguru.com/ramair/
Obviously, colder air, or better flowing air is a benefit..but by and large ram-air is a non-issue.
Here's the link...
http://www.vetteguru.com/ramair/
SSSSE YA
Enthusiast
Nice article..
I think the Vette guru has an exhaust leak... you gotta watch these guys who claim the rest of the world has been misled.
Air's not compressible at any automotive speed? I can clap my hands together and feel the compressed air escaping from between my hands before they meet...
You wouldn't have to compress it (much) anyway to gain. Some interia from the incoming airstream would be helpful.
At any kind of RPM there isn't any air stacking up and waiting to pop into a multi-cylinder engine's ports anyway. Especially on a Viper with 5cyl on each side competing for air in the plenum. There wouldn't be any 'slowing down' of incoming air occuring at like 6000 rpm
I guess he likes the divergent nozzle because air could go in but find it hard to come back out-like a fish trap...if you were piping it into something other than an engine that's inhaling as fast as you can put it in.
I'll take any boost over atmospheric myself.
Thanks for the article!
Air's not compressible at any automotive speed? I can clap my hands together and feel the compressed air escaping from between my hands before they meet...
You wouldn't have to compress it (much) anyway to gain. Some interia from the incoming airstream would be helpful.
At any kind of RPM there isn't any air stacking up and waiting to pop into a multi-cylinder engine's ports anyway. Especially on a Viper with 5cyl on each side competing for air in the plenum. There wouldn't be any 'slowing down' of incoming air occuring at like 6000 rpm
I guess he likes the divergent nozzle because air could go in but find it hard to come back out-like a fish trap...if you were piping it into something other than an engine that's inhaling as fast as you can put it in.
I'll take any boost over atmospheric myself.
Thanks for the article!
