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Discussion Starter #1
So right now I have a spoolin performance mini ram manifold and I have the chance to get a nice equal length ram horn manifold in a trade (fabricated one and not an ebay special). I am still assembling the motor and turbo setup so it would not be much extra work in terms of fabrication to swap to the full ram for me. I am mainly trying to find out what if any gains (outside of looks) that the full ram will give me. Car is also a street car and not a race car.
 

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Yes there are real gains in peak power vs spool time. There was a video someone posted some time ago where a shop strapped a car to a dyno and did some testing for cast vs log vs mini ram vs ram ... and that was the only thing they swapped on the car. I'll have to see if I can find the video again, but there were noticeable gains IIRC. If it's a street car and you aren't worried about peak numbers I'd stick with the mini-ram personally.

EDIT: My bad it was a ramhorn vs a log.

Here's the video.

And this thread has some good manifold design theory.
 

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Discussion Starter #3
The motor right now with the mini ram will make over 400whp easy and most of the time when just cruzing around I will keep the boost down and be closer to 325 whp - turbo is a gt3076r. The spool time would interest me though...assuming that a full ram will spool quicker?
 

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^ Right?

Just read the link, holly hell, for all you n00bs, go see who Pat is/was/will always be remembered, and get to know some of our OG's seems like almost all of them popped up in there..

/thread
 

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Classic Man
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Ok so here is the things to consider (give or take) on manifold design.

You need a good collector. So logs and most cast go out the window.

Next you need to decide something. Whats more important? Top end power or a very marginally quicker spool time and less top end power?

Generally, the higher RPM you need your power the longer the runners of the manifold should be. Longer runners helps avoid cylinder cross contamination but also allows for loss of energy from the gas pulses that actually drive the turbine. So its always a trade off.

So in a nut shell, both mini ram and ram horn are pretty decent designs. Both have a runner for each cylinder, both have a nice 4-1 collector to direct energy at the turbine. The ram horn has longer runners and will have less cross contamination. The mini ram has shorter runners, will deliver a bit more energy to the turbine quicker and spool up a bit quicker, but suffer from greater amounts of cross contamination which will hurt you at the top.


So there it is in a nut shell. Always a trade off, never a clear answer.
 

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Classic Man
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So what would be the benefit of running a top mount over a ram manifold?
You are going to answer this yourself, so play along. :)



What is the main difference between a top mount, and a ram horn? Other than the shape of course. Think about runner length here....
 

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I can honestly say on a street car my cheapo ebay cast was better than my miniram and my miniram was better than my ramhorn. I have a ramhorn now and its great for top end power because it just keeps making power as you go up. But the spool was alot quicker on the log and on a d16 that i only rev to 8000rpm, I want as much spool as I can get in the lower rpm range.
 

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I can honestly say on a street car my cheapo ebay cast was better than my miniram and my miniram was better than my ramhorn. I have a ramhorn now and its great for top end power because it just keeps making power as you go up. But the spool was alot quicker on the log and on a d16 that i only rev to 8000rpm, I want as much spool as I can get in the lower rpm range.
Did the cast manifold hold the power through all gears to redline?

Did you use the same DP for all 3 manifolds?
 

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The Great Weldini
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you know FarmerD, people are always looking for the magic bullet the fountain of youth. what they tend to forget is that regardless what you do in life there'a always a reaction for you action with a consequences. there's a saying i always say that my friends and family hate: "the right thing isn't always the right thing to do." what people always say is that makes no sense but it does if you pay attention. just cause some is right "for you" it will always impact "friends and family" negative. the same way in building a engine. so in turn you and i can have the same identical build but due to temperature and evaluation in where we live our build will not be the same; even if we live on the same block.

so this will be the on going question/s which will always be better?

Full Ram vs Mini Ram?
4-1 header vs 4-2-1 header?
equal length header vs short header?
sequential firing orders vs non-sequential firing order?

and so forth on. the answer here is very simple build a engine and start with a base or a foundation. then add and take away a piece at a time and create a diary of everything you've done and doing. i learned this from Steve(BigTuna) but the problem here it take alot of time, patience and most of all money. we Americans want instant result and gratification so we will always be on these damd boards asking how much powa do i get with a chink powa turbo of if i buy a ebay log manifold? you've failed already. a true build has nothing to do with the top name brand or cheapo shit but more a compilation of time, patience and the right combination of parts and tweeking, to make all those parts to work together. i know from experience. i've blew my motor three time till i figure out what was the problem cause the same thing kept happening. yes it was $3k later but i don't care cause i did everything right it was just one piece that kept failing and when i found out i thought it was the best product but it was garbage.

