Hi, I'm am posting because after enjoying my V8 swapped FB for a while I have grown curious about the road not taken. By this I am referring to turbo II swaps, Bridge port, street port, turbo 12a's and so forth. Also I would like to gather the real world experiences from others for those who are currently debating on how they are going to get more power from their FB.

I'll go first,

If I were to tell others about my experience with my ford 5.0 swapped FB I would tell you that it like any other swap cost about twice as much as you think it would. It presented a never ending series of mechanical challenges, and seemed to $25 and $50 me to death. After it was up and running it took a solid month of daily driving to chase out the bugs, which of coarse cost more money and stranded me on the side of the road a couple times. Who ever tells you a V8 swap is more reliable has not gone through the process of trouble shooting any swapped car. It is now reliable, but it took a lot of work.

The stock rear end and the stock mustang trans aren't exactly a perfect match, the rear end gearing is sooooo high compared to a mustang rear that second gear is now first gear and first gear is completely useless, unless you want to burn tires. The high gearing lends itself nicely to acceleration, but freeway cruising feels a little strained after 65mph, 65mph=2500rpm which on a v8 is on the high side for cruising. Living with the car day to day is not to dissimilar from the car in stock form, it starts every time, has a very nice sounding exhaust, and is very well mannered in daily driving. I drive a mix of freeway and city, and I average between 21 and 23 mpg depending on what I'm up to. My only complaint in this department is the dual 2.5" Fox body mustang exhaust I adapted to the rx7 scrapes on steep driveways, but in all honesty I'm just too cheap to have a legit exhaust made. As with any project car you will need a daily driver!

Performance wise It's nice, I have not noticed any changes in handling, the car still grips the road very well as it did in stock form. My big fear was my FB would be an under steering pig, if any thing it the extra torque and new and improved power band translates to over steer on demand. Power wise, it does feel silly fast compared to it's former self, others with stock 5.0's have reported mid 13" quarter mile times. It's a very nice feeling to know that I can blow the doors off of so many cars which left me in the dust not to long ago. I mean honestly I couldn't count how many times I've been beaten by shabby civics with ebay turbo kits and ratty swaps when my car was 12a powered and now they are small fish, it's a nice feeling.

Looks wise the car looks exactly as it did when I started, the only thing giving away my cars v8 status is the dual exhaust which is easily spotted underneath the car, which once again is a result of my cheapness. I went through great lengths to keep the car as normal looking as possible, no hood scoop allowed! Also I don't care much for aftermarket gauges so with a little work all my stock gauges work accurately with the swap, speedo, tach, temp, oil psi, and etc. also I was even able to make the shifter look exactly the same as stock.




I am not here to endorse V8 swaps, I am posting because I could've used some real world insight as to what I was getting into before I started my project, I spent about 2 months researching and debating as to what route I was going to take with my car, and I ultimately decided on the V8 swap. But in all honesty it was a shot in the dark as to what kind of car I would have after many months of hard work and money was spent. Please, to those with built FB's put in your input, and those who have questions, please ask. Who knows this thread may be FB FAQ, or sticky worthy.

 

I built an S4 TII series 2, it too cost a lot more than I imagined in bits and bobs that complete the finished product but I can say without hesitation it is my finest achievement (kids aside!). It's running a Microtech LT-8, behaves amazingly off boost with no fuss and when you want it too it all goes apeshit and ruffles some scooby feathers. I'm not anti V8 but I wouldn't have it any other way in a Sev.
\

 

Ahhh boost, that is the one thing that really makes me wonder what could've been.

 

Nothin compares to a boosted FB in my opinion, although praps a little biased haha.

The noise is addictive enough.

 

My S5 turbo blow-through R5 13B cost me almost precisely as much as I expected, but that's because I spent a lot of time planning and researching, and then stuck to my plan. Power is great, but it didn't turn out as well as I hoped, mainly due to the difficulty of tuning a carb with boost. So I'm pulling it out and redoing it with an REW block and EFI (and a lot more power).

