3500 plenum upgrade.

[IsaacHayes]

I kept looking at the 3500 UIM (plenum) and thinking how I want one on my car. Well going to do it, not doing any other performance stuff or anything radical. But I've had the manifolds off several times and figured why not. I'm not going to put 3400 heads on, as the cost of gaskets/bolts and decking the heads would put the total cost of this project higher than a complete 3400.

So I'm not going to make my car "fast", just give it a little more pep than it already has just for fun. The 3500 plenum once port matched to a large port 3400 lower will outflow a ported 3400 plenum. Not only that, it has no runners, shortening the overal runner length by about 3" which equals more high end HP. In addition, it has equal flow to all the ports, and a larger plenum volume. The TB neck doesn't open up until after it passes the first 2 ports. It can accept a 65mm TB without porting as well.

There are several issues with this swap, as it's not plug and play. I've got them all sorted out, but the main one that will make me nervous and take time is that since I must use a large port 3400/3100(2000+) style lower manifold, and I don't have roller fulcrum rockers there will be clearance issues with them. I'll have to grind on the LIM like bszopi did, and check. I could just bolt on new 3400 heads that flow better (larger valves) and have roller rockers without issues, but that puts the cost through the roof. I'm not looking to get serious, just wanting a little boost in power, so forget that idea.

The 3500 plenum will give you a increase in power on the high rpms above 5000, and also it gives a decent bump on the low end as well! I hope this will help with my granny tranny gearing. It's supposed to have a flat power curve instead of the exponential power ramping the traditional 3100/3400 manifolds have. So you get gains all over the RPM range.

Not sure what my peak gains will be, but I'll have the larger lower and the even better 3500 upper.

I'll be the first old style head 3100 with this setup. And the only Beretta with a 3500 UIM. I'm going to go with a CAI in the fender, but I will wait until I have the manifold on, as the TB neck extends further out so I have to wait to see what bends/pipes I need.

[nocutt]

Quit screwing around...*cough*cough*turbo*get*one*cough*cough*...who said that  

[IsaacHayes]

And now I need your guys help!! Below I've photoshoped some pictures of what my motor would look like painted. Which do you like better? With or without the red lines? And should I grind off the bottom tabs like in the last picture to make it look cleaner?

A)
B)
C)

[IsaacHayes]

Bah nocutt, If I had the funds, tools, time I would. Probably get a 93 3.1l 5spd project car and do a 3400 TGP chip setup. Add extra goodies to the motor as well. Might go with a CSC intercooler and headers...  

But alas this is my daily driver and can't be down for long.

Consider this an engine dress up mod instead!    Now vote for which combination you like!!

oh and, quit screwing around and finish your car!!! hahaaha    

[nocutt]

Cee-foe-soe  

[zach82]

(nocutt @ Apr. 22 2006,16:22)Q
U
O
T
EQuit screwing around...*cough*cough*turbo*get*one*cough*cough*...who said that ÂÂÂ
*cough cough* screw turbo* cough* sb v8 * cough  

Anyway, on the topic, I think it looks much better with the tabs gone.

[IsaacHayes]

nocutt: I agree! Fo reel, no doubt!  
zach: I agree, tabs will be gone!

I think the red lines makes it look too much like an engine cover or something. Reminds me of a pontiac motor or a quad4 engine cover or something....

I wonder if I can find any heat resistant chevy decals that are the correct size. Otherwise I'll hand paint it on there with the aid of a stencil/outline.


Should I take off the tab on the side by the PS pump and Alt? The stock 3100 manifold has this, and I can't figure out what I'd use it for, and it sure isn't used in our application for anything.....

[rweatherford]

Guess that's why I like B with no tabs...    

[woody90gtz]

B or C

[JeffD]

What's the 3500 UIM off of, I WANT ONE!
And, uh I like C.

[IsaacHayes]

woody90gtz: B/C, so do you like it with or with out the tabs? With or without the red lines? LOL. What I'm asking is what do you like specifically?

scberetta3800: how come you want one? Don't you have a sc3800? You'd have no need for it! The 3500 plenum is from the 3500 60degree V6 motor. Pontiac G6 has this motor. Do you like the look of it a lot or something? Stock the intake doesn't look good at all (worse than a 3400 intake). Painting it up like I did with decals and all really made a difference though! I think I like my painted version better than a 3400 intake without lettering even.

