3500 TB, 3500 UIM on 3400?

[keithk831]

I'm looking at different options for my 3400 top end, and I have a question. 60degreev6.com makes a 3500 plenum ported for the 3400 LIM. If I got that and bought a 3500 throttle body, is it possible (or has it been done) to use that TB on the 3400 without changing to the "drive by wire" setup? Can I simply swap the linkages? If so, would it be worth doing that instead of spending $300+ on a billet 65mm throttle body for the 3400 plenum?

[bszopi]

No, you can't just swap linkages. The DBW setup is a completely different beast. I have seen people convert DBW TBs to manual TBs (not the 3500 one, but others), so it is possible.

[Superdave]

I tried a while back, it would have taken too much work...

[whitelightnin04MC]

I'm glad this thread got started. I've been thinking of doing a 3500 upper but have a few questions. I searched a little and read a few of the topics, but most of them didn't seem to answer the questions that I have. I'm curious as to what modifications need to be done to put the 3500 upper onto my 3400 lower. What has to be done with the map sensor, the evap purge, and anything else that may arise from doing the swap. I've already got the plenum spacers and a 62mm tb. So, aside from the throttle body adapter plate, what else will I need to buy and do to make this work?

[IsaacHayes]

http://60degreev6.com/showthread.php?t=33133

I think that covers everything.

[whitelightnin04MC]

It sounds like a lot of little modifications. I don't have a vacuum controlled tranny. I've got a 2004 Monte Carlo. I'd really like to talk to someone who's done this on a newer car and maybe get some pictures of what has to be done. I know what all the parts are, but I work and learn better with visuals and hands on.

[whitelightnin04MC]

I just took some pictures, and so far, it looks like all i have to do is block up the IAC port on the 3500 plenum and then mount the MAP sensor somehow. Does the MAP mount to the 3500 plenum the same way it does to the 3400. I've got to mount it and run vacuum hose to it from a vacuum port on the manifold. Does anyone know if the harness will reach. My MAP harness is really short for some reason. I remember because it was a pain in the butt to hook back up when I installed the spacers.

[IsaacHayes]

You can run some rubber tube from the manifold to the MAP and secure the MAP somewhere else even on the firewall like the old motors. I'm just going to use the 98+ style MAP found on caviliers that the 3500 uses. But you could just zip tie it to the coil packs or whereever and run some rubber tube to it.

Tap the IAC/Evap hole with 1/4" NPT and run that vacuum to the FPR.

[whitelightnin04MC]

So you are saying that a 98+ Cavi map sensor will work? Is the harness different? If it is, I'll probably just use the one I have. It's harness is really too short to do anything with. Could I splice the wires and make them longer?

[whitelightnin04MC]

I guess the MAP is my only issue. I'll be searching the j-yard by my house for some late model cavi's and sunfires. So, I should get the map sensor and the male connector together right?

Isaac man, I gotta tell ya, seeing your finished manifold make me want to do this even more. I see all these people with the 3400 Engine cover and your manifold totally dominates them in every way.

[IsaacHayes]

Yes get a Cavy map and the harness that connects to it. It will fit into the plenum. Then solder the wires to your old harness connector and use some shrink wrap. That is if you don't have the 3500 MAP. They are the same style. The 3500 does have a bracket that holds it down, but it also has a rubber grommet that seals it up too. You could make your own bracket really easy out of some metal L bracket cut to shape if you wanted I bet.

I went with the 3500 MAP since mine came with it and the bracket. Looks nicer than relocating the big old stock MAP somewhere and running another vacuum line.

Isaac man, I gotta tell ya, seeing your finished manifold make me want to do this even more. I see all these people with the 3400 Engine cover and your manifold totally dominates them in every way.

Thanks that means a lot! I took some time to gasket match it, and cut off all the tabs and grind the casting seams smooth and paint it and all just as I had envisioned it.

Here's another picture.



EDIT: Since you have the 65mm TCE TB already, just get the TB adapter on the store here and you don't have to worry about a throttle body. The adapter even comes with o-rings so you don't have to buy gaskets! I'm using a 56mm 3400 one with the adapter since I can't afford the nice 65mm TCE unit yet.

[whitelightnin04MC]

Actually, I've only got the 62mm tb. At the time, I didn't have too many plans for the car, but since then, I've acquired headers and a couple other goodies. The 62mm won't be a problem will it? It may not be the best thing, but it's sure an improvement over the stock 3400 TB.

Also, are you saying that I should try to find a 3500 map with connector before I settle on a cavi sensor? I"ll look at what they have this saturday. Man this thing is gonna look PIMP.

[IsaacHayes]

62mm, still that's a lot better than my 56mm. Good enough. The 3500 map is the same map as a 98+ cavi uses. Either one works. You'll need the wiring harness connector either way unless you use your old MAP. When I bought my 3500 plenum from a place on car-part.com they shipped the whole plenum with all accessories bolted on, so I got the map and braket with it. I still had to go to a junkyard and find a 98+ cavy/sunfire and have the sensor connector fall into my pocket. It was easy cause they had pulled the engine already and the wiring harness was just right there with a good length on it. I got some other stuff that day that I payed for too. I don't know what they'd charge for a connector, but minimum $10 and I wasn't sure if that was per part lol.

Are you going mod and paint your plenum too?

[whitelightnin04MC]

Are you going mod and paint your plenum too?

Hell yeah! BTW, you got PM.