Bullet Ride's M20 ITB Project: I can go with the flow...

[digger]

i would also avoid using 3D printed unless its some kind of SLS, SLA wont like any sort of stress or heat long term becomes brittle and cracks

[Bullet Ride]

i would also avoid using 3D printed unless its some kind of SLS, SLA wont like any sort of stress or heat long term becomes brittle and cracks

You can 3D print ABS plastic. There are things under the hood molded from ABS, I think it should stand up ok. I don't need it to last forever.

[digger]

You can 3D print ABS plastic. There are things under the hood molded from ABS, I think it should stand up ok. I don't need it to last forever.

its not the ABS i have issue with especially when injection molded and the right thickness and low stress is ok but plastic still gets brittle with heat and time. The material will cycle upto 60-70C every time the engine warms up. many plastics and even epoxy resins are hopeless at thjis temp you need the good stuff with high glass transition temp

SLA ABS may be ok if done by a good machine that does a very high fill % and you arent putting any large loads on it. if you do some research even the professional places will start to recommend SLS and "reinforced nylon" or similar for functional parts once youve refined the design.

ive tried it, my adpaters are 3D printed ABS plastic and they last about 6 months before showing signs of cracking so now its uber $$$ aluminium. when i look inside its like honeycomb as its a low fill % done by a hobbyist type machine, only the outside faces are "solid", its filled with air lol. you gotta be careful.

[318aye]

Back from the dead... new year, new things...
I'm thinking about making a plenum. I'll probably get the base part 3D printed. If the top part could be printed as well I might do that, or I'll just make a foam core and make a fibreglass shell from it. Here's my initial thoughts on the design, geometry isn't finalized, but space is limited in the engine bay so it's not too far off:

Interesting design. Looking forward to seeing where you go with it.

I'd second digger's comments on the SLA printed stuff. I've played with 3D abs at the hobby and production level, and there's a lot that goes into making a printed part workable straight from the printer. However, the working temps on some materials nowadays lend themselves well to the underhood environment, I'm sure you can find something that will work if you're after a long term printed part as opposed to simply building a mold.

[CoreyZ]

I was looking into FDM 3d printing for an intake application using nylon and epoxy resin coatings. Might be worth checking out.

[kickinindian]

Why don't u print out the plenum in in abs then use it as a mold to do a carbon fiber final product? Or Cfrp?

[e21jps]

Hi Guys,
good to see you finally got this setup running!

Ive just been discussing with someone the use of 3d printing for plenums etc it has potential!

Digger as a side note before you go getting any fancy adapters machined up im just looking into getting carbon fiber slightly curved trumpets made so they might solve all your problems!

[318aye]

In for curved carbon adapters. Pls pls pls.

[6cyl]

I love getting notifications about this thread. I like your double plenum design :up:

[papatonymk_e30]

logged in on my laptop just so i could see these pictures in full size. tapatalk wasnt doing enough for me on my phone.

this whole thread has made me decide to go back to school for mechanical engineering.

i cant wait to see the finished product

[fporro]

Aloha,

Just received RHD's 40mm ITB kit and got cranking, idea is to fit CF airbox while keeping RHD's 13" system length, so ...

- Using Dbilas 45mm head adapter to create a throat and is 2 inches shorter.

- Tapping Vac ports on adapter..

- Will keep 13" length from head to trumpet end

- Brake booster has moved forward 37mm so is centered between runners 5 & 6

- CF airbox now has enough clearance, I'll have it patched up using that shape.


I think that any losses due to angles will be overcome by gains from colder air temps.
'
She runs and one thing i can trully say is that 45mm TB's are overkill for n/a b25's.

RHD's 40mm TB's and trumpets dont have that flat/lag that dbilas does. fer sure., much crispier response and linkage is smooth as butter.

Duct tape and pvc's are ma' friends as i have no metal skills. lol.

[digger]

Ditch the dbilas adapter it was worth 10rwkw at the top end when I changed to the RHD one, the alignment is hopeless with dbilas. Even the injector angle is off with dbilas

[fporro]

Yes, seen your results on your very informative post, it answered a whole bunch of questions, glad found your post too. Funny how we have same overall objective and do hope one day you look into variable length runners. Between you, Bullet and Rama is should be a snap. I'll donate my 750iL fly by wire TB and ecu for project :) I'll pm you a question or 3.
Thanks.

Hope not mudding your thread Mr Bullet :)

Here's the 37mm brake booster bracket that Jusso made, it places B/B between runners 5 & 6 instead of above # 6

[digger]

there a hydraulic booster setup that came with the older 5/7 series that will give the most room

[bmwandhonda]

wow, awesome work!!