Choosing KA manifold

[elpiar]

I'm in the process of choosing a turbo manifold for my KAT project. One of the candidate is JGS manifold. What is your opinion on what he wrote in the website describing the manifold design:

http://www.jgstools.com/turbo/index2.html

"Don't believe the hype, our basic manifolds work very well and will provide better response and spool up than larger header style turbo manifolds. Spool up and response is all about volume, higher volume manifolds take longer to build the pressures needed to build boost at lower RPMs (when compared to smaller volume manifolds). Think about trying to fill a bucket with a hole in the bottom and to spool the turbo you will need to fill it to the top. The larger the bucket, the more water flow (AKA RPM) will be needed. Also the bigger the hole in the bottom (the hole in the bottom represents the turbo), the more water flow will be needed. Any header style manifolds will increase volume therefore increasing the boost threshold point (AKA spool up). Combining the pulses at the turbine does make an increase in efficiency but its made at the cost of spool up (there are no free lunches). But if its efficiency your after its always an option to run a larger more efficient turbo and still maintain the spool up of a smaller turbo on a larger more efficient manifold. We aren't saying the basic turbo manifold doesn't have its down-falls but for the majority of people looking to make 300-530 WHP, it fits the job and the budget very well. And as many have said "its all in the curve"."

KA-T gurus, How accurate is the statement above?

Does anyone had any experience with the JGS manifold? Dyno curve? opinion on spool? top end power?

Would ETD racing manifold be better design because of the directional runner?

http://www.etdracing.com/ka24.html

[elpiar]

anyone?

[silnismo]

http://www.ka-t.org/forums/viewtopic.php?t=19185

There you go.

[elpiar]

THanks!any experience with ETD racing manifold?

[98koukile]

Looks cheaply made IMHO, like why not do a log manifold if your just going to half *** the middle runners anyways?

[frsh13]

I just saw this.... maybe a little above your budget

zerothread/250010

[WDRacing]

The JGS is a good manifold. It's not the greatest for breaking 450WHP but it's very good for the money.

WD

[elpiar]

Does anyone has a good semi-scientific article on any turbo manifold design (not only nissan's)?

I want to educate myself deeper in this area.

[Swedish Mike]

JGS will work fine, old and proven design (most stock turbo cars use it).The only boring thing about it is the steel, I like stainless better because of the rust thing...

[nissanfanatic]

Does anyone has a good semi-scientific article on any turbo manifold design (not only nissan's)?

I want to educate myself deeper in this area.

It works under all the theories of thermal dynamics and fluid dynamics. Minimal bends, large radius bends if possible, and smooth merge collectors. You want all the runners to merge into the collector at a minimal angle, hence why all the full race and good manifolds have the crazy bends. They are large radius, so flow is not affected very much. But where the collector is, the runners are coming straight at it.

The next thing to consider is for your power level, you want to factor in the size of your wastegate and the size of your turbine flange. Find the area of both, combine, and then use reverse equation for the area of a circle to find out what diameter pipe would be the same size as the turbine and wastegate openings combined. Then you can calculate flow velocity and ensure it is not exceeding 300ft/sec which is the point where gas will experience drag and be a restriction.

I have already done the T3 38mm equation and it will support up to around my power level before it becomes a restriction. I think I am a little over. So 400whp is a safe assumption.

Also study the helmholtz theories on frequency and fluid to determine how long each runner should be if you really want to go in depth to power production at a specific RPM. I would include proper diameter, but you are really limited on that due to selection, so you would use a set diameter of usually 1.5" and then adjust length. From the sounds of it, you want a pre-made manifold. Any of the common "baller" manifolds will work(Full race, GroundZero, peakboost, ect).

[WDRacing]

Does anyone has a good semi-scientific article on any turbo manifold design (not only nissan's)?

I want to educate myself deeper in this area.

Grab Corky Bells Maximum Boost. Simply a must read for everything turbo related.

[nissanfanatic]

I still haven't read that book.. I never got around to buying it or borrowing it. hehe

[Edub1]

I'm wondering if the two pipes that come of the stock mani could be fitted with 2 180* bends and brought up to a flange in the middle of the manifold. I'm talking E motor of course. For a cheap DE mani I'd go SSautocrap even though I hate them like poison.