[Supras] richness under boost

[Walker, Brian (Rich. Dist)]

Do the shops that 'professionally' tune engines use a clamp mount at the
exhaust exit for A/F readings? I do see concern for one lean cylinder
throwing the avg. mix readings off but I thought this was the way dyno
tunes were done.

Brian

-----Original Message-----
From: Jim Jobe [mailto:jjobe2 at supratech.org] 
Sent: Tuesday, November 06, 2007 11:46 AM
To: Sean Cavanaugh
Cc: Walker, Brian (Rich. Dist); Supras at supras.com
Subject: Re: [Supras] richness under boost


Those that mount the sensor before the turbo, how are they accounting
for the new pressure differential between the air it's reading and the
air inside the cell?  Basically what I've read is that's how not to use
the sensor.

On Tue, Nov 06, 2007 at 11:21:31AM -0500, Sean Cavanaugh wrote:
> Re: [Supras] richness under boostrx-7s pretty much ALWAYS have a
flamefront. heres a video of a pulled 13b motor running.
> http://www.youtube.com/watch?v=Wi8Qyr3IFRg
> 
>  the heatsink adapter that Innovate makes works very well as that is 
> what my rx-7 friends are having to use for their wideband. 
> http://www.diyautotune.com/catalog/innovate-motorsports-hbx1-heatsink-
> bung-extender-p-73.html?osCsid=c6c12f9a698b80c73421e5188634b61d
> 
> If it can last on an rx-7, it will last on a supra. and yes, to
properly tune a car with an o2 sensor, it has to be as close to engine
as possible. hardcore way would be to run one on each exhaust runner
right as it enters the manifold. Ive even seen some people fit one in
the manifold BEFORE the turbo in the collector area.
> 
> another thing to note, the LC-1 isnt exactly the best wideband unit
either. friend has had to have his swapped at least 3 times (the
controller part, not the sensor) for issues. Most have flipped over to
using a TechEdge unit instead. its also way more compatible with
aftermarket ECUs (likeMegaSquirt) that can run in full closed loop mode.
> 
> -Sean
> 
> 
> From: Walker, Brian (Rich. Dist)
> Sent: Tuesday, November 06, 2007 9:30 AM
> To: Millenia2000 at hotmail.com ; Supras at supras.com
> Subject: Re: [Supras] richness under boost
> 
> 
> Sean, this brings up some good info. I understand not wanting the
sensor in direct flame constantly as you mentioned but how will random
flame fronts effect the sensor? I would imagine most places in the DP
are going to see a flame fairly often. In fact this weekend at an event
I was told the car fired a large flame out of catback at one point. I
also recall last season when the old DP developed a hole (at the flex
joint, behind sensor location), flames were seen under the car many
times.
> 
> Still seems to be reading well (same readings I always see, with no
input changes) Sensor has been in for ~2.5 years. 
> Brian
> 
> Date: Mon, 5 Nov 2007 18:33:46 -0000
> From: "Sean Cavanaugh" <Millenia2000 at hotmail.com>
> Subject: Re: [Supras] richness under boost
> To: <supras at supras.com>
> Message-ID: <BAY126-DAV137B6C520834B7CFAB86DFCA880 at phx.gbl> 
> Content-Type: text/plain;       charset="us-ascii" 
> 
> Just buy an Innovate LC-1 for 200 bucks and install it in stock O2 
> sensor location. Just having a wideband in the car helps out a LOT. My

> old NA supra ran MUCH smoother just from that (used narrowband output 
> for ECU and wideband output for tuning). Whoever told you not to use 
> wideband O2 sensors for long periods of times must have been referring

> to old obsolete non-heated sensors. Newer 5 wire wideband sensors are 
> heated and have no issues (unless you install it in an RX-7 where the 
> potential flamefront directly in the exhaust flow will melt it.)
> 
> -Sean
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