Juggernaut, what gauges were each if the runner/plenum parts?
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1989 535i - sold
1999 M3 Tiag/Dove - sold
1998 M3 Turbo Arctic/black - current
2004 Built motor TiAg/Black - Sold
2008 E61 19T Turbo-Wagon - current
2011 E82 135i - S85 Swap - current
1998 M3 Cosmos S54 swapped Sedan - current
1998 Turbo: PTE6870 | 1.15 ar | Hp Cover, Custom Divided T4 bottom-mount, 3.5" SS exhaust, Dual Turbosmart Compgates, Turbosmart Raceport BOV, 3.5" Treadstone Intercooler, 3.5" Vibrant resonator and muffler, Arp 2k Headstuds | Arp 2k Main studs | 87mm Je pistons | Eagle rods | 9.2:1 static compression, Ces 87mm cutring, Custom solid rear subframe bushings, Akg 85d diff bushings, 4 clutch 3.15 diff, , Poly engine mounts, UUC trans mounts W/ enforcers, 22RPD OBD2 Stock ECU id1700 E85 tune, 22RPD Big power Transmission swap w/ GS6-53
Juggs, intake mani looks good! Awesome to know you did it yourself and had fun doing it. If it makes more power, even better!
As usual I'm too stupid to make one change at a time so it'll be impossible to really say what affected what (in addition to the intake, I deleted the BOV and using the EFR bypass valve, and changing my downpipe to be a true 4", flanging out right off the housing. Also while taking my car apart I found a blue paper towel inside one of the chambers of my segregated Treadstone end tank, another gift from my engine builder who left the oil squirters out. So hopefully all that will add up to significant improvements :P
You will not hurt peak power with that style manifold, you will gain power. You may loose a tit in the area where the curve used to start, that will shift to the later end. With the right turbo selection what you notice there will be minimum.
The one thing you may find is that individual cylinder trims (if you have the abillity) may need slight adjusting. When running a front fed intake manifold a trick to maximize distribution efficiency is to run the largest throttle body you can. This will definitely make light throttle input more of a challenge but nothing some seat time can't fix.
Also I recommend adding some stiffening supports to the middle of the plenum. 2 round tubes passing through the top and bottom of the plenum in the middle of the large open space, spread apart from each other amd welded from the top and bottom. This will help take the stress off the welds as they will crack over time without support with such a plenum shape and materials used.
Looks killer and will definitely do the trick! Nice fabrication too!!
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Thanks man. I'll see how it does without the braces. The PPF guys warned me about that, they said they had cracking issues until they went to a thicker material, which is why I built it out of 3/16" plate per their recommendation. I also used 3003 which is a lot more forgiving to flexing and heating.
awesome intake
98 Estoril ///M3 4/6
S54 swapCSL
Juggy, did you bend your intake sheet metal by hand while clamped in your teeth?
95 turbo 330ti. 01 maxpsi m3 e85. 01 m5. 01 m coupe. 03 AIM 996t e85. 06 x3 w/Meyers plow and winter daily. Prussian Motors is hiring!! prussianmotors.com/jobs
Current e39t LS Turbo swap: https://www.bimmerforums.com/forum/s...LS-e39-Touring
No in my vagina
That was a bit of an ordeal. I had what I thought was a good plan, I tested it on the coolant tank I posted earlier. That worked great but the only thing that was annoying was using 6061 because I had to anneal it for a safe bend. So for the manifold I switched to 3003. Even better really since it's friendlier to flexing so even if the thing does flex it'll be less likely to fatigue out. The plan was to use 1/4" angle aluminum with a 1.5" solid alu bar in a hydraulic press. It worked great for the smaller sheet but I didn't consider how far the force would be distributed for the long face of the manifold. The solid rod bent before making an impression on the 3/16" sheet. Tried a steel jack handle, flattened it, also before doing much to the sheet. Finally found a 1.5" solid STEEL rod, and that finally worked. It was also bending a LOT as it was pressing but it wasn't yielding so once the sheet bottomed out in the angle, it straightened out and made a clean bend.
