fmic on stock TII
#1
slowmotion
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fmic on stock TII
i just purchased an old school hks fmic kit and i was wondering if it would be a bad idea to install it on a basically stock TII. All I have currently is a 2.5in racing beat downpipe, presilencer to a corksport catback on my s5 and I'm currently not hitting fuel cut.
#3
Top Down, Boost Up
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Changing the intercooler setup isn't going to make you run lean. The same volume of air will be flowing from the turbo to the manifold, but the difference is you should see lower IATs. Lower IATs help with knock resistance and have a positive effect on performance.
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#8
Are you experienced?
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Changing the intercooler setup isn't going to make you run lean. The same volume of air will be flowing from the turbo to the manifold, but the difference is you should see lower IATs. Lower IATs help with knock resistance and have a positive effect on performance.
Yes...... and if this is a concern for "running lean"; you don't think the ECU knows this using the IAT? Engineers are not completely dumb, some of them can be silly though : )...
Just install it and have a blast!
#9
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The stock TII has an intake air temp sensor and a boost sensor, so you should not worry about running the engine lean as long as your fuel pump and fuel injectors can handle the increased load. The stock fuel injectors are usually good for up to 11psi boost, but there are a lot of variables involved, so it is a good idea to closely monitor your engine as you increase the power level. Even a cheapie narrowband AFR meter will help monitor the situation if you know how to use it.
If your engine is not currently hitting fuel cut with the downpipe and performance exhaust, then there may be something wrong with your system. You should be at about 10psi boost with those mods since you are nearly at sea level. You may want to troubleshoot that before adding the FMIC. Are you sure that a previous owner didn't install a fuel cut defenser? It looks like a little electronic box that is usually tied into the wiring on the passenger side front shock tower near the stock pressure sensor. It may not have any writing on it.
http://www.drifting.com/forums/attac...problem-6-.jpg
That can actually happen if you bypass the stock overboost fuel cut.
#10
Rotary Revolutionary
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+1
Perhaps the OP still has the stock airbox, in which case it might be possible to not it fuel cut even w/ a relatively free flowing exhaust.
The downpipe made the biggest difference in my experience, I had a cone filter and ran open downpipe (stock) and didn't hit fuel cut, gutted the cat and ran a Greddy PE, still no fuel cut. (except in the cold, even w/ the stock DP I would hit fuel cut below 50* in 4th and 5th gear)
As soon as I installed a 3" DP and RB system I couldn't give it more than half throttle w/o having to back off.
Intake temps with the TMIC are terrible, in most cases it actually INCREASES temps from the AFM. In warm weather you will have nothing to worry about but when it cools down boost will creep up even more than with the TMIC. I would strongly suggest The following:
- Port the wastegate
- Clean out the fuel system (check tank, change filter, lines where neccessary)
- FD Fuel pump
- Clean stock primary injectors
- 720 secondary injectors
- Rtek 1.7 or 2.1
- Rising Rate FPR
Perhaps the OP still has the stock airbox, in which case it might be possible to not it fuel cut even w/ a relatively free flowing exhaust.
The downpipe made the biggest difference in my experience, I had a cone filter and ran open downpipe (stock) and didn't hit fuel cut, gutted the cat and ran a Greddy PE, still no fuel cut. (except in the cold, even w/ the stock DP I would hit fuel cut below 50* in 4th and 5th gear)
As soon as I installed a 3" DP and RB system I couldn't give it more than half throttle w/o having to back off.
Intake temps with the TMIC are terrible, in most cases it actually INCREASES temps from the AFM. In warm weather you will have nothing to worry about but when it cools down boost will creep up even more than with the TMIC. I would strongly suggest The following:
- Port the wastegate
- Clean out the fuel system (check tank, change filter, lines where neccessary)
- FD Fuel pump
- Clean stock primary injectors
- 720 secondary injectors
- Rtek 1.7 or 2.1
- Rising Rate FPR
#11
slowmotion
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I do still have the stock airbox at the moment..but to install the fmic kit ill have to ditch it.
Me not hitting fuel cut wasnt completely true...i hit it at WOT in fifth gear. Thats the only time I have so far.
Me not hitting fuel cut wasnt completely true...i hit it at WOT in fifth gear. Thats the only time I have so far.
#13
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If there were no AFM measuring the volume of air entering the turbo, no boost sensor measuring pressure changes, and no IAT sensor measuring air temperature, this would be a concern. However the AFM, IAT sensor and boost sensor feed the ECU the data it needs to correct for intake-side changes. While a simple EFI system, it is actually fairly dynamic to a point.
When someone cranks the boost up too far, and injectors cap out, the fuel pump decreases flow, and timing is no longer retarded enough, then you have a problem. Just adding a more efficient intercooler is not along these lines.
The best you could hope for with a 100% efficient, imaginary intercooler would be IATs that are equal to what they were at the AFM. The turbocharger is what increases the air temperature; not the TMIC.
Example: You could have 80*F air come into the turbo, have it skyrocket to 250*F via compression, and then have it exit the intercooler at 120*F. This would be 76% efficiency in this example, which is along the lines of a real-world quality intercooler, yet IATs are still 40 degrees higher than they started out.
From my datalogs, I can put my TMIC at somewhere around 60% efficiency, and I have not seen IATs surpass 140*F during a full throttle pull (typically lower than that depending on ambient temp). They're not horrible, but they're not great either.
Efficiency calculation:
E_ic = (T_in - T_out) / (T_in - T_ambient)
E_ic = intercooler efficiency
T_in = air temp from turbo
T_out = air temp after intercooler
T_ambinent = ambient air temp
With the airbox and stock TID removed, the turbo will breath more freely. When I did this, I immediately noticed the stock turbo holding more boost in the higher RPM range. So as the others have pointed out, hitting fuel cut may become more of a possibilty. This is especially true if you have an open exhaust system.
When someone cranks the boost up too far, and injectors cap out, the fuel pump decreases flow, and timing is no longer retarded enough, then you have a problem. Just adding a more efficient intercooler is not along these lines.
Example: You could have 80*F air come into the turbo, have it skyrocket to 250*F via compression, and then have it exit the intercooler at 120*F. This would be 76% efficiency in this example, which is along the lines of a real-world quality intercooler, yet IATs are still 40 degrees higher than they started out.
From my datalogs, I can put my TMIC at somewhere around 60% efficiency, and I have not seen IATs surpass 140*F during a full throttle pull (typically lower than that depending on ambient temp). They're not horrible, but they're not great either.
Efficiency calculation:
E_ic = (T_in - T_out) / (T_in - T_ambient)
E_ic = intercooler efficiency
T_in = air temp from turbo
T_out = air temp after intercooler
T_ambinent = ambient air temp
With the airbox and stock TID removed, the turbo will breath more freely. When I did this, I immediately noticed the stock turbo holding more boost in the higher RPM range. So as the others have pointed out, hitting fuel cut may become more of a possibilty. This is especially true if you have an open exhaust system.
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