when should i go to a fmic?

[90T5I]

i kno throwing a fmic on a stock turbo with stock psi is kinda pointless cause all u will do is lose volume and increase turbo lag. but i want to start building my dsm soon once i get it up and running again like im going to maft as a first mod. but thats off topic. when is a good time to consider going to a front mount? or do i even need to? could i jst put a bigger higher performance side mount in? im not big on flashin my turbo-ness around. . Maybe a noob question but what is a sleeper? not relevant to this post but i was curious

 

[jrohner]

You have something wrong if you put on a front mount and lose power.

 

[MY1GDSM]

I think this thread is about dead. If anyone can't figure out what they shoud do, after all the Good input. Well... Let them get left behind the rest of the pack

 

[Rob10_99]

The bigger the Fmic the better, you will be upgrading your car till it blows out something almost guarentee'd! I would suggest going with one of the ETS FMIC kits, good price and VERY good fitment. It was made for the car.
As for anything else, you live in oregon (where I am at ATM) cold air is sweet for power.

 

[MY1GDSM]

The bigger the Fmic the better, you will be upgrading your car till it blows out something almost guarentee'd! I would suggest going with one of the ETS FMIC kits, good price and VERY good fitment. It was made for the car.
As for anything else, you live in oregon (where I am at ATM) cold air is sweet for power.

 

[niddydsm]

If the OP's mod list is correct, he shouldn't be worrying about mods affecting turbo lag when he's got a stock exhaust. I can't imagine anything but a 4" race core with 3" pipes could make the 14b seem laggy with a decent exhaust.

so having a bigger exhaust will make turbo lag??

 

[nlzn]

so having a bigger exhaust will make turbo lag??

Don't take this as being mean.

I'd suggest reading up on how turbos work via a google search and you'll answer this question for yourself.
The only problem arising from a big DP is the possibility of boost creep on that turbo.

Sidenote: don't let anyone ever tell you a 3" exhaust on our cars decreases backpressure and actually produces less HP. First they are DYNO PROVEN and second, even if there's a small amount of low end torqued sacrificed we all know more flow @ higher rpms = more power, period.

 

[kenamond]

so having a bigger exhaust will make turbo lag??

No. Just the opposite.

Boost from the compressor is driven by the turbine on the exhaust side. The turbine on the hot side is driven by the exhaust stroke. The piston pushes air out the exhaust ports and through the turbine. Because the turbine is connected to the compressor, that makes the piston have to push harder on the exhaust gases than it would if you had no turbo. So this extra force on the crown of the piston during the exhaust stroke subtracts torque from what the power strokes are doing in other cylinders. But at the same time, the turbine is driving the compressor which is forcing more air into the cylinders. There is a (big) net gain in torque/power, or folks wouldn't have turbos on their cars.

Back to the turbine.

Turbines, just like compressors have pressure ratios/airflow/efficiency maps. In terms of a turbine wheel, if the pressure downwind of the turbine is 5psi and the pressure upwind of the turbine is 10psi, the pressure ratio across the turbine is 2.0. However, if you can drop the *downwind pressure* from 5psi to 2.5psi (by...let's see...putting a 3" catless exhaust with mandrel bends and blah blah blah), then at a PR of 2, the upwind pressure is now 5psi instead of 10psi. Now remember that the part of the motor that has to fight this 10psi is the piston crown during the exhaust stroke. In this case, if the piston crown has to push on 5psi air instead of 10psi air, the negative torque at the crankshaft during the exhaust stroke will be halved, which is the same as adding that torque back to the power stroke.

Also, if you have 10psi exhaust left in the combustion chamber when all is said and done and then you start the intake stroke, there's not quite as much room in the cylinder for clean air-fuel mix, and the fuel-air...due to valve overlap, has to force that exhaust out of the cylinder. So you have intake air at boost pressure pushing out exhaust at 10psi (in this example). This exhaust is also hot. So it takes up room and preheats the new fuel-air charge a bit and resists being pushed out of the cylinder. If you drop that exhaust pressure to 5psi, there will be roughly half of this exhaust and half the heat energy, and it'll be resisting the inflowing air/fuel mix half as much, so you get to fit more cool fuel/air mix and preheat it up half as much.

