What should my car run?

[mdurbahn]

Ok since the nearest drag strip is a 4 hour drive and I haven't been able to take my car their yet maybe some of you guys could help me out on what I should expect when I get their.

Car:1967 Coronet R/T
Engine: 440, bored 30 over, KB pistons, adj rockers, edelbrock performer rpm cam, mildy ported 452's, performer rpm intake, 750 cfm old school carter
Ignition:Fbo dist. stage 2, ecu, and coil
Exhaust: Hooker Comp Headers and TTI 3" pipes
Tranny: 727 5.1 kickdown, shift kit, 2800-3200rpm stall
Gears: 3.91's

Car feels like it has alot of power but doesn't feel as quick as my turbo 2.2 I might add a 125shot of nos to fix that though. What should this run with good street tires?

[blownzoom440]

what compression,lift on the cam.off hand i would say mid 13's. when you comeup with some hp numbers you can use this. www.wallaceracing.com/Calculators.htm

[Don]

Nitrous??

You don't have the cam for nitrous, it will take twice as much juice to get you the same power you'd get if it had the correct exhaust port profile.

You have Hyperejectic Pistons, you can't run giggle juice with glass pistons you'll blow the top ring out of it or blow the piston up.

You'll probably blow it up by adding the juice.

You want it go quicker???

Put a Racer Brown Cam in it.
Get a real carburetor
Build a fuel system that can handle the power.

You've got lots of good stuff, it time to crank some tork into that baby!

[Alikazam]

Ummm, I hate to disagree, but you can run nitrous on Hypertuectic pistons. Just not a lot. a 75 to 100 hp shot should be alright. Do NOT attempt to shortcut the fuel system though like Don said. You have to be able to support the whole system, engine and nitrous. If it'll be around 500 hp, you'll need 50 gph @ 6-7 psi.

I'd check with NOS about proper cam specs, though with the fairly mild Edelbrock performer cam, you should be alright in that land. Mid 13's should be doable with the setup you already have. Your stall is a little high for the power range of that cam, but not terribly so. Good luck!

P.S. Don said I shouldn't run nitrous either, but I used to run a 50 shot on my cast pistons without problems on my 390 hp 360. I put forged in just recently so I could go up to 150.

[Don]

Nitrous Vs. Cam Vs. Pistons....together or enemy's?

Yes you can run nitrous on a Hyper-ejectic piston, but not for long and as long as their is no detonation the piston will live for awhile as long as the shot is small.

If your cam exhaust lobe profile is not designed for nitrous then it will work but you will need twice as much to get the same power, sorta like running alcohol.

Alikazam: Are saying that you can support a 500 HP engine on a 50 GPH Fuel Pump?

500 HP engine will burn about a minimum of .5 gallons of fuel on a pass, my 450-475 HP engine will burn .75 gallons on a pass but I burn some on the return road so just use .5 gallons in 11 seconds and now coonvert that to an hour.....2.7 gallons per minute x 60 minutes=160 GPH at pressure of 6.5 to 7.5 depending on the carb.

Now factor in the gear ratio in 1st and 2nd of 2.45 and 1.45 and add a bucket extra fuel for the mass consumption rate as you launch and you'll easily be able to see that a 500 HP engine will need a minimum of a BG 220 pump for a well prepared race car.

The heavier the car the more fuel you'll need as you load the motor harder, the more RPM you spin the motor the more fuel you'll need.

Our 9 second Dart will burn 1 gallon of 110 fuel in 9.8 seconds it gets about 4 passes out of a 5 gallon jug.....we run a BG 400. This year on alcohol we'll run very close to the 9.2 and we'll burn close to 2 gallons of fuel in that 9.2 seconds at about 12-15#s of pressure, is our pump big enough?

The rule for fuel requirement:

13 sec. car 1 gallon in 35 seconds
12 sec. car 30 seconds
11 sec. car 25 seconds
10 sec. car 20 seconds
9 sec. car 15 seconds
8 second car 10 seconds

A good stock pump (not some Chinese copy) will flow at about 70 GPH if you do the math you'll see that it will pump a gallon of fuel in about a minute, they max out at about 4500 RPM and start to drop off if you run them any higher.

