RX7MONSTER

Hello,

We got a T04S on a RX-7 FC.

Details :


Hi-6 CDI x 2 on leading coils
bosch coils
motec m4 ecu -latest version
t04s 60-1 , .70 a/r , p trim rear, HKS. was a .84a/r hotside but i swapped it to a 1.00a/r hotside for extra topend. and got a v-band welded onto it proffesionally..

3" exhaust system, gutterd cat

stock port motor , claimed to be rebuilt. starts first shot..

600bhp fuel pump
sard fuel reg, rising rate... set it to 40psi base pressure
b10egv spark plugs all around
stock throttle body ..

removed every bit of emmisions on the car

4" hks hiper muffler

HKS Manifold - cast
HKS 35mm GT1 wastegate, tricked to run 23psi.. wont budge any further even with the vacume mod to push the springs tension..


HKS Type S FMIC
Water Injection - mechanical, 100% good. Rice racing model.

no air filter 4" pipe off the turbo.

the car only made 310rwhp on 23PSI boost , spiking to 25PSI boost.,
intake temps where low 16c

oil temps where low
water temps didnt got past 78C


310rwhp is discusting.. @ that boost pressure

did i do anything wrong when i changed the exhaust housing to a 1.00a/r.. it is a genuine garret exhaust housing i used.. i got it sandblasted etc to be cleaned good.
butto clutch
lightweight flywheel
the redline drops off around 6500rpm on the dyno

fullboost by around ~4000RPM MAXIMUM!

what do you guys think it is.. the tune was 12.1:1 A/F Ratio
timing was good apparently
its a series 5 RX-7 jdm import

i removed the water lines going to the TB
thanks

Maxthe7man

Considering that it still runs after 23 psi at 12.1:1, I would say the timing map needs to be revisited, along with that air fuel, drop it to 11:1, and put some more advance into..
I would set the boost at 15 psi first, then push the ignition upward, even at 15 psi it should make 400, leave the water injection off for now..

T04Eneedy

your timing must be severly retarded,or something

RETed

Can you confirm this?
Compressor wheel inducer and major diameters?

Dunno what this means...but are you running part of the stock exhaust system???


What is this thing?
It's no surprise it's creeping on you with such a small WG.


Wow, that's some ridiculously low intake temps!
Is that due to the water injection?

The water temps sound a bit low.
You should be running more around the 90C range...at least over 80C.
Fuel atomization gets all weird at low temps like that.
Where is the water temp sensor?


I think the turbo is not a true TS04...

Got a pic of the dyno sheet???


-Ted

pistonsuk

i know the feeling... i just made 300rwhp on a very similar setup (20psi, haltech, 60-1 .84 hotside, FMIC, 11:1 AFR, ported motor, full 3inch exh). the next day i comp tested my engine at 75psi and tore it down. i had large gaps between the side and corner seals and 4 broken corner seals. i am now trying to build a very tight engine. i hope this fixes the hp issue.

make sure the air intake sensor of BEFORE the water injection. i logged some runs on mine with it after and the moisture affects the readings ALOT.

more info: Timing: 32 deg advance at 0psi linear to 14 deg advance at 15psi 8 deg split above 10psi

PM more questions

good luck,

justin

ps... anyone have some very low mileage steels forsale?

Carl Byck

I've never seen the IAS before the water injection. How will the ECU know what the temps actually are?

RX7MONSTER

I will try answer all of this at once.
The wastegate is the one that comes from HKS as a package with the manifold and Turbo...

The turbo is HKS T04S ( was .84 ) but i changed to 1.00a/r for the extra top end needed on a race track..

The intake temps are fine @ 16-18C maximum

Water temp went to 90C MAX on the track giving it hell.

Timing aparently is all perfect form the tuner? I paid him $400AUD to tune it, apparently its all sweet??

BUT. My engine is leaking oil from the backplate... Could this be it?
only does it @ high rpm loads

exhaust is pretty much full 3".. not 1 bit of it is stock

RX7MONSTER

Btw, Im kinda over this car at the moment.. i ran 13.0 @ 114MPH. 2.3 60ft

I have put down a deposit for a modified FC from japan that has claimed power output of 700PS, using NB Seals,T88,Power FC,3 core rad,big cooler etc...
I will fit water injection on it and if it hasnt got CDI already...

Apprently it did 297kmh top speed in some competition...

Lukus

An oil leak won't cause a drop in horsepower...

mazgtr

Unless its blow by
and the motor is weak

I.E side seal

pluto

sounds like the engine is about 20 degrees retarded in timing. I would definately zero the timing again to make sure you're set correctly.


I bet your EGT is probably sky high


To give you an example, I recently tuned a single turbo supra. and for a few days, I couldn't figure out why the EGT was so high (800C after the turbo) where the a/f ratio was around 11.4-11.5. The car only felt like a 450rwhp car at 18psi on pump gas.

After checking with the timing (supposely preset already from the manufacture), it turns out that the timing was 8 degrees retarded. I readjusted the timing accordingly and put it on the dyno. It made 561rwhp@18psi on pump gas. EGT is around 690C. Too retarded timing will definately take away hp.

Lukus

He mentioned it was from the back plate, hence my comment.

RX7MONSTER

It is from the back plate in the passenger side corner ( drivers side in USA )...

The guy at the workshop usualy does Piston engines, but he wanted to give a rotor a shot first time tuning it.

He said he did the timing.. but could he be wrong? I dragged the car.... 13.0 @ 114MPH 2.3 60/ft , it didnt feel that fast on the track.. even @ 23PSI boost.

What are the chances he didnt know how to change timing perfectly?

I will scan the dyno chart, the a/f curve is perfect

cheers

Lukus

Have you done a comp test yet?

RX7MONSTER

Hi,

Not yet. Althou the engine was suppose to be rebuilt around 10,000klms ago.

I think i need to do a comp test?

I will do that soon

Lukus

It should've been one of the first things. 10,000km is a fair distance. In the grand scheme of things it's not much, but on an engine you're expecting to pump out considerable power, you need to make sure everything is spot on.

You need to cover the basics.

RX7MONSTER

What are the chances its the timing? This guy has never done rotary's before, he said the set the timing to what rice racing told me to put it on... althou he mightve made a mistake. i will get a compression tester off a freind and give it a comp rough comp test... the engine "feels" like it has lots of compression.. but who knows... it doesnt even feel that fast anymore, im kinda use to the 230rwkw... 23psi is allot of boost

Lukus

I personally would've gotten someone who had tuned rotaries before to tune it if it was my car.

OLD RX-7

ppsssst, May I ask which dyno shop you went to ??

Regards the old boy