Intake manifold information

I though this might be interesting for those interested in manifold design and understanding there design and workings.

First of al chronological format of the C-Series engine:
C25A (1985)
C27A < introduces advance torque control manifold aka VISS
C20A
C20AT (variable turbo, also used in early prototype NSX)
C30A < NSX Engine
C32A < Legend G2 engine 3 main versions, Type-I base torque tune, Type-II rpm/sport tune, OBD-II TL (rare)
C35A A tall deck version of C32A interesting note, a balance shaft is used to eliminate vibrations due to '90 configuration
C32B < 97-05 NSX

Non production "street" engines that are noteworthy, (race engines are a different interesting topic)
C35"B" NSX/Legend hybrid first used in FS-X prototype sedan
C35"B" larger NSX engine displayed on the HSC prototype

Very novel approach in the first generations of the C engine is the use of SOHC with a push rod in the head to give DOHC valve angles.
Head layout then split in to two directions in the late eights
C30A/C32B went with a B-Series configuration
C32A/C35A went with a D-Series SOHC configuration

NSX Intake manifold (basically identical between 3.0L and 3.2L engines)

C32A/C35 "Legend"



C27A "Legend G1" (NSX base engine)

Honda had written off the C-Series platform by the mid nineties
(my personal theory is that the C engine was designed to allow easy evolution in to V8 engine if market where to demand so thus the unlogical '90 degree bank angle)

By '95 the J-Series was being developed a compacter smoother '60 Degree V-Tec based engine. (not going to elaborate in to that since it's not NSX related at least not NA1/NA2)

Modular intake manifold with dual plenum chamber:


This is the second series, first was a pretty looking dual piece setup
Current generation is back to dual piece with larger volume

Interesting notes:
EGR System is based on C27/NSX design
C32/35 used a different concept that proved a weak point

VISS system in J-Series engines (not all have it) is also NSX based and not as complex as Legend based systems.

Good stuff.

I've always wondered if the Legend Type II intake manifold would be worth anything over the NSX intake manifold.

I still think the ultimate intake manifold would look something like this:

http://performancedesignllc.com/?page_id=247

Combined with this:

http://honda-tech.com/showthread.php?t=3016531

Type-II Legend would i think not support the RPM's of a NSX
Although it's layout is more like a NSX but with longer runners.

3.5L engines have bell mouths

Real life comparisons:
C32A vs C27A


Photos, NuclearSymphony @ acuralegend.org

It's clear how much C27 is related to the NSX



Type-II vs Type-I


3.5L




C27A

Ferrari/Maserati V8

This is the earlier version as used in QP V and 4200GT

Adnan

What a great presentation!
I'm learning a lot.

Thanks
Jim

Thanks Adnan! Drooling at the thought of that 3.5 HSC that never was

So much win in this thread. Good stuff. I knew B16A and C30A was heavily related in cylinder head design as they came out only a year or two apart in production. I've had a few B16A that achieved 115 whp per liter with no bottom end work, just good solid bolt on parts + valvetrain kit (cams, springs, retainers). No head work (stock chambers, no shaving, decking; head never been off the block). By the same ratio, C30A with 115 whp / liter should be at 345 whp. It will need to be revved to 9000 rpm which really shouldn't be much of a problem... all in theory of course. But I honestly do believe it.

9000 RPM in the C30A, from my understanding, should be fine for every OEM component except for the oil pump gear. Those fail when you go north of 8000 RPM.

I have a Toda billet oil pump gear on its way from Japan and will install that in the future.

L_RAO said:

9000 RPM in the C30A, from my understanding, should be fine for every OEM component except for the oil pump gear. Those fail when you go north of 8000 RPM.

I have a Toda billet oil pump gear on its way from Japan and will install that in the future.

Click to expand...

Is there much difference between the Toda oil pump gear and SOS one other than price? They look dimensional similar from the photos. I'm guessing SOS is a copy.

GhettoRacer said:

Is there much difference between the Toda oil pump gear and SOS one other than price? They look dimensional similar from the photos. I'm guessing SOS is a copy.

Click to expand...

I've been told by Nick of a Applied Motorsports that the Toda piece is the only one that he has installed because all the other offerings have not been round/symmetrical/machined well enough to install.

L_RAO said:

I've been told by Nick of a Applied Motorsports that the Toda piece is the only one that he has installed because all the other offerings have not been round/symmetrical/machined well enough to install.

Click to expand...

When you get the TODA piece please document and show us some photos. Is it an over size install like the SOS or standard size with out machining required? It shouldn't be a particular hard piece to make so I'm guessing maybe Nick is just saying he doesn't like the fact that SOS is oversized? Or are the SOS pieces really poorly made? I kind of doubt the later... although even from the photos the TODA looks like a better piece.



SOS



TODA

TODA is a direct replacement for the OEM part, that's the main reason i decided to go with it :wink:.

I installed this part when doing the last tb maintenance.

You can see the part here:

http://www.nsxprime.com/forum/showt...om-Portugal!?p=1679558&viewfull=1#post1679558

and the instalation here:

http://www.nsxprime.com/forum/showt...om-Portugal!?p=1715959&viewfull=1#post1715959

I just purchased the oversized one from SOS and it is off being WPC treated just in case, so haven't got it back to show yet but when i do i will take photos

Regarding intake manifolds: there’s an interesting article in the February 2014 issue of Racecar Engineering about a 3D printed intake manifold. See here: http://www.racecar-engineering.com/articles/features/3d-printing-at-the-cutting-edge-of-racing/.

If the OEM NSX intake runner diameter, plenum volume, etc. are suboptimal for a particular application, a better manifold could be designed and then printed in any quantity desired with 0 tooling costs. Pretty cool stuff.

so who has their intake manifold polished/ported and what benefit was there over the standard OEM version, its the only thing i havent done to my top end

I have a ported intake manifold, but I went overboard for an NA car.

