guy wants to sell me a turbo II set up for 1000
 

So it seems ive been polishing a turd, my 87 NA motor has a blown coolant seal. It needs to be deflooded every time i start it, loosing coolant out the overflow, slight overheating etc.

Anyway i was brain storming doing a V8 swap but decided ill give the rotory at least a chance so the hunt for a good motor started. Found a guy on craigslist with a few rx7 cars and he offered to sell me just about everything to do the NA to turbo swap except the driveshaft for 1000 bucks. the motor he is selling me had a lack of power concern he states and he decided to just do a V8 swap. So we checked out the engine and spun it over. it spins freely and i laid eyes on all 6 apex seals, rotors look to be in good condition at least not carbon fouled. he thinks an apex seal got stuck in the slot by the rotor locking down on it. So im seriously concidering buying everything off him even down to the hood and rebuilding the motor. turbo and manifold been ported and the twinscroll deleted, turbo trans exeddy clutch.

I seached and it seems using the NA wiring harness is the better route but yeah what do you all think? sound like a deal?

if he modified the turbo that is probably why is is responding poorly. but you can get used turbos relatively cheap still.

I think it is worth taking a chance on it. If you open up the engine and see major damage, then you can probably sell the parts for nearly what you paid, or you can buy replacement parts for the rebuild. A crummy used J-spec engine and transmission sells for about $1,500, so I think that this is a decent deal.

Almost all of the original driveshafts are toast now, so you would want a new one anyway. You can send the turbo to BNR to see if they can rebuild it, and if not, then just buy a good core turbo that can be rebuilt. I would also look into getting an Rtek upgraded ECU.

Dude states he got the engine from japan and showed me some tags and oil filter all have japanese writing so i belive him. Also states the intercooler is jspec cause it says "rotory turbo". Dude told me he was on the highway and ot felt like he "dropped a piston" hes guessing stuck apex seal. So he just removed the engine and trans and decided v8. He stated the engine still idled just lacked power.

So a ported manifold and turbo with twinscroll delete is no good?

Not if it was modified by a goon. Does the owner have a receipt for that work to show that it was performed by a professional and that it is covered under warranty?

It sounds like the owner bought a crummy used J-spec engine, hacked it up a little bit, and drove it until it finally broke.

Modified goon special. He does have a un touched turbo as well. Anything else i can look for before i commit? Based on what i saw engine seems rebuildable, but im very new to rotory.

Even if it's blown... I would say get it. But I would personally rebuild it. $1,000 for a TII swap (without driveshaft) is cheap. Your decision should be based on YOUR expectations of the car and YOUR financial well being.

^ This

Plus, see how much the guy wants for the unmolested turbo.

You can price the turbo rebuild levels here:
BNR Supercars - Bryan Nickell's Rotary Supercars - Mazda RX-7 2nd Generation (1987-1991)

alright seems i can get a fresh turbo rebuild for around 400 bucks with all the mods. seems likely this is the route ill take.

pick up the parts, rebuild the motor, replace fuel pump with walboro255, replace rear end and trans with turbo 2, install clutch, custom drive shaft made, modify the original wiring harness for the new motor, replace motormounts and transmount with poly bushings, install turbo hood and stock intercooler. also ill need an aftermarket boost gauge.

for the motor, dude states you can run up to 14 psi with the module that fools the computer to ignore higher than stock boost which is included in this deal. does this sound smart? he states i can make upwards of 270 crank hp with 14psi and stock intercooler. well i like power but longevity is number 1 in my book. ill have the money in a few weeks at most for the parts, then the wait for more money to afford the engine rebuild kit and all the other bullshit ill need.

anytips from the people in the know?

Running anything above 10psi with stock injectors, ecu and intercooler pretty much equals a blown motor..

I think we now know what happened to the engine, lol. That device is called a "fuel cut defenser (FCD), which bypasses the car's overboost fuel cut safety feature. This is fine as long as the car has the supporting fuel pump, fuel injectors, aftermarket fuel computer, and turbo and intercooler modifications, but otherwise 14psi is going to blow the motor.

