TeamRX8

iTrader: (25)

no surprise with the smaller divided housing, how is the load holding up at higher rpms is the question

FazdaRX_8

iTrader: (1)

From recent logs on 4psi , it climbs to 170ish.

But forwhatever reason the car doesnt like to go past 7400rpm. Standing on the throttle it goes 7300,7400,7350, 7370.
Maybe to rich, wo2 is pegged, lc,1 reads 11.1.

Or maybe a broken intermitten plug wire, i have the bhr kit, just need to test the wires

Turblown

Am I missing something here? 1000rpm difference from JUST a turbine housing swap? That is impossible.

FYI guys a .84 P trim turbine housing is about the same volute as a 1.06 GT35R( T3 or T4)

TeamRX8

iTrader: (25)

I thought going from an open 1.0 AR to a divided 0.84 AR was generally considered to be a big change, but will defer to your expertise

FazdaRX_8

iTrader: (1)

1.00 divided to .84 divided, on a p-trim.




fine call me a liar.....

TeamRX8

iTrader: (25)

Thanks for the clarification

Turblown

I'm not calling you a liar, its just that something else was also changed( outside air temps makes a big difference), or you are basing this off just driving conditions.

I have done back to backs on many vehicles, piston and rotary. To get a 1000rpm jump takes going from a 1.19-1.32 down to a .84/.81.

FazdaRX_8

iTrader: (1)

I wanted to share this

I have found it increasingly annoying that my stock wideband does not seem register in WOT situations, its placed 3 inches from the turbo inlet. this makes it challenging for tuning, so

I decided to install my second wideband in the downpipe about 10 inches away from my turbo, my Friend who tunes his RX-7 tunes this way so I thought I would try it aswell.

my hypothesis was that the stock wideband becomes saturated or something due to the extreme heat and pressure present before the turbo.

after the install was complete a test run was in order, in 3rd gear WOT, the stock wideband read 10.9 from the AP unchanged for the entire run.
the secondary wideband however read, 11.5 and a apv lean spike of 12.4

so it seems my hypothesis was correct for my situation.

I have added more fuel to my tables since then......

MazdaManiac

iTrader: (3)

Well, yeah - you can't put it before the turbo.
I thought that was pretty well understood.

I don't think I've ever seen anyone even try that.

TeamRX8

iTrader: (25)

how do you know which is correct and which is not?

if your hypothesis is actually correct you might try installing a high temp isolator fitting instead to prove it out

FazdaRX_8

iTrader: (1)

I am going to pretend that you forgot this is a top mount and leave it at that.......

TeamRX8

iTrader: (25)

it doesn't matter, he just told you straight out, I was going to lead you around the long way to demonstrate how your assessment and logic is flawed, which is all too common around here

the O2 sensor will not read properly in a high pressure system, this is why it has to be installed after the turbo


.

MazdaManiac

iTrader: (3)

What does that have to do with it?

All of the proper top-mount systems put the O2 sensor in the DP, just after the turbo.

Chris

iTrader: (10)

yikes, mounted the o2 pre turbo??? That needs moving.

MazdaManiac

iTrader: (3)

I'm not certain that this has anything to do with it - the temperatures are simply too high and the gas velocity too low for the pump to make its own reference. The heater just goes out of range.

Now, several of the early top-mount systems put the O2 sensor too far away - essentially in the physical stock location, which is too great a distance (in terms of piping) from the exhaust ports.
Another salient point is that the sensor, should the WG be VTA, must be unaffected by the gaping hole in the gas flow that this causes.

TeamRX8

iTrader: (25)

You can address the temp, especially since the top mount pre-turbo position is not much different than an NA manifold. That piece of info comes from someone smarter and more experienced than me and likely anyone else on this forum. Believe it or not, your choice.

MazdaManiac

iTrader: (3)

The distance/position isn't really relevant since the gas is doing something totally different. Port-to-inlet EGTs are WAY over N/A EGTs and the gas velocity is low.
The whitepaper on the Denso WB puts its thermal saturation point at 2000°F. It was essentially designed to work at 1700°F.

TeamRX8

iTrader: (25)

you would argue with GOD about the creation of the universe if you had the chance ... next time do your homework before you shoot your mouth off. Temperature matters, but you have nothing to indicate what the actual temp is or that the same thing still applies when temps are lower like in a piston engine or alternate fuel rotary ...

MazdaManiac

iTrader: (3)

Were there such an entity, you are correct.

FazdaRX_8

iTrader: (1)

I did pre turbo in the beginning to avoid the lag, and at the time sfr and turblown had the sensers preturbo. They where tuned this way, and so was my car (by mm) and I dont ever recalling you telling me about the sensor position during our tuning session.

In any case its fixed.

bumblebeerx8

iTrader: (7)

ok question is where the hell is mine supposed to be?

TeamRX8

iTrader: (25)

bumblebeerx8

iTrader: (7)

lol my thoughts exactly lmfao

wcs

iTrader: (2)

Beside the Maf right after the BOV

FazdaRX_8

iTrader: (1)

yes!