That's a somewhat simplified view, but I hope it gives you a feel for how exhaust back pressure trickles up wind to rob torque/power on a turbocharged engine. So a big exhaust is better. No exhaust at all is even better (as long as you don't catch things under the hood on fire).

 

[->PrOjEcTGS<-]

Just get the FMIC and never look back!! You'll need it in the long run. I'm glad I did!!

 

[tkelly27]

so having a bigger exhaust will make turbo lag??

No, I'm saying if you've done mods that make you think your turbo is laggy, and you still have the stock exhaust, you really have no idea what your turbo is capable of, spool up wise.

 

[jrohner]

Don't take this as being mean.
Sidenote: don't let anyone ever tell you a 3" exhaust on our cars decreases backpressure and actually produces less HP. First they are DYNO PROVEN and second, even if there's a small amount of low end torqued sacrificed we all know more flow @ higher rpms = more power, period.

Plus there is already backpressure before the turbo, and considerably more backpressure than any non-turbo car would have. The pressure in the exhaust can be considerably higher than your boost pressure.

 

[Jed_Atreides]

Also from personal experience, and also living in FL, where it gets to like 90-100 degrees in the summer, if you get a FMIC, upgrade the radiator too. Since the FMIC sits in front of the radiator, it reduces the cooling performance of the radiator and when you have the A/C on, boy does the car over heat fast.

 

[pboglio]

I don't know, I saw zero difference on the logger with Fluidyne aluminum radiator. Same thing with pulling the condensor core. Only thing that made a difference in engine temps was running Redlines Water Wetter and wiring the passenger fan on continuous duty cycle.

Radiator efficiency is heavily determined by airflow, blocking the fmic hurts, running the fan more helps.

 

[niddydsm]

Don't take this as being mean.

I'd suggest reading up on how turbos work via a google search and you'll answer this question for yourself.
The only problem arising from a big DP is the possibility of boost creep on that turbo.

Sidenote: don't let anyone ever tell you a 3" exhaust on our cars decreases backpressure and actually produces less HP. First they are DYNO PROVEN and second, even if there's a small amount of low end torqued sacrificed we all know more flow @ higher rpms = more power, period.

i know how the turbo works just a buddy of mine keeps tellin me that he needs back pressure in order for his turbo to spool right... didnt think he knew wtf he was talking about

No. Just the opposite.

Boost from the compressor is driven by the turbine on the exhaust side. The turbine on the hot side is driven by the exhaust stroke. The piston pushes air out the exhaust ports and through the turbine. Because the turbine is connected to the compressor, that makes the piston have to push harder on the exhaust gases than it would if you had no turbo. So this extra force on the crown of the piston during the exhaust stroke subtracts torque from what the power strokes are doing in other cylinders. But at the same time, the turbine is driving the compressor which is forcing more air into the cylinders. There is a (big) net gain in torque/power, or folks wouldn't have turbos on their cars.

Back to the turbine.

Turbines, just like compressors have pressure ratios/airflow/efficiency maps. In terms of a turbine wheel, if the pressure downwind of the turbine is 5psi and the pressure upwind of the turbine is 10psi, the pressure ratio across the turbine is 2.0. However, if you can drop the *downwind pressure* from 5psi to 2.5psi (by...let's see...putting a 3" catless exhaust with mandrel bends and blah blah blah), then at a PR of 2, the upwind pressure is now 5psi instead of 10psi. Now remember that the part of the motor that has to fight this 10psi is the piston crown during the exhaust stroke. In this case, if the piston crown has to push on 5psi air instead of 10psi air, the negative torque at the crankshaft during the exhaust stroke will be halved, which is the same as adding that torque back to the power stroke.

Also, if you have 10psi exhaust left in the combustion chamber when all is said and done and then you start the intake stroke, there's not quite as much room in the cylinder for clean air-fuel mix, and the fuel-air...due to valve overlap, has to force that exhaust out of the cylinder. So you have intake air at boost pressure pushing out exhaust at 10psi (in this example). This exhaust is also hot. So it takes up room and preheats the new fuel-air charge a bit and resists being pushed out of the cylinder. If you drop that exhaust pressure to 5psi, there will be roughly half of this exhaust and half the heat energy, and it'll be resisting the inflowing air/fuel mix half as much, so you get to fit more cool fuel/air mix and preheat it up half as much.

