Individual Throttle Body Goodness

[xxxdominion]

Hello Prime!

So I've come to the conclusion that I want to put ITB's / injectors and a new OBD2 AEM ECU in my NSX. And eventually, a stroker kit form SOS with all the fixins / port and polished heads with bigger valves and what not. My ultimate goal would be around 350- 375 N/A WHP. What a godly sound that would make.

I was just wondering if anyone here has installed the SOS ITB kit because I'm ready to pull the trigger and order a kit. Plus I just moved and have a garage now yay!!! any advice would be helpful! Have a good weekend!

 

[Jeff@Carbon6]

The SOS kit is a nice complete kit. It can be a little fiddly to get the linkage correct and get the tb's synced but all in all very well engineered. You may want to look into a light flywheel also. That will really make the revs come up fast...

You may also want to look into filter options. Driving around with open horns can be asking for cylinder scoring from debris. Just something to think about.

 

[johnjohn]

I just put the SOS kit on this last week. The 1st thing i'd say is order them as soon as you can, it took most of the summer for SOS to get them to me.

 

[Rusted_nailz]

Dan is selling his itb setup in the market place right now. No wait

 

[Rusted_nailz]

Link. http://nsxprime.com/forum/showthread.php?t=175685

 

[J KRIB]

If you decide to get the ITB kit from SOS and the AEM ems ask Chris for the ITB base MAP. If you are gonna do the 3.5L motor get the larger ITB'S 50mm or 52mm. Not sure if it is gonna be in your budget or not but apparently the TODA cams are supposed to kick ass with ITB'S since you can run lumpier cams, I am saving up for them myself.

 

[cherylmejia]

i dont understand why he is trying to sell for 7K? i thought the kit was only 4700 ?? am i missing something?

 

[ALwAyS4SaLe]

Comes with aem with all associated gauges and tune which comes out to 10k new for everything... It's essentially a turn key install ...

 

[macninja77]

Im gonna get some for my 05 soon as i get some cash together

 

[Ponyboy]

Not as purdy as jeff's but it's got a bigger engine.

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[nismor32gtr]

ITB kit

Not as purdy as jeff's but it's got a bigger engine.

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Call me crazy but isnt the point of the ITBs to increase the air flow into the combustion chambers? why would you add a restrictive intake pipe and filter instead of just adding individual filters on the ITB horns. If you did it for cooler air then building a box with a large opening on the top of the box and using 2 large K/N flat filters to like you would use to replace the stock ones in the stock air box would allow more flow or having one at the end of the box for ram air perposes. The box looks good but your increasing the air flow and then just resticting it again. Take it from a guy that has built many air boxes for triple carb straight 6 engines and when you enclose it and add a 4-5in diameter pipe and filter they get starved for air like going back to a stock instake system with a single throttle body. You could have gotten the same effect from just porting the intake manifold and and putting a very large throttle body.

 

[Ponyboy]

Take it from the guy that owns the car, has done multiple dyno runs in it w/ the box open and closed that showed minimal loses via the filter…you're crazy.

 

[docjohn]

lol............

 

[liftnot]

thou shall forgive the youth Shawn:wink: 4 they think they know it all in the digital age. We are so "old"-school. Use the virtual dyno next time to see the gain:smile:

 

[Ponyboy]

thou shall forgive the youth Shawn:wink: 4 they think they know it all in the digital age. We are so "old"-school. Use the virtual dyno next time to see the gain:smile:

Good point. Hope I didn't run him off. Just didn't feel like explaining the build again. I'm feeling…aged now.

 

[davidf]

Where did you get that airbox? Very sexy.

 

[Ponyboy]

Where did you get that airbox? Very sexy.

It's the prototype version of the airbox that SOS was intending to market. Don't know if it's changed but I'm waiting on the production edition and then will switch them out.

 

[greenberet]

Call me crazy but isnt the point of the ITBs to increase the air flow into the combustion chambers?

No, I believe the point of ITBs is to get a quicker throttle response by moving the throttle plates close to the combustion chambers.

Airflow into the engine is determined by how restrictive the intake system is, at what rpm resonances are set up, etc. Where along the intake path you have the ability to choke the airflow with a throttle shouldn't impact the maximum amount of air the rest of the system can flow. Ferrari put individual throttle bodies on the 109 bhp/liter F50 in 1996 but they didn't on the 109 bhp/liter Enzo in 2002 or on the 126 bhp/liter LaFerrari in 2014.

Replacing a restrictive single throttle intake system with a free flowing ITB setup can let an engine breathe more air, but not because of where the throttles are located.

 

[stuntman]

Take it from the guy that owns the car, has done multiple dyno runs in it w/ the box open and closed that showed minimal loses via the filter…you're crazy.

Pic of your filter setup? What were the losses?

 

[Ponyboy]

Pics are in my gallery. The losses averaged a little over 8hp (IIRC, 8.4).

 

[stuntman]

Pics are in my gallery. The losses averaged a little over 8hp (IIRC, 8.4).

Thats a pretty good amount... I think you'd have smaller losses by going to a larger filter, larger tube to your airbox, and getting ambient air from outside the engine bay.

 

[Ponyboy]

I think you're on the right track. The present version is an SOS prototype that incorporates a "smallish" box and a filter w/i the engine bay. My idea was to use the stock filter box with bigger tubing - everything bigger along the stock intake path (well, except the filter). So there's def. room for a little improvement.

Actually, I've been attempting to put something together similar to the Kakimoto NSX air box and tubing and ditch my desire to make it look as OE as possible.

 

[stuntman]

^That's nice!

You want a decent sized plenum (some math behind it) and an nonrestrictive inlet.

Check out the size of the 3.2L S54 BMW M3's iconic "Motorsport" intake plenum (the filter is in the center of the plenum and spans the entire width of the airbox):

(on the racecar, both kidney grilles in the front fed the intake)

BMW's 4.0L S65 Plenum:

 

[Ponyboy]

IIRC, you want an airbox volume of something like 3.xx your displacement. However, that was from a motorcycle airbox text book. But then you have to measure your harmonic resonances and vary where the intake runner length makes the best power which then varies your trumpet length and diameter. It's all very computational fluid and solid mechanics engineeringish that'll make your head spin if you let it. Add to that engine bay size limitations etc and you've got a lot of variables that affect the end result - and will likely negatively influence the ideal size.

In the end, and now, I just want everything as big as possible so that any restriction is minimized. Have tried a few outside the community options and the fab date is really long. Considering that, the CF fab'ers on prime are a persnickety bunch and haven't answered my request for custom fabrication so maybe outside the community is a viable option after all.

I'd bet greenberet knows a few formulas to determine the ideal size and shape of an airbox...

 

[GhettoRacer]

any dyno charts of your all motor setup Shawn? looks and sounds good. been tracking much lately?