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Engine & DrivetrainDiscussions about the engine and drivetrain of your vehicle.
This is a discussion thread titled "s/c - boost bypass -", within the Engine & Drivetrain forum, part of the Technical & Vehicle Assistance Forums category.
can anyone give instructions on if or how to do this to our 4.7 s/c engines . these ford guys have so many options for there lightnings. check this page out- http://www.rpmoutlet.com/boost%20bypass.htm they say +3 lbs of boost from this $5.00 worth of parts --- is it true?
can anyone give instructions on if or how to do this to our 4.7 s/c engines . these ford guys have so many options for there lightnings. check this page out- http://www.rpmoutlet.com/boost%20bypass.htm they say +3 lbs of boost from this $5.00 worth of parts --- is it true?
If I am correct in my statement, the Toyota 4.7L S/C does not have a system in place that does what the one you are refering to does. The Toyota 4.7L S/C DOES have a bypass actuator and it does work in a fashion like what the Ford does. It prevents cativation under partial and small throttle opening. BUT, at WOT the 4.7L S/C produces ALL the available boost it can and is NOT limited to a preset level electronically. The ONLY time the boost is lowered is when the TRD Piggyback ECU opens the boost port relay during a shift. Then, the relay allows boost pressure to flow into the lower chamber of the boost port actuator and open the plenum and allow intake air to bypass the S/C. Once the shift completes, the relay is shut and the full intake charge is then allowed to flow into the S/C. If you remove the lower hose, then you remove the lowering of the boost during a shift. I do not believe that mod is workable on a Toyota 4.7L S/C. Lastly, the Ford folks have engineered the S/C into the engine from the FACTORY, it is not a "bolt on" option. You purchase a lightning or you do not. Pros and cons to both.
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, shift kit, and more to come.....and.... YES... it is a CAMRY....
If I am correct in my statement, the Toyota 4.7L S/C does not have a system in place that does what the one you are refering to does. The Toyota 4.7L S/C DOES have a bypass actuator and it does work in a fashion like what the Ford does. It prevents cativation under partial and small throttle opening. BUT, at WOT the 4.7L S/C produces ALL the available boost it can and is NOT limited to a preset level electronically. The ONLY time the boost is lowered is when the TRD Piggyback ECU opens the boost port relay during a shift. Then, the relay allows boost pressure to flow into the lower chamber of the boost port actuator and open the plenum and allow intake air to bypass the S/C. Once the shift completes, the relay is shut and the full intake charge is then allowed to flow into the S/C. If you remove the lower hose, then you remove the lowering of the boost during a shift. I do not believe that mod is workable on a Toyota 4.7L S/C. Lastly, the Ford folks have engineered the S/C into the engine from the FACTORY, it is not a "bolt on" option. You purchase a lightning or you do not. Pros and cons to both.
SCDTRD
ok - i do not posess your infinate wisdom when it comes to the dynamics of the s/c engine-but .... i do posess a s/c tundra like you so bro plz explain to me exactly what that mod is you did on your s/c vac. line and what does it do. did it help anything, does it cancel the boost cutoff during shifts? i looked close at your pic and cant see where that hose goes from the t fitting..... looks like over the top to somewhere. well plz excuse my ignorance in this field and any help you can offer is greatly appreciated. p.s. when the he11 are you on the site i never can catch you to chat. later bro-keep that tundra screamin through lagrange !
ok - i do not posess your infinate wisdom when it comes to the dynamics of the s/c engine-but .... i do posess a s/c tundra like you so bro plz explain to me exactly what that mod is you did on your s/c vac. line and what does it do. did it help anything, does it cancel the boost cutoff during shifts? i looked close at your pic and cant see where that hose goes from the t fitting..... looks like over the top to somewhere. well plz excuse my ignorance in this field and any help you can offer is greatly appreciated. p.s. when the he11 are you on the site i never can catch you to chat. later bro-keep that tundra screamin through lagrange !
The mod that you see in his picture is a fuel pressure regulator(FPR) mod. This allows your FPR to work off boost vacuum vs engine vacuum giving you more fuel pressure and volume. Check out this thread... free mod (for superchargers)
Also there are pulleys that will allow the TRD S/C to make up to 14psi of boost. Mike in Houston can get them for you. But you will need the Unichip, boost controller, and a water injection kit in order for use these pulleys...otherwise you will run to lean and your intake charge will be to hot. Hope this helps...if you have any ?s please PM me...
ok - i do not posess your infinate wisdom when it comes to the dynamics of the s/c engine-but .... i do posess a s/c tundra like you so bro plz explain to me exactly what that mod is you did on your s/c vac. line and what does it do. did it help anything, does it cancel the boost cutoff during shifts? i looked close at your pic and cant see where that hose goes from the t fitting..... looks like over the top to somewhere. well plz excuse my ignorance in this field and any help you can offer is greatly appreciated. p.s. when the he11 are you on the site i never can catch you to chat. later bro-keep that tundra screamin through lagrange !
