Supra Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
6,785 Posts
Shit, i think Im still rockin' the free boost cut mod. I might have wired in a fcd when I went single, but damn if i remember. BTW, my car has 181,XXX miles so i think its safe to say doing it the free way is safe
 

·
Registered
Joined
·
436 Posts
Discussion Starter #4 (Edited)
Also found this thread where someone claims (and is verified by BLKMGK) that the boost pressure sensor only affects fuel cut and not the sequential system, thereby relieving the need for a BCC if you disconnect it. "Read page 3 of this thread:
http://www.supraforums.com/forum/sh...cc&pagenumber=3 (THIS IS A BAD LINK, GOOD LINK POSTED BELOW)

Jason S. apparently verified with toyota powertrain engineers that the mkiv boost pressure sensor is only used to initiate fuel cut. It does not affect stock twin sequential operation or fuel pump voltage as claimed in the mkiv.com faq's. He says to just unplug the sensor and save your money on either bcc or fcd. BLKMGK verified that his car used to be that way when he bought it, and sequential turbo operated fine and fuel ran rich on the dyno.

I'd like others who have run with just the sensor unplugged to chime in and verify. It seems logical from the explaination in the thread.
Curt, do you have a way to verify this?"

Thoughts?
 

·
Registered
Joined
·
342 Posts
This would be good to know

George
 

·
Bench Racer of the Year
Joined
·
692 Posts
Chris, you're link doesn't work. I am very interested to read that thread and find out more information.

Brian
 

·
Registered
Joined
·
3,621 Posts
How come in this chart it says that

Turbocharger Pressure Sensor effects:

Fuel Cut off
Engine Speed Change Estimate
Turbocharger Control
EGR Cut-off Control
Fuel Pump Control
Evaporative Emission Control



Seems like the free fuel cut mod is not such a good idea :scratch:
 

·
Registered
Joined
·
13,581 Posts
the link in the very first post says it's for cars equipped with a MAP sensor. The stock MkIV uses a MAF sensor.

I don't get it ...are you trying to save $50 on an experiment that could damage or hurt your Supra or has no proven track record of even working?
 

·
Registered
Joined
·
436 Posts
Discussion Starter #11
Nick 95 6sp said:
the link in the very first post says it's for cars equipped with a MAP sensor. The stock MkIV uses a MAF sensor.

I don't get it ...are you trying to save $50 on an experiment that could damage or hurt your Supra or has no proven track record of even working?
Thanks for clearing that up. The purpose for the question is two-fold. First, I'd like to learn more about how my car operates. Second, I wouldn't might saving the $50-75 for a BCC, $275 for a fields replica harness, and the time it takes to tune/install the BCC. This being said, I'm not about to do anything to my car that could potentially cause harm or does not have a track record of success. The thread about the pressure sensor made it seem like quite a few members had tried this and I wanted to get some input about its reliability/track record. Trust me, I'm not going to use my car as an experiment!
 

·
Registered
Joined
·
13,581 Posts
I agree it's always better to question and understand, not just go along like the blind leading the blind. My comment about saving money came across sounding more narrow minded than I intended.
 

·
Registered
Joined
·
436 Posts
Discussion Starter #13
Nick 95 6sp said:
I agree it's always better to question and understand, not just go along like the blind leading the blind. My comment about saving money came across sounding more narrow minded than I intended.
No worries.

Here's another link to a thread I found while searching: http://www.supraforums.com/forum/showthread.php?t=218863. It's in the MKIV Technical forum, but isn't receiving much traffic. This should solve the whole pressure sensor concerns stated above. Any thoughts on this?
 

·
T88 YOU
Joined
·
3,567 Posts
the mkiv supra IS equipped with a MAP sensor for that purpose, a maf is not capable of accurately determining manifold pressure so a MAP sensor is used for the aforementioned 6 tasks, the MAF is only used for fuel compensation. basically the FCE is just a blow off valve for the map sensor, it just releases excess pressure when it sees more than probablly about 12lbs which is right before fuel cut. it will work but it will probablly be ugly!
 

·
Registered
Joined
·
436 Posts
Discussion Starter #15
SupraDupaFlyBoy said:
it will work but it will probablly be ugly!
I'm assuming the "it" refers to the device for sale by 3BarRacing.com in the first post. What do you mean "it will probably be ugly?"
 

·
T88 YOU
Joined
·
3,567 Posts
i mean having brass fittings coming off your intake manifold will "probablly be ugly"...
 

·
Registered
Joined
·
2,182 Posts
Chris99 said:
Jason S. apparently verified with toyota powertrain engineers that the mkiv boost pressure sensor is only used to initiate fuel cut. It does not affect stock twin sequential operation or fuel pump voltage as claimed in the mkiv.com faq's. He says to just unplug the sensor and save your money on either bcc or fcd. BLKMGK verified that his car used to be that way when he bought it, and sequential turbo operated fine and fuel ran rich on the dyno.


Thoughts?
I would like to see some documentation or a letter from Toyota or Toyota engineers which state this. I'm not just gonna trust what Jason S. says without some proof.
 

·
Registered
Joined
·
2,182 Posts
KevinB6876 said:
Says it only works on MAP sensored vehicles. MKIV's are MAF equipped.
Ok ignore this stupid statement. I need to read the entire thread before I post lol. Seems MKIV's do have a MAP sensor after all. I never realized this, thanks for pointing this out, assuming of course that you're correct. :)
 
1 - 20 of 20 Posts
Top