That's a somewhat simplified view, but I hope it gives you a feel for how exhaust back pressure trickles up wind to rob torque/power on a turbocharged engine. So a big exhaust is better. No exhaust at all is even better (as long as you don't catch things under the hood on fire).

Thanks man i thought i understood how it worked and you just confirmed my thought . I started second guessin my self about back pressure because my idiot of a friend kept tellin me i was gonna get poorer sppol time with my new 3' catless exhaust

 

[fuzzydoodle]

Kenamond........You the man!

No, it wasn't hooked up.

Ahhhhh the elusive "interfooler"....

 

[greentsiawd13]

i think im more confused after reading this.
i was in the market to get uicp but i have big plans for the future so i want to just get the fmic to save $ on the uicp that i might not need later
my next question is how small is to small i dont want to cut up my bumper stop or remove it completely like i see on most cars

 

[PIMking]

I don't know, I saw zero difference on the logger with Fluidyne aluminum radiator. Same thing with pulling the condensor core. Only thing that made a difference in engine temps was running Redlines Water Wetter and wiring the passenger fan on continuous duty cycle.

Radiator efficiency is heavily determined by airflow, blocking the fmic hurts, running the fan more helps.

That is exactly what I'm going to do when My FMIC gets here friday. Im going to take out the A/C condensor and flush the cooling system. then put the FMIC on the vehicle.

I'm also looking into have the fan come on at a lower temp.

 

[chico904]

i think im more confused after reading this.
i was in the market to get uicp but i have big plans for the future so i want to just get the fmic to save $ on the uicp that i might not need later
my next question is how small is to small i dont want to cut up my bumper stop or remove it completely like i see on most cars

That was my point on my post earlier on saying that if you plan on upgrading any of the pipes, you might as well just get the kit.
Do you mean how small is too small for an intercooler? I dont really think there is an intercooler that is too small, as long as it performs well. Just measure where you want to mount your intercooler to where the crash bar is and just look for cores that are not any higher than that.

 

[greentsiawd13]

do you know if any of the ebay $200- $300 fmic kits r ok?

 

[PIMking]

DSM INTERCOOLER KIT 1990 - 1994 1ST GEN 4G63, Mitsubishi Intercooler Kits, XS Power Inc.

that kit is 300!!!

 

[chico904]

DSM INTERCOOLER KIT 1990 - 1994 1ST GEN 4G63, Mitsubishi Intercooler Kits, XS Power Inc.

that kit is 300!!!

That kit would be a good kit for you.

 

[PIMking]

That kit would be a good kit for you.

me?

Mine will be here Friday.

 

[Jed_Atreides]

DSM INTERCOOLER KIT 1990 - 1994 1ST GEN 4G63, Mitsubishi Intercooler Kits, XS Power Inc.

that kit is 300!!!

Nice setup. I recall years back XS power was selling turbos that were held together by JB welds or some sort of industrial glue, instead of bolts. Ppl were buying them off Ebay for cheap and then got screwed when they fell apart.

At least I don't see glue marks on the FMIC

 

[PIMking]

Nice setup. I recall years back XS power was selling turbos that were held together by JB welds or some sort of industrial glue, instead of bolts. Ppl were buying them off Ebay for cheap and then got screwed when they fell apart.

At least I don't see glue marks on the FMIC

Any proof on that? I haven't heard any of what your saying.

Please provide proof if your going to throw someone under the bus, Because plenty of people have ebay FMIC and had them for years with no issues..

 

[MY1GDSM]

Wups..

 

[pboglio]

Any proof on that? I haven't heard any of what your saying.

Please provide proof if your going to throw someone under the bus, Because plenty of people have ebay FMIC and had them for years with no issues..

They should have used JB weld, would have held up better. Yep, it was some kind of adhesive. The compressor housing was designed split style for easier molding instead of a lost core method. I'm surprised you guys never saw these when they came out.