For anyone contemplating doing a blow-through setup on an EFI block, I highly recommend just going EFI from the start. The carb setup won't save you money over a MegaSquirt and some upgraded injectors. Not saying you can't get great results from a blow-through setup if you know what you're doing, but it ended up being too much of a headache for me, and I knew the results would never be as good as EFI anyway.

 

well my opinion may be useless, but, I just went to a 13b six port in the 84 gs with a dellorto side draft and header, nice exhaust. ya it is not boosted, but for my dd that see 75 to 100 miles a day, stop and go traffic and weekend runs, I am more than happy with 145 to 150 hp in a na that runs like a switch watch and starts with a blip of the key hot or cold. love the dependibility of a carb engine with no hassles, none the less will still blow the doors off most cars when needed. just my .02 worth

 

My original idea was to turbo my 12a with a blowthrough, I always wondered
how a blow through setup would've worked out. What kinda carb are you using?

 

Just like the post above this was also some thing I was considering, although my original ambition was to use 4 port irons with a large street port. So I presume with 75-100 miles a day the dellorto is alot more streetable then I thought.

 

way more that most peps thought. this thing runs absoluley perfect. it has taken me more than month.....250 dollars in jets, and a lot of late nights/ early mornings to make this correct. I feel a lot of relief right now knowing my ride is correct and running where I want it to be. I have requested a archive post on my dellarto jetting and tuning so others may jet close and tune as I have done. good luck with project and keep up posted

 

+1
This is very similar to my setup and I am very happy. Once I got the Mikuni tuned properly to get rid of the off idle bog it is as drivable as a stock car and with the large streetports makes good power. I realize that its not mega power like SOME of the turbo cars but still fast. Coupled with a properly tuned Re-Speed supension I was able to stay with the FDs (some highly modified) at the Tail of the Dragon this year, (they all thought I had more than a SP 4port under the hood). The biggest perk is the reliability and if something does happen to go wrong everything is so simple that diagnosis and repair is simple as can be. As far as I am concerned it is the perfect car!!!

 

45 DCOE. If I were to do it over, I'd just adapt a Nikki to the 13B manifold and boost-prep that. In a blow-through configuration, I think a 4-barrel would be easier to deal with since you have a different set of jets for WOT driving.

And yeah, I'll vouch for snivley whiplash's car. It's pretty quick for an NA, and runs far better than I was expecting. He's really got that thing tuned well.

 

You mean low. The gearing is too low. You have no top end because the rear end ratio is low. Sorry, HUGE pet peeve of mine. You are not describing high gears, low.

Anyway, pretty much what everyone has said is correct. I got on here in high school thinking I could do things far cheaper than everyone says they can be done... and I did... when it came to buying the big parts. I scoured the forum and ebay and got all kinds of great kit for dirt cheap...

But then I had to go to the hardware store and get some bolts... and then I had to go again... and then I had to order some BS $20 part off ebay... and that went on for a couple years and all the sudden I understand why people say to budget so much.

I have a few bits of advice:

1: PLAN AHEAD. Writing down "I"m going to buy an s5 block, and a 60-1" is not a plan. Plan down to what gauge wire you are going to use for every electrical bit you add, and where you will procure hardware for anything, down to the last bolt.

2: IF IT ISNT STAINLESS OR ZINC/CAD PLATED, GTFO. Common, everyday nuts and bolts that you pick up for whatever, become tomorrow's 2 hour curse fest drilling out a rusted through, snapped fastener.

3: SEE #2, AND IF IT'S EXHAUST, EXPECT TO SPEND SOME MONEY. Normal bolts don't work for exhaust... period. If you build an exhaust, get every joint v-banded, you'll thank me later. And if you use traditional hardware, get HIGH quality (not hardware store spec) stainless studs with copper plated lock nuts. Voila! Exhaust is now an easy thing to service.

4: LEARN TO SOLDER. I don't care what your EE friend said about proper butt splices. Well soldered, dielectric grease packed with shrink wrap joints have NEVER failed on me. And they look SO clean.

5: NEVER EVER EVER ACCEPT MESSY WIRING. I've bought many modded vehicles and have yet to find one without some JANKY *** wiring. Clean that **** up! See #4! Buy some self fusing silicone tape and braided sleeving and make it look pimp!

