Pedestrian X

hey im looking into swapping a 13b turbo into my FB and have heard some years are crap for the turbo and other better so i thought i would hop on over to the 2nd gen forum considering theese are the engines that are in your cars.. most of them at least :] im gunna rebuilt it a port it out and a lil bit of other stuff nothin too fancy ya know. so any info you guys have woudl be great, tnaks alot

CrackHeadMel

iTrader: (2)

the S5 engines have about 200, electric OMP, different injectors and a few more misc things, there the better engine in my opinion, the S4 engines have roughly 180 hp, mechanical OMP, less touq etc, i dont know specific numbers, but im sure you could find them in a search

Pedestrian X

what years are this engine in?

rico05

1989 - 91 TIIs have 202hp stock, 1987-88 have 180hp stock. Go for a 89-91, little more expensive, but well worth it. The Zenki (87-88( motor is a good unit, but the Kouki (89-91) has a better turbo, wastegate, and manifolds. Good luck!!

Pedestrian X

ok, awsome thanks alot guys. now im on the hunt for a 89-91 S5 13B turbo II to rebuild, this shoudl be fun. :]

Felix Wankel

Be careful with the crap electric MOP. It likes to go out and costs an arm and three legs to replace.

Pedestrian X

then i take it you cannot just premix with 2 stroke engine oil or something of the suck?

Felix Wankel

It puts the car in limp mode, and it hardly runs.

Pedestrian X

limp mode? can you elaborate?

rico05

Basically, it burns out a resistor in the ECU. The ECU dosen't think taht the OMP (or MOP as it is also called) is connected, and to prevent eninge failure, it burns out part of the system, making the car run on "Limp Mode". No power, not able to revv, etc. The mechanical OMP is best, but the electric one is just as well, seeing as the motor it comes on is better.

fatboy7

the stock ecu thinks the engine isn't getting oil, so it retards the timing or somthing. Anyway, in 'limp mode' the car turns into the gutless wonder

Felix Wankel

What you do is put a S4 front cover and mechanical MOP on it, then run a Haltech. Mazda computers are crappy anyway.

rico05

Well a buddy of mine had his OMP go bad, and it actually burned up a part of his ECU. I have the ECU in my garage, and sure enough, it is fried inside (well one little transistor is all black and fried) BTW, is this fixable?

TurboII RudeBoy

The 86-88 turbo motors are built better and forget the bullshi bout better turbo n manifolds get an 86-88 and drop a haltek and a nice turbo.i've ripped alot of rotaries apart and i have a thing against the 89-91's only thng thy r good for is if u wanna replace a stock motor in a series 5

autocrash

Is there a way to simulate the OMP? so that the ECU thinks the OMP is doing great, when actually it's removed?

Felix Wankel

I'm with you. I'd rather have a little bit lower compression rotors anyhow.

CrackHeadMel

iTrader: (2)

I asked the same question a few days ago with no response

It should beable to be done, i dobt maza made the omp send cryptic messages to the ecu just to say its there

TurboII RudeBoy

I've said this so many times.but one thingthat would be a hell of a one time screamer is a turbo motor built with 91 non turbo rotors,it would scream up toboost then after that it would be over:P

CanadianRX7

umm the 87-88 turbo has 182hp and 183 lb-ft and the 89-91 turbo has 200hp and 196 lb-ft.

i would get a s4 engine with a s5 turbo and wastegate

NZConvertible

The whole compression argument is silly. You can’t run heaps of boost just because you’ve got the S4’s lower compression rotors. The S5 had 6% more compression, that’s all! That means if you run 6% less absolute (not gauge) manifold pressure, the effective compression ratio (static CR multiplied by boost pressure ratio) is exactly the same. As a example, 10psi boost on S5 9.0:1 rotors is exactly the same as running 11.5psi boost on S4 8.5:1 rotors. Any difference in power would be minimal, and unlike boost, which you have to wait for, higher compression is always there.

TonyTurboII

The S4 is the motor to have. More reliable OMP, and lower compression. The rotors are also beefier than S5 rotors, which will take a dent to the face with detonation, the S4 is much more resistant to this. The S5 has a better wastegate design, but the S4 can have its problems erased with some porting.

Your question is a good one, and I still cant decide which one I want.

rico05

Beefier rotors? Explain? The rotors weigh exactly the same and are made of the same thing!! A well built engine using the appropriate amount of boost and fuel is always es, wahtever series you own. How many electric OMPs fail? I have not personally heard of more than the one. Mine kicks ***. I still say go S5. If you got the $$$ for Haltech, it dosen't matter which engine you go for.

Felix Wankel

Buy what you want. I'll be damned if I overpay for a S5 engine/car when I can make the same power with the dirt cheap older stuff

rico05

So the same power can be had cheaply from a S4 car? I am looking for a blown TII of some sort for a project next summer, and I am just soaking up all the TII info I can. I assumed since the S5 had different intake, turbo, and wastegate, it was better. How about a very thorough explination of your logic. Convince me

fcturbo2

That is the best way to go IMO!