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-   -   Supercharged 3800 Swap (https://www.rx8club.com/non-rotary-swaps-196/supercharged-3800-swap-259888/)

kickerfox 12-22-2015 02:55 AM

LFXs are expensive.

Enginerd 12-22-2015 11:56 AM

Even from the junkyard? I know they're fairly new but at least as a crate motor they're less than an LS. I know it'd be more expensive than any of the V6 builds on here but I'm just thinking ahead, hopefully when prices come down a bit and donors go up.

Prescription 8 12-22-2015 01:34 PM

LFX are pretty new engines, an older 3.6 would probably be easier to find for a decent price, Maybe get lucky on a part-out somewhere.

But for me the boost and tuning abilities of the 3800 make it easier for me to do myself.
I haven't looked into the internals of any of their "high feature" v6 engines, but they do run a pretty high compression ratio. And the integrated exhaust manifold of the LFX raises concerns with turbos. I wonder how those engines handle egt's

Tuning the 3800 uses free open source software and a $260 interface. I'm fairly certain the LFX ecu's need something more sophisticated and expensive, Like HPTuners which requires you buy credits to unlock an ECU.

And since 3800's are so plentiful if I blow mine, I'm sure I can find another one laying around somewhere for under $500.

All in all it looks like a great engine, It's just expensive to purchase and run. And I plan to beat the crap out of this car. The 3800 is pretty small and a little heavier but pretty stout when tuned properly.

Enginerd 12-22-2015 11:52 PM

Now that makes a lot more sense than just being expensive. I know there's at least one cadillac model LFX that uses twin turbos so I guess it's possible in some way.

I'm just trying to evaluate all the possibilities where cost isn't necessarily a major factor but still a minor one. For your circumstances the 3800 is the sensible option. For mine so far, the LS makes a good case for itself.

Prescription 8 12-28-2015 11:33 PM

Ah that's right! I do recall reading something about a turbo Caddy with that 3.6 V6. I just never really looked into.
I stayed away from an LS because they're just over done in my opinion. Every drift event I go to has at least 3 or 4 LS swapped cars. I'm not debating their capabilities or anything, but I want to be different and have a somewhat out of the box build.
Kicker's build is pretty out of the box, but he has very different goals than I do, IE keeping everything working and making it all pretty.

Since I want a stripped out racer I think a cheap and plentiful V6 like the 3800 was a good choice, considering that I likely will damage the engine in one way or another, And since the 3800 isn't as saught after as an LS they stay cheap and easy to find.
My only real competition with the engine is those Fiero guys and their 3800 swaps haha
For a V6 the weight is a bit on the heavier end, pretty comparable to an LS, but with enough boost I'm sure I can make up for it... heh

kickerfox 12-31-2015 01:56 PM


Originally Posted by Prescription 8 (Post 4736173)
My only real competition with the engine is those Fiero guys and their 3800 swaps

Said no swapped RX8 owner ever.

Khurram 02-03-2016 10:39 AM

Hey,

Just wondering any updates on this build?
Post some pics :-)

Cheers,

Prescription 8 02-03-2016 11:08 PM

No real progress yet. I've been focusing all my time to making the money to pay off my largest debt. Which is almost done. Hopefully by the end of this month I can begin getting the rest of the parts and work towards getting this baby running this year.

I did hold up the camaro exhaust manifolds to the heads and found I can flip them to point em forward to route for the turbo, but they come up and sit next to the valve covers which is also where the frame rails sit on the 8.

At least the rear manifold on the FWD version has a flange with welded on runners, so I can chop those off and use the flanges to make my own manifolds.

wankinit 03-18-2016 03:33 PM


My only real competition with the engine is those Fiero guys and their 3800 swaps haha
Ha! I use to be one of those fiero guys! If I kept it long enough, I would of definitely swapped in that 3800 sc. I was drifting in that car before it was a sport (that's how old I am.) might have something to do with all that "dukes of hazards" I watched growing up. (Again, my age)
Good luck with your build, I'm looking forward to its completion.

Prescription 8 05-17-2016 08:21 PM

Tore out some more panels, including the dash. Tossed all the junk into the bed of the S10 I just did a trans replacement on. Runs great for a '94 beater

I plan to pull the hvac and see how I can fashion my own dash. I'm still on the fence on rather or not I want to use whats left of the factory dash and mount a panel to it. But I think a custom dash would add to the fun factor of the build.


Next up I gotta get a new steering and set that in place so I can get to mounting the engine and see just how much of a pain that steering shaft will be.

