have any of you turbo 12a oor 13b guys who have a turbo setup maybe those who custom fabd everything ever used a turbo off of say a saab? or any other automaker? if so how successful was it and how much should i pay for a good turbo from the yard?

 

I'll sell ya a working twin

 

ok... heres what i know about turbos thus far.
Im not saying these turbo chargers will be perfict for your rotary, but they are cheeper than paying 1500 for a T3/T4 hybrid turbo
a few things you should be sure of when thinking about a junk yard turbo charger....
1. check the play of the turbo, basically check to see if the turbine and compressor can be pushed back and forth inside the housing... if their is alot of play, move on to the next turbo!
2. check for oil in the compressor housing. if you find oil in the compressor housing then the engine has had an oil leak at one time or another, which indicates poor matinance on the owners part, and the parts are no good!
3. check the turbo for oil cakeing.... on the oil inlet and outlet ports there should be little or no oil build up.
4. try and find a turbo that is water cooled as well as oil cooled, those turbos dont undergo as much heat damage as other turbochargers, making them more pracitcal for your application.
5. check to make sure the turbine acutally spins, if it doesnt, the berrings are shot and the turbo is junk.

ok as far as rotary turbos go, its a tough call... I personally think that a T3 turbo should flow enough air to feed the rotary. But I have hurd people saying the only turbos that work are the mazda rotary turbochargers.

Now, this is important, as far as the rotary engine goes.... DO NOT use anything smaller than a T3, it wont supply enough air.
This means that the SAAB turbos wont work...
what you want is a Garret T3
now if you do a search for the Garret T3 turbo, you will find the prices to be outragous!
dont worry, they can be found anywhere

your best bet is to look in a late 80's chrysler
the 2.2L dodge engine came with the Garret T3 turbo on it.... i dont know the specifics, but make sure it says Garet on the turbo, and that it is in a mid to late 80s chrysler
I got mine from a Dodge shadow turbo... its a really shity car.... but it has a nice turbo system on it!
as far as prices go... mine cost $70 canadian... so its not that bad!
just keep in mind that you need to re jet your carb to take the extra air comming into your engine and you will be fine
if you have any other questions, just PM me

 

t3 turbos will choke off the exhaust end of the rotary engine.

the stock TII turbos are like .84 a/r for S4 and 1.15 for S5.

i do not recommend the t3 turbo. i would recommend a t4 or a t04b for starting a turbo project which can be found new in box for around 300 bucks on ebay.

i have the s5 going on my 12a.

carl.

p.s.

you probley wont need to rejet either.. thats wut rrfpr is for.

 

0.88 A/R for Zenki (S4) and 1.00 for Kouki (S5).
(Compressor) size is Hitachi HT-18.
Compliments of ReTed.

Daryl

 

what do u mean the t-3 will choke the exhasut? could u explain it a lil more, i was also plannin on goin with a 2nd gen turbo because the turbo and manifold bolt right up to the se's i've heard and could run the stock boost with no problem

 

What should the parts list be in order to successfully put a turbo set up on a 12a Carburated(ie,oil lines,turbo,exh. manifold,carb,etc). I assume hes staying carbed. I would like to know this for myself as well as knowing how you know how much psi you will be running and how do you control how much psi your running with a carbed setup.

 

basically you will get more HP if you go with a T4 or a turbo II turbocharger..... the T3 will restrict exhaust flow, but if you are on a tight budget.... A t3 should make good HP for how much you are actually going to spend.... as far as the carb goes, you do need to re jet it! the RRFPR boosts the pressure of the fuel, but with small jets, its hard for the carb to respond to the amount of air coming in. on a fuel injected engine you would have to change your injectors, or increase the duratoin of your pulses, on carbs the jets must be changed in order to make maximum HP.
If you have the cash, get a big T4 turbo, or even a Twin. but he said he wanted to know which junk yard turbo would work, so the T3 is your best bet

as far as a parts list goes, you need oil and coolent lines, a but load of fittings to install them, you absolutly need a good RRFPR and a boost controler.... dont waste your money on an electrical one! people will believe anything! the $600 electronic boost controllers work just as good as the $25 brass mechanical ones
you need a boost guage, and an air fuel ratio guage. for simplicity and cheepness, just keep your nikki carb, it is more customizeable than a holly, and you cant change the venturies in a weber, so your prity much stuck at the boost level you had the carb made for. pick up a couple of larger jets, for the carb, there only something like 3 bucks each, so even if you dont use them now, you can use them later when you turn the boost up (and you will).

as far as boost level is concerned... its totaly up to you.... if you want to run 50 psi... go for it, but it will only last for a second or two....
But seriously though
it depends on your compression ratio, if you can get your hands on some 12a turbo rotors then you may be able to get away with 15 psi
for relyability i would stick to 8-10 psi on a 12a with NA parts
you could go more, but the engine wont last as long

 

SORRY BUT I MUST INTERJECT HERE.

