Twin Throttle Bodies (No 56k.)

[cke]

Seems like it'd be half the headache of dealing with ITBs, but you're going to still have to tune like a mofo.

It's a progressive setup, but it'd be able to deliver much more air to the runners.

This is a setup for a... Hyundai.

http://www.rpw.com.au/Photos/Twin%20Throttle%20Body/Hyundaitwinbig.jpg
http://www.rpw.com.au/Photos/Twin%20Throttle%20Body/4g15twintb2.JPG
http://www.rpw.com.au/Photos/Twin%20Throttle%20Body/4g15twintb3.JPG

It seems like they took the TPS port and threw on an actuating arm to the other throttle body's cable linkage. The adjustability point allows you to tune deliverage. In this case, it's 30% throttle and up.

So you can retain stock emissions controls and still gain a lot of AF benefiets.

Thoughts? Comments?

[ZackieDarko]

if you could make that work CORRECTLY it would be pretty impressive

obviously not "one of a kind" because this person had it done first but it would be very very impressive none the less

hell i'd do it if it were possible and a write up was done on it

[cke]

The thing is, I'm considering building my own IM. After doing a little research, I stumbled across this.

ITBs are great and all, but depending on various factors, it doesn't stay streetable and retain emissions controls.

This would be a great compromise.

[Bglad420]

Thats pretty original!

[cke]

I was thinking about this all day today.

Instead of having a mechanically actuated second throttle, why not utilize a secondary style controller and have it open up at a given RPM?

Have it toggleable, programmable, et cetera.
Though having completely different fuel maps would be required to switch along with it.

I think this would be the best idea.

[88eyeguy]

You could control the fuel and timing maps with MegaSquirt. That would be my suggestion, though I don't know whether you'd have to convert to OBD 1 to use MS or not.

[bobafett]

im pretty sure than megasquirt doesnt care what OBD you have, it doesnt really use those functions, as far as i know...

if you want tunable ignition u will need to convert to DIS of some nature, or at least an electronic dizzy. but dis with crank trigger seems to be the way to roll from what i hear...

[88eyeguy]

yeah, you're right. I was just checking on the MS site. You have to change your ingition system anyway, since the megasquirt replaces your ECU. but it's cheap and really effective if you know how to tune or can get it efficiently tuned.

[cke]

I'm probably sticking with an OBD1 conversion. ;)

I've built my fair share of circuitry and know how long that would take me, compared to the half-a-work day of effort required to do an OBD1 conversion, provided I have an already converted dizzy.

[cke]

Additionally with MS, you can still use the stock ECU to control ignition and so on. Check out the Honda success stories. The dude with the CRX (B16, ITBs) did that.

[AccordEpicenter]

that just doesnt look like a very good manifold design and having the 2 tbs is gonna make air moving 2 different ways in the plenum. Sounds funky. If you want REAL gains you need to get a different intake mani

[cke]

hahaha, what do you expect? It's an Elantra intake manifold! I was just using that as an example.

Crazy Aussies and their Hyundais.

[gfrg88]

why dont you just use a huge jg edelbrock intake manifold for a b18c5, thats what i plan on getting

[A20A1]

Why not lower the signal output from each tb throttle position sensor... that way when both throttles are open it is equal to one normal tb open output.


I dunno if that is progressive, the throttles look like they are directly connected making them synchronous.

I can't really tell by the pics but I don't see any mechanical delay in the linkage. Usually there will be a part of the linkage that will begin opening the secondary once the throttle on the primary was partly open. Also the rod connected to the secondary throttle would have a smaller radius (Quicker Opening Rate), the smaller radius would allow the secondary to catch up to the primary throttle so both plates reach WOT at the same time, even though the secondary was delayed.

In the picture the radius on the primary and secondary are both set at the same distance. ( the third outer hole in the annodized blue part. )

I'm just going off of how carburetor progressive secondaries work.

[A20A1]

Anyone use these TB's before?
http://www.dh-racing.com/index.html

[cke]

25hp or more?

Sensors indicate large amounts of BS emitting from the URL, captain.

[A20A1]

Ahaha, it says
"Gauranteed 20 hp at the wheels"
instead of
"Garunteed 20 hp increase over stock at the wheels"

[2drSE-i]

325 seems like an aweful lot for a TB anyway. i had been contemplating a dual TB setup for a while, i just like the know-how and tools...and money...to do anything about it. seems like a good way to get some power and MPG to me.

[gfrg88]

im just going to try that ford tb to see how it works out.....

[Legend_master]

The Hyundai manifold is to thin and the corners are to jagged, but I still give props for all the hard work. I think this setup would yield better air flow and give the ability for dual mini turbos (factory eclipse etc). Or you could go all motor. Either way you can use the throttle setup from the ITBS to make this work and you would not have to worry about the mechanism problem. Your main problem is fuel and I would definitely go OBD1 for that. G/L with the project.

http://img.photobucket.com/albums/v667/Legend_Master/twinthrottleconcept.jpg

[Versanick]

I think AccordEpicenter hit the nail on the head here, that air is going to be flowing both ways in the plenum, probably impeding flow to the runners. Without the manifold actually being properly engineered to flow air from both directions in the plenum (aka primarily having air flow to one side of the plenum from one TB and the other from the other TB, or something of that nature), the cut and pasted throttle body on the opposite side will probably do as much harm as good. I'm doubting much of a power increase, with hard-to-predict outcomes at different RPM's. air flow patterns change with airspeed.... there are so many factors involved.

Definitely find a nice BLOX or AEBS manifold and if you want, a bigger TB. even ITB's aren't that huge an advantage over a really well designed regular manifold.

[A20A1]

Even some ITB setups have plenums prior to the filter