Prescription 8 09-14-2016 03:33 PM

After failing to properly modify my sub frame, in part due to rust, and mostly due to my inexperience and such, I decided to buy a new front sub frame.
New sub frame came from Tennessee with far far less rust. They even included all the bolts that mine didn't want to give up.
I still couldn't get the drivers side control arm off.

You can clearly see the difference between Chicago area vehicles and Anything south of Illinois haha.


I will cut the factory steering rack mounts off again and likely get someone to step in with drilling and welding so I don't screw this one up. More welding practice for me on scrap!

I also got my clutch and PP and am working at getting the flywheel balanced and driveshaft shortened.

Prescription 8 10-04-2016 03:30 PM

Got the brackets on the frame cut off and ground away. Hit it with some flat black just to stop any rust before I can move on.


I got some assistance from kicker on drilling the mounts for the rack this time. Still in the processes of welding that up and getting it all settled.

Flywheel, Clutch and PP have arrived and have been used to get the Slave cylinder spacer figured out.
Thanks again to Kicker for getting that one machined for me.

Clutch is a "Stage 3" 6 puck sprung copper ceramic with a PP capable of holding 375 ft-lbs, so the seller says.


Here's part of the Dakota bell housing, with the solstice trans and the Colorado slave cylinder and of course that pretty spacer.


I also have the Wilwood 3/4" bore master cylinder which pairs perfect with the slave and stage 3 clutch.

And I have the Wilwood proportioning block so I can delete the ABS and get my braking system situated.

Prescription 8 10-05-2016 04:05 AM

Boy what a difference 15 minutes and an experienced teacher do to my welding skills. haha
Just some test weld of tubes into exhaust pipe adapters to get ready for welding the frame.


Thanks again to Kicker for the welding tips and helping me get the steering rack situated. It's nice having someone there to confirm my thoughts or tell me how wrong I am haha.

Anyways we got the tubes mounted and welded along with the stop washers for the rack.
Just gonna box in the front side of the tubes with some pipe sections to make it a little cleaner looking and help give it a little more strength, though I doubt it's really needed.

No_Doritos 10-05-2016 11:31 AM

Nice progress so far. Mag I ask how much that prop valve cost you? I need one as well for my 350/5 speed swap. I haven't looked yet cause I'm stI'll sourcing a good engine.

Prescription 8 10-05-2016 12:20 PM

$75 for the Wilwood valve off eBay. There's other valves that are adjustable and cheaper available, and also no adjustable ones.

Prescription 8 10-06-2016 03:41 PM

Once again with kickers help, and most of his welding....
I got the washers backed and encased with some exhaust tubing.

For the top I made cardboard templates using the tube from a paper towel roll, then shaped everything on a bench grinder for as close a fit as I can get.

I almost went with getting these welds tigged so it would be all nice and pretty looking. But at this point I just want to get it going and get it done. This car has no room for pretty stuffs haha.



Once the primer has a good chance to dry I'll get some black paint on it and get it up back in the car so I can get the tie rods and steering shaft sorted out.

kickerfox 10-06-2016 04:01 PM

Don't blame all those goobers on me! :P

Prescription 8 10-06-2016 09:24 PM

Nah that must be some instability in my power line

Prescription 8 10-11-2016 06:46 PM

Got the subframe painted up with some gloss enamel. Lets see how that lasts...


Kicker made a sweet adapter plate to fit the wilwood clutch master in the car, moved over the studs from the stock master, and added studs for the wilwood.



And here it is all bolted up together to test fit it.



While out the pedal was reinforced with some washer welded in as it was already cracking pretty badly.

Got that installed in the car and fits perfect.


Next I was trying to decide where to fit the wilwood balance block
I think I may tuck it between the brake and clutch master, but forward so it's closer to the strut tower. Then I can make a bracket, keep it away from hot surfaces and make it easily accessible.

kickerfox 10-19-2016 11:29 PM

That subframe looks great.

Bwek 10-20-2016 01:40 AM

Nice job guy, You probably could've gone with an NC subframe and steering rack,

that's what i'm doing for my swap

kickerfox 10-20-2016 02:14 AM

There's quite a few things different about the Miata's sub vs. the 8. It may or may not bolt in the car (I hear it does) but the suspension is different. They are not directly interchangeable.