You may want to just disconnect the FCD and get the car running at the stock boost level until you have the time and money to install high-flow injectors and a fuel computer, and tune the engine. Also, the engine is rated for regular unleaded fuel if you run it at the stock boost level, so you may just want to keep it that way in order to save money. Most people are quite happy with 0-60 in 6.7 seconds.

You don't need a custom driveshaft if you have a Turbo II transmission and Turbo II rear end. The custom driveshaft is for when you have a mismatching transmission and rear end.

I like to perform these mods when I buy a used RX-7:
- Replace the pulsation damper
- Replace the two o-rings under the oil filter pedestal
- Send the fuel injectors out for cleaning and flow testing
- Install a Fumoto oil drain valve (F106 without a nipple) so I don't need to deal with the oil drain plug and crush washer.
- Check to see what else needs to be replaced due to age or damage from the former owner.

sound advice. pushing the motor doesnt sound like a bright idea. so ill run stock and get myself schooled up on running with a turbo, then slowly i might build up the power.

i already have a turbo pulse damper so thats done, and the rest i can do with the new motor when its out on the stand.

so knowing he blew the motor due to overboost do you guys still think its salvagable? he told me he was cruising when the power failed. and remember i did lay eyes on all apex seals. im one paycheck away from getting everything bought.

If he was over boosting the Turbo there's a good chance it needs a rebuild.

The limit on a stock turbo is 12psi, anything higher is inefficient and will cause it to blow its seals and to run that you need upgraded ecu, fuel pump and upgraded secondaries.

The most you should run on a stock setup with a fcd is 9psi, fuel system can't really handle more and stock ecu won't retard timing beyond 9psi boost.

If he was running 14psi he's not too smart. Only a hybrid (modified) stock turbo can efficiently see beyond 12psi

At minimum check the end and side play of the turbo if you can inspect it, if it has either it probably needs rebuild.

Rotary >Pistons

oh yeah thats easy enough, i check turbos all day long at work. plus he has everything tucked away in a closet so yeah ill check the turbos out. im leaning on getting the stock turbo he has as opposed to the one he ported out and modified just to keep things simple first time around.:nod:

I got a nice s5 Turbo setup for $200 shipped here on the forum in like new condition. No end or side play.

Have to replace my stock turbo because its in bad condition, I'll be selling it after I remove it.

Rotary >Pistons

cool. running the s5 turbo for more power? i should be fine with sending my s4 turbo out for proper mods via the link i was giving by evil right?

S5 has better boost control and was told boost comes faster, as far as power they're both going to give you the same power.

It has a better wastegate design so it controls boost creep better (comes from bigger exhaust and upgraded intake), though most people port the waste gate on both s5 and s4. S5 has a dual waste gate design with 2 holes, s4 has one.

The link he showed you is pretty much where everyone on here upgrades their turbo or gets it rebuilt, they're very well known on this forum.

Rotary >Pistons

thanks for the tips, well haha im starting to lean more toward just repairing the motor thats in it. infact the main reason im thinking the turbo swap is because my transmission is pretty well shot and he had the trans to sell me too.

so next question, could i install a turbo transmission to the na? im sure i could right? that way i can leave the rear end, driveshaft alone and not have two motors taking up space in my one car garage currently holding the car and 3 bikes. all in all, my goal is to have a nice running rx7, turbocharged or not. sorry to be bouncing back and forth i guess time changes minds.

it's gonna cost more than $400 to rebuild it by the sound of it. multiples of that if you have someone else rebuild it, maybe even if you do it yourself.

be prepared, and no i'm not on the bandwagon that this sounds like a great deal the more i hear of it.

the S5 turbo only spools faster due to the higher compression engine it originally came on. it will spool slower than a proper twin scrolled S4 turbo on the low compression S4 engine.

Why would it spool slower? Everything Ive read regards the s5 as can upgrade over the s4 on an s4 car.

