Here is a question for you guys. (I have thought about this for many years, but never tried to see if it will work.)
Run 880cc injectors, a Walbro pump and to meter the air, use two stock 7MGTE AFM's, but only pull the signal from one of them. (In theory, it should give you 1/2 the airflow reading for the TCCS.)
Both AFM's have sensors, and the air screws are set to the same depth, so the amount of air each flows is the same.
The air filter would be mounted on a 4" ID pipe, that is necked out to a flat plate with two retangular holes cut, along with the bolts to mount the AFM's. (So the honeycomb screen sides would be mounted to this flat plate, the AFM's back to back, one up, and the other sensor facing down, so you can get them close, but not touching, and allow room for the two 3" hose connectors on the other side.)
On the "exit" side of the AFM's, fabricate a 3" dual to single 4" "Y" pipe. This is then tied into a 4" feed pipe that hooks up to a 4" inlet turbo. (And has the BOV port(s) and PCV port, as well as a ISC port if you still run that.
Just like stock, all metered air would be in that intake pipe, and any bypass air would be put back there as well, so the TCCS would not be confused.
In theory, the TCCS would "see" the same Hertz rate needed to calculate the fuel, since the injectors are now 2x as large as stock.
And the fuel cut should be up near 24psi or perhaps even more as I was able to boost 12 psi easy on the stock AFM and 440's with no fuel cut. (At about 15psi, it would fuel cut all the time, and inbetween 12 and 15, it would cut if there was a spike the stock CT26 waste gate could not deal with. I think the stock waste gate is on the small side, and it's limited in how much it can open, no problem with 12psi or less, but a problem when you start to run higher boost pressure, and the exhaust gas pressure/volume increases as a result.)
Of course, a setup like this would have a larger turbo, and a better waste gate design. (Easy to handle say 21 psi on what is basicly a stock TCCS, and perhaps a Super AFC to fine tune, with an Ebay manifold, medium sized T4 turbo, and a solid motor with metal head gasket etc.)
What do you guys think? Any TCCS issues I have not considered? I'm wondering if it can even calculate at that low of a hertz rate for the rpm?
It would in theory, be about 1/2 of what stock is. So, if stock it's 34hertz at 2000rpm, on cruise control at 70mph, it would be about 17hertz at 2000rpm on cruise control at 70mph.
The trick is, when you are WOT, and 1250hertz boosting at 4500rpm, it's going to be about 625hertz at the same boost pressure, and 4500rpm.
The guy who's going to do this is at the stage where he's either going to buy 550's and run a Lexus meter, or go this route, and we fabricate the mounts/Y pipe needed with 880's. (We have the two stock meters/sensors.)
Now, I've run the MAFTpro with 53% mainscale removed on 780s, so I think the stock TCCS can cope with this type of hertz rate change, but I want to make sure before this guy buys a set of 880cc injectors he will not use if it does not work.
Thanks in advance for any feedback.
Run 880cc injectors, a Walbro pump and to meter the air, use two stock 7MGTE AFM's, but only pull the signal from one of them. (In theory, it should give you 1/2 the airflow reading for the TCCS.)
Both AFM's have sensors, and the air screws are set to the same depth, so the amount of air each flows is the same.
The air filter would be mounted on a 4" ID pipe, that is necked out to a flat plate with two retangular holes cut, along with the bolts to mount the AFM's. (So the honeycomb screen sides would be mounted to this flat plate, the AFM's back to back, one up, and the other sensor facing down, so you can get them close, but not touching, and allow room for the two 3" hose connectors on the other side.)
On the "exit" side of the AFM's, fabricate a 3" dual to single 4" "Y" pipe. This is then tied into a 4" feed pipe that hooks up to a 4" inlet turbo. (And has the BOV port(s) and PCV port, as well as a ISC port if you still run that.
Just like stock, all metered air would be in that intake pipe, and any bypass air would be put back there as well, so the TCCS would not be confused.
In theory, the TCCS would "see" the same Hertz rate needed to calculate the fuel, since the injectors are now 2x as large as stock.
And the fuel cut should be up near 24psi or perhaps even more as I was able to boost 12 psi easy on the stock AFM and 440's with no fuel cut. (At about 15psi, it would fuel cut all the time, and inbetween 12 and 15, it would cut if there was a spike the stock CT26 waste gate could not deal with. I think the stock waste gate is on the small side, and it's limited in how much it can open, no problem with 12psi or less, but a problem when you start to run higher boost pressure, and the exhaust gas pressure/volume increases as a result.)
Of course, a setup like this would have a larger turbo, and a better waste gate design. (Easy to handle say 21 psi on what is basicly a stock TCCS, and perhaps a Super AFC to fine tune, with an Ebay manifold, medium sized T4 turbo, and a solid motor with metal head gasket etc.)
What do you guys think? Any TCCS issues I have not considered? I'm wondering if it can even calculate at that low of a hertz rate for the rpm?
It would in theory, be about 1/2 of what stock is. So, if stock it's 34hertz at 2000rpm, on cruise control at 70mph, it would be about 17hertz at 2000rpm on cruise control at 70mph.
The trick is, when you are WOT, and 1250hertz boosting at 4500rpm, it's going to be about 625hertz at the same boost pressure, and 4500rpm.
The guy who's going to do this is at the stage where he's either going to buy 550's and run a Lexus meter, or go this route, and we fabricate the mounts/Y pipe needed with 880's. (We have the two stock meters/sensors.)
Now, I've run the MAFTpro with 53% mainscale removed on 780s, so I think the stock TCCS can cope with this type of hertz rate change, but I want to make sure before this guy buys a set of 880cc injectors he will not use if it does not work.
Thanks in advance for any feedback.
