zayne0

as the title says. whats your experience? i am buidling a truck and am concerned with daily driver issues in the downlow rpm. i realize that single planes make there power mid and up high. but are they that bad with off idle power and torque? did you even notice a difference in a stop light to stop light hot rodding? i dont have anyone to go for a ride with to see for myself so im counting on you guys. thanks all!

.boB

iTrader: (1)

Historically, single planes don't do well for the street because they have a carb sitting on top of them. A carb needs to have a decent intake charge velocity to work well. That keeps the fuel atomized and in suspension throughout the intake track. You lose that with a single plane manifold. At lower velocities, the fuel will fall out of suspension and run across the floor of the intake track like a stream.

Multi-port EFI doesn't have that draw back. The fuel is injected just before the head intake port, and it comes out well atomized. Intake charge velocity becomes much less important with a dry manifold.

If you're using a central port injection - like MSD Atomic - then you're dealing with a wet intake manifold again. The injectors don't need a high velocity air charge to work correctly. But the manifold still does. At idle you'll be injecting a well atomized mixture but it can still fall out of suspension at low rpm's; just not as much as a carb will.

97WS6SCharged

iTrader: (1)

If you setup the motor around using a single plane efi manifold it should be fine. A single plane will want a different cam than a normal LS long runner manifold. Also with a truck you could use a 4bbl type throttle body instead of an elbow which would also help with low speed and throttle response.

That said, I've got no complaints on mine (other than gas mileage HA!). Pulls hard from any speed, runs 40 mph in 5th gear with factory 3.42s, gets tons of looks. Now it just needs some turbos to wake it up.

ls6jay

Need the right cam and lots of gear.

.boB

iTrader: (1)

That is an excellent power curve! The peak HP number doesn't mean much, but that flat torque "curve" is perfect.

Yes, and no. With port injection you can run a pretty radical cam, and it will still run well. At lower rpm's the EFI will compensate well enough to not be a problem. But at WOT it will scream like a banshee. Unless you're ridiculous about it and choose something like a sheet metal or a Victor intake.

I run a 427cube engine with a huge cam on an IR system with 52mm throttle bodies. The engine makes well over 600hp. In theory, that should never perform well at anything below 2,500-3,000 or so. Vacuum is very low in that range. But, it will idle very nicely at 850 rpm's, cruise all day at 1800-2000 rpm's, and get 20mpg doing it. Carbs could never do that.

The EFI system will use essentially the same components regardless of which IM you use. They don't really care what they're bolted to, as long as the principle is the same.

Of course, choosing the proper cam and matching components is always the key to getting the most out of your engine. I think choosing mismatched hardware and components is the main reason people are disappointed with their power production after the build is done.

ss performance

iTrader: (17)

I agree with what the other have said, the cam is very important.

Sometime a little power loss down low is not a bad think for a daily driver. You will be a little more docile at the lower rpm. Easier to control in low traction conditions.

Then when you tromp on it it will scream.

Good luck.

zayne0

thanks guys. i appreciate the input. to be specific about things the engine is an l31 vortec that i am converting over to be run off an ls1 computer. i am wanting to run rhs efi intake but i have no clue who to talk to on cam specifics. i will be turboing the engine after i have the fuel injection setup and tuned.

ss performance

iTrader: (17)

Give Martin@Tickperformance a call. They are a sponsor on here and he is good with cams, or Brian Tooley would be good as well.

I have dealt with both and they are good guys to work with.

Sales@Tick

iTrader: (3)

I like single plane manifolds. I feel that they offer more potential with the right combination.

That said, with the wrong combo they can be turds. Just like any other combination.

97WS6SCharged

iTrader: (1)

Thanks! Credit where it is due though. Martin is awesome to work with and knows his stuff. Now I just need to convince him to send me some turbos to test on it.