Looking for opinions on Nos for an HP500EFI?

Has anyone tried Nos on this engine.

Looking for 500rpm more, 100hp or so.

Another question is AS&M has a mono blade intake butterfly made for the 500efi. Along with the computer recal, they claim 35hp. Has anyone tried this kit?

Thx for any info

Get the dental grade NOS so when you scrap your engine you will have something to do until help arrives. Just a thought!

Nos is for people who can't build real motors!


quote from a professer of mine LOL!

"NOS was made so we could sell parts"

There has been a lot of discussion on this subject before.
The bigest problem with using NOS is that you have to prop for the higher RPM while under NOS but then the boat will be very hard to get on plane with the big prop.
I believe that you will have to add a lot more that 100 HP of NOS to gain 500 RPM. I went from 365 HP to 600 HP and gained 600 rpm.

Canada Jeff?

Hi, I'm new to the OSO site. I'm from the central New York area and about up to my butt {so far} in snow for another 5 or 6 months. Reading the posts from some of you guys in the more southern areas helps us northerners realize that the whole country isn't frozen solid. Been lerking in the darkness on OSO for a while and thought I'd jump in on this one.

Sun 288 - I posted a question about nos on another site. Most responses were negative for I/O uses. Basically too much of a hassle for the gain plus potential engine damage. I have a 500 hp 502 {not an HP500} and was looking for some extra hp for a quick romp every now and then. After reading the responses I decided to forget it. Some of the OB guys seem to like it though.

Sorry 'bout the long intro in paragraph 1 Sun 288. Didn,t mean to disrupt the thread. Good luck with what ever you decide.

Bill

tinkereer soemthing just doesn't seem right about your numbers at all.

for an extra 235 hp you should haev seen WAY more than a 600rpm gain

NOS works well if you are sure you are adding enough fuel.

It's only feasible in short (5 sec) bursts or so.

Once you shoot some juice, you'll likely pick up a lotta speed, and when you stop spraying, you will only lose some of that speed, not all of it. Gets the hull freed up real well.

It's not a bad idea.

Prop for your non nos wot rpm (5200).

If you are hydraulic lifters, you shouldn't shoot any more juice than whats needed to get you to 5600 or so.

If you are running a mechanical cam then you can spray and spin it to 6200 for a short burst (with forged 502 guts).

have fun.

mcollinstn, I am thinking the same. Get the boat going a little faster, for a burst, Only hold the button for 5 seconds or so.

Right now I'm propped to turn 5100 trimmed out at WOT. I'm sure 100hp shot would get me to or close to 500rpm. This is a 28' Boat.

But I need some real world experience here. Or a company that has put a kit like this together for the hp500. A kit that recals the computer and adjusts fuel and timming when button is pressed. Thats probably the only way I will consider doing this. Or if someone out there has this fine tuned with many hours of trouble free op.

But I think I'm asking to much.

US1 Fountain, hello.

Thanx for the thoughts guys.

LMAO