T2 engine swap question

[sc0rp7]

Nice and very informative posts Kain, I agree with most of your logic and whilst I think you are intelligent, I think you should try to be a little less condescending in your posts.

Also:

1.The series of motor is more important for the wiring and electronics that come with it than for the actual keg itself. The S5 TII harness will plug up, whilst if he got an S4 harness he would need to modify the 20 year old brittle harness you referred to.

2.The S5 turbo has an upgraded waste gate when compared to the S4 turbo and normally will not creep with the stock cat-back exhaust.

3.The Rtek is handy in certain low modification situations because it allows you to retain the stock driveability of the car without having to have it precision tuned every single time you change anything.

4. The S5 AFM has a very similar air flow capacity to the S4 AFM, and they both do cause a considerable restriction on modified cars, especially TII's

- Chris

[kain]

Nice and very informative posts Kain, I agree with most of your logic and whilst I think you are intelligent, I think you should try to be a little less condescending in your posts.

Also:

1.The series of motor is more important for the wiring and electronics that come with it than for the actual keg itself. The S5 TII harness will plug up, whilst if he got an S4 harness he would need to modify the 20 year old brittle harness you referred to.

2.The S5 turbo has an upgraded waste gate when compared to the S4 turbo and normally will not creep with the stock cat-back exhaust.

3.The Rtek is handy in certain low modification situations because it allows you to retain the stock driveability of the car without having to have it precision tuned every single time you change anything.

4. The S5 AFM has a very similar air flow capacity to the S4 AFM, and they both do cause a considerable restriction on modified cars, especially TII's

- Chris

i appreciate the comment. i just think its foolhardy when someone says something to not at least step back and look at the scenario a little bit.

the s5 turbo does indeed have a better waste gate system, and a true twin scroll system. however the fact remains that the ports are generally too small to prevent boost creep on any exhaust with no restrictions. not to mention the stock cat backs are restrictive so that will in fact produce negative lifespan results of the engine.

while you are indeed correct about having to generally re tune the car when a part is modified, it plays a not so significant role in how things turn out when you have spent the time and energy is a fully programmable system. anything changed with also affect the rtec. when the ecu does not know whats going on, it wont compensate.

airflow meters can vary in complexity and how they operate. however, a flap type vs plunger type although quite similar in operation where a pathway is kept restricted by a sprung restriction, the design of the restriction makes a huge difference. that being said, i still think the s5 is superior in design to the s4.

im a little confused about the whole s4 vs s5 thing you mentioned. running an s5 engine in an s4 car and visa versa is quite simple. the fact remains that these plastic pieces are brittle after age, and corrosion on the contacts is ugly.

also the fact remains that you are paying 500 dollars for a tiny improvement. depending on what rtek and what series rtek you choose makes a big difference in the tune ability of your engine.

wanna run e85? sorry. rtek wont handle that. wanna use high imp injectors with low imp injectors? sorry. cant do that. want to run twin fuel pumps? nope. sorry. want to run zero split or positive split timing? whoops. nope.

just like with anything you have to think about the future. will the rtek work will a stock engine and a little bit of boost? yah. works well to re tune. however, anyone who modifies cars probably will want something a little bit more. more power, and later on down the road will indeed achieve it. you should anticipate this and prepare for it as something that will be inevitable in the future. you will want more power and most notably will need more fuel and more finite timing control. assume this. its always better to start big and use little than to start small and overuse what you have.

for example, my setup is way overkill. hell... when i went meth injection at 250 whp was making a lot of people scratch their heads. however, the fact remains that i will have this at my disposal in the future. same with fuel. i have huge injectors and a huge fuel pump. are they overkill? yes. will they support me currently at 250 wheel hp? yes. will they support me till about 350 400 or so wheel hp with meth? yep.

all im saying is think about it. your gonna spend 500 bucks anyways, so whats another 500 or 700 more on all new harness and connectors and ecu?

[sc0rp7]

All very well stated, and I think we agree in most aspects here..

I agree if you think that in the end you plan on building an eventual monster of some sort, you should consider going with the best upgrade for future mods as well. This may be a full top of the line stand alone EMS, especially with a new wiring harness and more capabilities, or it may be a simple RTEK 1.7 with 720cc secondaries and no control over AF ratios or timing whatsoever... Do the research and decide on what you believe your goals are, then buy whatever best suits your situation.

to reply to the key points mentioned kain:

1. You are completely correct about the S5 turbo's waste gate. I agree with everything you said whilst clarifying that it will normally start to creep on an exhaust with no restriction i.e. no catalytic converter, etc. and somewhere over 2 1/4" piping...

2. I was also referring to the lesser RTEK's that dont allow adjustments and will compensate because of the AFM reading a different amount of air taken in.

3. I agree with your logic and reasoning on the S5 AFM being a superior design (shape), but the fact remains that on the RX-7, S4 AFM is larger and therefore has very similar air flow characteristics. All I was saying here is that the S4 AFM isnt really worse than the S5, but that a restriction in air flow is a restriction in air flow, regardless of shape and they both cause very similar restriction.

4. Interchanging the S4 and S5 engines can be done, but if you have the correct series harness for your vehicle, aka: the correct series engine, then the ecu harness plugs directly into the factory dash harness of your vehicle rather than having to modify it as S4 and S5 dash harnesses are not the same and this is the connection where you connect to the ignition coils and get your factory power and ground from, etc. You get the idea, I was merely stating it was easier with the same series engine.

5. The 500 dollar thing, that goes back to my original statement of depending on application as well as depending on the budget you are working with.

6. I agree with everything you stated a RTEK cant do except for the twin fuel pump thing, you can run as many as you want. Wire a relay, wire a hobbs switch if you want the second one boost activated, whatever you require. Everything else goes back to choosing whats right for your application.

Your statement about people normally wanting more and more from a vehicle is very true. What most people in that situation lack is the ability to know when they have enough, before they start having to drop multiple thousands on that motor thats pinned, because they blew it apart, or that late S5 rear housing thats got a stronger casting, etc. Going bigger and getting more is not always better, because of cost most notibly.

I like your example, as you have a goal of where you are headed... Good luck and if it fits your overall goal and you know what you are doing then other peoples opinions dont really matter.

- Chris