~300Bhp setup, intake mods needed? comments please
 

Hey guys,
I'm new to mods. Need help please.
My aim is to tune my S5fc turbo 2 up to 300ish bhp.
My current mod list:
Racing beats Rev TII
K&N drop-in
adaptronic ECU
walbro 225 fuel pump
Koyorad N flow
HKS EVC 6 boost controller
HKS super SQV bov
Everything else is stock.
What do you guys think? I did some research and found lots people have their intake moded while someone saying it's not necessary... (I kinda don't want to... it's not easy to customize a cool air box) Any other comments? How big of injectors do I need? For turbo upgrade, is stock enough with those mods? or should I go for BNR Stage2

By the way, I just did a compression test last Friday. I got three even bounces from both rotors but it seems that it only bounced to ~83 psi.....which is close to a rebuild.... is it normal to have lower pressure if you take off the Schrader valve?
If it's really 83 psi, is it still worth tuning before a rebuild?

Thanks in advance!

get a bnr stage 4, get bigger injectors, and better intercooler. then 300 will be easy.

This might help you plan out upgrades.
FC3S Pro v2.0: From Mild 2 Wild - Power

The stock turbo is not enough for 300HP at the wheels, I find they max out around 250WHP
A hybrid would be a good choice for your power goals, the stage 2 you mentioned will do just fine.

The stock 550cc/min injectors will barely just support 300whp @ 10:1 and 85% duty cycle cap, I'd run 720cc/min secondaries.
Note: Your stock injectors are now nearing 30 years old and are more than likely not flowing 550cc/min anymore.

The issue with the stock TID is that the S bends in it are very restrictive, switching to a 3" intake like most (including me) usually yields a 2 - 3 PSI gain in boost pressure.
Shows exactly how the stock TID is so inefficient.

The stock intercooler will be a bottleneck in your setup, should you choose to keep it. IATs skyrocket past 12 PSI.

83psi is pretty low, although there could be some variables that would throw your readings off. Do you have any hot start issues? Lower compression engines tend to have hot start issues. Try finding someone with a rotary specific compression tester locally to be sure.

Thank you very much for your advice!

wow, I've been learning stuff from FC3S pro for a long time and I forgot this! Thanks man.

wouldn't bnr stage 4 be an overkill? I wonder how much of the turbo lag you can feel on a bnr stage 4

My goal is ~260hp at wheels and 300 from the engine. Since my engine is pretty old, I don't want to put too much pressure on it.

My local tuner told me that the stock S5 turbo can do 300hp no problem..... I'm wondering how much psi can a stock s5 turbo do? I did some research and the answers are different.

I have bought 2 sets of 725cc injectors. You think only the secondaries need an upgrade?

I agree that the stock TID is very restrictive...I'm planning to mod it too. did you DIY the 3" intake?

I thought the turbo and intake will be my bottleneck....didn't think about the intercooler. (I thought a turbo upgrade will help lower IATs) Any aftermarket kits you recommend?

I have neither hot start issues or cold start issues. That's why I was thinking maybe there could be other reasons. Unfortunately, I live in a small town here and even the Mazda dealer doesn't have a rotary specific tester. :( I'll try another regular tester this week just to compare.

The only problem I have right now is that when I declutch, RPM drops quickly (drop to <500 then come back). Sometimes it seems like it drops too hard (especially declutch from 3rd, 4th gear) and the engine just stops.... kinda dangerous on the road..
I suspect a dirty throttle body and IAC valve.

Get a haltech, 4 ID1000 injectors, a walbro 255, front mount, and a bnr stage 4. thats gonna be the most reliable way to get to 300 whp +

Y, that's similar to my setup. Recommended. 300 whp with this setup is a walk in the park.

For what it's worth, I made 330hp to the wheels with a BNR stage 2 and plenty of fuel and Power FC to go along with intake/exhaust. (ID725cc/1000cc + Deatschwerks fuel pump) S5 TII engine is otherwise a fresh rebuild with stock parts and ports.

What's your intake mods and did you get a front mount intercooler?

I think SirCyg might've missed the adaptronic part in your original post. Both are capable of doing what you want to do.
I think adaptronic's are pretty recommended by other rotary builders, I've spoken to a couple people about them
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I think some people have made 260WHP with the stock turbo before, check the dyno/time slip section. I had my car dyno'd before I built my hybrid and it put down 229. Mind you my engine is ported and had 720 secondaries. There was also a huge lean spot in the stock ECU map when you bump up the boost and use an FCD. I'm pretty sure it could've hit 260WHP with a standalone.

Most people say 14psi is the max for the stock turbo and even then your turbo's oil seals still might not like you.

If you already have 4x720cc injectors and have a means (standalone) to control them, then install all of them. More fuel is better than too little fuel.

Yes, I made my own intake tube with a 3" 45 degree bend from vibrant.

I can't really speak for any aftermarket kits as I built my own mid-mount IC setup. I hear the rotary works V-mount is pretty good.
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There is a rotary meet in the GTA in August, I will more than likely be there along with countless other people well versed in the FCs. Try to make it out, we can chat about it in person.

Adaptronic is still new to the game. haltech has has been doing it for years. they have great shit

Thank you for your detailed information! Good stuff!
I'll try to reach 260 with the stock turbo this year and upgrade it maybe next year.
Did you use the titanium 45 Degree Mandrel Bend from vibrant to make the intake? Any cuttings or other mods involved?

Yeah I'm really excited about the rotary meeting in August! I'll be there for sure! See you in August.

haltechs are not cheaper and I don't know a tuner that can do haltech......I guess adaptronic unit will be fine since I've people using it with no problem on Rx7s and Rx8s. Plus it has more new features?

Adaptronic makes a damn good ecu, I have one in my fc, with a holset hx40, adaptronic been running it for almost a year now, works and doesnt give me problems.

I used a 45 degree 3" aluminium pipe (PN# 2175) from vibrant and cut to fit.

https://cimg1.ibsrv.net/gimg/www.rx7...c724b019db.jpg

IMO titanium is overkill for everything other than racing, where every gram of weight matters.
Also the TID never sees pressure, you could build it out of PVC pipe if you really wanted to.

As for ECU choice, ask your tuner what he would prefer. Everyone has their preferences and I'd cater to whatever the guy tuning my engine likes.

I've heard good things about adaptronic, but I don't have any real experience with it. But Haltech makes great units. Good support too.

the if we look at the literature, the stock turbo is spinning 110k rpm, which is actually already on the high side. more boost = more turbo rpm, which is why turbo life gets so short so quick.

this is also why the hybrid turbo is a nice setup, airflow goes up, turbo rpm goes down (how much, depends on the compressor wheel that is chosen).

the intercooler is fine up to 350, the stock turbo is what creats more hot air then the stock intercooler can handle at 12 psi, the stocker( well ARC top mount) held AITs great thru 20 psi with a compressor thats designed for it.. BW s257.

there is a limit for the stock intercooler, but its not a pressure limit its a flow limit, I ran 18 psi to make 320whp. so what ever the CFM for 320hp is you are probably good, besides its not worth block the radiator or having longer spool times of a FMIC IMO

Thanks bro. I'll try to get one from JRP.

Right.. is there any hybrid turbo you recommend? BNR?