6: DO NOT PLAN A BUILD AROUND PARTS YOU ALREADY HAVE. That's great you have a $500 engine and a rolling chassis and figured, "why not?" You will now spend 10X that on an engine you may not really want once you're done. The big parts, are the cheap part of a build. Get parts that fit your needs. And no, that .48 A/R T3 your friend gave you off his Honda will NOT work on your rx-7!

7: DON'T GET TOO DEEP IN THE WEEDS. Chances are you're thinking of doing some stuff to your car it REALLY doesn't need, or some kind of complete tear down or some such non-sense. I know, I did it. Changing parts step by step is SO much smarter. Once you commit to taking the car off the road, the chances of you ever driving it again reduce to almost zero. You think you'll take the car apart for a couple weeks and do the engine swap, the ECU, the turbo, rebuild your suspension, and make a custom wiring harness and just knock all of it out at once... you won't. And if you do all that one at a time you'll still drive your car

8: YOU WANT A STANDALONE. Carbs are cool. If I had a simple N/A rotary I'd want it carb'd. However, now fuel injection is cheaper and superior in every way. And chipped stock ECU's suck. Get control over your stuff. Look into megasquirt, seriously. If you follow rule #4, it's easy, or you can buy them assembled. The new MS3 is freakishly powerful and freakishly cheap. Sequential injection, ignition, boost control, nitrous control, launch control, anti-lag, etc etc blah blah blah. All for less than 1 IDA carb. It really doesn't make any sense NOT to.

 

yeah, I'm contemplating B6T right now. be nice to have my 200hp and also get 30+mpg and maybe get to listen to the stereo too. and if the swap cost $1500 then at 12mpg improvement and $4/gallon, it will have paid for itself in under 20k.

the difficulty is, I don't see the swap running nearly that much given that I already have a Miata trans on the shelf, and the north-south oil pan will fit perfectly over the FC subframe, which is bad because it justifies the engine swap even more.

EXTRA bad is, it looks like converting a BP engine to rear drive/turbo is even cheaper than converting a B6T to rear drive, since in both cases you need to get a Miata intake manifold and oil pan, and a RWD-compatible exhaust manifold... and BPs are cheaper/easier to find than B6Ts.

Extra extra bad is, I'm not out of rotary parts yet, and while annoying after a while, they do make neat sounds. It's just a question of if it's worth about ten cents a mile *more* to enjoy.

Another way: I have a friend who traded his STi in for a WRX because having a WRX saved him $200 a month in insurance. A dime a mile difference for me can be like $300 a month difference...

 

Corollary: Never use stainless fasteners on things that thread into steel/iron, and never ever EVER use stainless fasteners on exhaust parts. They will gall, and if you are lucky they will pull the threads out when you remove the fastener. If you are unlucky, they will break.

I hate solder joints because they seem to be the ones to fail - the wires fail next to the joint. I use the heat shrink butt splices that cost $2 each, but then I've been on the same Megasquirt install for about 40,000 miles that involve a whole lot of bouncing around off-road, and have never had an electrical issue. I also use them professionally because I need to do connections that are idiot-proof and also reliable, because comebacks suck.

If you do solder joints, at the very least use a nice stiff heat shrink to cover the joint to maybe do some stress relief. (And use a heat gun, not a lighter)

Lies. But then, some of us have a habit of acquiring parts with an eye towards future projects.

For example, besides the loads of RX-7 parts littering the place (engine parts/whole transmissions/rearend parts mainly), I have

- Miata trans
- VW Syncro rear beam assembly
- MC2 Audi engine (200 Turbo)
- WK Audi engine (5000 Turbo, early)
- Two spare 10v Audi heads
- Spare K24 turbo and a couple spare wastegates
- Complete RD engine (early Golf GTI)
- Rebuilt PG shortblock (Corrado G60 engine, all forged and 8:1)
- Early 1.8t pistons (13:1 in an 8v)
- Misc. intake manifolds for VWs including a rare dual DCOE manifold

PS - Didja know that the Corrado G60's flywheel is *slightly* larger in outside diameter than the RX-7 N/A flywheel, so it can be machined down to accept the Mazda ring gear? And that the clutch disks are near-as-dammit the same size? And that the bellhousing to clutch depths are off in the correct direction for fabbing an adaptor plate? And that the VW engine is almost exactly the same length as a 13B and will just barely fit under the FB hood? And that clean A2 chassis Golfs run $2500+ locally so that there is no chance that I'll ever own one again?

