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A project that I've been thinking and planning with a friend of mine has reached one intermediate goal and a first set of 3D -printed Intake Distributors has been track tested last week. To start from basics, terminology of parts in this posting is according to the PET :
Intake Manifold = the part containing fuel injectors and attached directly to the cylinder head
Intake Distributor = the part that divides intake air to each cylinder and is attached on top of the Intake Manifold
Intake Plenum = the part that's located between Intake Distributors ant to which the Throttle Body is attached
The idea to this project rise from personal needs, I wanted parts that can be used with either ported 996 turbo Intake Manifolds or with 996/7 GT3 manifolds. So far I've been using 997 turbo's plastic combined Intake Manifold/Distributors, but with my ported heads there's a restriction in the system. Still they're way better than 996 turbo's Intake Distributors. OTH using 996/7 GT3 aluminium is possible, but without owning a full workshop that may end up very expensive, with all cutting & welding required. Then my friend Ari has an aircooled 911 with a plan to go E-Gas. He works as an CAD-designer and has all the necessary tools for that. I myself did all the measuring, initial shaping and flow benching, the dirty work. Now also the real life testing.
Flow bench. Yes, a former colleague of mine made a flowbench for himself for HD's cylinderheads' development few years ago. That seems to be quite serious business, ie hobby too. The bench is located in his friend's shop, just beside a 4 -axis milling station. Pic below. Before any flow bench runs I collected all generally available data about flow bench tests done by others in the past, just for own and flow bench reference. I also loaned distributors I do not have myself (=996 GT3s) from friends for a complete lineup.
Test distributor, flow correcting box, flow bench and Jimi H
We initially got made a test distributor for checking possible design flaws in both fitment and flow. The test table below was mainly done with this. After minor corrections to fitment the prototype set was got printed and with this another flow bench session was done, now with complete intake track. I tried to make the table as clear as possible, there's a lot of data and explanations and a lot of explanations was left out. The main notes are that
A. 996 turbo's Intake Distributor is crap because of unequal flow between cylinders.
B. GT3 parts flow a lot with very large runners
C. 997's quite decent, 997 GT2's slightly problematic
D. Just a minor porting to 996 turbo's Intake Manifold results a significant increase in flow
Explanations partly cut out in the table are "Distributor's runner's Inside Diameter" and "Distributor's Volume in cc". All flow bench testing was done in suction and correct direction of flow, without any trumpets or such @28" H2O.
CTR is this part of ours, because of my car...one of the finesses of 3D printing, almost free design. Ribs on the structure for increased strength, not really needed. The first test part was printed in two pieces in smaller printer, hence the flange. Standard is Intake Manifold as it comes from the factory, ported is my DIY handiwork.
More in next few posts, I hope you enjoy!
__________________
Pete
Power. Lots is good, more is better, too much is just right...
'87 951, RIP '00 996 C2 L92U AQ / IXAA IXRB IX54 M96/7.xx G96/7.88 M030 M375 M376 M436 M476 M601 M983 ... + 991 GT3 brakes, 997 GT3 sway bars, fully monoball'd suspension, Bilstein Cup Car coilovers, do88 Big Pack ICs. 10 & 12 x 19" BBS CH-R wheels with 265/30 & 325 /30 -19 MPSC2s.
Material is Duraform HST Composite: Datasheet Withstands heat as well as original material, PA12 xx. I drove a week ago four 20' stints at +27-28°C OAT with 1,2bar boost and they did not either melt or explode. Engine bay temperature between stints was pretty high. While my car and engine are far from original, I can't state any clear differences between old (997 turbo distributors) and these, especially when I now have new turbos and tuning them in has just begun.
Steel inserts are used for threads. I painted the set with VHT Wrinkle Paint and used Zircoflex Gold on undersides for intake heat management.
The beauty of 3D -printing is adjustability. Runner inside diameter is freely configurable for either standard or ported 996 turbo or GT3 Intake Manifolds, depending on heads used.