A good boost controller DOES make a difference, and is better than a brass/mechanical one.

The mechanical ones will always be bleeding boost out, making the wastegate respond slower.

A good simple electronic one, like the Profec B - will keep the wastegate fully closed until the desired boost level is hit. Thus, making full boost sooner, and more powerful. Plus you can control how abruptly the wastegate opens.

I have mine set to open a little more gradual, to avoid the instant wheelspin of full on boost. it works great.

And as far as Turbos go (at least cheap ones). You can't beat a good working S5 stock turbo, and it will bolt on to your 12A with minor modifications. There have been several write-ups on this already.

I know several people running over 20psi on a daily basis with their 12A turbos, running on pump gas - using stock high compression rotors, with blow-through setups. BTW, these have been running for years.

It's all in the tuning.

Also, a Nikki being more customizable than a Holley? You've got to be kidding.

 

try and find some over sized venturies for a holly, seriously, if you can find it, then you proved me wrong!
holly carbs are famous because of the tuneability, HOWEVER tuneability has nothing to do with ease of customizeation.

im just saying... the guy is obviously cash oriented.... if hes talking about junkyard turbos, he probably doesnt have the money to buy a $600 boost controller and a $400 carb
the mechanical boost controllers do the job, they arnt as precise and as "pretty" as the electronic ones, but they work... and in the end.. thats all that matters

I was going to turbo my rotary, but its to expensive to get the HP I want.
as far as this set up goes, it is the best bang for the buck.... of corse you are going to find people running better set ups, but they spent 3 grand... where you only spent $500.... its all about the money to performance ratio

Try to find a semi truck wrecking yard... they use T4 turbos, there isnt one where i live (that or i havent found one yet) so i have to settle for the T3

if you go turbo with NO intercooler, then 8-10 PSI is the max you will be able to get without damageing your engine

with a properly intercooled sysetm you can go up to 20 easy on the stock rotors assuming the exhaust system was built bigger

 

dont do it.!!! go with a s5 turbo or even an s4 way better and way cheeper than finding a good used t3 that will cost a lot more to set up and will never be able to be tuned to run corectly. good used t2 turbos can be found for $100-300. you will need an engine to exhuast flange and a extra gasket to use as a spacer if you want to bolt up a t2 turbo set up to your se engine. learn from people that have done this before. not someone that has thought about it and did not. Directfreak knows what he is talking about. as well as quite a few other of us. I got my boost controller for $100 , yes it was used but new they are more in the 250 - 350 range not higher. hybrd turbos can be bought for far less than 1500 also. do searches on this forum read and you will get to know who to ask. pm them

 

I have to agree with Direct and Kuhl.
The stock T18 is practically a full T4 with just a slightly smaller compressor for reduced lag.Anything T3 or Honda intended is just gonna be way too small.Backpressure is the bane of turbos and rotaries as well with their open ports and high overlap.No point in having full boost at 2000rpm if you cant make any hp past 5000rpm.

The stock T18 is bigger than nearly any stock car turbo.Forget diesel truck turbos,they arent built the same way as gasoline units.Diesels dont rev much so the turbines are quite small.On the flip side,diesels have no throttle plates so the compressors tend to be quite big.This is exactly the opposite of what you want.The stock T18 has a big enough hot side to pass the rotary's high exhaust volume,but the compressor is small enough that it can get spinning at a decent RPM.

PLUS.....on a 12A the T18 has even more potential.Since the 12A has less intake volume,port volume and chamber volume,the turbo can build more pressure without having to push more CFMs and go outside of its effeciency range.Thats why guys can get 20psi out of a small stock turbo on a 12A,when the 13B maxes the turbo out at about 12psi.Boost is just a measure of resistance on the turbo outlet.Because the 12A intake ports and manifold are smaller,it fills up quicker, and on less air.

 

wut he said ^^^^^^

 

That's weird, because I ran 16psi on a stock engine with no intercooler without any problems.

 

What do junkyards charge for a used turbo.... seems pretty risky that you'll even get a good one, but what do I know...

 

I thought when picking fuel pressure regulators for a carb turbo you wanted a boost referening pressure regulator and not a rising rate pressure regulator?

 

so i have a 1985 GSL and im putting a 13B in it and if i go get a turbo froma second gen it will bolt on pretty easy just like that? what else will i need to do? what is the best year turbo to get and how much should i pay for it?

 

same difference.

carl.