so pick one and build. you have to start something in order to learn.

without risk, there is no reward,
and without failure, no learning. - T.S.Elliot
 

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^ That being said ... there is nothing wrong with asking for advice or figuring out the effect something will have on your build. Real numbers aside certain things will always have a certain effect, such is the case with a 4-2-1 vs a 4-1 they will shift your power band in different directions. How much it is shifted and the actual power it makes will be based of a large number of incalculable variables but the general principle will always remain. That's why I come to the forums and seeing the scientific approach some people here take to their builds and lines of questioning I believe that is why many people are here.

Personally I don't want a number. I have my own set of goals, and there is such a vast knowledge base here that it would be ungodly stupid not to tap into it. Sure I could buy parts and throw them at my motor until something worked, but why ... when I have access to so much helpful information. Even if it's something as simple as ... will this turbo get me where I'm shooting? It's worth it to ask that question instead of buy five different turbos to get to the power band you are looking for.

It's okay to learn from other people's mistakes too.
 

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So what would be the benefit of running a top mount over a ram manifold?
I'll play... nothing performance wise!
Just mainly for looks and easy access to the turbocharger.

Every car I've seen with a top mount tends to be either a laggy street car or drag car. Pick your poison.
 

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MuthaFuckaUppa
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I don't think my manifold was laggy, but then again I have never compared it to another one. Small turbo on a top mount with some what small primaries, a nice 4-1 collector. I am sure the few coats of ceramic paint and heat wrap helped with the spool. I believe my runners were 28" long, and each one was with in 5% of each other.
I take a few things into consideration on a turbo manifold. Equal length runners, primary diameter, collector shape, and scavenging.
Runner length is not as critical to me as efficiently flowing exhaust.

Spool time is often used in correctly. My set up did not make "full" boost until about 3800 rpm, however the turbo started "spooling" around 2600 rpm. If you look at the torque curve you can see how the air flow made power. The torque tapers off in the higher rpms do to the turbo not being large enough to flow the air needed to continue making power. I wish they would have taken the engine speed down a little more on the dyno before starting.

TD04L WRX at 16 psi, homemade top mount, 2-1/2" exhaust with no cat, resonator, and chambered muffler.

I would go with a full ram over a mini ram, and never use a log.
 

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I don't think my manifold was laggy, but then again I have never compared it to another one. Small turbo on a top mount with some what small primaries, a nice 4-1 collector. I am sure the few coats of ceramic paint and heat wrap helped with the spool. I believe my runners were 28" long, and each one was with in 5% of each other.
I take a few things into consideration on a turbo manifold. Equal length runners, primary diameter, collector shape, and scavenging.
Runner length is not as critical to me as efficiently flowing exhaust.

Spool time is often used in correctly. My set up did not make "full" boost until about 3800 rpm, however the turbo started "spooling" around 2600 rpm. If you look at the torque curve you can see how the air flow made power. The torque tapers off in the higher rpms do to the turbo not being large enough to flow the air needed to continue making power. I wish they would have taken the engine speed down a little more on the dyno before starting.

TD04L WRX at 16 psi, homemade top mount, 2-1/2" exhaust with no cat, resonator, and chambered muffler.

I would go with a full ram over a mini ram, and never use a log.
Damn ... looks like about 130 wtq @ 3250 ... that looks like fun. Full boost by X RPM is not as important as the power band one is looking for. I think manifold design is more important when you get into higher numbers and racing, not nearly as much on the street. For the street I'd go with whatever form factor fits your needs/space confinements/looks best to you.

I think my new manifold is going to be a miniram ish type manifold, by the looks of the other ones I've seen lying around the shop. I think that has more to do with pairing the runners properly ... mmmmm twin scroll.

Side note I totally agree that many people think about spool time a little off, using when a turbo reaches full boost as opposed to when it starts spooling. My old setup looked a lot like your dyno, just slightly lower numbers. TD04HL-13c on a cast manifold, almost identical exhaust. Thing started spooling just under 3k (full boost, 14 psi, by 3.6 - 4K) ... 120ish wtq by 3k.
 

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Classic Man
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I think manifold design is more important when you get into higher numbers and racing, not nearly as much on the street.
Not really. A proper street power band should be way different than a race car. Manifold design can be adjusted to move that torque where you need it.
 
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