Twin plenums and TB's ?

[Doubt_Incarnate]

i'm getting back to work on my car, and i've decided to go the easy way out, im switching back to my iron head setup. to keep it from looking run of the mill i'm pondering trying to peice together a dual plenum and throttle body setup. I know someone else has tried it, but i cant find the thread anymore, it may have been back when it was GMF. What size plenum would you recomend? i was going to snag some t6 aluminum 3" squar tube from ebay, and use a couple of stock TB's.

[RacerX11]

Something like this? It isn't twin TB, but could be made to work with twin TB's quite easily.

If you have access to someone that can weld aluminum good, you can build it the way I did. I chopped off the end of the intake ports on the middle section of the MPFI intake. I then cut some 1/8" thick aluminum plate aproximately 2-1/2" x ~12" or so. I rough-cut the opening for the intake ports, then welded this to the runners. I then used a grinder to open up the holes to match the ports, and radiused the ports for a smooth transition into the plenum. I then took some 0.090" aluminum sheet, and bent it around some 2-1/2" OD pipe to make a U-shape. I trimmed the legs of the U to length, and welded this to the 1/8" plate, completing the shape of the plenum. All that was left was to weld on the ends of the plenums, and flanges. Constructed it this way allowed me to clean up the inside of the port entrance much better than if I had used a pre-made tube for the plenum.

Marty

[RacerX11]

Here is the intake installed. I used a Y-pipe, and single Ford 65mm TB, but it wouldn't be much harder to use twin TB's and a balance tube.

Marty

[Doubt_Incarnate]

Yeah, thats sweet. prety much what i want to do, but with 2 TB's. i was going to just make some plenums that would bolt to the top of the middle intake. what size did you make your plenums? was there a noticable different in performance? what was the trade off? why do you have to have a balance pipe?

[Guest]

I gotta ask....

You're going back to an iron head set-up because of looks?

[Doubt_Incarnate]

no, i just dont want to have cut up my existing harness to change to the new connectors, my soldering isnt worth much. i dont want to have to search for the electrical problem later when my crappy soldering inevitably fails.

maybe my soldering sucks because of my crappy tools, i should get all new tools

[fivepointhustla]

I have been trying to find pictures of that intake for a while. I knew your screen name was something x11 but couldn't remember. I have a stock fiero intake whick sucks ass. My 3.2 (bored stroked 2. Just dies because of the intake. Me and a million other fiero owners would be more than interested in that intake design. Would you be willing to sell that to me a or make one for me? I really need that and I'm sure a little extra cash never hurt.

How does it perform? Any bottom end lose? Driveability issues?

[geoffinbc]

no, i just dont want to have cut up my existing harness to change to the new connectors, my soldering isnt worth much. i dont want to have to search for the electrical problem later when my crappy soldering inevitably fails.

maybe my soldering sucks because of my crappy tools, i should get all new tools

Get premium solder man. And use the stuff for TV and delicate electronic repair.

Man I have tossed so many rolls of shit solder in the garbage. With good solder just heat up the wire and touch the solder to it. It should flow in very nicely. If it balls up bad and drips off then either it is extremly dirty, but most freshly stripped wire never has this problem, or your solder is shit.

A clean gun makes a difference but it does not have to be an expensive one.

[sharkey]

no, i just dont want to have cut up my existing harness to change to the new connectors

stop right now. i said the exact same thing i didnt wanna hack up my harness or swap a harness, and thought i could get the power out of the ironheads. well, i was wrong. after a year of building the engine, 3 weeks to swap it in, build the headers and exaust, a build totaling $5g canadian, i ended up with basicly the same power levels and 1/4 mile times just a few tenths faster than a stock 3.1l, a swap i could have done in a weekend and spent $500 on. all of it because i didnt want to swap a harness.

had a just swapped the harness from an 87-90 cavy, everything wich would have plugged in. i could of then used gen 2 or 3 top end, and could have built a hybrid or 3400, and i would be in the mid-low 14s without ny problems, all for the same money.

[torq455]

Franz did that same set up. I forget he s/n. He said the top end was great, but he lost a lot of the low to midrange. The runners are way too short. So, in short, made it slower due to no torque. The throttle was extreamly touchy

[Superdave]

no, i just dont want to have cut up my existing harness to change to the new connectors, my soldering isnt worth much. i dont want to have to search for the electrical problem later when my crappy soldering inevitably fails.

maybe my soldering sucks because of my crappy tools, i should get all new tools

Get premium solder man. And use the stuff for TV and delicate electronic repair.

Man I have tossed so many rolls of shit solder in the garbage. With good solder just heat up the wire and touch the solder to it. It should flow in very nicely. If it balls up bad and drips off then either it is extremly dirty, but most freshly stripped wire never has this problem, or your solder is shit.

A clean gun makes a difference but it does not have to be an expensive one.

x2

I solder for a living (kinda).. get yourself a Flux pen, a cood coating of flux on your wires before you solder helps transfer the heat better and will get you a solid connection w/o much work.

[TurboZ24]

I always use a silver content solder with my butane soldering iron. I actually get it from radio shack of all places, because it's the thin wire, works way better than that thick crap you see at most places.

I was thinking that if I wanted to mod my motor anymore, I'd mod the upper intake manifold like that, but I'd put a crossover before the TB and use like a 70+ mm TB or something like that. Now, if I do a TT setup for a different chassis, I might do dual throttlebody, but with a crossover tube between them.

[Hybird]

What exactly would be the point to the crossover in there? Equalize pressure or somethin. .

[RacerX11]

What exactly would be the point to the crossover in there? Equalize pressure or somethin. .

Yes.