I've researched a little bit and it only brought me more confusion. I'm about to rebuild a S4 TII motor. However, the entire exhaust (including turbo) was lost to the void.

In this build I'll be using a new racing beat exhaust with an S5 turbo i managed to snag. I'm sending the turbo out to be rebuilt (likely BNR with the upgraded compressor wheel + waste-gate actuator upgrade). I will also have a street port completed on the housings. Initially, I plan to run stock boost for a while...

So the question is (since funds are somewhat limited and I'm almost over budget)... Would a fuel tuner be necessary, and if so, any suggestions? BTW, I will be using a fuel cut defender and a turbo timer as well. This will be going into an '87 TII with a new clutch assembly.

If I run stock boost levels, is this safe on a stock ECU/Tune with stock injectors? I do have an upgraded walboro fuel pump, only because the stock one was DOA. I appreciate any advice or knowledge =)

 

if you can keep it at stock boost levels you will be fine, if you run into boost creeping issues you will not.

 

yes an SAFC or a RTEC would be recommended and partially necessary.

dont run a turbo timer. no need to.

 

Very cool, thanks for such quick responses. I was afraid I'd need one, and i suppose it's confirmed. I'll use some of the funds from a turbo timer and place it towards a tuner. It won't hurt me to avoid being lazy and let my car idle a few minutes before shutting it off =p

I'll look into the SAFC and RTEC as well, I appreciate the suggestions.

 

There's no need to let a water cooled turbo idle before shutting down unless the car was just run hard.

Turbo timers are actually pretty counter-productive, it's MUCH better to simply drive the car calmly to cool it down as you have air flowing through the engine bay while the car is moving.

I can virtually guarantee you that an S4 turbo is going to get boost creep with an aftermarket exhaust/intake. Porting the wastegate is absolutely necessary.

Also with a BNR it will be moving more air at stock boost levels than a stock turbocharger, this will require more fuel. Having a ported motor will make more fuel even more necessary... You are looking at a minimum of Rtek 1.7/720cc secondaries as well as a fuel controller and wideband readout.

You may also need an upgraded clutch and tires to put the power down since the power levels will be so much higher than stock.

 

Thank you K-Tune. I will be running an upgraded clutch and some wider tires in the rear. Unfortunately, I don't know a lot about the AFC piggy-backs or about tuning turbos in general. This will be my first turbo car, so I'm learning the challenges that go with it.

I can probably spend about 400-500 on a fuel tuner and if it gives me potential for future modifications, I'd be happy. In the end, I'm looking for 285-320 HP total. Currently, I'm looking for stock boost levels to get the vehicle running and on the road.

I'm also learning that the build cost is going up in price, but I'm more concerned about getting it right the first time, even if it means I might not have the car on the road for this summer. I'll look into the injectors as well.

*Edit* It looks like the RTEK 2.0 might be right for me. It would eliminate the need for a piggyback and also eliminate the need for a fuel cut defender, which means I need to buy less stuff. If anyone has any thoughts or suggestions, I'm open to them. I'll have to go with larger secondaries, but it'll also open the door for future tuning and future mods for more power (am i correct to believe this?).

 

The 2.1 is commonly used with hybrid turbo setups. It's also very easy to setup and use, which is a bonus if you're going to be tuning it yourself.

 

http://fc3spro.com/TECH/FM2W/power.htm

best info u will ever read

 

Rtek is less cost effective if you wind up needing a professional tuner to tune the car, as it still is very time consuming to tune with. in the end it may cost you more than a more capable ECU would. if you plan on learning to tune the car on your own then it is ok, it still takes longer and costs more in fuel to tune with overall though.

 

"http://fc3spro.com/TECH/FM2W/power.htm" <--- very nice info, thank you.

I ordered a few items today. I'm still debating the engine/fuel management portion. There's only one tuner that's "local" to me and they're about an hour away. I'll call them and see what they use for fuel management and check pricing. If it's too much, I'll be hitting some books, doing some heavy reading and learn to tune things up.

Yes Karack, the RTEK looks very attractive for all the bells and whistles that come with it. On the other hand, I don't have a palm device to use with it at the moment. Is there anything else that would be able to get the job done at a comparative price point when taking a professional tune into consideration?

 

Palms are dirt cheap on ebay. You can also use a null modem cable and emulated Palm OS on a laptop to make tuning easier: https://www.rx7club.com/showthread.p...ghlight=laptop.

But I'd agree that if you're handing things over to someone else to tune, you may want to pick whatever EMS they're familiar with.

 

Very cool, thank you. I do have a laptop, so that solves the issue of the palm =) Now to send the housings and misc parts for cleaning. I'll take pictures and post a new thread for the actual rebuild once I get the parts and start the assembly!

 

I realize you are a on a budget, which is going to be tough with a rotary but it would be in your best interest to save up for a few of the things that would be more beneficial. First of all, you can never have enough horsepower. Save up, get a Haltech ECU, 1000cc + injectors for more power later if you want it, and most definately go with a wideband AFR set up so you can see what your fuel system is doing. These components are critical and will allow you to tune and not have to worry about detonation. You will have to port the waste gate on the turbo also. It is crucial to prevent boost creep. Just a few suggestions to help you out. Hope it is helpfull.

 

Your best bet is too talk to who ever will be tuning your car... Find out what he suggests works for himself, you and your car... Then post back with specifics.

The place where I'm taking my car for tuning recommended I go with the apexi powerfc. He's knowledgable with it, it's in my budget, it had a lot of features, and it's almost plug and play (banzai) so I can install it myself.