Yes the compression is higher on an s5 engine that's a given, so it'll spool faster on it.

Rotary >Pistons

You need to read the FSM. Twin-scroll works, but it was made unnecessary by the S5 divided manifold. I'd rate them pretty close, but removing a moving part from inside the exhaust stream is always a good idea.

Sounds like bad idea. You are lining yourself up for bad rotary experience.

I dont understand what you're trying to say, so it really doesn't answer my question.

Ive never read of there being drawbacks to using the s5 over the s4.

Rotary >Pistons

me or wthdidyousay? im tryin here!

I'm pretty sure he's talking to you, there's nothing wrong with me using an s5 turbo.

What you're doing is going to be a lot of work, is what he's trying to say and maybe more than you're thinking.

I personally got my Turbo2 for $1000 with blown coolant seals, there are some deals on turbo project cars if you look around and be patient.

No matter what you do I'll do what I can to help.

Rotary >Pistons

OP: From the FAQ:
If I were you, I'd price it as if half the block was trashed and a turbo trans. 500 or so because the time and effort to part everything out has to be worth something to you. And it's a 20+ year old engine whose coolant seals don't have much of a life expectancy left. Better yet, take a battery and compression test it since the trans and engine are in one place.

No, you do not understand the answer to your question. There's a difference. The full functionality of the twin-scroll system is outlined over 6 pages in the FSM and more in the training manual, so please forgive me for not re-writing it for your viewing pleasure in the thread regarding purchasing a turbo swap. The Factory Service Manual, read it.

I've run the same turbo with an S4 and S5 hotside with the same S4 engine/tune/everything....It's barely noticeable. Although, I'm using the stock flywheel which dampens turbo response.
/Threadjack.

wow ok mazda drive shaft all day. seems like a better idea to just repair my motor and buy the turbo trans along with clutch etc? what would be a good price to pay for the trans and components?

what i'm saying is the series 5 doesn't have to rely on the twin scroll to spool to the turbo as quick as the S4. the S5 also has a solenoid to overshoot boost by holding the wastegate shut longer, giving the impression it kicks in harder than the series 4 turbo.

the turbos are very nearly identical except the s5 manifold compliments the turbo hotside design where a properly functioning series 4 manifold with twin scroll compliments the series 4 turbo hotside design. the wastegate is the major difference between the 2, where the S5 is obviously superior in almost every way except that it tends to wear the bushing in the turbine housing much quicker, allowing slop and boost leaks(internal exhaust leaks bypassing the turbine wheel, as well as pushing the wastegate open easier, impacting response) as well as slower response due to those leaks over the series 4 with smaller WG arm and flapper.

so what i'm saying is if you have a decent series 4 turbo with a full functioning twin scroll there isn't much benefit to switching to a series 5 turbo unless you NEED the bigger wastegate due to creep.

many people get the impression that the s5 turbo is much better because they had ridden in a series 5 car, which responds much better than the S4 due to the extremely low compression rate of the series 4 engine. add in the series 5 boost solenoid and it just picks up better all around, making the car feel faster because it is. could the series 4 also benefit from a boost control solenoid to alter overspool? yes, but the twin scroll generally did that without it, if it wasn't leaking or stuck open.

the main reason i consider the series 5 turbo better is because the manifold and turbos tend to crack less than the series 4 do.

My car has a full exhaust so I think ill benefit from the better wastegate

Rotary >Pistons

what about me?

what was the question again?

oh, yeah... plan on a blown rotor and housing. at the rate people have and continue to go through them, you may have some difficulty find replacements for a decent price. i know i'm about close to doubling price of the turbo FC/FD stuff because it has become nonexistent in the past 2 years. and imported engines are even less than 50% good versus junk.

i know plan on just rebuilding my na engine and replacing the jacked up trans i currently have with the turbo trans. im gonna offer 200 bucks for the trans, slave and clutch components. sound good?