Update: In the process of aquring the 3500 upper. Need a large port 3100/3400 lower still. I'll have to go to a junkyard to get a part I need to build my own EGR adapter. I have a throttle body and adapter on the way to me. I'm going with a 56mm TB from a 3400. That's only 4mm bigger than my stock one, but everything will bolt up to my stock cables/etc. There are no other stock TB's with 65mm opening that accept the TPS, IAC, etc easily. You could get a 70mm from a vortec v6, but that's too large for the ECM. The 3500 is designed for a 65mm electronic TB. The next best option that doesn't cause problems with the stock tuning, is a machined billet 65mm TB from TCE, but that's close to $300. So 56mm TB will have to do.

Some of the moddifing I'll be doing to get all this to work is:
*Gasket matching the LIM, port matching the UIM to the lower.
*Grinding out material from the LIM to clear my stamped fulcrum rockers.
*Grind on the TB neck of the UIM to clear the FPR.
*Grind off the front and side tabs on the UIM to improve looks.
*Mock up my EGR adapter and possibly extend the EGR pipe to it.
*Tap the IAC port of the UIM for vacuum for the FPR and trans modulator.
*Modify the stock MAP sensor vacuum tube to fit the UIM.
*Transfer the shaft of my stock TB to the 56mm unit.
*Modify the IAC passage of the 56mm TB to work with the TB adapter.
*Pick up the correct bolts for the UIM, and gaskets.
*Tap the LIM with a 3/4" NPT for the coolant pipe, or get a push-in style pipe.
*Paint the valve covers, and both upper & lower intakes black.
*Paint the red bowtie and white "chevrolet" lettering.

I think that's all really. Most of the stuff will be done without tearing into the car first. Only thing would be the coolant pipe if I swapped that, and to check rocker clearance first to see if I need to grind more before bolting it all up.

I can't wait for the stuff to get here so I can start putting it together on the workbench.  

[bonecrrusher]

Option E polish it...  

[IsaacHayes]

bone: Heh, but polishing makes my fingers tired! Money spent on a polisher can be saved for the actual parts! hehe. Seriously though, when I first saw this manifold I thought imediatly that it would look great black. Post a pick up when you get done polishing it. It will look pretty good I think, but I'm going black all the way for mine!

Hey, with yours polished like it is now, people might think at first glance when you pop your hood you have a top mount intercooler!!  

[IsaacHayes]

Ok guys, I think we've figured out no-tabs is the way to go. I really like the all black manifold without painting the grooves in the top the best. I like valve covers with color, but really don't think the shape of the gen3 covers goes well with color. I think the iron head gen1 covers were good, as they had a flat top that you could keep bare metal and it made a good contrast.

But I figured might as well see what it would look like in photoshop real quick if I were to paint the covers.

So once again, vote for your favorite. Remember that my car color is a Aqua (blue-cyan type color, not deep blue) so I don't want the engine paint job clashing. The pictures don't show the color of my engine bay, so keep that in mind when choosing. In addition to picking your favorite, also state which you would choose if you could only do black, orange, or polished.

1) Black: 2) Red:
3) Orange: 4) Yellow:
5) Red + Stripes: 6) Polished:
I figured I'd throw in #5 with the red lines again since the red cover balances out the lines a little better. Also added polished valve cover.

[IsaacHayes]

My thoughts: Red clashes with the bowtie logo and doesn’t go with aqua car color (would be ok with a black or red car). Red ridges; same thing, and they don’t look good without the red valve color. The yellow is just too bright, too many colors. The black is neutral and would look good in any cars engine bay. The orange I like, it’s more subdued than the red or yellow, and blue-car/orange accents go alright together, while making you take notice at the engine some.

So it’s down to black or orange. The Black scheme looks like a nice factory motor you’d find in a corvette or something. It’s nice but not over done. The Orange takes it one step further and catches your eye from a distance so you take a closer look and then see the nice black manifold with lettering and notice it’s not a standard 3100. Polished valve cover looks good too.

I could for either of the 3 right now. The 3 look good on screen. Which would you do?