Nagase

iTrader: (6)

In wanting to push a given turbo to the greatest power, would a ramhorn manifold (assuming well made, I'd been wanting ARTech) make more or less power than an Absurdflow low mount?

I'd been operating on the assumption that nothing beat an equal length ramhorn for strictly maximum power potential, but in doing searches I read that the ramhorn was put down the list, and under the low mount. I'm at a bit of a loss as to why.

Could anyone shine light on this?

Savington

iTrader: (31)

Theoretically, yeah, but nobody's ever done the back-to-back on it. I might get to it this year if I decide to swap manifolds.

bbundy

Some observations

If you look at most any seriously fast professionally done import turbo drag motor they are all long runner equal length jobs. I suspect some of those guys know what makes the most power.

What is also interesting is if you look at any WRC cars by teams with million dollar budgets that hav to run a serious intake restrictor limiting top end power thus making low end torque and turbo response the most important thing they are trying to gain they are also long equal length turbo manifolds that look more like a full header with a turbo stuck on the back.

Bob

Faeflora

iTrader: (2)

Twinscroll manifold and twinscroll turbine housing for super mostest power.

miatamike203

Equal length twin scroll will make the most power out of your turbo. Doing twin scroll lets you run a bigger A/R with killing spool. This will allow you to flow more air then your comp wheel would ever flow.

Nagase

iTrader: (6)

Awesome, but not what I'm asking.

Faeflora

iTrader: (2)

OK fine I answer the question.

No, I would not think that low mount beats ramhorn/long tube for peak power potential.

BUT low mount has kind of mid-length runners, and the runner merge area is not at 90 frikken degrees like a log. So I think that for overall driving a low mount should have better spool and power under the curve than a ramhorn. Prob better for daily driving and shiz.

If however you are spinning your motor to 8500 RPM like a boss, I think there's probably a strong case for long runner.

Savington, if you get a ramhorn from Abe, are you going to increase your redline?

kotomile

iTrader: (24)

Would be interesting to see a back-to-back.

I like the ABSURDflow if for no other reason than its packaging, sturdiness, and simplicity. Seen only two in person and they both looked damned solid.

IHI

How does the BeGi S4 fit in this story?
That is equal length, isn't it?
I prefer to talk about max torque over a wide RPM range as it is giving more the a big peak in a small RPM range. There are a lot of tuners claiming +500 hp and I do beleve them. When viewing dyno charts you see the 500 hp can't be used in a normal way as it just there at redline and under 5500 rpm or so it is doing worse than a well balanced performance engine.
The same thing for comparision: I drove an old Alfa 75 1.8T. At 3000 rpm boost kicked in, causing the car going sideways and left me with hell of an impression. Wow, that car was superfast! While... It wasn't. Drove the same car with a GT2860 instead of a T3 and it felt quick bit did not kick *** as the T3. Well.. It beated the T3 in every way. But the torque came so smooth that it felt smooth. It did not lose traction, it just went forward very fast. It is not just BHP's that count. It's how they are developped.

Dyno's should have some average function build in. They should not just give peak BHP but it should be measured over the whole RPM range.

shlammed

iTrader: (8)

Whatever doesn't choke you up top will make the most power.
So if there are no limits in the turbo manifold for restrictions you will not be lacing that out

18psi

iTrader: (76)

You guys are going way off topic.
We all know about the curve argument. OP asked about maximum power.

All the f/i big dogs in the drag racing world use ridiculously long equal length runners. It has been proven time and time again that it nets the most power on other cars. I don't see any reason for that not to be true on a miata.

Though since our heads flow so horribly it might not be as beneficial to use that concept on our cars unless ported+good im+cammed/etc.

miatamike203

18psi has a good point there, this is why i think a twin scroll will get you the most whp and wtq.

Nagase

iTrader: (6)

Guys guys, I know what the F1/WRC/Drag racing guys do. That's why the absurdflow lowmount being put higher than the ramhorn confused me:

https://www.miataturbo.net/showpost....9&postcount=11

That's what I'm talking about.

1slowna

iTrader: (1)

In terms of max power and spool time a long runner equal length manifold is the best bet. The argument i always see against this is that theres more volume to fill before the gases hit the turbo so it takes longer but this is ridiculous statement because the manifold is already "primed" so to speak with exhaust gases before you even hit the throttle. also if this theory were true rear mount turbo kits would be absolutely worthless on all cars and i have seen first hand how well a rear mount kit can preform.
http://i89.photobucket.com/albums/k2...301/BMW_02.jpg
i am pretty sure bmw knew what would make the best power and the best low end torque when they built this manifold for their 1980s 4cyl f1 engine. that engine made over 1000hp at 2.0l displacement on 74 psi during qualifying, and thats with older turbo technology then we have today.

JasonC SBB

Any PS and AC friendly versions yet?

bbundy

I will say I have seen a lot of longer runner manifolds that I think used too big of tubing. I think you loose more energy expanding the flow and slowing it down into a large runner and then compressing it and accelerating it through the turbo than you do if you make runner cross section area closer to the area of a gasket match or slightly smaller so you keep more constant velocity between the head and the turbo inlet. Your likely to disturb smooth flow as well. Miata exhaust ports aren't that big.

Bob

bbundy

Hooking the manifold up to a blower and blowing constant velocity air through it and measuring flow resistance is not quite the same as hooking it up to an engine with periodic flow pulses phased across different runners and having the presence of reflecting waves.

Bob

TurboTim

iTrader: (9)

I am not sure why Savington would get a ramhorn from Abe/ARtech when he could get one from me for raw material cost. Then again Abe is more official/professional than I am at it and would be a better choice for production builds.

In an ideal world I/we would have back to back testing on runner lengths/designs and runner diameters but this ain't no ideal world and everyone will still have their own opinion on the matter. With zero actual real world experience to form my opinion, I think a short ram manifold would tend to be more durable for track usage and for most setups (stock-ish engine and small-ish turbo) perhaps more area under the curve (again, w/o actual data that's a guess). If doing a drag or rally car where you either have fancy antilag and/or running in a rpm small window I'd do with a longer tube/equal length jobbie. Or if you want to look cool with a maze of pipes under your hood.

I'd run a begi manifold. haha.

TurboTim

iTrader: (9)

Of which? where there's a will, there's a way.

musanovic

iTrader: (2)

I like the way you think