My S4 N/A is giving the maximum torque at almost 7800rpm, so I am thinking about getting a S5 N/A ECU for rising the rev limiter from 8000rpm (S4) to 9000rpm (S5 ECU)
It is getting +170rwhp also at 7800 rpm just before the rev cut on stock ecu.

Mods:
CAI, S5 VDI, TB mod, all emissions removed, free flow true duals, timing 2º more advanced, turbo model fuel pump, pinneapple sleeves inserts, weight 2000lb

I want to know which sensors are different, I know that maybe I will have to change also de MAF. Should any sensor more be also swapped?

Thanks for the help and happy new year everybody

 

You will have to rewire most of the car for it to work. Try looking at Rtek.

 

170 is pretty good for stock internals. How are you activating the VDI (or do you just have it wired open)?

For that setup, I agree that the RTek is probably the best solution - by staying with the S4 ECU you can keep the same injectors (low impedance) as well as the other sensors. The trailing plug timing will also be correct for the S4 block, although I'm note sure how much difference that really makes.

http://www.pocketlogger.com/index.php?pid=rtek7

Unfortunately it doesn't look like they make their "stage-1" chip for the S4 NA (only the S5) so you will have to go with a "stage-2" kit which essentually gives you a fully tunable plug-n-play ECU (not cheap, but with the weak dollar it's a pretty good price). Compared to the price of having to buy an S5 ECU, harness, new injectors and other sensors, it's may not actually be that much more.

Good luck,

-b

 

Are those metric pounds?

 

Is that 170rwhp untuned or tuned..? Kind of curious because i'm looking to get roughly 180 out of my car for the track an autoX.

 

Firstly i was activating aux ports and VDI with an electric air pump and a rpm switch. Once it stopped working (pump overheating) I wired them open, losing some power in the mid range. Trying to avoid huge rpm jumps I am using 15" low profile wheels, but the car still needs closer gear ratios.

I thought about going rtek, but I have installed a safc II waiting to be tuned to lean out a little so I was looking for the cheapest way to increase the rpm limit.
Aren´t S4 N/A injectors the same than S5 N/A ones?
Does rtek allow to change the rpm limit?


The car weights 910 kg with near 10 kg of fuel, so I think the it will be near 2000 lb (US units)


I have an SAFC II installed but not tuned yet. Hoping to get 10 hp from it. I am also racing the equivalent to autoX here in Spain. It is a nice car to race with, we have won the rwd regional championship against hillclimb cars such bmw m3 e30. The main problem of the car are the endless gear ratios and the trouble of making a shorter final gear.

Here there are some videos of the car

http://www.youtube.com/watch?v=dRaCgEB7vW4

http://www.youtube.com/watch?v=aFfHMvZFkZc

http://www.youtube.com/watch?v=P7OaX...eature=related


Otherwise, it I swap a S5 N/A ecu, should I change the injectors? Is the AFM the only sensor that might be changed?

Thanks for your help

 

180 will be tough w/o porting. It can be done, but you're right on the edge of what's realistic with the stock internals.

-b

 

I thought that the S5 rev limit was higher because the rotors are lighter and machined to tighter tolerances... And that running too fast on the older rotors could cause the e-shaft to flex or the stationary gears to deform and allow the rotors to contact the rotor housings.

 

open the aux ports and VDI with a factory air pump just like the s5's did. Electric air pumps are a dead end. I went that route 4 years ago and gave up on them. I did 172rwhp on an s4 n/a with s4 manifolds (no VDI).

 

I have hear that s4 rotors and e-shaft can turn up to 9000rpm without problem, can it be possible without engine failure?



Nice numbers! Which mods have you done? A/F ratios? Timing advance?

Thanks

 

that was years ago... I think the crank angle sensor was rotated, plus it also had an SAFC messing with the load signal, so who knows what the actual timing advance was. Rtek 2.1's weren't available then. As far as mods, it had a street port with T2 rotor housings (which don't have the diffusers in the exhaust ports). It had Racing Beat header to a straight midpipe (no cat) and a Racing Beat catback. I had the aux ports running off an electric airpump for a while but it was unreliable so I wired them open again before I sold the car.

If I could go back and do it again, I would go ahead and get an rtek

 

Thanks for the info

I have found a chipped N326 ECU (1986 N/A) without rev limiter. Could it be swapped instead of my S4 N/A 1988 N327 ECU without changing the MAP or the AFM?

I am also looking for a Fidanza aluminium flywheel, they told me it needs a counterweight. Can I put one from a S4 N/A with auto transmission without any vibrations problem?

 

Where did you hear it?
Did they mention any machine work for clearancing or lightening the rotors?
How about balancing the rotating assembly?

I wouldn't... Not on a stock rotating assembly and not with stock steel apex seals.

Around 7000 RPM sustained, the apex seals "chatter" against the chromium coating on the rotor housings and ruin the coating.

 

i had a 87 that had what i was told was a stock re-worked ecu and i was turning 10k rpm's.i drove it like that for over a year but then i let my buddy drive my car and he stalled it and got t-boned and totaled the car.i picked up a 88 shell and engine swapped it but when the engine was out i found oil poring out of the header so i guess i blew an oil seal.now im running an 88 engine on a 87 set up (because i had just previously bought 4 new injectors for the 87) and am running a stock 87 ecu.so,i managed to pull 10k shifts but ruined my engine in the process after a year of running it like that.i suggest staying with the 7k redline.i'll never risk hurting my baby again.question though,how about them guys who make 14k shifts,whats their secret?

 

their secret is either a very well built motor with clearanced rotors and/or a 2 piece e-shaft with center support bearing...

Get the chipped ECU with a higher rev limit or get the RTEK. Just try not to go overboard on revs as you will eventually cause motor failure being all stock internals... Also, if you are not already, pre-mix... this helps alleviate apex seal chatter some at eh aforementioned rpms as the apex seals are better lubricated.

- Chris

 

S5 ECU has the electric OMP too,so that is a problem unless you go Rtek.

 

Thanks everyone for the info. I think I will better install a turbocharger and turbo ECU and other stuff for filling up the mid range, then with wider tyres keeping the same profile I will get higher speed per rpm at the same gear. Then the ceramic clutch will be a must.

Would you recommend the fidanza aluminiun flywheel with s4 auto counterweight?

Cheers