SC400TT Project Car Stage II
04-06-07, 01:39 PM
#182
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I'm with Ryan on this one, even doing a 97 complicates things. The newer you go the more emissions you have to deal with and Ryan is right on the Later 98 and up Rods are a compromise you don’t want for boosted applications.
04-07-07, 10:07 AM
#184
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Would you still say the same of staying with pre-97 if I plan on rebuilding the engine with all forged anyway? I am the padawan learning from the masters 
04-08-07, 01:05 AM
#188
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Wow, this is an amazing project. I actually think, that this was the first time I ever looked at every page of a 59 page post, and enjoyed it. Can't wait to see a track or dyno video.
04-26-07, 02:04 AM
#191
In Stage II, I am adding the fuel enhancements even iof someone else has to make them, so, I have a question for all you tech guys out there regarding the Stock ECU.
Gang, I have been pondering this just for the last day now, and have not found anyone that is sure of the answer, so I want to post up here to see if anyone can provide the correct information.
I will be keeping the stock ECU on my SC400 Project Car even after I install the built engine which I am just now picking up from the machine shop. I will be adding a piggy back with an external Delco MAP to the system. So, I will have 2 Walbro 255 pumps, and 2 separate fuel systems in the car. The stock one stays in place, and the secondary includes 8 440 cc injectors run by the piggy nack that will connect to the stock ECU, and will adjust fuel on the secondary fuel system, and will change timing as necessary.
MY question is does anybody know what the Stock ECU is doing when we hit the Rev limiter past 6500 rpm? Is it an ignition cut, a fuel cut, a timing change, or a combination of the above? My reason for asking is this:
I am adding the BoostLogic built A340 4 speed trans and Precision trany to the equation, and I have no experience on how the car will shift until I get it on the road. They did adjust line pressures and make several modifications to the stock valve body so that the tranny will shift much quicker, but it will still be civil during normal driving. I am sure there will still be a delay between gears, although shorter. If I shift the gears manually, and miss the sift point and cause the rpm to hit the rev limiter, if this is a fuel cut, will this not caus ea temporary lean condition? If I am in high boost when this occurs, I am concerned about the danger to my engine...
I can adjust the piggy back to change the pulse cycle of the secondary injectors in the map and adjust the timing when past 6500 rpm as a safety factor, if needed, or I can tune in a fuel cut as well. But, I will need to know what the stock ECU is doing...
Thanks,
Ryan
04-26-07, 07:41 AM
#192
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Though I don't have a definitive answer for our application, from reading about other limiters I gather that it's an ignition cut. It interrupts the signal to the coil alternating on/off.
If you ever spent time in Neutral just letting it bounce off the limiter, you see how quickly the RPM's get back up. On mine it seems to oscillate maybe 150 - 200 RPM's. Can the fuel be shut off/on that quick?
If you ever spent time in Neutral just letting it bounce off the limiter, you see how quickly the RPM's get back up. On mine it seems to oscillate maybe 150 - 200 RPM's. Can the fuel be shut off/on that quick?
04-26-07, 08:45 AM
#193
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Fuel can be cut off that quick. Just order the injector not to fire on the next cycle. 100% to 0% fuel in milliseconds.
Boost cuts on Toyotas are like this. It feels like you hit a moose. BAM and the fun is over. It's done this way to save the engine. Injecting fuel in a car that's overboosting and killing the ignition is not the best idea.
In Ryan's case, a fuel cut rev limiter would be bad for him as at redline the main ECU cuts fuel and the piggyback still adds its share (depending on how it's wired). Instant lean condition. I think that was his question.
Ryan, that's not a problem for you as your stock rev limiter should be ignition cut. I don't have the V8 Manuals so I can't look up the specifics but your tuner should set you straight just fine.
Boost cuts on Toyotas are like this. It feels like you hit a moose. BAM and the fun is over. It's done this way to save the engine. Injecting fuel in a car that's overboosting and killing the ignition is not the best idea.
In Ryan's case, a fuel cut rev limiter would be bad for him as at redline the main ECU cuts fuel and the piggyback still adds its share (depending on how it's wired). Instant lean condition. I think that was his question.
Ryan, that's not a problem for you as your stock rev limiter should be ignition cut. I don't have the V8 Manuals so I can't look up the specifics but your tuner should set you straight just fine.
04-28-07, 06:12 PM
#195
Hey gang, I have a few pics for ya. I assembled the BBKs, preparing them for install. Remember, I have picked up the engine from the machine shop...
The Brake kit ncomes from Revolution brakes, formerly known as Precision brakes, the calipers are genuine Wilwood. Wilwood does not make a kit for the SC, but Revolution does.
Nice stuff, well machined.
Ryan
The Brake kit ncomes from Revolution brakes, formerly known as Precision brakes, the calipers are genuine Wilwood. Wilwood does not make a kit for the SC, but Revolution does.
Nice stuff, well machined.
Ryan