street_ruler

Year: 87
Model: turbo II
Specifics 5Lug & 5spd

The motor seems to want to revv higher than what the stock tach shows. Its smooth all the way to 7k and seems like 8 or 9 wouldnt be unimaginable.

Is there a management system that will allow you to revv the engine higher? ideally id like to revv to anything from 8k - 9k and run about 10lbs of boost at that level. im not looking for wicked boost as this is a daily driver and i want "safe" or "reliable" power.

Also for tuning a local guy is selling an HKS FCON. does that need to be tuned or is it a "pre tuned" ECU thats got some rather safe tune to it thats plug & play?

thoughts on the over-rev and FCON?

diabolical1

iTrader: (3)

it might seem that way, but it's not a good idea. first of all, there's no point to it. graphs/plots are out there. second (and most importantly) the engine is not prepped for it. the apex seals are too heavy, the engine is not THAT balanced, and it's not clearanced for those revs - well, maybe 8000, but no higher.

it's not just a management issue. the engine itself is not prepped for 9000. honestly, one of the advantages of having a turbo is that you won't have to rev for power/torque. also, daily driver status with increased revs sort of goes against the idea of reliability.

i believe the FCON needs to be tuned. it's been a while, but from what i remember about it, it was the HKS's offering for a 90s stand-alone.

Evil Aviator

As mentioned above, the redline is based on mechanical limitations, not the ECU. If the engine is not ported, then the peak horsepower will be around 6,500rpm, and the power will drop as the rpms increase from that point, which means that at higher rpm the engine will make less power and incur more wear... not good.

Race engines rev higher because 1) They are built and balanced to do so, and 2) They are "ported", which means that they make their power at a higher rpm, so it is advantageous to run them at a higher rpm.

If your engine seems to rev up quickly then it is likely low on compression and will soon need a rebuild. You can check the compression to see if this is the case.

The FCON needs to be tuned. If you want a pre-tuned ECU, then I suggest the Rtek Stage 1.
Rtek7 ECU Upgrade Detailed Information

street_ruler

with that rtek7 stage 1.X chip, how do you control boost? i presume you need an external boost controller? I didnt see anything about that in the writeup.

also aside from porting the turbo housing, which i dont want to do because i dont want to remove all that stuff and deal with it, is there another way to control boost? can we add an external wastegate somehow?

Sgtblue

iTrader: (16)

You port the wastegate (what I think your asking) to control boost creep. If you don't want to go to that trouble, seems like the easiest solution is to maintain some backpressure in the exhaust tract.

rxmiles

iTrader: (11)

Don't do it, keep it safe. Rotaries are very smooth hence the reason has a warning buzzer. If not properly modified the engine can get hurt by over revvving..Besides you're going past your peak power band.

RYU_NA1

Mind if I ask what's everyone's preferred aftermarket ECU solution?

Evil Aviator

Posted in your other thread:
https://www.rx7club.com/new-member-r.../#post11623586

Rbas

The fcon could be a pretty tuned ecu, it all depends on what model it is. The PFC fcon has a pretty loaded map and goes between the ecu and injectors to fool them and adjust the fuel curve. It also has it's own boost pressure sensor which allows it to adjust this fuel map as per what boost you are running. Then there is the fcon vpro which is a full stand alone system.