Who has gone 3.4 to 3.8 swap (nay sayers stay out)

[pyrokilla]

I don't wanna hear bull**** about cost. I just wanna know who has done this to confirm a few parts of this swap.

[SkAchilles]

Its exactly the same as doing an LT1 swap basically. besides front springs, all the same things need to be replaced. If you are spending the money and going to the work, swap in an LT1, not a 3.8

[MustangEater8251]

<blockquote>quote:</font><hr>Originally posted by SkAchilles:
Its exactly the same as doing an LT1 swap basically. besides front springs, all the same things need to be replaced. If you are spending the money and going to the work, swap in an LT1, not a 3.8<hr></blockquote>


Sorry I to be a nay-sayer, but what he said, same things for the v8 swap.

also might want to look into if 3.4L and 3.8L guage clusters are different. For some reason i think they are. I may be wrong.

But the power difference. Look at my sig. I got rid of my 3.4L for a 3.8L, not worth the costs in my opinion from what I see.

main reason I did it is I got rid of a car with 130k, dead tranny, bad brakes, tires, interior wiring and trashed interior, to a car 7 years newer, with 30k, fully loaded, showroom clean, for $3,000 less then the blue book value, and I knew the previous owner(my dad is awesome ;) )

I would go lt1

[3.4 slow to go]

I'm going to be doing one. Having a logistics shortfall right now :( :(

[MustangEater8251]

also thinkging about this on my way home.

If you don't have a 5-speed might have problems with a pcm, and gear ratios.

unless you change your gears, or maybe get a 5-speed pcm, and put a th700R-4 tranny with it, might be cheaper, then buying another 3.8L tranny, I would assume the 460le bell housing would work with a th700r4.

[speedracer95v6]

I am in the middle of this swap(3.4L to 3.8L). The 4l60e should bolt right up to either engine. From the books i have, a 4l60e has the same bell housing on both engines..and the v8 version looks the same too (as far as the bolt pattern...we put one on an old 4 popper and it fit..) other than getting the gearing changed(need to fix that stuff in the pcm..3.4l came with 3.23 stock, 3.08 for 3.8L unless y87) and you will need to figure out the 02 sensor situation at the and after the catalytic converter. If you get an engine with all accessories, computer, wiring harness, and mounts, you should be on your way. Other than the 02 sensor figuring out, the exhaust is staight forward...just get headers and a Y pipe...the old exhaust wont hook up unless you have everything from heads to the catalytic converter. Adding headers and Y will give you slightly better horsepower, so you might as well. While my 3.8 is sitting around, I am going to put the stage I xtreme energy cam, port my heads and intake, port throttle body, and install headers and Y. I'm leaving out the catalytic converter and putting in 02 sims. I'll have to have computer worked on(i have a place locally that can adjust advance, gearing, and limiter). They said they should be able to tune 15-20 rwhp..just gotta run 91 octane. Hope this helps.

[pyrokilla]

<blockquote>quote:</font><hr>Originally posted by speedracer95v6:
I am in the middle of this swap(3.4L to 3.8L). The 4l60e should bolt right up to either engine. From the books i have, a 4l60e has the same bell housing on both engines..and the v8 version looks the same too (as far as the bolt pattern...we put one on an old 4 popper and it fit..) other than getting the gearing changed(need to fix that stuff in the pcm..3.4l came with 3.23 stock, 3.08 for 3.8L unless y87) and you will need to figure out the 02 sensor situation at the and after the catalytic converter. If you get an engine with all accessories, computer, wiring harness, and mounts, you should be on your way. Other than the 02 sensor figuring out, the exhaust is staight forward...just get headers and a Y pipe...the old exhaust wont hook up unless you have everything from heads to the catalytic converter. Adding headers and Y will give you slightly better horsepower, so you might as well. While my 3.8 is sitting around, I am going to put the stage I xtreme energy cam, port my heads and intake, port throttle body, and install headers and Y. I'm leaving out the catalytic converter and putting in 02 sims. I'll have to have computer worked on(i have a place locally that can adjust advance, gearing, and limiter). They said they should be able to tune 15-20 rwhp..just gotta run 91 octane. Hope this helps.<hr></blockquote>

Thanks for the helpful post!

[SkAchilles]

not sure about the 3.4 and 3.8, but the V8s have entirely different bolt pattern on the bell housing. As for the o2 sensors, what the hell are you talking about? You know that the engine wiring harness is what they plug into, right? If you have an engine, wiring harness, and PCM, why would you have to worry about o2s?

I guarantee dash harness will not plug right up since all 3.8s are OBDII, thats wiring issues there. You will probably have to get VATS disabled in the PCM, new k-member, rubber fuel lines from fuel rail back, new exhaust, radiator, hoses, intake plumbing, and other than that it will go right in. If you are doing an engine swap, the 3.8 seems like a waste of time to me when an LT1 is the same labor.

[MustangEater8251]

3.8L and 3.4L is a different bellhousing as far as I know... both will botl up on the tranny end but I don't htink so on the engine end.

[Jerriko]

The bolt patterns for the 3.4 and 3800 are identical. The 700R4, 4L60 and 4L60E use the same case. 90 degree motors used to have different trans bolt patterns but that was changed when the 3800 FWD motor was created to save space in the engine compartment.

[RedFrk13]

Yeah, the 3.4 and 3.8s have the same bolt pattern, v8s are different. I think it would be fairly easy to replace a 3.4 with a 3.8 as long as u got the mounts and wiring harness. The hard part would be splicing the two harnesses together. Another issue might be the 4l60. I think prior to 95, they used a vacuum modulator instead of some electronic part they use now, so that might cause some problems.

Then again, I custom fit one fit into an S10, so anything looks easy to me! :D

[speedracer95v6]

I have the wiring harness but the 3.4L only has 2 02 sensors whereas the 3.8L has(from everyone i have asked) 4. I have the 02 sensors on the exhaust manifolds on my 3.8L, but the people i bought it from didnt includ the connector(to the rest of the wiring harness) that had the catalytic converter 02 sensors. I will have to get that connector and the sims.

[3.4 slow to go]

3.8s have 4???? interesting. I haven't found any wiring for the other two. Not in teh holy book haynes for a 95 3800, my point to point wire track downs, or in Magnus's point to point refrence.

[RedFrk13]

<blockquote>quote:</font><hr>Originally posted by speedracer95v6:
I have the wiring harness but the 3.4L only has 2 02 sensors whereas the 3.8L has(from everyone i have asked) 4. I have the 02 sensors on the exhaust manifolds on my 3.8L, but the people i bought it from didnt includ the connector(to the rest of the wiring harness) that had the catalytic converter 02 sensors. I will have to get that connector and the sims.<hr></blockquote>

So your saying you didnt get a complete wiring harness? All the tranny wires and connectors were cut off?

I would assume the wiring hasnt changed so you will be able to solder your original tranny wires to the new harness. It should work fine.

I dont have the back 2 o2 sensors connected at all yet because I need 50" extentions for each. It runs fine without them except for some codes. I have been daily driving it like this for 5 months now.

Here is the pinouts for 3.8s, each o2 sensor has 4 wires, but only 2 give info to the computer.

Pinout

[ November 23, 2003: Message edited by: RedFrk13 ]</p>

[94BlkMaro]

I am right behind you forget the ls1 i am looking for gas mileage with more power. I have seen a 3.8 supercharged out of a grand prix gtp and a I was wondering if it is the same as the gm 3.8 and fith the same. [img]graemlins/burnout.gif[/img]