A Carter Hi Flow 120 GPH mechanical really doesn't flow 120GPH they actually flow about 100 if its a good one, we port them out, clean up the chambers and open up the inlet and outlets to improve them to about 116 but thats about all your going to get out of them, they will however go to 6000 RPM before you see any drop off. Do the math and you'll see that one of these will support a high 12 second car just barely and without the port work only a 13 second car.

There's lots of things "you can do"
....are they right?...No

In my opinion...If it says Edelbrock it probably needs to be thrown away, there is nothing in their catalog that I would use with the exception of their manifolds (after about 10 hours of re-working them).

[Alikazam]

It needs to be able to feed at least 50 gph @ the pressure required, to be considered "safe" for use with nitrous for the total amount of horsepower being produced is all. Other than that, that's all I'm sayin as far as fuel is concerned.

Your method of "fuel needs" is very good as well and is right out of the BG book, and those guys are very good too. Fuel systems are, if anything, one of the places people should over build. In my case, I run a Carter 120gph mechanical for my 390 hp 360 for the carb, and a completely separate Holley blue pump on a 1/2 inch fuel line to feed my nitrous system. Sure the blue pump could probably feed both the nitrous and engine, but why when the mechanical is up to the job? On a dyno, my carb's fuel pressure drops to around 1.5 psi @ WOT near 6000 rpm (I shift at 5800). I put in all sorts of toys and tried to see if the carter was up to the task of both but it couldn't hold pressure to the nitrous sytem by itself even though holley gives you a T connection to splice into your fuel line. It just needs its own dedicated system if you want to run a mechanical for the engine, or a really good electric for both (like the BG220 or up).

I may disagree with you on certain fine points Don, but I don't think I'd ever say you steered someone wrong . Congrats on the updated website btw.

[Don]

A 120 mechanical should be able to support a 400 HP engine, after that a good electric pump should definatly be a consideration.

Yes the nitrous should have it's own dedicated system thats a good decision you made to use the Blue pump to feed the giggle juice. In my opinion the Holley Blue could never supply your engine and the Nitrous, I know some bike racers that use a Blue for both, 200 HP on a 4 cylinder pushing a 400# vehicle.

Fuel pressure is only a measurement of fuel restriction and although you may have 6 psi you can still be out of fuel and conversly if you have 1.5 psi you could actually have enough fuel.

The higher pressure allows the fuel delivery system to react quicker to demand and force more fuel through the N/Seat. This is why we always design a fuel system with smaller lines after each restriction point, 10 to pump, 8 to reg and 6 to carb for example.

The dyno is only one tool in an arsenal we have in our war chest. We don't drive dyno's and it's common to tune an engine on a dyno and once you get it bolted between the fenders it's undrivable or a poor performer. It will still need a good tuner at the track to get the most out of it.

The pump your referring to can be improved, we open them up and clean the casting slag from the reservoirs, open up the inlet and outlet holes and get them to flow about 10% more than they do out of the box. I'll bet with those mods that pump pressure will jump to about 2-3 psi.

One issue with the dyno is they don't simulate the G forces working on the fuel in the line pushing the fuel back to the tank and starving the pump inlet in 1st and even 2nd gear. This causes the pump to cavitate and foam the fuel in the chambers, this foamed fuel is then compressable unlike a liquid and drops off the fuel presure and fuel volume drastically. We like to see at least 4.5 psi on a mecahnical pump just to ensure that we have adaquate fuel delivery to the carb and the bowls aren't running dry.

If you look at the design of the metering block you'll see several bleeds in it , those bleeds need to be submersed in fuel in order for the carb to properly meter the demand. If the float level drops below the bleeds the carb will show a drop on the fuel curve. It may not show any signs of leaning on the plugs as the pump catches up as the G forces drop and the rate of RPM increase demishes in high gear, you still hurt your time slip and a ample fuel supply will usually increase the MPH.

A WEGO A/F guage will show this as it records the info through the entire pass and the drops in the A/F ratio are obvious on the graph.

We vary in opinions on some things but we're more all out performance orientated here whereas you like the street strip program, there's always compromises to be made when you try and accomplish both.

Your Van is awesome and that motor is one of the nicest builds and installs I've seen in a long time, you do good work my friend. If all my customers were as knowledgable and dedicated to there Mopars as you my job would be easy, but then again if it was easy everyone would be doing it.