GM 3800 V6 Swap
 

The car:


2004 RX-8 6 speed
94,000 miles, second blown motor. Rusted to bits body.
Total gut in progress.

The engine:


Came from a 1998 Pontiac Grand Prix GTP (So I was told)

Clean engine, well taken care of, Already had a smaller pulley.
Decided to put new Main and Rod bearings for piece of mind.


Also got a new timing chain on it and a complete gasket set with aluminum carriers to thwart the common leaks these engines have.


Got around to a test fit.


Yes, it's a heavy engine, It's also a gutted car and considering the shifter location I think the engine sits pretty far back still.


As far as mods to fit, I think some modding to the supercharger is in order to nestle it up against the firewall and turn the throttle body to the side so It can actually fit and work.

Then I'd probably need to space the sway bar forward a couple inches and drop the steering rack, which will happen with a hydraulic rack I'm fairly certain.

Then there's plenty of space around the engine for exhaust or turbos should I decide to switch over.

I have a manual flywheels that fits, It'll bolt to a Doge Dakota Bell housing that'll make it fit to my Pontiac Solstice Transmission.
So far it's looking VERY promising.

No more VR6 swap? Did you verify it is an L67? Even if so, pretty lame in stock form. Much like the VR6.

You have a pontiac solstice transmission? Did it have an ecotec with it?

Here's a good site for 3800 GM performance parts. 3800

I don't think I would have gone GM, but why not go with the ecotec motor the transmission was connected to from the solstice?

ZZP has a lot of good stuff for the ecotecs as well. ecotec

Once I was able to get a good look at fitting the VR6 I realized the cost of such a project would really make it take forever to get finished. Too much custom fab and machining cost for me.

It is in fact an L67, beefy rods (compared to the NA counterpart)
It's listed at 240hp and 280 ft-lbs stock, but the forums claim that's a conservative rating.

I do have the trans, came from an '08 Solstice. I didn't get the engine, but I have the same engine in my G6, neat little engine but the 3800 has more room for power.

I ordered from ZZP for the G6 as well as the gasket set and t-stat for the 3800.
The 3800 will bolt right up using a Dodge Dakota bell housing, and I didn't really want to go with another 4 cylinder.
I was thinking I'd keep it supercharged until everything gets finished, then invest in turbos for more fun potential.


These engines can push 500-600hp on stock internals fairly easily.
With the smaller pulley, larger injectors, meth injection and a tune I'm being told 400 ft-lbs of torque isn't hard to accomplish.
So we'll see

How did I know he'd be the first one here to try and shit on your swap.

Looking good! Great engine! Can't wait to meet up with youon race day. :)

Don't hold your breath. I'm not that either of your swaps will ever be completed. But it's nice to know you are thinking of me.

Looks like it fits nicely. I'm jealous of all that space.

GLWB

Thanks! I'm sure with the accessories and supercharger in place it'll take up a bit more space.... just a bit.
The haters just fuel the need to finish :yumyum:

Right 9k. Cause we both spend 1000s of dollars and 100s of hours of research for no reason.

Prescription8 - At least you have ready-to-boost engine management. :) I'm still trying to decide between pggy-back or go stand-alone and attempt to get it exempted. There's something about the challange of maintaining total drivability and compliance that I seem to enjoy. Some of the guys here don't get that it's the journey not the destination that fabricators enjoy. They just assume buy a bolt-in kit and be done with it but that's the same as just buying a car and being done with it.

It is quite a journey I'll admit that haha.
But yea it seems the 3800's ECU has quite a lot of room for tuning and variables.
I did some research on ems/magasquirts and a lot of people just recommend using the stock ECU.
I understand there's some limitations as to how high the tables go regarding MAF Freq, but alas there are ways around that as well.

As much as I'd like to run a stand alone with pretty minimal wiring. I think tackling the stock harness and getting the stock ECU tuned will be my best and most cost effective option.
Plenty of wires to dig through!

Just use a larger maf and adjust accordingly. Done.

Yup. The common solution is one of gm's v8 engine's maf and tb (lq4)

After some weighing of options and some other parts popping up I'm leaning towards going turbo from the beginning. This way I can avoid having to modify the super charger, and I'll get more potential for fun.

Im surprised it fit behind the battery brace. Its gonna gain some real nose weight that iron motor and turbo system. Im just curious why you didnt use an LS1. Approximately the same weight, tried and true platform, swap options already available and not too far from that 6 cyl dimensionally speaking. Plus they make more power easier and more reliably. Im not bashing your build but I believe the obvious choice over the 3.8 would easily be the LS motor.

LS Swaps are just too common IMO. Every drift day I attend there's at least 3 or 4 LS swapped cars there. I want to be different and do something that hasn't been done. I enjoy the challenge of making it all fit and work as well as having something unique.
Can't buy a swap kit for a 3800 after all lol

https://cimg1.ibsrv.net/gimg/www.rx8...022b6106cc.jpg

Theres a reason they are popular. Its cool to be different but......its also cool to have a car that works well.

Just because it isn't an LS motor doesn't mean it won't work well...

So I weighed the long block today out of curiosity.
294.4 lbs

Guess we will never know. Only LS swaps and a windsor swap have ever been able to test how well they work. The 3.8 can be a badass motor. Takes alot more money to make it do the same things the LS will. 295 lbs isnt light for a stripped down longblock.

It may not be light but I think it'll work out well regardless. I'm pretty sure with the full gut and some relocation of items I can probably balance it pretty well. Hopefully lol

I see a lot of V8 and 4cyl turbo swaps. I think it's about time V6 swaps start to fill in the mix

Plenty of V6 swaps have started...

Yep. 3.8 is a decent motor but takes a lot of money/work to make into a formidable power plant. Splayed mains, pricey heads, and parts market is small/expensive. LS motors work well because you can make a lot of power with "junkyard" parts. Guys routinely make 450+ hp with a rectangle port top end 6.0 and a large cam. Your 3.8 will take much more money and innovation to get to that number. You seem to know Kicker well and he is quite innovative. Good guy to know. Judging from your previous build and the pace of his, it's not likely we will see any results soon though. Don't mind the rotary guys trolling this thread. They love to see swaps fail. I'm excited to see a RecipX8. I would have chosen a better motor though. I daily'd a GTP for a while. Fun but nothing to be proud of with the amount of money I had in it.

I don't mind piston swaps, I can appreciate a clean build done properly. The problem is that 99% of the pistion engine swaps result in failure or even when they do run the car overall is still a jalopy. But there are a couple (exactly two) that I can appreciate. As for this one, well it will never happen, mark my words.

Not true. There are many swaps I read about and don't comment on.
I don't claim to know more than anyone, but when people who know more than I do offer advice, I usually consider it a good idea to listen.
If someone chooses to ignore conventional wisdom that is proven, and choose to waste time and money, go right ahead.
They'll get no attaboys from me, and deserve any scadenfreude they endure.