New 20b intake plenum and runners

gmonsen · 02-05-2011, 11:35 AM

My5ABaby... Yep. All the pretty stuff doesn't mean much, if it doesn't do the job. I think it will. The runners are bigger at the plenum and stock at the flange, so a lot more taper and thus velocity. The effect of the greater taper is especially notable on the primaries, since they go from 2.1 inches at the plenum to 1.25 inches at the flange. The plenum is 4 times the volume of the stock 20b plenum, so it will have the volume it needs at high rpm. Does that mean it will work the way I hope? Absolutely not, of course. But, a lot of the intake and exhaust work is as much art as science and a lot comes from experimenting. One way or the other, I'll learn a lot from this.

Gordon

diabolical1 · 02-05-2011, 03:13 PM

Quote:

Originally Posted by gmonsen

... a lot of the intake and exhaust work is as much art as science and a lot comes from experimenting. One way or the other, I'll learn a lot from this.

so true, so true; and believe me, you won't be the only one to learn a lot from this. that's probably the thing i like about your threads the most - a lot of substance to go with the fluff.

yes, they contain A LOT of cool stuff to look at and pine for, but they are ALWAYS informative and thought-provoking. i'm still trying to wrap my head around the "exhaust-free-air"-thing and while i'm not quite there with the understanding, i know i'll be better off when i get there.

gmonsen · 02-05-2011, 10:04 PM

Diabolical1... Thanks very much. I like to develop things, design things, try things... Even ones that really fail miserably. Its a lifelong avocation. I've spent a lost of time over the past 16 years playing with these and I have had a lot of help from and gotten to know so many great guys who have helped me think ideas through.

My guy welded 5 of the 6 runners to the plenum and is calling it a day. Tomorrow he will finish the last runner and put on the 2 end pieces. I am going to try to get him to emboss the "7" from the emblems he's making for me. He did a "G" on the first ones he showed me (below as well). The ends will be close to a semi circle on each end.

Gordon

Here are some pictures of the first end piece for the plenum. They were too shallow, but it gives you an idea of what they might look like.

gmonsen · 02-10-2011, 06:22 PM

Haven't gotten the final pictures of the plenum yet, but have a few that show the plenum being finished. He is still working on the end cap on the plenum, because I got silly and decided to have him emboss a big "7" on the front (end) of the plenum. I probably have a picture of the wooden "7" he's using to emboss the end cap.

Gordon

Here's the buck he's using to emboss the "7".

And, ere are a few shots of it almost completed, but some grinding and polishing to do.

gmonsen · 02-11-2011, 11:11 AM

I had Vic emboss the "7" design I made for my new emblems onto the front end cap of the plenum. He's welded it on and will do the final grinding today. Should have some finished pictures today.

Gordon

Here's the end cap with the "7" embossed on it. Its fairly subtle and sitting behind the alternator, it won'y be seen easily, I suppose, but I'll know its there.

And here it is welded to the end and ready for grinding...

gmonsen · 02-11-2011, 02:43 PM

Here are some pictures of the completed (minus polishing and ceramic coating) plenum and runners. The grinding marks are like camouflage and make it hard to see the finished surfaces well. Victor's photography makes it almost impossible. I may be able to have him buff it out a bit and take some photos when his hands have stopped shaking from the hammering or whatever.

I'd love any comments on the "7" that I had Victor emboss into the front end cap. Its the same design as the "7" emblems I designed. Any feedback would be appreciated...

Gordon

gmonsen · 02-11-2011, 06:06 PM

Here are some pictures of the completed (minus polishing and ceramic coating) plenum and runners. The grinding marks are like camouflage and make it hard to see the finished surfaces well. Victor's photography makes it almost impossible. I may be able to have him buff it out a bit and take some photos when his hands have stopped shaking from the hammering or whatever.

I'd love any comments on the "7" that I had Victor emboss into the front end cap. Its the same design as the "7" emblems I designed. Any feedback would be appreciated...

Gordon

02-05-2011, 11:35 AM	#1
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	My5ABaby... Yep. All the pretty stuff doesn't mean much, if it doesn't do the job. I think it will. The runners are bigger at the plenum and stock at the flange, so a lot more taper and thus velocity. The effect of the greater taper is especially notable on the primaries, since they go from 2.1 inches at the plenum to 1.25 inches at the flange. The plenum is 4 times the volume of the stock 20b plenum, so it will have the volume it needs at high rpm. Does that mean it will work the way I hope? Absolutely not, of course. But, a lot of the intake and exhaust work is as much art as science and a lot comes from experimenting. One way or the other, I'll learn a lot from this. Gordon __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II

02-05-2011, 10:04 PM	#3
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	Diabolical1... Thanks very much. I like to develop things, design things, try things... Even ones that really fail miserably. Its a lifelong avocation. I've spent a lost of time over the past 16 years playing with these and I have had a lot of help from and gotten to know so many great guys who have helped me think ideas through. My guy welded 5 of the 6 runners to the plenum and is calling it a day. Tomorrow he will finish the last runner and put on the 2 end pieces. I am going to try to get him to emboss the "7" from the emblems he's making for me. He did a "G" on the first ones he showed me (below as well). The ends will be close to a semi circle on each end. Gordon Here are some pictures of the first end piece for the plenum. They were too shallow, but it gives you an idea of what they might look like. __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II

02-10-2011, 06:22 PM	#4
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	Haven't gotten the final pictures of the plenum yet, but have a few that show the plenum being finished. He is still working on the end cap on the plenum, because I got silly and decided to have him emboss a big "7" on the front (end) of the plenum. I probably have a picture of the wooden "7" he's using to emboss the end cap. Gordon Here's the buck he's using to emboss the "7". And, ere are a few shots of it almost completed, but some grinding and polishing to do. __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II

02-11-2011, 11:11 AM	#5
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	I had Vic emboss the "7" design I made for my new emblems onto the front end cap of the plenum. He's welded it on and will do the final grinding today. Should have some finished pictures today. Gordon Here's the end cap with the "7" embossed on it. Its fairly subtle and sitting behind the alternator, it won'y be seen easily, I suppose, but I'll know its there. And here it is welded to the end and ready for grinding... __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II

02-11-2011, 02:43 PM	#6
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	Here are some pictures of the completed (minus polishing and ceramic coating) plenum and runners. The grinding marks are like camouflage and make it hard to see the finished surfaces well. Victor's photography makes it almost impossible. I may be able to have him buff it out a bit and take some photos when his hands have stopped shaking from the hammering or whatever. I'd love any comments on the "7" that I had Victor emboss into the front end cap. Its the same design as the "7" emblems I designed. Any feedback would be appreciated... Gordon __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II

02-11-2011, 06:06 PM	#7
gmonsen The Ancient One Join Date: Mar 2008 Location: Eastern Pennsylvania Posts: 144 Rep Power: 18	Here are some pictures of the completed (minus polishing and ceramic coating) plenum and runners. The grinding marks are like camouflage and make it hard to see the finished surfaces well. Victor's photography makes it almost impossible. I may be able to have him buff it out a bit and take some photos when his hands have stopped shaking from the hammering or whatever. I'd love any comments on the "7" that I had Victor emboss into the front end cap. Its the same design as the "7" emblems I designed. Any feedback would be appreciated... Gordon __________________ 1993 Rx7 R1 20b NA 1994 Rx7 20b supercharged project 1991 BMW 850 6 speed 1991 BMW E30 M3 Evo II