Next Project: Ideal throttle body size?

[BBVNSX]

Kaz tested big bore throttle bodies for NSXs. He mentioned what he found here:

http://www.nsxcb.co.uk/showthread.php?10146-B-line-motorsports&p=94119#post94119

In a nutshell: a bored-out throttle body can increase an NA2’s power but not a mildly-modified NA1’s. If vendors claim differently, I assume it’s just marketing hype.

If we look to GT-ONE bbtb+tune, they claim that power increased from 268 to 304 ps in a mild tuned AT car (not sure but i think they state only Exhaust...) and the rev limit was increased to 8000 rpm for the AT... but i agree that this could be just marketing hype. And kas is really the guy to trust on this matter...:wink:

using those formulas 74mm TB can theoretically deliver 316whp and 363 engine hp

316whp and 363 engine hp should be enough for me, especially if we could achieve this number without opening the engine :biggrin: :biggrin: :biggrin:

 

[greenberet]

If we look to GT-ONE bbtb+tune, they claim that power increased from 268 to 304 ps in a mild tuned AT car (not sure but i think they state only Exhaust...) ...

A stock automatic is rated at 256 ps (252 hp). If GT-ONE claim a 12 ps increase with nothing other than a new muffler, their claims seem to be rather high. Which probably helps boost sales.

 

[L_RAO]

In addition to my 74-mm Blox TB equipped (and ported) intake manifold, I will also flow test and dyno test this kick-ass BBK/Edelbrock oval TB equipped (58 mm x 2) intake manifold that Ponyboy was nice enough to lend me.

A big thumbs up to Ponyboy!

 

[A.S. Motorsport]

Ahhh a LT-1 TB i really like those, although getting a universal hose on there is going to be a little tricky.
BTW it's gonna be to big for a mild NA car. (stock displacement that is)

The math behind the those LT-1 TB's
Surface area of the valves 2642mm
that times two: 5284mm

A NA NSX should be able to do with just 3850mm TB valve surface area, equaling about 70mm = ~320 HP flywheel.
Quick rough calculation learns you that equates to roughly 12mm per HP or 0,08311 HP per MM
Allowing the LT-1 Tb's to flow a NSX well in to the 430HP range on it's flywheel 350-365 WHP NA

A 6mm spindle to which the valve attaches takes up about 408 mm Surface area on a 68mm TB
A few weeks ago i was at a motorsport industry convention in Germany and there i saw displayed a idea I've head for years a TB valve with out a spindle

All strictly theoretical, i have the feeling i'm missing a factor in my calculation.

A bit off topic,
Lotus designed LT5 engines with tipple valve staggered throttle bodies (LT5 = Lotus designed DOHC Corvette ZR1 engine c.a. 1989)
I recall that being to vary the way air entered the manifold and interact with plenum and runner breathing.

It head one tiny valve that opened earlier than the twin larger ones.
A very interesting engine as it has valve actuated second runners (runner per valve! with 16 injectors)
Each runner head it's own injector 1 runer per valve equaled 16 runners 16 injectors, 8 runner control valves.

 

[Ponyboy]

In addition to my 74-mm Blox TB equipped (and ported) intake manifold, I will also flow test and dyno test this kick-ass BBK/Edelbrock oval TB equipped (58 mm x 2) intake manifold that Ponyboy was nice enough to lend me.

A big thumbs up to Ponyboy!

You're welcome, buddy. Sorry it took so long to get to you. Hope the testing proves useful.

 

[96cxt]

Looks geat. I'm interested in the outcome.
Do you have pictures of just the manifold with the new flange on it with out the throttle body on it? Will you still have the Idle control working on it?

Side note:
Since you are going with a much bigger throttle body you are letting in more volume of air at partial throttle (normal driving), so the MAP sensor will signal the ECU for more fuel which inturn will give you more power at less throttle.

But keep in mind this will make your throttle very sensetive in normal driving/ partial throttle. This is not a big deal but just something to keep in mind.

 

[L_RAO]

Looks geat. I'm interested in the outcome.
Do you have pictures of just the manifold with the new flange on it with out the throttle body on it? Will you still have the Idle control working on it?

Side note:
Since you are going with a much bigger throttle body you are letting in more volume of air at partial throttle (normal driving), so the MAP sensor will signal the ECU for more fuel which inturn will give you more power at less throttle.

But keep in mind this will make your throttle very sensetive in normal driving/ partial throttle. This is not a big deal but just something to keep in mind.

No, I should be getting my finished IM/TB unit soon. The guy who did everything is quite meticulous so he wanted the TPS, IACV, and all other misc. vacuum holes to be as close to OEM as possible.

Thanks for the heads up. I am looking forward to getting rid of that vacuum reading and seeing how much power it translates to.

 

[L_RAO]

I love working with meticulous people. Here is a new throttle cable bracket designed from scratch for the Blox TB setup.

This lovely piece will be done in about 2 weeks, and then we are ready to begin testing.