Screw that, it's expensive as all hell. The thing to do is buy a proven MS1 or MS2 box cheap, from someone who is upgrading.

 

this is a good thread! um so anyways, since 1993 i've done just about everything. i had a 12A with a holley, 13B streetport with a dell, modded -SE's, and some stock cars. if we can mention FC stuff, i had a t2 with hybrid, then went 3 rotor, then back to 13BT, and the current FC shell came with an FD engine...

i happened to come across a set of Peripheral Port 12A housings, AND an ex pro7 car. my friends go road racing, so the P port has always been the final frontier.

the problem was that nobody in my circle of friends had DONE a p port. the older guys had done it, and it sounded awesome. Rob Golden used to work at the same dealership i did, and his P port REPU was legendary, 0-100mph by the end of the chevy dealer. we also, thanks to kim in norway, and SGT fox, had mazda's competition book, which tells you how to build the car i was building.

but then we hear things like this https://www.rx7club.com/showpost.php...32&postcount=2

"I wouldn't recommend it, unless you enjoy...

- blowing engines every 30k
- blowing 5k on each engine
- not making ANY torque
- not making ANY useable power below about 4000 RPM
- being heard coming a mile and a half away (LOUD!!!)
- idling at 1.5-2k RPM
- getting 10-12 MPG
- cruising around at 5k like a motorcycle (well, that sounds pretty cool, but...)
- overheating if you don't continually drive the car

So, no, I wouldn't recommend it And no, with a bridgeport there's WAAAAY too much overlap for forced induction - you'd be blowing your intake charge straight out the exhaust ports

Brandon"

that is a big list of problems!

so i put the 12A together anyways, put a weber on top, and i found out quickly that even though i had the recipe, it was going to take a bunch of tweaking. so tune i did. i spent a TON of time on the carb, and it really paid off!

it starts right up hot or cold, it idles by itself after about 30 seconds, no choke. cold idle is about 750 and it come up to about 1000 when its warm. i can cruise down the street @2000rpm in 1st gear and it doesn't buck or surge, its just like a stock 12A. i can even get it to idle without the brapping, although its no fun that way

power? the P port makes more Tq @2000rpm than a stock 12A does anywhere, and then it STARTS pulling. i've got mufflers and a stock air cleaner, so its corked up, but it really feels like a stock FD. my friend has a GTUs with bolt ons and the P port just walks away from him. i'm not used to a car with a power band that goes UP the higher you rev it, its FUN

downsides? yes. its loud! it also doesn't like mufflers. exhaust 3.0 will come soon. i can't smog it*, so its track only. the intake and exhaust manifolds are closer than they are on a side port, and its also REALLY sensitive to heat. 80c coolant temp feels like 50hp more than 100c coolant temp.

brandons list?

-it is a 30K motor? probably, but do you know how many track weekends 30k is?
-$5,000 engine? if you bought new rotors, rotor housings, etc etc it is. on a refresh you're just buying seals and gaskets for $1000. is $5000 for a NEW engine cheap? yes.

-torque? he's wrong, it makes tons of torque
-useable power under 4k? yes! i've driven this back to back, you can drive your sterling carbed/RB streetport 12A car, and you shift where ever you like, i'll take the P port, and shift @4. its close but the P port feels faster.
-loud? yes. it'll blow rags around the shop, like 10 feet away.
- idling @2k? the racers did this to make sure they had premix on decel. if i had EFI, i could idle it @750, the CARB won't let me though.
-10 mpg? who cares!
-cruising @5k. no...
-overheating? no, its the other way.

so its still a work in process, but its FUN

 

More like a big list of bullshit, from somebody who never drove one

that's just the thing. i'm trying to figure out exhaust systems. say, did you know that you can make a backpressure tester simply and cheaply? grab a '83-85 12A end housing oil plug (the bit where an oil line would go in if it had a real oil cooler), drill and tap for 1/8" pipe thread, install a 1/8" NPT to 3/16" double flare adapter, remove your O2 sensor (you have an O2 bung in your exhaust, RIGHT?) and thread this contraption into its place, then install a length of brake line. The brake line only needs to be about a foot long. Stick a long length of hose on it with your vacuum/pressure gauge on the end and go for a drive.

