[Supras] Crazy Lex tuning thought + Dawson

[Jim Jobe]

The TPS is used for throttle tip-in, called TPS based acceleration or
compensation, much like an accel pump in a carburator.  Think about how
far away the 7MGTE afm is from the throttle and intake valve.  It's needed
even on my car (AEM EMS) with the map sensor plumbed directly in to the
plenum.  In my experience with piggybacks, only the VPC makes the throttle
tip-in hesitation worse.  Most of the 7MGTE's I've setup respond the same
after installation of the s-afc, s-afr, maft, and/or lexus afm.  There are
many reasons as to why the 7MGTE throttle response sucks, however, the afm
is not one of them.

I personally don't feel the factory map is as rich as the bandwagon
suggests.  Not many on the bandwagon have put a wbo2 on a completely
stock car (nor have I), but I do know how shitty my car runs in the 10:1
range and the factory setup never ran that bad.

A mechanical solution will not work very well as the change will not be
linear and most likely on/off.  Although some have gotten away using one
of the openings on the accordian pipe and literally putting a small K&N
filter on it, then waiting for the ECU to trim it back out.

You could in fact add a potentiometer inline with the air temp sensor
or the coolant sensor.  Adjust until mixture is where you want it when
fully warmed up, but keep in mind the compensation will plateau then drop
again, adding fuel to cool the cylinders back down.

Skip the fancy lightshow with the narrowband sensor.  There are plenty
of charts available on the internet that show how inaccurate, no, how
ineffective the sensors are outside of the narrow band around lambda.
Wideband O2's can be had for $200-300.  Innovate LM-1 is cheap and works
well.  NGK/NTK is nice.  FJO is very good, about as good as you'll get
for the money under 4 figures.  Most of a simulated nbo2 output so you
can replace the factory sensor completely solving your emissions inspection
issue.

Personally, if you have the walbro, 550's, and other supporting fuel
system mods (proper feed/return lines and afpr), get a MAFT, MAFTv2,
or MAFT-PRO.  The cars I've seen with them run great and it's a cheap
solution.  The stock ct26 can handle random blasts to 15-16psi as long as
it's in good shape to begin with.  I can recall many a race we got in
to where we turned the boost controllers all the way up, CT26's spiking
to 16-18 psi and rolling off to 14psi.  I'd also recommend you fix the
bottlenecks in the IC piping (in particular the aluminum elbow and the
plastic pipe over the turbo, and the end of the 3k pipe).

On Mon, Oct 09, 2006 at 05:51:32PM -0400, berniek at technicaldevelop.com wrote:
> Dear Jon, Mike, Jim and list:
***ssscchhhhnnnniiiiip!***
>