Christmas is going to come about 2 weeks later than usual for me.

 

[sparky]

that's a work of art and science... I assume this is an expensive exercise?

curious that the triangular brace in top left is only connected on one edge ?

 

[96cxt]

Very nice indeed.

So i'm guessing these will not work for the drive by wire NSXs?

Can't wait... Any idea on price?

 

[Nero Tenebre]

Yes a DBW solution would be terrific Are you or he planning to make them and sell them if they prove successful?

 

[L_RAO]

Yes a DBW solution would be terrific Are you or he planning to make them and sell them if they prove successful?

I will do some research on what a DBW solution would consist of.

Very nice indeed.

So i'm guessing these will not work for the drive by wire NSXs?

Can't wait... Any idea on price?

Depends on what you're asking about...I was thinking about offering everything as a complete package, as in:

Ported intake manifold
Welded flange
All vacuum lines ready to go
Blox 74 mm TB
Throttle cable bracket

I already have 9 "spare" flanges and will have 4 "spare" cable brackets (machine shops have minimum orders). If you want just a particular piece, let me know.

 

[Nero Tenebre]

The main issue with the DBW TB is electronic calibration so you will need some electronics tools and the knowledge of how to tune/calibrate it. Also I hear you MUST have the car present bc it must be installed then calibrated. I don't think you can even calibrate it on another DBW car and ship it calibrated... So it's not as simple as just boring it out even if people sent you theirs. I even heard that if you try it your car may not run at all or have problems (most likely at idle like ITBs)

Look into it and see what you can find out. You have a knack for making the impossible work If it works out somehow without having to ship the car, I personally would not need the PP manifold so I would prefer it separately.

 

[96cxt]

I will do some research on what a DBW solution would consist of.




Depends on what you're asking about...I was thinking about offering everything as a complete package, as in:

Ported intake manifold
Welded flange
All vacuum lines ready to go
Blox 74 mm TB
Throttle cable bracket

I already have 9 "spare" flanges and will have 4 "spare" cable brackets (machine shops have minimum orders). If you want just a particular piece, let me know.

Well it depends on how much of the manifold needs to be cut off, how the vacuum lines will be ran, etc...
Will all the sensors bolt right up to the new TB?

 

[L_RAO]

Well it depends on how much of the manifold needs to be cut off, how the vacuum lines will be ran, etc...
Will all the sensors bolt right up to the new TB?

The manifold needs to be cut about 2 inches into the "neck" (where the OEM one internally tapers).

All vacuum lines and sensors will bolt right up, OEM style.

Are you still running the BBSC?

- - - Updated - - -

The main issue with the DBW TB is electronic calibration so you will need some electronics tools and the knowledge of how to tune/calibrate it. Also I hear you MUST have the car present bc it must be installed then calibrated. I don't think you can even calibrate it on another DBW car and ship it calibrated... So it's not as simple as just boring it out even if people sent you theirs. I even heard that if you try it your car may not run at all or have problems (most likely at idle like ITBs)

Look into it and see what you can find out. You have a knack for making the impossible work If it works out somehow without having to ship the car, I personally would not need the PP manifold so I would prefer it separately.

I just got some very interesting news...will keep you posted as I find out more.

 

[Nero Tenebre]

Oh I hope it's good news! I would love to get this final NA mod done before I have to open up my engine to go farther.

 

[ken sampson]

I will be selling my BLOX 76mm View attachment 95953DBW TB if anyone is interested send me a PM.

 

[L_RAO]

Ken,

What are you switching to?

 

[L_RAO]

So I had some free time the last couple of days, and here's what I did.

I took the (magnesium) belly pan of the intake manifold and painted it with high-temp engine paint.

(3) coats of primer
(3) coats of white
(1) coat of clear

 

[sparky]

how many hp did that add ?

 

[L_RAO]

how many hp did that add ?

I don't think it will add power, but minimize the power loss when the car is run really hard (i.e., heat soak).

This is probably a more effective mod for those running a PD-type supercharger.

 

[sparky]

I don't think it will add power, but minimize the power loss when the car is run really hard (i.e., heat soak).

I was being flippant of course, but now I see you're still on theme. The paint acts as an insulator / reflector of engine heat, to keep the intake / intake air a little cooler thus improving combustion and resulting hp. A small contribution then, to the extra 36 whp you're seeking, and we're all hoping for ... :smile:

 

[RYU]

Gold leaf f1 style heat shielding might work well there tOo

I don't think it will add power, but minimize the power loss when the car is run really hard (i.e., heat soak).

This is probably a more effective mod for those running a PD-type supercharger.

 

[racer9x]

I might be wrong, but I thought polishing or jethot coating was recommended for better heat desipation, can someone provide some input as I am also looking for solutions and would like to do it right the first time.

 

[sparky]

heat dissipation is not needed, rather heat insulation / reflection since the objective is to keep the intake plenum cooler, and the engine block is the heat source.