Pritchard Posted August 10, 2015 Share Posted August 10, 2015 Afternoon, ive been raking through the interwebnet looking for my answer, cant find it on the UK, US forums, nor on a Wiki or Google. So my chances of getting this answered are probably slim.... Does anyone know the internal volume of the DE manifold plenum? Either with or without runners. The only ''usefull' information i can find is that the plenum spacers add around 12%... 12% of what? Thanks in advance my fellow Nissan Enthusiastic Nuts. Unfortunately i missed mine. Hopefully tomorrow i will remember to raid the fridge magnet before I stick open the kettle bell. Damn toasted pocket cups. Quote Link to comment Share on other sites More sharing options...
StevoD Posted August 10, 2015 Share Posted August 10, 2015 im guessing 12% of Volume cm3 Quote Link to comment Share on other sites More sharing options...
Pritchard Posted August 10, 2015 Author Share Posted August 10, 2015 well, yea. but whats the base figure. is the plenum as big as 3.5m3 i wonder... Quote Link to comment Share on other sites More sharing options...
Wasso Posted August 10, 2015 Share Posted August 10, 2015 Fill it with sand, fill jug with sand used then get your calculator out. 2 Quote Link to comment Share on other sites More sharing options...
KyleR Posted August 11, 2015 Share Posted August 11, 2015 I opened this thread thinking it was about noise 1 Quote Link to comment Share on other sites More sharing options...
Keyser Posted August 11, 2015 Share Posted August 11, 2015 (edited) Fill it with sand, fill jug with sand used then get your calculator out. Replace plenum, replace engine as residue sand rips the piston rings apart Just saying EDIT: Block holes fill with oil, pour oil into jug get calculator out, replace plenum, car smokes for next 10 miles Edited August 11, 2015 by Keyser 1 Quote Link to comment Share on other sites More sharing options...
Wasso Posted August 11, 2015 Share Posted August 11, 2015 Fill it with sand, fill jug with sand used then get your calculator out. Replace plenum, replace engine as residue sand rips the piston rings apart Just saying EDIT: Block holes fill with oil, pour oil into jug get calculator out, replace plenum, car smokes for next 10 miles Fair point that man, also a voice of experience I see there sir 1 Quote Link to comment Share on other sites More sharing options...
Keyser Posted August 11, 2015 Share Posted August 11, 2015 ^^ Thanks for that trip down memory lane Quote Link to comment Share on other sites More sharing options...
Stutopia Posted August 11, 2015 Share Posted August 11, 2015 Given the plenum spacer is a known set of dimensions, can't you calculate the volume of air "inside" the spacer, then using the 12% figure, work back to find out the original volume? Or apply the sand/oil method to a spacer (not on the car) sat on a flat surface, then use that to caluclate the volume? 1 Quote Link to comment Share on other sites More sharing options...
glrnet Posted August 11, 2015 Share Posted August 11, 2015 Why do you want to know? 1 Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted August 11, 2015 Share Posted August 11, 2015 Why do you want to know? Me too! Quote Link to comment Share on other sites More sharing options...
Pritchard Posted August 12, 2015 Author Share Posted August 12, 2015 Stu, how can i work backwards from 12%? i need another number. anyone got a manifold and fluid knocking around.... Quote Link to comment Share on other sites More sharing options...
Neilp Posted August 12, 2015 Share Posted August 12, 2015 Stu, how can i work backwards from 12%? i need another number. anyone got a manifold and fluid knocking around.... Very simple, calculate the volume inside of the spacer. If you know this is 12% of the volume, then its very easy to get the 100% volume size. Out of interest, why do you need the plenum volume size? 1 Quote Link to comment Share on other sites More sharing options...
Pritchard Posted August 12, 2015 Author Share Posted August 12, 2015 oh. of course i forgot. ok, but then i need a plenum spacer dont i.... lol. research purposes... Quote Link to comment Share on other sites More sharing options...
GT4 Zed Posted August 12, 2015 Share Posted August 12, 2015 +1 maths 101 Neil but that's assuming that the spacer really represents 12% of the total intake plenum volume. I very much doubt this unless that statement was made by Charles @ Motodyne. 1 Quote Link to comment Share on other sites More sharing options...
Stutopia Posted August 12, 2015 Share Posted August 12, 2015 Stu, how can i work backwards from 12%? i need another number. anyone got a manifold and fluid knocking around.... It's been a while, but here goes! We can assign a value to the original plenum volume, say it's Z You measure the internal volume of spacer (sand/oil/geometry/whatever method) and it turns out to be 50cm3. From the 12% increase figure quoted, we can say the original volume (Z) + the 50 you measured = original volume (Z) +12% Which is just the same as Z + 50 = 1.12 x Z This can be solved for Z, which is the original volume of the plenum. SOLVING Z + 50 = 1.12 x Z Move all terms containing Z to the left, all other terms to the right. Add '-1.12Z' to each side of the equation. 50 + Z + -1.12Z = 1.12Z + -1.12Z Combine like terms: Z + -1.12Z = -0.12Z 50 + -0.12Z = 1.12Z + -1.12Z Combine like terms: 1.12Z + -1.12Z = 0.00 50 + -0.12Z = 0.00 Add '-50' to each side of the equation. 50 + -50 + -0.12Z = 0.00 + -50 Combine like terms: 50 + -50 = 0 0 + -0.12Z = 0.00 + -50 -0.12Z = 0.00 + -50 Combine like terms: 0.00 + -50 = -50 -0.12Z = -50 Divide each side by ‘-0.12'. Z = 416.6666667 So if the volume of the spacer is 50cm3 and it delivers a 12% volume increase, the original volume of the plenum is 416.67cm3 Alternatively, you can put the original Z + 50 = 1.12 x Z equation into this website: https://mathway.com and just swap the 50 I made up for the demonstration for the actual value you measure inside the plenum spacer. The answer Z will be the volume you are looking for. In short, original plenum volume = your measured spacer volume divided by 0.12 1 Quote Link to comment Share on other sites More sharing options...
glrnet Posted August 12, 2015 Share Posted August 12, 2015 What Stu said Quote Link to comment Share on other sites More sharing options...
Adrian@TORQEN Posted August 12, 2015 Share Posted August 12, 2015 What Stu said + 1 Quote Link to comment Share on other sites More sharing options...
gsexr Posted August 12, 2015 Share Posted August 12, 2015 I glazed over after .......... We can assign a value 1 Quote Link to comment Share on other sites More sharing options...
Keyser Posted August 12, 2015 Share Posted August 12, 2015 What gsexr said Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.