which one flows better... more specifically around 7000 RPMs on a 400sbc, does anyone have any experience with both???

 

LT-1 (it's has shorter runners).

 

If you're trying to turn a 400 to 7000rpms i assume you're shooting for some serious power?

In that event, don't look at either one of them. A converted carb style intake such as the accel pro-ram, or any other good single plane with injector bungs will outflow either one of them by far.

FYI, the stealth ram is maxed out at about a fel pro 1205 intake gasket IIRC. a 7000rpm 400 is going to have intake ports that could fit that whole gasket in it.

I'm not sure abot the LT1, maybe somebody who knows can chime in there. While there are some 9 second NA LT1s out there on stock intakes, it's not really the best intake to use to get there. In their case it's a use LT1 parts to get the LT1 record kind of thing. Again, i'm assuming you're planning on 600+ hp if you're turning it that high, thus the comparison to single digit LT1 cars.

edit, thought i'd add, the LT1 intake does have a handicap besides being a stock intake. Due to it's design, the front cylinders run leaner than the reas since they get the first shot at the intake charge. I bought the headers in my car off a 350rwhp miniram car and you could easily see the effects just look in the headers. The front cylinders were chalky white, the rears were carbon black. That effect will only get worse with more power. A converted single plane intake has no such problem. (and yes it is eerily similar to the old carb problem of inertia pushing fuel to the back cylinders on launch, but in port injection, that isn't what's happening

 

Ed, I believe you are right about how far you can hog out the LT1 intake (and many of the other intakes and bases).

The "basic" 1204 Miniram is very similar to the LT1. The basic Miniramcan be hogged to port match AFR 195s, but you are starting to get thin on the metal.

If you want to go SIGNIFICANTLY bigger with a Miniram to support a 7,000 rpm 400 SBC, you need to either: 1) have machine shop build up the ports and rework them or 2) get the BIG Miniram which go start at a 1206 (and can be hogged further). There is actually 3 sizes of Miniram (1204 - most common, 1205, and 1206).

Of course, I am not considering the Vortec.

 

i really haven't read anything about the mini ram, can you give me a link to a good site about it?

 

www.tpis.com
hope you're not scared to lay out some serious cash for an intake manifold. For around the same price you can go with ed's suggestion, for the same reason he gave. I have the lt1 intake on my 406, but not even close to enough cam to spin to 7000, so it's less of an issue. btw, i love it compared to my tpi.
oh, and it matches up quite nice to a 1205.

 

i have a big nasty turbo to put on it and dont wanna deal with the whole "blow through" conversion of the carb, also i simply want EFI even if i lose some ponies

 

ed, will it still have the problem with the air rushing to the front ports first if its boosted?

 

Actually, good thing you asked that question. The reverse happens under boost, air gets 'stacked' up against the back wall and the rear cylinders go lean.

Of course, if you're running some kind of SEFI computer, you can adjust the fuel; trim on the rear cylinders to make up for it. Or if you're sticking with a stock computer, there are aftermarket injector controllers that ride in series with the normal computer. These let you use low impedance injectors for really big flow rates, as well as add/subtract fuel relative to other cylinders.

But if you look at all the really fast boosted cars, they're all running converted single planes or sheetmetal intakes too. Better to just avoid the imbalance if you can.

 

click the green banner. then go to intake comparison to see some results between the HSR and the LT1 intake.

 

Nice pictures. Totally supports what i remembered about it being maxed out at a 1205 gasket. While yes you could weld some extra metal to "port match" it to the 1206, it doesn't change the fact that the runner itself is still smaller the rest of the way up. Port matching is overrated, the runner is what really matters.

 

agreed there.