HPJunkie

bobl,
I have a 502 mag thats been balanced and blueprinted, Have the brodix bb2 plus and a 741 roller cam. Im running a Nickerson carb and am happy with the top end but there some issues at idle and some midrange inconsistancies. Thats the reason for the EFI thoughts. Do you have the 502 efi intake with the side mounted throttle body? I have some reservations on that lower intake. How much did extrude hone charge you. Like you I spend most time under 4000 rpm also. Im only at 5-6k for short bursts. I cant go 90 plus for long on my boat. It would be built for drag racing. Did that 2000cfm throttle body come from AZM ? Did it fit the manifold without mods. How big were your injectors? Greg

GLH

LOL

Was the reason Hiroshima!

tomcat

Hi Greg:

I think that manifold was designed originally by Lingenfelter to develop low end torque especially for use with the Blackhawk drive which needed the help with two big surface piercing props below water at low speeds. Other than the throttle body orientation the MPI and HP500EFI are similar and make similar power all things being equal.

I'm biased of course, but for that kind of HP I would use an aftermarket EFI based on a single plane intake and FAST ECU. I'd get help from jspeeddemon and others on programming. There was some talk about an intercooler/carb box that would work with this layout.

HPJunkie

Tom who was talking about that? We could cut the top in half.........and then......... HaHa. No really I was trying to think in tomcat terms as far as that goes. The real deal is that I have one of those and it has the injector rail and all and I wouldnt have to buy a manifold or throttle body, but I could start to learn about the EFI stuff before spending more cash. Greg

bobl

HPjunkie, it's the sidemount whipple kit, with their 2k throttle body. It uses the stock 42 lb. injectors, with a piggyback ECU and 2 injectors in the throttle body. Whipple has since done away with this setup and gone to the top mount with larger injectors. My customer had the extrude hone done previously so I don't know exactly what he paid. I think around $400. He originally had added the BB1(rectangle) heads, small cam, intake work, stainless marine exhaust and reprogram. He gained about 7 MPH and was not happy with the results, so we went back and added the Whipple....he's happy now!


Bob

Whipple Charged

Can it be done, yes, but it's not really easy or cheap. First, you need to send the intake to Az. speed and extrude it, cut the runners. Second, 42 or 50lb injectors will not be enough, even at 80lbs of fuel psi, 1000hp is out of reach. I have some 65lb'ers which are the biggest available in a high impedence. With these, you'll still be hard pressed. You could put 2 more 65lbers up stream if you have to run the MEFI ECU. So, you can go with 8 96'lbers if you run a FAST or Accel DFI system but then your fuel rail will need to be modified or replaced. Third, your gonna need a big intercooler and big centrifugal SC, probably need 11-12lbs of boost with some really good aluminum heads, 540ci, big cam. A turbo would make it easier, probably would only need 9-10lbs with all the good parts. We don't have a SC that can mount sideways that will flow enough air for 1000hp.
Dustin

HPJunkie

Dustin are you saying that I would need 96lb injectors for 1000HP? I figured 72 but someone mentioned that since there is horsepower loss due to belt drive I needed to support 1200 hp and he/ they recommended 83 lb injectors. At 83 or 96 can they idle ok? Another person suggested that I should run 2 sets($)!? 1 for idle and the other for top end augmentation. I am currently running a procharger M-1 that I picked up on the board with a blow thru Nickerson. I am interested in learning about efi and have this manifold and machine shop service handy. Now I can only make 7 psi in the intake below the carb at 6000rpm without over speeding the blower, so I know Illl need a bigger blower but was hoping to not have to spring for a throttle bodie and intake as well as the computer and complete fuel system all at once. But if it won't idle steady and the fuel rail won't work or be too restrictive at 6000 vs my carb then maybe Ill pass. Even with a strip dominator with a 2000 cfm 4 barrel style throttle I am concerned about the big injectors not working right. I like the profile of the blow thru it fools a lot of people with a stock sun hatch. I also have a connection for 2 turbos. Whew thats a lot to say what do you think

HPJunkie

Dustin, I'm sorry but I emailed you last night before you replied here about the 2000 cfm throttle body. Thanks for you help. Greg Maurer

jspeeddemon

Greg I have been reading your post and you have received some excellent input. Holley makes a manifold that already has the cast in injector bungs, with a 4150 flange, Probe industries makes a throttle body, to mount your throttle body to, and I concur that you need at least 83 lb injectors and really probably should go with 95's. I have this setup on a M-4 with 12 lbs of boost and it is definitely a powerhouse. I can't see why a 502 cubic inches would be that much different, but the reliability would be a significant concern at this power level, related to crank, rods, and pistons. your margin for error, ie:lean, detonation, would be very tight. I will give you more details if you like. I run the FAST computer on mine, very user friendly.

HPJunkie

Jspeed,
Thanks, how many cubes are you running and what horse do you estimate? I'm concerned about getting a good map going before melting down. Can those maps be shared like on a cd or floppy? Are you running a wide band O2? Does probe have a website? Are you sequential or batch? How do you idle with 83 # injectors? thanks for the reply Greg