Compatible Throttle Bodies

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 8:25 am

Does anyone know of any larger throttle bodies that will work with the Fiero and its sensors? I have been told the J-body V6 throttle bodies will work, are there any others?

Aaron · Post by **Aaron** » Mon Oct 24, 2005 10:58 am

As far as sensors go, most every GM throttley body will work. Bolting it on is another story. But IMHO, it isn't worth doing unless you are fixing the plenum itself, so a cusom flange would be in order anyways, so you may as well. I think a built 3.4 OHV could make good use of a DOHC 64mm throttle body.

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 11:28 am

Thanks Aaron. I did see someone on Old Europe get one to work, he bolted it upside down. I think 62mm should be good, then I won't need to port it. That will be 10mm or 1 cm (love the metric system) bigger and should give me more flow.

I will be changing the plenum and runners, or at least modifying them. I got too many ideas at the present time, but in any case, I will need a bigger TB to get the 3.4 to 200 hp.

Now where to find one?

Kohburn · Post by **Kohburn** » Mon Oct 24, 2005 11:30 am

if you can find one a 96+ northstar TB is about as big as you are gonna find production - also an LS1 and some trucks use the same basic TB

whipped · Post by **whipped** » Mon Oct 24, 2005 12:46 pm

keep in mind that larger doesn't mean better

If you threw on a northstar throttle body for example, you'd only have to open the throttle body by 20% to go to "wide open throttle". Put your foot down more and you're not going to go any faster.

So it would be a touchy throttle, and you wouldn't go any faster once you opened it past 20%

Kohburn · Post by **Kohburn** » Mon Oct 24, 2005 12:48 pm

yeah - TB doesn't do much without supporting mods - primarily that damn stock plenum - the neck is so restrictive

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 12:56 pm

Well I have numerous options for this pleum/intake modification. In the current modification I am thinking about, I would be installing a new neck on the plenum, EGR delete, TB coolant delete, increase plenum size, and increase TB. That along with some major porting and so on. I think the Caddy will be too big. I think a 62mm would be perfect. I currently have a 3.4 pr throttle body, but I don't think it is all that much bigger than a ported Fiero TB.

I want something that will still give me some good air velocity at lower RPM, but flow enough to feed the engine at high RPM's. There was a nice cheap TB on the 60 degree site but Koburn bought it. You bastard haha

I thought you would have went with the Caddy set up, there are alot down here. Found a rebuilt for $125 CDN which would be $100 even in the USD.

Kohburn · Post by **Kohburn** » Mon Oct 24, 2005 1:14 pm

had a hard time getting anyone to respond to me to ship a N* tb so I grabbed that one for 55$ shipped

I also just ordered my fiberglass and 500* aluminum filled hightemp epoxy to build my new plenum

probably going to end up carving it out of foam - covering the foam then digging the foam out (the self expanding stuff doesn't dissolve like the blue foam does)

after a few extra coats of the aluminum epoxy ontop i'll sand it smooth and it'll look like a cast aluminum intake plenum

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 1:24 pm

Do you think in your situation that the N* would better suit your build? The aluminum epoxy actually looks like aluminum? I had no idea. I have never heard of or seen this stuff before. Thats pretty cool.

Good luck, sounds like your intake is going to be rather amazing. I wish I had more time and skill. I thought about converting a carb intake into an EFI intake but didn't have the equipment.

I think if GM would have done a better job with these intakes in the first place we wouldn't be sitting here trying to figure out how to make them better.

Aaron · Post by **Aaron** » Mon Oct 24, 2005 1:25 pm

Oversteer wrote:Well I have numerous options for this pleum/intake modification. In the current modification I am thinking about, I would be installing a new neck on the plenum, EGR delete, TB coolant delete, increase plenum size, and increase TB. That along with some major porting and so on. I think the Caddy will be too big. I think a 62mm would be perfect. I currently have a 3.4 pr throttle body, but I don't think it is all that much bigger than a ported Fiero TB.

Well the 91-95 DOHC had 62s, but they aren't removable from the plenum.

The 96-97 DOHC had 64mm throttle bodies, and they were removable. For your purpose, I think this one would be perfect. Might want to try http://www.car-part.com, but they are generally expensive.

Aaron · Post by **Aaron** » Mon Oct 24, 2005 1:33 pm

Oversteer wrote: I think if GM would have done a better job with these intakes in the first place we wouldn't be sitting here trying to figure out how to make them better.

GM did a perfect job from the factory, for what they wanted and needed. It needed to look good, and provide good low and midrange throttle response. For this it does its job, it just restricts at the higher RPM. Much like the DOHC intake. It is part of the cause of the motors running out of breath after 6000rpm. But for what GM needed, it was perfect.

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 2:14 pm

Thanks for the tip Aaron. I guess it would be hard to put an earlier TB onto the Fiero when it can't be removed.

Aaron · Post by **Aaron** » Mon Oct 24, 2005 6:16 pm

Oversteer wrote:Thanks for the tip aaron. I guess it would be hard to put an earlier TB onto the Fiero when it can't be removed.

Yah, kinda...hehe

You could get the plate itself out, but that doesn't do much good without the whole piece/assembly.

Shaun41178(2) · Post by **Shaun41178(2)** » Mon Oct 24, 2005 6:57 pm

whats your budget? Your best bet would be to get a truleo and haev them make it witha 65 mm tb opening.

You cna then get a cheap ford tb and bolt that straight to it with the stock sensors. I thjink someone else has already done it.

basically you tell truleo to make the tb flange 65 mm and with a ford tb bolt spacing.

otherwise just stick tothe DM ported tb and matching plenum. I picked up about 3-5 hp or so with just the tb by itself. I dynoed it like 6 or 7 years ago.

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 7:03 pm

I want to try and fail at making my own intake. A dual runner for a pushrod has been the failed attemp for the last little bit, but I don't think I am going to give up just yet.

I could afford a Trueleo but hate the way it looks. I want to make a good looking intake that will do the same. You don't realize how little room there is on top of the 60 degree until you actually try and put something there.

Shaun41178(2) · Post by **Shaun41178(2)** » Mon Oct 24, 2005 8:19 pm

buy mine.

Oversteer · Post by **Oversteer** » Mon Oct 24, 2005 10:48 pm

What the SS Enterprise?

Shaun41178(2) · Post by **Shaun41178(2)** » Mon Oct 24, 2005 11:31 pm

what else?

I am ready to move on. I got bigger fish in the pan now

Series8217 · Post by **Series8217** » Mon Oct 24, 2005 11:33 pm

aaron wrote:Well the 91-95 DOHC had 62s, but they aren't removable from the plenum.

I beg to differ. The 91-95 DOHC TB has actually been used for a 2p8 intake before.

Aaron · Post by **Aaron** » Mon Oct 24, 2005 11:43 pm

Hahahahaha I stand corrected. Not too shabby of a job either. And thinking about it, it isn't too bad of an idea, except you have to buy and waste an entire plenum. But you wouldn't have to worry about a flange, the IAC is integrated, not too bad of a plan thinking about it.

Oversteer. I have an offer for you. If you find an entire upper plenum, and want to cut off the throttle body, I'll buy the rest of the plenum off of you. I have been drawing up some ideas on a gutted 91-95 plenum with a big throttle body, and could use a plenum with no TB arm that way I don't have to cut one off and waste it. Let me know, they can normally be found on Ebay or the message boards for $20-$30, and I'll pay half what the plenum cost you (Within reason). If you're interested, make note of where to cut it. I need that far right bolt bore, and I need the plenum itself. I don't need any part of the intake arm or EGR adapter.