Factory Quad FI Throttle Bodies

[Wesley]

So I'm in the planning stages for a project of mine, and I was hoping to pick the collective brain for a couple ideas.

I want to run individual throttle bodies on my V8 (Ford 302) and I wanted to know if anyone knew which production engines (4 banger or otherwise) had individual TB's. I know that a couple BMW's had them, but if I'm going scrapyard hunting I'd like a few more options. It'll be EFI. I'd prefer to use a stock quad-tb setup so I don't have to hash out a linkage design from scratch, just one to link the two banks together.

I don't have the spacing in between intake ports on the cylinder head currently, so I'll have to work on an adapter plate later, but really I just want a few cars to look at if I head to a junkyard.

Thanks.

[Ockham]

As I recall, Stack makes an off-the shelf individual-throttle setup for Ford 302s. Of course, if you're going to FSAE it (on a shoestring budget, by the seat of your pants, and with lots of JB weld and curses), then I think some late-model Jaguar 4.2L inline sixes had individual throttle bodies. Not many domestics, methinks... Some old Triumphs, but have fun finding those in a junkyard. A lot of tuner cars have individual bodies, so I bet you could scare something up from a pair of Frankensteined 4-pot intakes, or parts from same.

[Wesley]

This is definitely in the spirit of FSAE.

I don't care if they're domestic or import throttle bodies, as long as there are four of them per bank and they're either common-rail or have a linkage already.

I thought about motorcycle TB's for a little but I thought it might be hard to find any big enough. They'd have to come off of a bike capable of 175HP or so (or 1.2L spinning 14k for the flow range to add up)

[AxelRipper]

we do have one rack of them lying around that I found in our OLD office... they're either off the f4i or (more likely) off the kawasaki that we used to run and was long gone by the time i got here

[dazz]

Well the only 2 candidates from the bike world that I can think of would be:

Kawasaki ZX-14 - 44mm for '08
Suzuki Hayabusa - 46mm for '99 & 44mm for '08

8x either of the above gives well over double the cross section of an 80mm TB which is a common upgrade size for the LS series engines. How big do you need?

The other thing is that some of the bikes run double butterflies to smooth out throttle response, something you probably aren't too concerned with...

[Wesley]

While that's true that the total cross section is larger, without a plenum you'll need a TB that's closer the total port area to reduce losses.

And yeah, the goal is to improve the throttle response, which shouldn't be hard over the current carburetor. 'Busa TB's should work, don't know how easy to find they'd be.

[dazz]

Yeah, hence why I was asking what size TB's your after? I'd be trawling the drifting forums fishing to score some bargains. And then there's always ebay!

If you decide to rob a bank, you should check out Harrop, they do a really nice setup for the LS series using 55mm butterflies (plenty of nice pics on their website too! Not to mention their other super nice upgrades http://fsae.com/groupee_common/emoticons/icon_cool.gif ).

[Wesley]

Well, I need to measure my ports first, however I'm in the wrong city to do so.

I figured I could get some ideas first, since I'm going to be limited to what is available OEM. (ie, cheap)

I would imagine somewhere between 40-50mm will be sufficient.

[Adambomb]

Hmm, I don't know of any off hand, but usually in these type of ventures my preferred method is to hit up a u-pull-it type yard and just spend an afternoon strolling around. Especially if you can find a yard with a lot of old imports, they usually have wacky stuff like that. I'm almost thinking there was some VW in the '80s that had ITBs. However, based on the time I've spent in Lawton, it seems there's not a lot of decent junkyards in OK. The only yard I know of in the state that met my standards was way out in Roosevelt. It was worth the drive though. Didn't see what they had for imports, but it was a big yard at least, and they let you roam it freely. If you ever end up road tripping, I know of a great one in Co. Springs, and a couple great ones in Omaha. Also driven by a few nice looking ones in KS.

I agree though, you're going to want bigger ITBs than you'd find on any bike, and also bigger than the combined area of a large single throttle body, since it's the pulses you want to deal with, and the plenum damps the pulses. Also feeding one 625 cc cylinder at 6500 rpm is different than feeding one 350 cc cylinder at 14,000 rpm. Just like the differences in singles and fours here.

[Wesley]

Exactly, yeah.

I'm also in Fort Worth, TX now, so there are more junkyard options. I just wanted to have an idea of which cars I should browse when I make a field trip one day.

[Kirk Feldkamp]

I was going to respond to this a while ago, but I couldn't find the link I had seen before. But hey, I found it! A fantastic resource. Enjoy!

Motorcycle Throttle Bodies! (http://www.microsquirt.com/viewtopic.php?f=29&t=6627)

-Kirk

[Kirk Feldkamp]

Bump! (because this is way more important than *anything* from Stanford)

[Wesley]

Wow, that's perfect, thanks.