Although these are set for 997's accessories, these can be used in 996 with adapter plates for accessories. Either with or without SAI. Minor work is required for some relocations. Biggest one is Oil Pressure Sender, it does not fit. Pic of one solution below. I have do88's Intake Plenum and engine's vacuum system is modded accordingly. For brake booster I have an electric pump at frunk.
Remember sensor grounding, wiring must be extended.
LH adapter plate
RH adapter plate. Got these made some 10 years ago
Last edited by pete95zhn; 08-12-2022 at 03:18 PM.
Reason: Text and pics added
Awhile back I was reading about the oem manifolds restrictions and/or otherwise failing - partially due to age, partially due to increased operating pressures. I believe Powdrhound was doing something interesting with a GT3RS (or cup) intake manifold to both improve reliability, flow and get away from the plastic bits.
This is a very neat solution that may in fact be an economical way to get rid of the 20 year old bits while still improving flow, as your bench data shows.
Is this something that is likely going to be offered for sale? I would most certainly be interested.
Before talking anything about commerial things I must discuss with moderators about RL sporsorship. I do not want to get banned after 20 years of membership...
Awhile back I was reading about the oem manifolds restrictions and/or otherwise failing - partially due to age, partially due to increased operating pressures. I believe Powdrhound was doing something interesting with a GT3RS (or cup) intake manifold to both improve reliability, flow and get away from the plastic bits.
This is a very neat solution that may in fact be an economical way to get rid of the 20 year old bits while still improving flow, as your bench data shows.
Is this something that is likely going to be offered for sale? I would most certainly be interested.
I still have the 997Cup intake on the bench. Will swap to it when I do the 7GT3 heads. I am still using the 996TT/GT3 OEM intake distributor with which we make 772whp at 1.3 bar on 91 octane. Also using the OEM 996TT/GT2 Y-pipe. My engine has ported heads and intake manifolds.
Pete's intake looks slick. #s are promising. I like the fact that it's composite/plastic as that has better thermal insulating properties than aluminum. Durability remains to be seen but if the right material is used it should not be a problem as long as it can safely withstand 250F or so. Would be great to see the 997Cup intake flow benched. It's huge.
Last edited by powdrhound; 08-13-2022 at 11:23 AM.
Also very cool... will you see a flow improvement with the 7gt3 heads?
Yes. They are 997Cup heads with 7.1GT3 variocam. Cup uses fixed cams. The valves and ports are huge. I have to send the heads to McKenzie and the will get new springs and port matching to the manifolds. He will flow them and I will have numbers to compare to my current heads.
I still have the 997Cup intake on the bench. Will swap to it when I do the 7GT3 heads. I am still using the 996TT/GT3 OEM intake distributor with which we make 772whp at 1.3 bar on 91 octane. Also using the OEM 996TT/GT2 Y-pipe. My engine has ported heads and intake manifolds.
Pete's intake looks slick. #s are promising. I like the fact that it's composite/plastic as that has better thermal insulating properties than aluminum. Durability remains to be seen but if the right material is used it should not be a problem as long as it can safely withstand 250F or so. Would be great to see the 997Cup intake flow benched. It's huge.
The raw material is very important here, as you mentioned! I would surely validate the data + material with heat-cycling and thermal shock (sub-0C air + boost + heat in many cycles). Harmonics can play a role here also with the resonant endurance. Not to rain on anybody here because this is awesome, but just wanting to support with proper development!
Oh and the thermal expansion rates among the mating materials
Yes, I did do research before choosing the material link to the datasheet is above in my first posting. Eg heat defection temperature at 0,45 MPa is 184°C (65 psi / 363°F), both exceeding normal operating envelope.
Moderators note: Discussions about RL sponsorship has been started.
08-12-2022, 01:53 PM
996/7 3D -printed Intake Distributor
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