SaabGuy

Why do they blow up? Is it because of over revving? Sitting too long? Lubrication? Why do some engines blow at like 70k miles and some run twice that??

What about the turbo rotary, more strees blows seals or no??

My T2 is gonna have 141k original miles on it and runs well... WHY??? What can I do to make it last like another year?

I've heard of putting some sort of special oil in the gas to help lubricate apex seals...?? Will Marvel Mystery Oil work?

Node

iTrader: (1)

The main reason for turbo rotaries blowing is because of detonation.
You do not want to have a rotary running lean.
Alot of people who don't know this will upgrade turbo or intercooler and exhaust, have too much air, and never upgrade the fuel, then they will run lean, and there engine will detonate
And on T2s the ECU automatically cuts the fuel to the second rotor once you go over a certain amount of boost (unless you get a small electronic piece that cost $20) and when the fuel gets cut it has a good chance of leaning out.
Just be sure to ask the people on the forum on which order and what upgrades to go and you should be good
There are other reasons for roaties going bad but I would have to say this is the main problem

gnat's-ass7

The problem is sometimes blowing your apex seals. If you know how a rotary works, the apex seals form (at different times and points) a closed chamber within the rotor housing for three different purposes-intake, combustion, exhaust. If you blow up an apex seal (by running too lean and getting pre-detonation), you lose the ability to do one of those three steps successfully. So you get combustion on two sides of the rotor at once, whereas it's normally only on one side, and whack...bad things can happen.

RXTASY1

The reason you hear about so many of them blowing is because of unproper tuning.
If you have the right fuel supply with the right air mixture, they won't blow.
The problem is, people modify their cars to breath better without giving it more gas.
The more modified you make your 7, the easier it will be to blow up.
I know this first hand. I have gone thru 3 engines in one year!
If I would have kept it stock, I would probably still be on my first one.
I have the need for speed, so I can't do that!
Im going to get a Haltech. Maybe that will help. I'm sure it won't be the "cure", but it should help to make my engines last longer.

gnat's-ass7

Let's short out Node.



Just kiddin' man, you rule.

SaabGuy

OK so detonation is very bad.... OK! Can you incorporate a knock sensor???

I am going to put the following mods on my car;
Racing Beat turbo back system
Fuel Cut Defender
Intake of some sort (Proly open conicle, or cold air something)
MBC

Of corse I will also put in an aftermarket boost guage and A/F meter sounds like a safe idea.

I will probably try to tune boost around 8-10 psi with the MBC, can I do that?

What can the stock fuel system handle?? What can I do with the little mixture control dial?


Whats the least expensive way to increase fuel supply?

RXTASY1

The stock engine has a crude knock sensor on it. You can buy good knock sensor (J&S) for $500.

Definately get a FCD or upgrade your ECU.

You will need a bigger fuel pump (Walbro), bigger secondaries (720cc), and some way to control the fuel (Apex S-AFC).

That should be good up to 300 HP.

Also a good A/F Gauge.

SaabGuy

Whats the max safe hp the stock fuel system can handle?

Can I adjust mixture screw a bit to compensate with the mods I want?

gnat's-ass7

The weakest link on your stock fuel system will probably only support 300hp. New pump, new injectors=happiness.

TPDNRX7

Your main concern with a rotary engine is its cooling ablity. Its the nature of the beast. Less area more heat than a pistion engine. Equals a higher chance of detoniation. Take a look at the size of the coolant runners next time you disassemble your engine. It's simple physics. The design of the engine is inhearant to this. Carbon build up is an other factor. The excess heat dosen't dissapate as well, so therefore the engine pre burns the gasoline before it enters the combustion chamber. Which equals more carbon. With suffcient porting and cooling, the rotoary can breath better and cool better, therefore less prone to detoniation. Thats why mazda redesigned the 13B to renesis model, better intake due to the PP port housings, and larger cooling passages make the reniesis a more reliable engine.

Yelow RX-7

i have a 87 NA. i wanna drop a turbo II in it. when i do this, i wanna hook it up with a 100 shot of NOS. then, i will get a better intake than what i got now. (i have an Akimoto Sports) now, when u get NOS, u have to use 92+ Octane. if i do this setup, how long do you think my engine will last? and if it wont last long, then can you tell me what will make it last long with the nitrous and the turbo?

ribs

NOS is gay! Don't do NOS. You will need to upgrade your fuel system if you are trying to run higher boost or NOS (ugh). This meaning fuel pump and larger injectors. I don't know if these cars have adjustable fuel pressure regulators, but that is a cheap trick on my car (944 turbo) to increase fuel for additional boost without needing to tune your ECU. Otherwise, an ECU upgrade (chip), fuel controller (apexi, greddy, etc FCON), or full engine management (the best and most expensive option) would be in order.

Yelow RX-7

so u r saying to go ahead with the turbo II, but not with the NOS?

vaughnc

stock fuel system's only good for 220-240rwhp. I wouldn't exceed 8psi. DEFINITLY get air/fuel, boost, exhaust temp, and coolant temp gagues before you do any serious mods.

Node

iTrader: (1)

NOS=bad ick gay no die!!$!@
dont do it :-D

ribs

NOS is REALLLY not good for rotary engines since by nature it leans them out, setting up a higher risk for detonation which is the death of rotaries. You can tune your car for NOS, but I personally would prefer to have it set up with more boost and fuel, properly tuned, and have it be fast all the time, and it will be more predictable and probably last longer, even with higher boost, so long as you have your fuel curve tuned. BTW, what vaughnc said is also an imparitive (I forgot about that)....get good instrumentation so you know when your car is in trouble...I just got a custom made gauge pod for my 944 turbo and am installing a real boost gauge and an air/fuel meter (aka lambda sensor gauge, EGT (exhaust gas temp) gauge). This is a predicate to me starting to play with boost levels and fuel pressures.

PaulC

87 NA +100 shot of NOS = lots of spare parts

I watched a guy with an RX3 (pretty sweet little ride) with a built 88 NA dropped in it along with a 75 shot of NOS. Hes trying to find a new hood now.

Also A turbo upgrade to anything more than say 250hp and you'll have to upgrade the entire drive train or you'll be breaking pieces left and right. I know others will argue but Ive been told this too many times now and seen the results of a few people pushing that 250hp mark. BUT occationally it does work and stay together and work, but I wouldnt bet on it. Just save the cash and get a T2.

Yelow RX-7

well, i know a friend who can hook me up with a Turbo II engine for around 900$. after i drop the TII in there, what should i do to add more boost? i wanna be able to keep up with a 2nd gen supra. or should i just go out and buy a supra?