sa22rally

Hi Guys been searching around and everyone seems to think its crap.
So naturally i dicided to do it haha.
actually this is different. heres is my plan and i have allready bought most of the parts but before i start spending to much time and money? Does anyone have any advice ore experience.
I have remowed everything from the stock wiring harness from the intire car and will not be reusing anything
a few questeing to.
what fuelpressure should i run with this setup offcourse i will take out the stock regulator from the unit.
is the 2 stock injectors gonna be enough?

4 port renessis rebuild with goopy.
Bridgeport this one offcourse only using the 4 port stuff Kyle Mohan Racing | Performance Parts and Services
stock intake with all valves fully open and fixed.
throttle body converted to 70 mm manuel.
Stock exhaust manifold (because of raceclass regulations)
3" from manifold to dual 2½" exhaust with only a 100 cell cat at each side i might fit a mufler before each cat iff its to laud.
Haltech elite 550
d585 coils
walbro fuel pump
6 speed gearbox with 5,33 rear diff.

Any advice is appreciated?.
And before you ask and start saying to buy a 6 port i believe the 4 port is gonna be a more powerfull engine with more torque i might not get 10000 rpm with HP but i hope and believe that i can get alot of torque from down low to maybe 8 or 9000 rpm.

But what do you think?

best regards and thank you in advance Rasmus Denmark

oh and by the way its a Tarmac rallycar.

NotAPreppie

A 5.33 rear diff? Holy crap!

9krpmrx8

iTrader: (46)

All of that is a waste of time and money. But it's your time and your money.

BigBadChris

iTrader: (4)

A few pieces of advice, take it or leave it. One, the four port will not be able to flow enough air at 8k or 9k rpm. Thats what the aux ports are for...to feed enough air as the engine spins up to redline. Two, I would not wire all the ports open. In a natural aspirated build, you want the Mazda intake system intact, they spent a lot of time working out plenum length and resonance. Three, you might not want the six speed trans on the four port engine. If you are gung ho for rowing your own gears, try the JDM five speed which was built for a four port. Youll find the shift points are much better for the power band of the four port.

sa22rally

Great response. I do have several 5 speed boxes since I'm in Denmark 75% of the rx8's are 192 hp 5 speed.
But from my Rx7 rallycar I feel the 6 speed paired to the 5,33 rear end would be better? Ore am I missing something.

As for the intake I feel and expect all the valves and stuff are there to make the engine driveable while not polluting but I might be missing something there to. I just can't get the old 4 port out of my head which are much mere torque willing than the 6 port?

sa22rally

It's awesome at least in my Rx7 rallycar I have the 5.13 and it's just so much faster than the 4,7 I had before. I've even seen 5,8 for the rx8 but that will
Bring to much stress to the drivetrain for rally driving

sa22rally

all right look at this guys and tell me why this is not an awesome calculation

this is the 6 speed with max 8000 rpm and 225/650r18 tarmac rallytires and the 5,37 ratio.
look at the Rpm drop men changing gears its only 2200 rpm for 2-3 and 3-4 and only 1200 rpm from 4-5 and 5-6 thats is just going to be fast ore again am i i missing something? unfortunatly ive read more about racing than ive raced
in the bottom theres a calculation for the 5 speed

Gear shift Difference after shifting RPM after shifting
from 1st Gear to 2nd Gear 3172 4828
from 2nd Gear to 3rd Gear 2200 5800
from 3rd Gear to 4th Gear 2227 5773
from 4th Gear to 5th Gear 1260 6740
from 5th Gear to 6th Gear 1256 6744
kmh / RPM 1000 2000 3000 4000 5000 6000 7000 8000
1st Gear 6.1 12.1 18.2 24.3 30.3 36.4 42.5 48.5
2nd Gear 10.1 20.1 30.2 40.2 50.3 60.3 70.4 80.4
3rd Gear 13.9 27.7 41.6 55.5 69.3 83.2 97.1 111
4th Gear 19.2 38.4 57.7 76.9 96.1 115.3 134.6 153.8
5th Gear 22.8 45.6 68.4 91.3 114.1 136.9 159.7 182.5
6th Gear 27.1 54.1 81.2 108.3 135.3 162.4 189.5 216.5



5 speed
ear shift Difference after shifting RPM after shifting
from 1st Gear to 2nd Gear 3368 4632
from 2nd Gear to 3rd Gear 2108 5892
from 3rd Gear to 4th Gear 2609 5391
from 4th Gear to 5th Gear 1904 6096
kmh / RPM 1000 2000 3000 4000 5000 6000 7000 8000
1st Gear 6.6 13.1 19.7 26.2 32.8 39.3 45.9 52.5
2nd Gear 11.3 22.6 34 45.3 56.6 67.9 79.3 90.6
3rd Gear 15.4 30.7 46.1 61.5 76.9 92.2 107.6 123
4th Gear 22.8 45.6 68.4 91.3 114.1 136.9 159.7 182.5
5th Gear 29.9 59.9 89.8 119.8 149.7 179.7 209.6 239.5

Harlan

iTrader: (3)

Wiring the ports open only makes sense if you plan on all high RPM driving. Since this is a rally car with a stand alone ecu its not that bad an idea. It will make it gutless down low, but it will also remove failure points and the potential tuning issues.

sa22rally

Yes it might kill it your right however i hope you are more right in tuning and failure potential.
I have actually just dicided to take my "spare" engine and get that dialed in on the haltech before building the "race" engine that way we can all get a picture of what a standalone and opening up the whole intake does to the engine.
i just have to finish the rollcage and the new wiring i hope we all have some answers before christmas

Brettus

iTrader: (2)

The SSV is a waste of time for your engine as it only has an effect below 3200rpm so may as well wire that open . The VDI comes in at 5750 on a four port so you probably wont lose much having that wired open either .
You are wrong about the 4 port being better than the 6 though . The extra torque from a 4 port is inconsequential vs the extra power from a 6 port at higher rpm.
However , with a bridgeport , you will make up for this to a large degree .
Sounds like you are on the right track to me .................

sa22rally

Excatly and its stil rally driving and 10000 RPm is really hard to control on loose ground.
You also have to keep in mind that I need the stock exhaust manifold and I bridge 6 port would probably have difficulty breathing