Ok.. If you have the S/C that has the hose that runs from the driver side around the back of the S/C to the relay, then from the relay to the BOTTOM of the boost actuator, then what I did was to Remove the hose, plug it off and just left the bottom of the bypass actuator open. What this does is eliminate the BOOST REDUCTION during a shift. The TRD Piggyback ECU still does a pressure reduction in the tranny at that time as well, so you will still have a shift stumble, but not as bad... I hope that helps!
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, shift kit, and more to come.....and.... YES... it is a CAMRY....
Ok.. If you have the S/C that has the hose that runs from the driver side around the back of the S/C to the relay, then from the relay to the BOTTOM of the boost actuator, then what I did was to Remove the hose, plug it off and just left the bottom of the bypass actuator open. What this does is eliminate the BOOST REDUCTION during a shift. The TRD Piggyback ECU still does a pressure reduction in the tranny at that time as well, so you will still have a shift stumble, but not as bad... I hope that helps!
SCDTRD
Oops, my bad did not read all the posts here...I thought he was talking about the FPR mod...
SCDTRD,
I have heard of a mod similar to this but was told that it might be harmful to the tranny in the long run b/c of the extra power going through it. I was told to at least get the Level 10 work done first (or something similar) and preferable the Unichip (to stop the boost dump) or it would burn up the clutch packs when it shifts from the extra power. Have you noticed any difference in your tranny? Let me know...I am taking my truck to the track this weekend and I might consider doing this to see if it makes any difference in performance...
Oops, my bad did not read all the posts here...I thought he was talking about the FPR mod...
SCDTRD,
I have heard of a mod similar to this but was told that it might be harmful to the tranny in the long run b/c of the extra power going through it. I was told to at least get the Level 10 work done first (or something similar) and preferable the Unichip (to stop the boost dump) or it would burn up the clutch packs when it shifts from the extra power. Have you noticed any difference in your tranny? Let me know...I am taking my truck to the track this weekend and I might consider doing this to see if it makes any difference in performance...
I too was told the same thing. I am getting the Level 10 and the Unichip. Also, I just do not like the idea of loosing boost. Boost is a terrable thing to waste! In all reality, I know what I did and drive conservatively. I learned my lesson the hard way when I toasted the tranny in my Tacoma. It was an A340F and this one is an A340E. Basically, same tranny, just more electronics. Yes, I DO notice a firmer shift. It helps, but when you go more than 50% on the TPS, the TRD ECU kicks in and still lowers the pressure or does a partial fuel cut... still stumbles. I will fix. I am not looking for a drag truck, just a dailey driver that I KNOW is running right. To me, I feel better knowing that at ANY time, I can push it to the floor and I will be rewarded with power. Now, I am not confident and will work thru the poor MPG and stumble until I get it all worked out. My Tacoma, once I got ALL the fuel mods and level 10 tranny work done.. had over 100,000 miles on it and was running strong. Toyota makes the best, that is why and ONLY why I stick with them. I will post more soon.. I have learned a lot in the past 2 weeks. Spent a week in Los Angeles talking to some VERY knowledgeable folks.. and will share soon!
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, shift kit, and more to come.....and.... YES... it is a CAMRY....
I also will take more detailed pics of the Bypass Actuator and the FMU mod and post today!
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, shift kit, and more to come.....and.... YES... it is a CAMRY....
I too was told the same thing. I am getting the Level 10 and the Unichip. Also, I just do not like the idea of loosing boost. Boost is a terrable thing to waste! In all reality, I know what I did and drive conservatively. I learned my lesson the hard way when I toasted the tranny in my Tacoma. It was an A340F and this one is an A340E. Basically, same tranny, just more electronics. Yes, I DO notice a firmer shift. It helps, but when you go more than 50% on the TPS, the TRD ECU kicks in and still lowers the pressure or does a partial fuel cut... still stumbles. I will fix. I am not looking for a drag truck, just a dailey driver that I KNOW is running right. To me, I feel better knowing that at ANY time, I can push it to the floor and I will be rewarded with power. Now, I am not confident and will work thru the poor MPG and stumble until I get it all worked out. My Tacoma, once I got ALL the fuel mods and level 10 tranny work done.. had over 100,000 miles on it and was running strong. Toyota makes the best, that is why and ONLY why I stick with them. I will post more soon.. I have learned a lot in the past 2 weeks. Spent a week in Los Angeles talking to some VERY knowledgeable folks.. and will share soon!
SCDTRD
The Unichip, pulleys, LSD, and Level 10 (or similar) is my plan as well...just need $$$ so it probably will not happen for awhile (home improvements)...The wiring harness will be nice for the Unichip, wish it was a stand alone FMS though...have you taken your truck to the track? I will let you know how mine does after this weekend...the weather is finally starting to cool down here at night...
The Unichip, pulleys, LSD, and Level 10 (or similar) is my plan as well...just need $$$ so it probably will not happen for awhile (home improvements)...The wiring harness will be nice for the Unichip, wish it was a stand alone FMS though...have you taken your truck to the track? I will let you know how mine does after this weekend...the weather is finally starting to cool down here at night...
The Unichip with harness and program should be around the $899.00 range. That is what Jack told me. Now, that does NOT include the cruise control module. There is more... long story....
