Aren't you going big cubes on an LSx block? With the money that your spending and the amount of torque your going to have, I would try out the vic. It is definitely geared toward mid-top end performance though. For all around drivability, the Fast would probably be tough to beat but I highly doubt it pulls as hard on top. I don't really think the elbow is a big deal, you would probably have access to alot more info on them over on tech.

In all honesty, I think your traveling into virgin territory to an extent with your build and don't think many on here will have any first hand input on what your asking. Sure, others have done it but very few. I certainly have no experience with the vic intake but I want to run one on a radical build in the future. Tech is probably where your going to get the best info on this question in general.

 

i think someone need to be a test dummy on this topic and see what works best! i wanna go with a LSXRT on my build im starting but it will be a couple months before thats all said and done.

 

I've played with the idea of doing a intake manifold shootout. Similar to what I did with my talon a few years back.

I'd love to test:

My stock NBS intake w/78TB
NNBS intake /87mm TB.
LSXRT w/ 87 TB again
Elderbrock Pro Flow w/87TB


I'd likely buy a Pro-Flow for myself to keep, but i'd need the others sent to me for testing. I will also cover the cost of the dyno time, labor. But what has to happen is willing forum members step up and send me their manifold with a expected 1 week turn around.

The basics for the test would be the same as I did with my old turbo eagle talon cam shootout. Timing stays the same (very safe side, as no knock for any tests) Fuel stays the same, Boost is only adjusted to keep boost the same for all test. Example, if new manifolds lowers boost after swapping, it is flowing more and making more power, but needs to be raised to the same level of "restriction" aka boost to see the power gains.

Need input on this, but I was thinking a even 15psi for all tests and 2500-7000RPMS.

This is an example of the dyno graphs of big cam shootout I did a few years back. Same boost level, different cams.

Tested some tops names of that time:
GSC Motorsports (this company let me keep their cams, as they said if I did the test it would beat any others on the market..they were right!)
HKS
Bryan Crower
ForcedPerformance

 

only if i had one... i'd like to see these results for sure! hopefully someone can step up too the plate.

 

Is the Holley Modular Hi Ram available for cathedrol port heads?

 

I heard on another forum from a guy at holley that they are almost ready on cathedral port & Ls7.

If you download the instruction sheet from holley website you find the parts numbers are already out

 

Foose, I would be willing to send you my NNBS intake depending on how soon you want to do this. I've been tossing around either throwing it on or buying the pro flow for myself. I would say no more than 15psi because there is a lot of us only running 10psi or less

 

10-12 would be a good baseline for a test.

 

Foose, I dont think you should raise the boost to equivalent levels. What you really want to test is how well the intake flows air...which means the mass flow rate (governed by the compressor wheel rpm) needs to remain constant. So if one intake has "less boost" than another at identical boost controller settings, then it is therefor flowing air more easily and is a better intake. By raising the boost it will skew the results even more in favor of the "best" intake.

A better test would be to do a low rpm, 3rd gear, locked converter pull to whatever you want. This will demonstrate the low-rpm characteristics of the intake which is very important for a street driven engine. Youre only interested in cathedral port intakes, right?

I personally went with a stock truck intake because I wanted low-rpm torque in my build, and not a high-rpm screamer.

 

Atomic, guys said the same thing about my cam test, but as you can see it works well keeping the level of back pressure (boost) the same. The manifolds that flow better will make more power at the same psi, that simple, and thats what most are looking for. If you want to then run less boost to have the same power or turn it up more and use that power is the builders choice.

If you don't add it back in its going to be very tough to see the gains, at that point all you have to graph is where boost was lost and at that point only guess how much power was to gain.

I think 10psi maybe a better base line as stated. Also a little easier on the test rig. I like to a couple pulls on each to get a good average to go from.

Alpinestar, I will keep you posted. If I can get another manifold to test, ill order the Pro-Flow and x-link adapter. I already have a 87 TB.

Atomic as far as low RPM locked pulls, it's hard to do without knock. I don't spend much time at 1500-2000 WOT tuning, as that never happens. Also to load base tune/dyno would require hours of dyno time to complete.