Prescription 8 10-20-2016 12:20 PM


Originally Posted by Bwek (Post 4787318)
Nice job guy, You probably could've gone with an NC subframe and steering rack,

that's what i'm doing for my swap

I could also just swap in the Miata engine and call it a day.
But this is more fun :mdrmed:

The Mustang rack looks like it'll net me some quicker steering than a miata rack. And the modifications to the frame weren't terrible heh

Bwek 10-21-2016 12:17 PM

2 Attachment(s)

Originally Posted by kickerfox (Post 4787321)
There's quite a few things different about the Miata's sub vs. the 8. It may or may not bolt in the car (I hear it does) but the suspension is different. They are not directly interchangeable.


Not sure where you heard this info, I have an NC subframe in my 8 with 8 arms attached to it and everything Bolts in, the NC rack also fits perfectly Even all the little Brackets for the Abs lines and brake line bolt on to the NC subframe the same way as it did with the 8 Subframe.

Prescription8 I'm Sure there are alot more mustang ratios available than Miata So that would make sense esp if you want a faster ratio.

Not putting in a Miata 2.0 in my car, 2.3 disi :)

Not to thread jack, just in case there is any doubt lol
Attachment 217743
Attachment 217744

Bwek 10-21-2016 02:44 PM

miata parts
 
I actually have an nc subframe/steering rack in my car with the 8 arms and knuckles, it does work not sure where you got your info from kicker,

Priscription8 a faster rack would make it worth it for sure, not using a miata engine in my car but a mazdaspeed3 so far its been pretty much bolt in

Prescription 8 10-21-2016 06:18 PM

Well bolt in definitely speeds things along. I hear those are somewhat peppy motors too

kickerfox 10-22-2016 10:21 PM


Originally Posted by Bwek (Post 4787638)
a faster rack would make it worth it for sure, not using a miata engine in my car but a mazdaspeed3 so far its been pretty much bolt in

What's the lock to lock on the NC?

Bwek 10-23-2016 03:20 PM

2 Attachment(s)

Originally Posted by kickerfox (Post 4787751)
What's the lock to lock on the NC?

Ill have to check next time i get it up on the hoist.

Figure my post is useless without Pics

Attachment 217736

Attachment 217737

Prescription 8 10-24-2016 10:01 AM

Oh wow that frame looks a lot closer to the 8's frame than I thought, I must have found pics of the wrong year Miata or something when I googled it.

Bwek 10-24-2016 10:52 AM


Originally Posted by Prescription 8 (Post 4787912)
Oh wow that frame looks a lot closer to the 8's frame than I thought, I must have found pics of the wrong year Miata or something when I googled it.


Yep its basically Identical except for the Steering rack mounts and the motor mounts

suicide-racer 10-29-2016 03:16 PM

It's amazing how much room there is behind the dash in the 8.

Cheers John

Prescription 8 10-29-2016 03:38 PM

Without the steering column in there it feels sooo spacious

suicide-racer 10-29-2016 04:44 PM

Was worried about how much my engine would require cut out the bulkhead, until I removed the dash & seen the space behind.

Cheers John

Prescription 8 10-29-2016 05:14 PM


Originally Posted by suicide-racer (Post 4788972)
Was worried about how much my engine would require cut out the bulkhead, until I removed the dash & seen the space behind.

Cheers John

Don't forget about the wiper motor and linkage in the cowel

suicide-racer 10-29-2016 05:20 PM

I know. Engine is very close to it. Almost forgot all about it. Just going to clear it.

Cheers John

Bwek 10-30-2016 08:57 PM


Originally Posted by Prescription 8 (Post 4787912)
Oh wow that frame looks a lot closer to the 8's frame than I thought, I must have found pics of the wrong year Miata or something when I googled it.

yep it bolts right in and the arms bolt right into the nc subframe.

Looks like you're making more progress than me, ive been hunting for a S2 rx8 trans to steal the tail shaft housing,

are you cutting your firewall? I just started cutting today made me shed a tear haha

Prescription 8 03-07-2017 11:51 PM

Got the steering shaft finished, added a u-joint and just tacked it in to check fitment, It's good so I'll need to do a final weld on it.

So then I was able to get around to the test fit


Got the trans super far back and found I still had room to push the engine further back


It all seems to fit neatly in the bay, Pretty nice package. Still trying to decide how I want to handle the serp belt.

No_Doritos 03-15-2017 11:17 AM

i just love the fact that your swapping this 3800 into the rx8. i recently picked up a 99 buick park avenue ultra with a supercharged 3800 s2 engine. loving the power and the dependability of it.

keep it coming. looking forward to more update.