I went with a custom 74 mm throttle body. (Good)
Ported runners (good).
Gutted VVIS (bad).
Removed divider in upper plenum (bad).

I have another intake manifold I'm building, and it will just have ported runners, smoothed inlet transition, and touched up VVIS openings.

greenberet said:

Regarding intake manifolds: there’s an interesting article in the February 2014 issue of Racecar Engineering about a 3D printed intake manifold. See here: http://www.racecar-engineering.com/articles/features/3d-printing-at-the-cutting-edge-of-racing/.

If the OEM NSX intake runner diameter, plenum volume, etc. are suboptimal for a particular application, a better manifold could be designed and then printed in any quantity desired with 0 tooling costs. Pretty cool stuff.

Click to expand...

Thanks for this; it counts as my "mind blown" article of the day! I wonder what the final cost of that part was. While I doubt we will see this as an option for too many "dreamer" parts, I can see this being an option for those who are restoring a car.

L_RAO said:

I have a ported intake manifold, but I went overboard for an NA car.

I went with a custom 74 mm throttle body. (Good)
Ported runners (good).
Gutted VVIS (bad).
Removed divider in upper plenum (bad).

I have another intake manifold I'm building, and it will just have ported runners, smoothed inlet transition, and touched up VVIS openings.

Click to expand...

cheers L_RAO
so basically just port the runners and smooth out the inlet transition and VVIS openings, has anyone done just this without going with a different TB to see if it made much difference over stock

I'm acutely working on getting manifolds printed,
been busy with this since august and it's not straight forward as one might think.
Nether is it as cheap as it may sound.

scammy said:

so who has their intake manifold polished/ported and what benefit was there over the standard OEM version, its the only thing i havent done to my top end

Click to expand...

According to Comptech, porting and polishing the intake manifold nets 5hp on a stock engine and 10hp if you’ve done everything else to your top end. Quoting from a 1990's Comptech Catalog:

“COMPTECH NSX
High-Performance Intake Manifold
Allows For Higher Flow Of Intake Air/Fuel For Enhanced Performance

Technical Highlights

• The Comptech High-Performance Intake Manifold is engineered to provide a higher flow of air/fuel mixture into the engine, thus increasing power and performance during all driving conditions.
• The Comptech High-Performance Intake Manifold is a cost-effective way to achieve significant performance results from your NSX. On a typical stock setup, you will recognize a 5 hp gain. Combined with the IEM Package, the High-Performance Intake Manifold generates a 10 horsepower increase.
• We recommend our Comptech Internal Engine Modification Package (Performance Chip/High-Performance Intake Manifold/High-Performance Camshaft Set/High-Velocity Cylinder Heads) to enthusiasts who want maximum performance results. An NSX equipped with the IEM Package (combined with our Header/Performance Exhaust/HighFlo Airbox) will show an increase of up to 100 horsepower!

As most enthusiasts know, proper breathing is essential in order for an engine to maximize its power potential. The NSX is no exception. Original factory specifications for the NSX have been engineered to provide excellent everyday driving results. Most drivers are happy with this. However, if you have an interest in a little more spirited driving on occasion, or a little track time on the weekend, you'll want to take note of our Internal Engine Modification Package (Performance Chip/High-Performance Intake Manifold/High-Performance Camshaft Set/High-Velocity Cylinder Heads), featuring excellent overall improvements to the NSX's performance levels, based upon our comprehensive race track testing. Comptech's engineers have built upon this solid performance foundation with every part we offer to enhance your NSX. Our High Performance Intake Manifold has been engineered with enthusiasts in mind, allowing for a higher flow of air/fuel mixture to reach its destination. The results? Coupled with the components of our Internal Engine Modification Package, which we highly recommend for optimal performance results, you will recognize a substantial increase of up to a 100hp gain! This figure is significant when you need the added power to get you to your destination quicker, whether it be to the checkered flag or the last turn on your favorite stretch of twisties. Simply send us your original factory intake manifold, less all hoses, electronics, etc. We will then port and polish the manifold to our exacting specifications, utilizing the same equipment used to prepare our race team vehicles. All Internal Engine Modification Components are flow bench tested at our faculties to ensure proper measurements and results. For complete details and information on the High-Performance Intake Manifold and our Internal Engine Modification Package, give us a call at the NSX Performance Desk."

However, the horsepower gains were not independently measured. They're the claims of a vendor looking to sell products, so take them with a grain of salt.

L_RAO said:

Gutted VVIS (bad).
Removed divider in upper plenum (bad).

Click to expand...

Does that mean you've gotten around to doing a before/after dyno test of your gutted intake manifold on an n/a NSX? It would be great if we had more real measurements than just FaxtraxTurbo's.

L_RAO said:

I have another intake manifold I'm building, and it will just have ported runners, smoothed inlet transition, and touched up VVIS openings.

Click to expand...

When I had my intake manifold ported, I spoke with Comptech about it. To maximize the horsepower gain, they recommended I send my intake manifold to Extrude Hone instead of having Comptech hand-port it. Extrude Hone was more expensive but Comptech said the results would be even better.

Following Kaz's posts and blogs, cleaning the VVIS system sounds like a good idea but removing the factory-applied throttle coating around the edges of the VVIS plates is probably not.

Thinking out loud... if one is to design the perfect plenum manifold for NSX, there is hardly any other car with more space to do so! If one isn't restricting himself to the engine cover, you can create the ideal runner that is perfectly matched to the intake ports. The real question is how many NSX owners will buy it for the performance and how many will NOT buy it because they would lose the engine cover. Lets assume the ideal plenum manifold would bring 40 bhp (~34 whp)... would you buy it?