I still have yet to actually do this. But, i want to see what my backpressure is before I start making changes again.

I idle the 6 port half bridge at about 900, which is LOWER than I've ever had a street port idle. But then I am also not using massive amounts of idle advance like I used to. I turn the idle up to about 1600 in competition just to prevent the possibility of stalling, but really it's not necessary.

I tell you what, though. The 6 port is a lot "softer" feeling than the TII half-bridge was. It's still a lot better feeling than the early opening 6-port street port I did, though. It's true, the 6 ports just close their end ports waaay too late. The T2 engine was a solid torque brick from 2000 to maybe 8000, the 6-port has a definite ramping up effect, still not as bad as a street port but still not what I want!

 

My car is slow.

 

See my #3. And stainless exhaust hardware (real QUALITY stuff, not hardware store spec) is ballin' when used with copper nuts. Steel on steel is poopy for exhaust.

I always heatshrink with a proper gun, and pack the joint with dielectric grease. I've had GREAT luck with soldering. I also bundle and route all my wires and anchor the harness. I don't know how/where you'd had solder issues but they only time I've seen issues with it is when there is a gaggle **** of wires that bend funky or where the joint or the bare wire is exposed. Yes, I have seen plenty of solder failures where you have some dinky 22AWG wire with 1/2in of copper exposed flopping in the wind next to a rigid joint, but I haven't really seen any well thought out solder failures.

That was directed more towards the newbs that get on here saying "I have a 5.0 out of my old stang" or "my friend gave me a T3 out of his old honda" and think they'll swap that in for cheaper than a rebuild of the engine they have, or want to know if that T3 will take them to 400hp. Obviously, if you can build an entire car with the parts you already have, this doesn't apply to you, but then, neither would this thread would it?

MS3 is so much more capable out the box than MS1/2 it's almost funny.

 

stainless steel fasteners suck period.
their not very strong, you may as well use cheap low grade bolts from the hardware store.

I first went blow thru turbo on a s5 jspec engine. It was cheap fast and fun, the car pulled low 12's in the quarter mile. 300hp

I went haltech efi turbo blah blah and it sucked the fun out of the car because it go so expensive and didnt fit into any autocross class so I sold it all and was hard to drive fast anyway but straight.

Im currently ITB haltech s3 6 port. The cars fun again and Im loving it.

Stock drive line has handled all of the tasks, I see no reason to upgrade it unless your making 400+hp or have a v8

 

do it! you will be really glad you did.

 

ms3 does add more features, but when you take features vs price vs learning curve (how long does it take to learn the ecu?) vs other stuff (availability, reliability, ACCURACY etc etc) the MS units still seem ok, but not that great.

and if you really look no ecu is that great, haltechs fail the accuracy and reliability part....

 

you need a racing beat exhaust.

 

lies!!
I raced you from a roll on the highway with 115whp more then you and it was super close.

 

While true, MS1 suits me just fine, and both boxes I bought were $80 a pop. You can't convince me that MS3 is ~400-450 better. $400-450 buys a lot of transmissions and radiators and entrance fees and gallons of fuel so that the car can be driven instead of sitting like a statue.

Priorities. Sometimes good enough really is good enough.

When I put MS on my VW, you better believe that it'll be MS3, because I'll need to control five coils and (preferably) five sequential injectors. The RX-7 doesn't need anything that exotic unless you want to tinker.

 

on a stock port, thats right. the GSL-SE isn't sequential injection, and those run fine.

however on a big port engine, if you don't have sequential injection and an injection timing map, i'm not sure it would work better than a carb, at least a part throttle low rpm.

and actually at idle you can hear the difference between sequential injection and non