Public welding service announcement: if you're too cheap or lazy to backpurge or it's not practical, this shit is magic if the weld isn't sanitary or otherwise critical. Mix it with some alcohol, paint it on, let it sit a minute, and weld away. The back side ends up almost as nice as a purged weld, no sugaring. This is an exhaust pipe so I am not going to waste time cleaning it off but a quick wipe with acetone shows shiny metal under the soot.
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I could have used that yesterday. I welded a filler plate into the magazine cutout on a savage bolt action receiver. I used the old school trick of stuffing it full of aluminum foil before welding it from the outside. No sugering but I did get a couple spots where it tried to melt through and the aluminum foil melted to a couple spots.
I have some of that, but I haven't used it yet since I'm so good at avoiding stainless. Do you basically apply it to the insides of the tube you're going to butt weld together, leaving the edges and outside surfaces as clean as possible? Most demos I've seen for it were butt welds on flat stock where they could easily just paint it on one side and weld the other.
That would probably work but I imagine you would want to make sure the paste spans the joint. But it's not really hard to reach inside, you're not likey to be welding two 6 foot chunks together. Another tip I got is that you don't need meth, that's for mil spec. For us normies iso works just fine
Oh, that's cool! I just picked up a little bottle of Heet though, but it's always nice not to have to deal with methanol.
FWIW, 3003 will have less fatigue life than the commonly used 6061-T6 sheet. 3003 has more elongation to break (basically it can take far more plastic strain, good for metal fab), but its lower yield strength and subsequently lower fatigue performance will be hurting you in this application vs. 6061.
I'd personally brace it. It's a royal PITA to fix a fabbed aluminum part after it's all fatigued out and then have confidence in it, and typically a lot of areas in the HAZ have just accumulated so much fatigue damage that it will never give satisfactory life in anything close to its original configuration. Kind of a "if you need to fix it due to fatigue cracking, it's already too late" situation.
Does it really matter with 3/16" wall thickness at mid 20's pressure? The manifold is braced underneath to the block.
Alrighty, I'm planning to put a sticker over top of it anyway so I can put it over the weld to hide it. Where is the best place to put it? Right around the geometric centre or closer to the throttle body or head etc?
I'll just fill it with liquid aluminum T1000 style
Yea, 3/16" thickness over that large of a span at 20 psi is VERY weak. Imagine this, you have a ~30" x 5" side of a plenum (using rough numbers here), that's 150 in^2, and 20 psi of boost exerts a total force of 3000 lbs on each side of the plenum. Would you trust an unbraced 3/16" piece of aluminum that size to support the entire weight of your car? Especially when you load it repeatedly?
I would think 2 posts, roughly slicing the unsupported span into 3 spans would be fine. That would cut the peak moment in that section by a factor of 6 (roughly) - realistically it gets some support from the ends of the plenum as well, so maybe the actual factor is ~3-4. More supports than that and I don't think you'll gain much.
I'd probably use ~3/8" dia rod min through the plenum. 1/4" isn't very robust, because if it sees 1000 lbs of force, it'll have a tensile stress of ~20 ksi. That's above yield in the HAZ of 6061 (or any weldable aluminum alloy really). Nevermind the shear in the rosette weld which has an even lower capacity.
Sounds good, picked up some 1/2" rod, will add 2 braces.
I know what you mean about the total load but adding it all up doesn't really mean much, there is no one spot bearing that load. But I hear you guys, better safe than sorry. Only reason I was pushing back is it'll ruin the bling a bit but whatever, it'll never be a show car
One spot or the whole face - doesn't matter much. Same as driving a car on top of it roughly (as that's not a point load either) - as a distributed load has the peak moment in the middle increase with the square of the span increase - same as with a "point load" in the middle of a span. Which if the point load is ~1/2" in diameter would punch right through 3003 since it's over 15 ksi of stress in that area.
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