The wire harness is a MUST. I will NOT hack into my wire harness. I have heard and SEEN horror stories where the wrong wires were cut, connections added resistance and "strange" things happened, the vibration caused the connections to come loose... and the list goes on. I have not gone to the track simply because I know it is not ready. We have an 1/8th mile here, not too bad...
The cool temps make a WORLD of diff., don't they! The ONLY thing I wish Toyota had done was to put a FIXED volume MAF on the darn truck. The "interpolation" crap is for the birds. On the Tacoma, it is a FIXED 2½" MAF. So the ECU KNOWS EXACTLY how much air is passing at any time. The Tundra interpolates and samples 1/10th of the air and makes a good guestimate based on that. So, using that line of thought, if there is a temp rise or fall or humidity increase or decrease.. the change is exaserbated by the fact that it is guessing up or down. That is why the S/C demands that you do NOT put a FIPK on the intake. TOO much air, that is not compensated for = lean = bad for engine.
The Unichip can convert to am MAP sensor, but I think I will put a fixed Supra MAF on mine. It is 3½" and should flow enough air. As far as the pulleys, I am rethinking that whole idea. If you properly plumb, time, and get the A/F correct for the current application, there should be AMPLE power already there!
I can not see putting a 14psi pulley set on an engine that already has 10.5:1 CR and pray it holds!
Lastly, I was JUST in San Antonio two weeks ago! On the North West side. I forget the area, I was there for a day. The brisket is awesome! Good BBQ.
Talk to you soon!
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, shift kit, and more to come.....and.... YES... it is a CAMRY....
The Unichip with harness and program should be around the $899.00 range. That is what Jack told me. Now, that does NOT include the cruise control module. There is more... long story....
The wire harness is a MUST. I will NOT hack into my wire harness. I have heard and SEEN horror stories where the wrong wires were cut, connections added resistance and "strange" things happened, the vibration caused the connections to come loose... and the list goes on. I have not gone to the track simply because I know it is not ready. We have an 1/8th mile here, not too bad...
The cool temps make a WORLD of diff., don't they! The ONLY thing I wish Toyota had done was to put a FIXED volume MAF on the darn truck. The "interpolation" crap is for the birds. On the Tacoma, it is a FIXED 2½" MAF. So the ECU KNOWS EXACTLY how much air is passing at any time. The Tundra interpolates and samples 1/10th of the air and makes a good guestimate based on that. So, using that line of thought, if there is a temp rise or fall or humidity increase or decrease.. the change is exaserbated by the fact that it is guessing up or down. That is why the S/C demands that you do NOT put a FIPK on the intake. TOO much air, that is not compensated for = lean = bad for engine.
The Unichip can convert to am MAP sensor, but I think I will put a fixed Supra MAF on mine. It is 3½" and should flow enough air. As far as the pulleys, I am rethinking that whole idea. If you properly plumb, time, and get the A/F correct for the current application, there should be AMPLE power already there!
I can not see putting a 14psi pulley set on an engine that already has 10.5:1 CR and pray it holds!
Lastly, I was JUST in San Antonio two weeks ago! On the North West side. I forget the area, I was there for a day. The brisket is awesome! Good BBQ.
Talk to you soon!
SCDTRD
Yeah I live on the North Central side...next time shoot me a PM and we can compare notes...Did you eat at Rudy's? They have some good BBQ there as well as Casey's...I had thought about contacting Pro-M about a new recalibrated MAF and see what they had to say, but until i start with the other mods i doubt it would make much of a difference. This whole Toyota thing is much more complicated than the 5.0 Stangs I'm used to...But if it was easy everyone would be doing it and the mustang is the perfect example...Fairly easy to tune and parts are cheap and plentiful...
[quote=scdtrd]I also will take more detailed pics of the Bypass Actuator and the FMU mod and post today!
SCDTRD, Thank you for the explanation on your mod- but if you could show more pics it would really help me out befor i attempt it. hey and i can trade - i have a cheap mod you may like if you live where lots of insects and bugs are- keeps radiator and tranny cooler like new . check my pics - i got sick of picing bugs out of the fins.
Ok.. I took close up photos of the custom Boost port plumbing and the FMU mod as well as the Bypass actuator mod. I added some of my "other" fast ride too!
EnJoY!
SCDTRD
__________________ The Beast: 1994 Toyota Camry V6 XLE
The Mods:
Front tower Ractive Strut Bar, Whiteline rear AntiSway Bar, Rage Breaker 17.5x7 Rims and Falken Ziex 512 rubber, Limo Tint, Pioneer DEH 7700MP Head Unit, Polk 6x9 rear and Polk 6.5 Front speakers, Tokico struts front and rear, Carbon kevlar brake pads, Cryo treated rotors, ZEX 82021 N2O system, Polished and ported upper and lower intake runners, sh
s/c - boost bypass -
--- is it true? 
scdtrd your the s/c MAN!
p.s. when the he11 are you on the site i never can catch you to chat. 
later bro-keep that tundra screamin through lagrange !
Photos are up!