Naturally Aspirated Power!!
 

Ok, My motor started life as a fuel injected 502mag, it is now a 509" with a side mount whipple(5lbs boost) and some mild head work. It makes 630hp @5200.
The side mount whipple computer is starting to get some age on it and has been phased out. My question is, would it be possible with aftermarket heads and maybe taking it to a 540" that I could keep my fuel injection and still make at least the 630hp(maybemore:cool-smiley-027:) without a supercharger?

Scott

Try Speedwake and ask "Noise Pollution" about that.....He did that exact build last winter and re-built it carb'ed this winter because of all the problems. (came close in power but not quite)

It has been done before. Im pretty sure the lower intake plentum is going to need some major work to get it there. Do a search on forums, oso member ARTIC FRIENDS made like 650 or so with a custom monoblade throttle body N.A. before he bolted on his blower. Why not go carb?

I am doing something similar to what you are doing and I am projecting to make well over 800 hp. It can be done, just need to open up the wallet wide !!!

I also have 2 Whipple computers for sale really cheap.

If you get to the point of purchasing the 540 kit, you may want to try www.dyno-flo.com. They gave me the best price on forged eagle stuff.

Thanks for all the input guys, I feel I've got one more summer left on my setup then I'm gonna build something new:cool-smiley-027:. Obsessed, not really against going carb I just kinda like the ease of fuel injection, as a matter of fact a buddy of mine with the same boat, is in the process of building a carbed 540 and thinks 650hp should be easy.
I guess if its built and tuned right a carb should be just as user freindly, I don't know a whole lot about carbs so thats kinda why I was shying from them. Sounds like ditching the efi is the way to go.
Scott

Scott,
Its all a matter of preferance in my opinion. I had the same motor as you in my boat, no super charger. When it was time to upgrade I was all over the place on what to do. I ended up swapping over to carb mainly for tuning and $ reasons. I didnt want to be at the mercy of others to get things done(programming ecu), and uprading the fuel system and intake porting was big $, in my eyes. Good luck!!!

For Dyno numbers on a naturally aspirated 540 with all accessories see the thread titled "Thanyou RM Builder"

Chris

Obsessed you are right on with being dependant on other people. I think I'm gonna start trying to put something together after the Emerald Coast poker run. The blower surge is killer around the dock, when the wind is blowing and I've got to go in and out of gear alot is when it gets nasty. Thanks for all the suggestions

went that route last year.
540ci ,630lbs trouqe, around 600+ hp. Ran ok but not completetly happy with the tune. If you buy a program to due the tunning yourself, thats the only way to do it. The intake has to be machined. I went carbed this year. A whole lot easier to tune. first 2 Pic 's of machine work I did to the intake.
3rd pic is this year.
The Fuel Injection thing can be done, but
Big $$$$$$$ question, How much time and money do you want to spend

naturally aspirated power
 

i have a n/a 509ci in my baja and it makes 612hp with a rather small cam,cant see why you would need the charger to make that much horse,it must be cool with the charger though.

I tried and spent too many $ on trying to dial in the fuel injection. Finally, 540s and 1050s, a good combo.

650 hp with a 509 = 1.27 hp per CI
650 hp with a 540 = 1.20 hp per CI
800 hp with a 509 = 1.57 hp per CI
It shouldn't be that hard to get those # out of a BBC
at 1.5 HP per CI it gets a lot more costly,but it is good reliable power. just takes real good heads and about 11.0:1 pistons,
and lots of money on the internals.

To be honest, My motor just runs better on the carb. Better mid range. It was way fat at an idle before. The big problem with the 502 mpi injection, the throttle body and the intake really dosen't flow enough air. Thats why I did all the machine work on the intake. It helps.

ak, the motor was built by the guy I bought the boat from. I think it was built more for standing up to the charger, than for building big power.
The blower whine is pretty sweet at about 5200rpm but the surge at idle and around the dock is starting to get old:cool-smiley-011:
Noise, mine is still fat at idle and a little at takeoff. Mark at Precision Marine is doing everything he can to get it right and they are top notch at what they do, he told me the side mounts are just tough to get right. Looks like he's gonna be building me a carb motor next winter:drink:. By the way nice pic of the bilge looks good:D
Scott

Thanks Scott
Mark at Precision Marine did my tunning on the ecu. He is a great guy to work with. As far as the air/fuel ratio it was close. A little lean on the mid range. Its hard for anybody to tune something when they don't have the motor. He was very willing to work with me. I didn't feel like sending it back any more.

I am talking with MR HORSEPOWER ordering some new parts my old set up was 650hp 637tq with a 850 bg, then went to a 1050dom and picked up 20hp from nickerson that got stolen so, after talking to DEAN GELLNER MR H we will change some other stuff to next month and might get 750hp he was saying just how much coin I will have next month.:D

that power level is obtainable w/o the blower, but I would not consider it a great marine package as you are going to have to step it up quite a bit and will not be very user friendly...Rob

My naturally aspirated 540 is about as user friendly/simple, and reliable as you can get.

660hp / 660 tq .. Carburated ... easy

Chris

I spent alot of time dynoing my 540 last year,I made 657 hp at 5400 and 665 ft lbs tq at 4800 using a ported 2000 502 mpi lower,stock upper plenum and a bored out throttle body on Crocketts dyno with CMI headers with the blower belt OFF. Keep in mind my motor is built to run as a blower motor so it only had 8-1 compression and a cam ground for max power running my blower too so it would have had a little more tq and probably a few more hp. My boat (272 Baja) runs 76 mph with a 26 pitch labbed 4 blade with this set-up,my drive has a nose cone and hd xr internals plus upgrades for when I'm running faster with the blower so there might be a mph or 2 gain in speed if I had a std drive. For reference My boat ran 62 mph years ago with the stock 502 mpi. I searched high and low trying to find someone to bore out the throttle body,I now have a source if you need it done,Smitty

mine is user friendly since 2000 its been pushing 650hp, I WILL CHANGE MY CAM AGAIN AND INTAKE CARB, should be about the 750hp its lumpy at idle with the 114 center its idle was 600 to700 it will be under 1000 with the new cam just alittle lumpier:p:D. I have only about 50 hours on it my bodys been broken for the last few years. but hope to be out running in july and save racing for next year. art