Prescription 8 05-01-2017 12:13 PM

I acquired the parts and dropped them off at a local machine shop to get my driveshaft jig made. While that was being done I began working on my exhaust manifolds.
To keep cost down I went to a local metal supply shop and got some hand rail tubing and elbows. Not ideal but the ID and price make it almost perfect for my build.
I also dropped the $40 on a harbor freight tubing notcher, Modified that according to a youtube video and got pretty decent results.
For my first try at fabbing a manifold I think it came out fairly decent.
Then Kicker stopped by and got it lined up even better than I had it.


The bottom log is just set in place for the pic

I haven't decided if I want to mig it all or have someone tig it all for me. Either way I'm planning on getting the manifolds ceramic coated to help hood temps and thwart corrosion.


The driveshaft jig got made and I began drilling the holes at one end for the flange.
I can use this to line my trans up with the diff. This should put my engine exactly where it needs to be so I can get my engine mounts going and settle everything in place.

No_Doritos 05-18-2017 06:00 PM

ill say this again, i love the fact that you are doing this swap. i love the 3800 engine because its so versatile, compact, and has gobs of power when built up right.

this swap was honestly my next choice next to the 4.3l chevy engine when it comes down to overall fun and reliability. but, i am going with a 5.3l ls based engine this time around in my 8.

Prescription 8 05-24-2017 02:14 AM


Originally Posted by No_Doritos (Post 4819828)
ill say this again, i love the fact that you are doing this swap. i love the 3800 engine because its so versatile, compact, and has gobs of power when built up right.

this swap was honestly my next choice next to the 4.3l chevy engine when it comes down to overall fun and reliability. but, i am going with a 5.3l ls based engine this time around in my 8.

Thanks! I'm excited to get it done. Don't see many 3800 RWD setups that aren't Fiero's or Camaros heh



To update the thread:
Got a bracket made up with the help of kicker.
It'll hold the wilwood proportioning valve and a couple of mounts to clip a couple of custom hoses I had made to feed the block.
I later got the end changed with a 90 degree fitting.
I plan to make little 180 degree bends to go from the clipped in hoses to the block.

mtmetzger 06-02-2017 09:37 AM

Interesting engine choice. A local guy is selling one for a few hundred... Looks like it's coming along nicely!

No_Doritos 06-04-2017 12:05 PM

are you welding the injector holes shut? may i ask why if so? give us some dirt already. lol

Prescription 8 06-04-2017 03:31 PM


Originally Posted by mtmetzger (Post 4821733)
Interesting engine choice. A local guy is selling one for a few hundred... Looks like it's coming along nicely!

Yea these things are everywhere. If I blow this one up I should be able to find another fairly cheap heh



Originally Posted by No_Doritos (Post 4821979)
are you welding the injector holes shut? may i ask why if so? give us some dirt already. lol

Yessir.
The Supercharged 3800 has the injector holes in the heads. The N/A Camaro uses the manifolds for the injector holes, so thus I'll end up having 12 holes for 6 injectors, had to close up one set. If anything I can always drill and tap em for meth injection heh.

Prescription 8 06-04-2017 03:49 PM

Kicker welded up my injector holes, then went the extra step to smooth out the inside of the port.

Went ahead with the cross member beneath the car to mount the trans and fab a ppf mount to hold the diff.

Started with round tube and some steel plates to make inserts for the frame rails.


Did the same for the other side

also took some plated, drilled matching holes and welded on some nuts just to make assembly easier.
Got some square tube and cut it to length with a bit of an angle to match the frame rail angle.

Notched the square tube to fit around the brake/fuel lines and welded it up to the side plates. Bolts in place perfectly.



Some 3/16 was added to cap off that notch so the tube was still closed off and strong.

da67goatman 06-05-2017 01:51 AM

So not going supercharged? or just not with the factory Eaton?

Prescription 8 06-05-2017 02:08 AM


Originally Posted by da67goatman (Post 4822034)
So not going supercharged? or just not with the factory Eaton?

Going turbo on a previously supercharged engine. So it has the lower CR and beefier rods.
I PM'd an admin about changing the name of this thread but never got a reply.

Prescription 8 06-11-2017 12:56 PM

Moved the trans out of the way and popped in the aluminum Isuzu driveshaft. It fits without rubbing the heat shield, ppf, or any other component. Things are working out as planned which is very nice.
Now to get the driveshaft shortened, finish off the ppf and complete the trans and engine mounts.

fireman33 06-29-2017 02:12 PM

i am liking your build i am starting on the same set up i have a 3800 out of a camaro with the t5 trans i was wanting to know if you have pics of the motor mounts it really would be help full to see it done so i have a idea how to do it

9krpmrx8 06-29-2017 02:21 PM

"Billed" :lol:


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