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Correct FMU setting for CTSC?!

Joined
19 November 2002
Messages
633
I have a 6lb bolt on whipple, I was just wondering what is the recommended setting for the FMU?
 
What is a FMU?

Fuel Management Unit

also (incorrectly) referred to as a FPR (Fuel pressure regulator), RRFPR (Rising Rate Fuel pressure regulator), or Boost-dependant FPR.

As boost increases, the FMU ramps up the fuel pressure at a set ratio (8:1, 10:1, 12:1, etc) dictated by the internal spring and/or diaphram.
 
Fuel Management Unit

also (incorrectly) referred to as a FPR (Fuel pressure regulator), RRFPR (Rising Rate Fuel pressure regulator), or Boost-dependant FPR.

As boost increases, the FMU ramps up the fuel pressure at a set ratio (8:1, 10:1, 12:1, etc) dictated by the internal spring and/or diaphram.

I beg to differ on the explanation that you give:rolleyes:, a Fuel Management Unit is a (electronic)device that manages fuel delivery based on several sensor inputs and uses a mapping to cope with changing engine variables, so monitors and manages.

A FPR however does just as the name suggests: regulates fuel pressure based on 1 vacuum/boost input, it does not manage anything, just changes fuel pressure based on this 1 input, it does not monitor anything:wink:

According to my info, for a low boost whipple CTSC, FP should be about 42-45psi at idle with vacuum connected, about 55-60 psi with vacuum disconnected and about 90psi at full boost (vacuum connected)
 
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Stop fighting boys, we know what he means and he is wrong!!! lol
I can only tell you what I used and what was told to me.
On my 91 3.0 litre with basic 6 lb whipple used kit, I was told to start at 42 psi at idle with the vacuum line hooked up of course.
My unit once installed and started was set at 48 psi, so I left it there and went to the dyno the next day.
We ran one run and at about 4500 rpm it was a little lean so I went up 2 psi and then went up another 2 psi. So I finished up at 52 psi at idle.
That is about where I have left it.
I do have a wide band and on the road, everything seems safe to me.
I actually plugged off the vent hole on the RRFPR and I get to 10.5:1 very fast now.
That is my experience.
I have videos and other posts in this section, you can search for threads I started.
I am no expert nor am I always correct, just trying to find the truths and spread the good word!
Seems more whipples are hitting the streets into the hands of new guys since turbos and autorotors are out there and we are getting the hand me downs.
Also a lot more do it your self ers!
Trev
 
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Stop fighting boys, we know what he means and he is wrong!!! lol

I hope you're not referring to me as being wrong :confused:

ffffanman said:
I am no expert nor am I always correct, just trying to find the truths and spread the good word!

I feel the same way. There are TONS of misconceptions (found on prime) which are beyond the scope of this conversation, but in the interest of the term "FMU" itself, I am 100% correct.

I don't claim to have coined the term or defined it in any way, however if you Google for "fuel FMU", you'll find that 99.9% of all the results refer to the "FMU" as a MECHANICAL means of raising fuel pressure to add fuel during the intake cycle. Just simply call any engine builder or shop that has experience with forced induction and ask what an "FMU" is, every one of them will tell you the same thing.

Cheers :biggrin:


PS: As far as setting your base fuel pressure with the FMU by using someone else's numbers and calling it good for your 6psi setup, I wouldn't recommend it. It would be a good starting point, but I would still take it to the dyno and/or hook up a wideband on the street to verify that you are indeed running sufficient fuel. What works on one car may not work on another that is identical. How do I know? I've been tuning cars (specifically Hondas) for close to 10 years.

But hey, its your car - do what you want ;)
 
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C-speed, have you seen many RRFPR's that vary each day or each start, mainly because they are older, like 10 years and the spring or what not can be worn?
It appears you have some nice experience under your belt!

Also have you ever seen the difference in changing the bleed type plug to a solid one. I can't believe how much faster the pressure rises.
Thanks
Trev
 
C-speed, have you seen many RRFPR's that vary each day or each start, mainly because they are older, like 10 years and the spring or what not can be worn?

Its not so much the variance on the same unit from day to day, its the variance from unit to unit, car to car, engine to engine. I can guarantee you with almost 100% certainty, that even if you took 2 IDENTICAL cars with IDENTICAL mods, tuned one of them and then put the same tune/map/rom, what have you on the second, the A/F (and power figures) will still be off - sometimes considerably.

Thats why I always recommend tuning a new setup/build to the dyno even when I provide a pre-tuned map from a different vehicle that had X A/F ratio and made X power. It's never the same.

Not to mention, judging from how paranoid and meticulous most owners are here on Prime, why skimp on $200 at the dyno (or whatever it costs in your area)? Its piece of mind, better fuel economy, and of course MORE POWER! :D

It appears you have some nice experience under your belt!

