The old cut up manifold into trumpets idea

[E92William]

Im now late lol but pretty sure It's this guy right here 13627547822, I would even consider used I don't think these fail at all. Small things one might forget when doing new stuff like this. Wonder where you'll figure out to place it. Really it doesn't matter much I'd think as long as it's near the runners, there's not much intake there to Heatsoak lol

[Dru128m]

Alright, IAT sensor finally arrived and is installed. Not sure that it's calibrated very well, reads about 20 degrees cooler than ambient, hopefully not a big issue. I was able to run the wires up to the big plastic wiring harness and drop the sensor down right in front of the trumpets. Moving forward from here, I hope.

[Dru128m]

Finally got a chance to data log a few runs with proper monitoring, and everything looks good so far. AFRs stayed rich as expected, still on the initial tune. Pulled strong to the top, really lights up around 4500 rpm. Sounds amazing at full tilt. Once I hear back from Bob I'll try get some sound recorded.

[Dru128m]

Tune revision #2. Now we're talking. All the right noises all the the way to 7700 rpm. Certainly picked up some power throughout the range, but above 3000 it's a new motor. I am not regretting this experiment. Even my wife likes it. So far I'm calling it a win.

[markslc1]

Originally Posted by Dru128m

Tune revision #2. Now we're talking. All the right noises all the the way to 7700 rpm. Certainly picked up some power throughout the range, but above 3000 it's a new motor. I am not regretting this experiment. Even my wife likes it. So far I'm calling it a win.

Originally Posted by Dru128m

Tune revision #2. Now we're talking. All the right noises all the the way to 7700 rpm. Certainly picked up some power throughout the range, but above 3000 it's a new motor. I am not regretting this experiment. Even my wife likes it. So far I'm calling it a win.

Interested in seeing a dyno and perhaps a diy year on this mod.

[E92William]

You should definitely record some videos of how it sounds at least inside the car. I love how ITB setups sound on inline 6s

[asbrr]

Any further thoughts on how you'd create an enclosure/plenum for the intake? Just to ensure cold air versus sucking in from the general engine bay?

[Dru128m]

The thought so far is no plenum. I may mount a plate to attach some filtration in a pipercross style. Temp management is gonna be handled by a ram intake coming from the bumper through the floor of a divider plate installed below the trumpets, and hood vents to let out the hot air. At least that's the tentative plans.

[Dru128m]

So I'm not really happy with any video or sound clips I've captured so far, but I feel I owe you guys something. This is the first startup after the headers, manifold, and tune installed. Once I can record more than wind noise I'll get you some WOT under load.

[b1aze]

Sounds like it would sound awesome on the street!!

Any chance you’ll put together a full DIY on sensor placement and other bits you had to do to get it there? Not sure id have the balls to do it to my daily driver but I’d think about it for sure

[Dru128m]

Yeah for sure. Once all the wrinkles are ironed out I'll throw a diy out there. I'd say we're still at the functional prototype stage. Maybe if it would warm up a little outside and quit snowing this would move a little faster.

[E92William]

I would just be wary of that open intake setup, a nice filter would cure it for me lol but I live in a very dusty area, I don't think it gets like that when it snows. If I was to do something like this Id make sure I have a brand new eccentric shaft sensor and valvetronic motor.

[Dru128m]

I have a filter that goes on it. I made one using the filter material we use at work for our turboblower, however it is rather hideous looking. I'm just saving you the nightmares, it's all for function right now. I just did the VCG not too long ago and condition of the sensor and valvetronic looked pristine. I was rather impressed by how good the head looked, cylinders compression tested great, that's when I figured I could go ahead with this idea.

[konner412]

Originally Posted by Dru128m

I have a filter that goes on it. I made one using the filter material we use at work for our turboblower, however it is rather hideous looking. I'm just saving you the nightmares, it's all for function right now. I just did the VCG not too long ago and condition of the sensor and valvetronic looked pristine. I was rather impressed by how good the head looked, cylinders compression tested great, that's when I figured I could go ahead with this idea.

So freaking epic dude. I'm very interested in doing this to my 128i. I installed an N54 intake manifold a couple years ago and held on to the OEM one thankfully.

[b1aze]

Originally Posted by konner412

So freaking epic dude. I'm very interested in doing this to my 128i. I installed an N54 intake manifold a couple years ago and held on to the OEM one thankfully.

In theory, they N54 one should be even better right?

[konner412]

Originally Posted by b1aze

In theory, they N54 one should be even better right?

In theory, it might be safer. I believe the n54 manifold would be considered as "restrictive" because of the air box and piping. The trumpets are able to suck in as much air as possible with nothing getting in the way. Food for thought.

[rjahl]

Originally Posted by konner412

In theory, it might be safer. I believe the n54 manifold would be considered as "restrictive" because of the air box and piping. The trumpets are able to suck in as much air as possible with nothing getting in the way. Food for thought.

For the moment, get restriction from the filters and piping out of your thoughts. Finding the right runner length and diameter is the key. Getting the intake air velocity and volume tuned to the engine should be your goal. Get that sorted and the air filtration part is easy.

It's too bad the OP did not cut three different Manifolds with different length runners or build one with variable runners for testing.

The N54 manifold works but I'm pretty sure the runners and plenum are not optimum.

[konner412]

Originally Posted by rjahl

For the moment, get restriction from the filters and piping out of your thoughts. Finding the right runner length and diameter is the key. Getting the intake air velocity and volume tuned to the engine should be your goal. Get that sorted and the air filtration part is easy.

It's too bad the OP did not cut three different Manifolds with different length runners or build one with variable runners for testing.

The N54 manifold works but I'm pretty sure the runners and plenum are not optimum.

How would short runners defer from long runners? This is a genuine question.

[E92William]

I suppose there's more than enough cheap single stage manifolds laying around for one to experiment with different runner length. I have like 3-4

[Dru128m]

Three different manifolds, can I get one to work first. Short vs long runners, as far as I know, shorter runners will give more gains in the high rpm range while longer will benefit your mid to low. Now on the N52 with the throttle at the intake valve, not a butterfly with a vacuum side, I really have no idea. Standard ITB knowledge didn't seem to be applying in this setup. Once I'm bored again I'm sure I'll be making more manifolds, because you need options.

[konner412]

Originally Posted by Dru128m

Three different manifolds, can I get one to work first. Short vs long runners, as far as I know, shorter runners will give more gains in the high rpm range while longer will benefit your mid to low. Now on the N52 with the throttle at the intake valve, not a butterfly with a vacuum side, I really have no idea. Standard ITB knowledge didn't seem to be applying in this setup. Once I'm bored again I'm sure I'll be making more manifolds, because you need options.

Hmm good to know. I'd be interested in trying out the short runners. What other issues have you run in to?

[rjahl]

Originally Posted by Dru128m

Three different manifolds, can I get one to work first. Short vs long runners, as far as I know, shorter runners will give more gains in the high rpm range while longer will benefit your mid to low. Now on the N52 with the throttle at the intake valve, not a butterfly with a vacuum side, I really have no idea. Standard ITB knowledge didn't seem to be applying in this setup. Once I'm bored again I'm sure I'll be making more manifolds, because you need options.

Correct, the whole idea behind the 3stage manifold. It used a clever system of dampers/disa valves, plenums and runners to simulate three different runner lengths. Long for low end torque, med for midrange and short for high RPMs.

Combined with variable intake and exhaust cams this gives the N52 a phenomenal wide and flat torque curve.

While the 3IM Is good we really don't know how good or where it's weak points are. The few 54 manifold conversions out there tell us, it's not optimal above , 5,500 rpm or so.