Is the Rtek 2.1 a good choice for 6 port turbo?
 

Hi, I'm going to turbo my 1989 S5 GTU and was wandering if the Rtek 2.1 upgrade a good choce or should I save up and just get a megasquirt or adaptronic? My goal is 300-350whp. If I don't get 350whp it's not the end of the world lol

My current setup is:

- Street-ported 6 port high compression engine
- Garret Air Research T04B35 AR. 60 and AR.80
- Cartech cast iron manifold
- 720cc injectors for primaries/secondaries
- Walbro 255 fuel pump
- 3in downpipe and exhaust
- FMIC
- S5 N370 AFM
- S5 N370 pressure sensor
- Blitz intake
- HKS bov

I would recommend waiting to buy a better ECU if you can't afford it. If you can't afford it the RTEK will work, but just be a lot more difficult to work with. I had a RTEK 1.7 and 2.1 previously. The tuning is very painful to do with this ECU. At 1st I wanted to save money and was wanting around the same power goals as you have. I am guessing I am around 350-400 right now. The RTEK is just so outdated. I think I heard that the RTEK will be going away also. I have not researched this however. I had issues when plugging in a palm pilot it would sometime cause the ECU to get reset. I used the laptop as well to program, but you can not save the ECU filel on the laptop to upload. I had saved t on the palm pilot, but it was old and it died and I lost the ECU file I saved. After doing retuning the whole car a few times with this I finally had enough and went to someone to see what they recommend and decided to just get that and pay for it. The good thing was I was able to sell the RTEK and not lose to much in the process. I figure the RTEK 2.1 is like $400 or something like that. Then you need a palm pilot so you go buy something for $100. I got the adaptronic because that was what was recommended my a mechanic near me and it is like $1349. Yep you can save my doing the RTEK , but it does not have any cool features like the new ECU's do. Their are safety features built in and so much more you can do with it. With the RTEK you program 1 cell at a time for your fuel map. That takes a long time! I can change all my cells at once with this ECU. I can go up or down a certian percentage. This is just my .02. Hopefully others will chime in.

I don’t think 720cc all around with be enough, it may be close. Also keep in mind you’ll need to upgrade your FPR, I didn’t see that explicitly listed.

Who will be tuning the car, you or a professional? Have you ever used an RTEK? First, no professional is going to touch it. Second, it’s a headache to use and very limited. Getting rid of RTEK was the best decision I ever made, and I’ve never looked back.

Thank you for your opinion. I spoke with a buddy and he said he can build me a megasquirt ecu and help tune it. He said if i give him a stock ecu case he can build the megasquirt in it and make it plug and play. I do however do I like the features of adaptronic also. Honestly Ive turboed hondas before but this is actually my first time turbocharging a rotary. Rtek is kinda old technology....

I have 2.1 for my setup which is similar-ish to yours. Making adjustments is a bit of a pain, but it seems to work just fine. A lot of the issues people have with resets and connection errors comes down to their choice in PDA. I use a palm m105 currently and it has virtually no connection issues.. its connector design is pretty solid and battery life is incredible.

Modern ecus do give you way more flexibility and options..but the rtek suits most needs just fine. I'm sure I'll upgrade to a Haltech someday.. but I'll never actually get rid of my rtek. You plug it in, check some setting boxes, and it just plain works. Super simple !

Not really, the RTEK was an interesting alternative to a SAFC and FCD when it was first offered but now haltech has their elite 550 lineup which is only about 150 more new if I recall and there are a whole slew of other ECUs that will better suit your needs.

Would I still be able to keep my ac and OMP if I switch to an aftermarket ecu? I think Rtek you can still retain a lot of the factory stuff.

a/c yes, OMP no.

but you asked if it was a good choice for a turbo engine, to which i say no.

I
 

I don't want to give up my OMP lol I think I will just save up and invest in a better ecu. Does anyone know how much power I can push out with a T04B ar60/ar80 on a 13b NA s5 @ 10-14psi?

haltech's have ecus that can drive the elec. OMP but won't have the failure check feature the stock ecu offers...that turbo spec. means nothing other then it's the frame size family of the compressor and turbine housings...need to know the size of the comp./ext. wheel.

You will probably be at the limit of the RTEK ECU/MAF, but it should be adequate. As long as you are okay with a lot of typing, it's a great platform.

The best thing about the RTEK is that it's literally a plug-and-play OEM ECU, plus the tuning features. There are no equivalents.

Just found out that Digital Tuning will be closing shop. They don't stock the stage 2 s5 boards anymore and will not be ordering additional boards. They will still provide support but shop is closing for good. 😔

not a big surprise, they never seemed to care about evolving with the times or doing alternate things to supplement business.

Do y'all think it will be safe if I hook up an FMU and drive it without boosting until I can get it tuned? Ive done this before with my turbo hondas but dont know if same rule applies to rotaries.

no, thats a perfect way to blow up a rotary. this isn't a honda that can survive a bit of a beating while fine tuning it.

Rtek filled a gap in the market for a long time that still serves many to this day. A gap that still exists. People have just gotten a little better at jumping the gap, that's all. It would have been nice to see DTi modernize the Rtek, but it is a huge amount of work with little money coming in to get that work done.

This is the turbo I got. I guess it states over 370hp ...
http://www.piersideparts.net/CB7488.html

rotaries make less power off the same air volume as common piston engines, so turbo ratings usually will be higher than you can expect to realistically see with these cars.

also hope you opted for a larger than the .69 a/r turbine, that's gonna choke power quite a bit as well.

It's a T4 flange, compressor ar.60 and turbine. Ar.80. A friend of mine just told me that he knows someone selling an rtek 1.8 chip for an s5 turbo. Debating on getting it just so I can drive the car temporarily with the 720cc until I get the adaptronic. I will just run low boost 5-7psi and monitor it with a wideband.

For your goals, you'll be better off going with a different ECU that will be better off in the long run.

Band-aid fix to maybe get it to start, Rtek 2.1 will probably work...maybe.

You have to admit, it is very cool to see such a grass-roots company making ECU's for RX-7's. I've always admired that company for keeping with it and making something so unique.

My 4 port turbo with 9.4 rotors has been completely fine on an rtek. Only things I really wish it had are learning capabilites for auto-tuning and a native interface for android/iphone or an actual computer. Other than that, it works great for my setup. I run a hybrid with 720x4 and the engine is ported.

The tuning resolution isn't great, but it'll do what you actually need it to do. No, it's not chock full of features and tuning aids, but if you're runnning largely stock components (boost sensor, knock, tps, afm, etc).. it works beautifully.

Thanks guys. I sold my N374 and decided to just save up for a standalone.
Maybe if Rtek still offers the S5 turbo 2.1 then I might've kept it but there's no point since they're closing shop.

honestly I would use a garret 3.1 turbo but it does kick in very late in 3 grand area

happy racing