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TeamRX8 12-06-2011 08:48 AM

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

FazdaRX_8 12-06-2011 10:47 AM

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 12-06-2011 11:01 AM


Originally Posted by TeamRX8 (Post 4138886)
no surprise with the smaller divided housing, how is the load holding up at higher rpms is the question

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 12-06-2011 11:22 AM

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 12-06-2011 08:16 PM

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



Originally Posted by Turblown (Post 4138997)
Am I missing something here? Nearly 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)



fine call me a liar.....

TeamRX8 12-06-2011 11:12 PM

Thanks for the clarification

Turblown 12-07-2011 10:28 AM

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 03-07-2012 11:53 PM

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 03-08-2012 12:09 AM

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 03-08-2012 12:10 AM

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 03-08-2012 12:17 AM


Originally Posted by MazdaManiac (Post 4207139)
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.

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

TeamRX8 03-08-2012 12:30 AM

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 03-08-2012 12:40 AM


Originally Posted by FazdaRX_8 (Post 4207143)
I am going to pretend that you forgot this is a top mount and leave it at that.......

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 03-08-2012 08:48 AM

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

MazdaManiac 03-08-2012 09:16 AM


Originally Posted by TeamRX8 (Post 4207153)
the O2 sensor will not read properly in a high pressure system,

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 03-08-2012 09:24 AM

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 03-08-2012 09:50 AM


Originally Posted by TeamRX8 (Post 4207363)
You can address the temp, especially since the top mount pre-turbo position is not much different than an NA manifold..

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 03-08-2012 11:46 AM

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 ...


Reasons for Inaccurate Lambda Readings – Exhaust Back Pressure
Wideband Lambda sensors primarily count oxygen atom numbers through measuring the oxygen ion current within
the molten electrolyte of the sensor’s pump cell. The exhaust gas pressure affects this oxygen ion current – more
pressure means more atoms per unit volume and a higher current at the same Lambda. At a higher exhaust gas
pressure
�� a rich reading will appear richer than it really is, and …
�� a lean reading will appear leaner than it really is.
This is the main reason you should position the sensor after the turbo where exhaust back-pressure is lowest.

MazdaManiac 03-08-2012 12:20 PM


Originally Posted by TeamRX8 (Post 4207518)
you would argue with GOD about the creation of the universe if you had the chance ...

Were there such an entity, you are correct.

FazdaRX_8 03-08-2012 04:38 PM

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 03-08-2012 05:27 PM

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

TeamRX8 03-08-2012 05:34 PM


Originally Posted by bumblebeerx8 (Post 4207886)
ok question is where the hell is mine supposed to be?

:uhh: :Eyecrazy: :squint: :)

bumblebeerx8 03-08-2012 05:58 PM

lol my thoughts exactly lmfao

wcs 03-08-2012 07:26 PM


Originally Posted by bumblebeerx8 (Post 4207886)
ok question is where the hell is mine supposed to be?

Beside the Maf right after the BOV

FazdaRX_8 03-08-2012 08:54 PM


Originally Posted by wcs (Post 4208018)
beside the maf right after the bov

yes!


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