You'll need the flywheel and starter, too. I'd want about 250 for the trans because I wouldn't sell junk, but I don't know what condition his trans is in. People agree to a lot of crazy stuff when you wave cash in their face, so feel free to start low.

seller is trying to convert over to v8 so he might not care. ill start at 250. thanks.

Well if he doesn't care, start with a 6-pack of beer! I'd start lower since you can't test the trans in any way. Transmissions off cars with modified turbo systems seem like they would've lived harder lives than most. Price also depends on how commonly they come up for sale in your area. So I can only give you guidance based on the my market.

thanks my friend. ill see how it goes. he is making a big deal about his 400 dollar clutch so i might just get a stock replacement from the parts store and go for 200 bucks on the trans and parts.

well i feel a build thead coming on, i started removing the engine today afterwork. all thats left is the mounts and wiring really. i got the rad and all that stuff out along with the powersteering and ac. here are pictures for you viewing pleasure.

it's rather difficult to grenade a turbo transmission. worst case is generally a worn/tired 2nd gear syncro and/or a cracked 5th gear syncro, or whiny input shaft bearing(they will whine for years but still not fail).

Thanks. Thats good to know.

ok engine is out. damn i couldnt belive how light the trans is lol. literally one hand i can pick it up. got to thinking why not just replace the gears in the trans? has anyone ever gone down this road? if not i know there is a junk yard rx with a trans in it i can use, condition unknown. what do you all think? rebuild existing trans? replace with junkyard NA trans and hope for the best? or buy the guys 300 dollar turbo trans and replace starter, flywheel, clutch, driveshaft etc? i know i need a new pressure plate clutch cause the fingers on mine are all kadywhompus.

next question, whats the best way to get the flexplate nut off? goddamn thats a big nut! :blush: also i read a thead a while back stating the engine could be rebuilt on a 5 gallon bucket, ilike that idea alot could someone locate it for me? already tried.

cant belive the engine is the size of the bellhousing lol!:lol:

transmission rebuilds generally only consist of replacing bearings and syncros. you don't want to know how much it would cost to remanufacture a transmission with new gears.. you are talking thousands of dollars for a still weak transmission.

the flywheel nut socket you can usually get at a tool store or at sears, it is a size 2 1/8". in a pinch a chisel and a hammer will work. i got mine from sears many years ago and it's done more flywheels than i can count.

buy junk yard one and put the two of them together best i can? or are you steering me away from retaining the NA trans? no major hp mods down the pipeline.

issues im having with mine currently is grinding badly in 3rd gear and sometimes into reverse everything else honkydory.

Na trans are cheap I've seen them sell for $75

Rotary >Pistons

steering you towards not dumping a bunch of money into the glass n/a transmission. most people just swap them out when they fail or rebuild it cheaply through a reliable rebuilder.

they can break even if you use brand new parts in them, i just had one a few weeks ago with a broken countershaft gear. the broken gear alone put the transmission into the scrap category.

no way am i dumping money into the trans, id just like to instead of possibly throwing in another junk trans to instead rebuild one out of two with the best parts they both have correcting the fluid leaks and installing a better shifter. I guess ill go this route, hey who knows i might get lucky and find a good clutch and pressure plate too. hopefully the junk yard rx is sitting just as i left it, trans about 45 deg angle to the deck.

anyway more progress today disassembling. man i need to start a build thread already.

If you can make sure it shifts all gears before buying it that'd be ideal.

I sold an na trans for $75 way back in the day, it might be cheaper at the junkyard though (it should be if you're pulling it IMHO).

Rotary >Pistons

also i have a friend with multiple transmissions so i might buy one off him too

Obviously make sure it shifts smoothly without grinding, just figured I'd add that.

Rotary >Pistons

With engine off my trans shifts smoothly. Im just gonna have to take his word. Hes a friend

only way to know if one is good is by installing it, bench testing it through the gears still cannot verify the syncros or even the bearings are good.

i have a pile of transmissions but since i can't know any of them are good i consider them all rebuildable cores and not for sale used.

Agreed.