Maybe a little ;)

Also have you ever seen the difference in changing the bleed type plug to a solid one. I can't believe how much faster the pressure rises.

Are you referring to the bleed valve to adjust the actual rising rate ratio? I've never heard of having to 'change' the valve? Typically they don't go bad and you can easily adjust them by hand or with an allen wrench (depending on the type/style).

But ya, if you adjust the ratio higher (close the valve), the pressure will rise faster as the manifold pressure increases positively.
 
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I am actually talking about a little plug or plug with hole, just like a jet on a carb.
I found that they installed this bleed bolt or screw on the low boost whipple set ups. The high boost regulators do not have it.
I took the solid no bleed screw from a hi boost and put it into my low boost regulator and as I say, the regulator jumps up in pressure faster.
You must not have seen this or done this before.
But now you know!
Trev
 
I am actually talking about a little plug or plug with hole, just like a jet on a carb.
I found that they installed this bleed bolt or screw on the low boost whipple set ups. The high boost regulators do not have it.
I took the solid no bleed screw from a hi boost and put it into my low boost regulator and as I say, the regulator jumps up in pressure faster.
You must not have seen this or done this before.
But now you know!
Trev

i got try this any pic for reference and where do i find the plug? thanks Trev
 
i got try this any pic for reference and where do i find the plug? thanks Trev

The plug is right next to the vacuumhose connector on the FPR.
On a low boost version this is supposed to have a pinhole drilled in it (about 1 mm), on the highboost version it is solid.

I have both a highboost and a lowboost FPR so noticed the difference when I started to check the FP on my car.

Reason that I can imagine is that with the lowboost version and a solid plug, the FPR rises FP too quick and thus gives too much fuel, on the low boost FP rise probably needs to be dampened to prevent overfueling on fast acceleration.

I have been researching the needed FP for the last 2 weeks (got a very useful contact on this from ffffanman :smile:)

My CTSC has been tuned on the Dyno when built (I know this as there was a WB bung welded in the exhaust). I myself had the car dynoed recently and even though it made perfect power and torque, it did show to be a bit lean.

As my FP was quite low, with the pinhole plug on the FPR I have now upped FP to 42psi at idle with vacuumhose connected, about 54 psi disconnected, getting 92psi at 6 psi boost.

I have installed a permanent WB on the car and am satisfied with the A/F numbers I see on it now:
on full acceleration it peaks at 10.5 momentarily, getting steady at about 11.4-11.6 on full boost accell. seems OK to me :smile:
 
Well , I have to agree with Crescent ( and anyone else who knows what they are talking about)
EVERY car is different, even the same model of car with the same mods!
you could start with the same approximate settings, but proceed with caution , you NEED a wideband, and you need some knowledge of what is going on.

There is a lot of widespread misconception the the "fmu" or "rrfpr" is a poor device , this couldn't be further from the truth, if it were then why would the "coveted" ctsc use it? even on their "hi-boost" kit? along with countless other commercially available sc/turbo kits , greddy/vortech/jackson racing/comptech/paxton - the list goes on.

The fmu operates on EXACTLY the same principle as the factory fuel regulator.
The stock regulator regulates fuel by using a vacuum diaphragm and a spring to exert pressure on a disk which , in turn has a seat which rests on an orifce to restrict or allow fuel to return to the tank, it it set up to provide fuel regulation between vacuum and atmospheric pressure , and will give a rate of rise of 1 psi per lb. under boost .

The fmu, has a larger body and diaphragm to exert more pressure on the seat/orifice, thereby giving it the ability to raise the pressure higher under boost,and they lack a spring,with the exception of one brand(because they are designed to only act under boost), there are basically two designs (although they may look different)
one (vortech,paxton,greddy etc.) are not externally adjustable,although with the use of an external bleed valve , you could.
Adjusting the first type consists of changing the diameter of the disk under the diaphragm, this changes the amount of pressure which it can exert on the seat, in turn altering the rate of rise.
the second type usually has a pinhole or a bleed valve , this will adjust how much boost the diaphragm actually sees, from my experiences , these are finicky at best (as per Trev's experience) and it is much better to use the simpler one, since the adjustments are fixed.

So , what does all of this mean? One of the oldest sayings I can remember when dealing with cars? - KISS - keep it simple stupid.
Of all the turbo hondas I have seen (a LOT) the ones who have the most trouble are the ones running some kind of piggyback or standalone , larger injectors, etc...
DON'T get me wrong , these have their place, but for most people who want to run less than 10psi it is (IN MY OPINION) an unnecessary and potentially troublesome solution
Which brings me to the next topic, on a car with an engine as expensive as the nsx , why is no one running a knock control unit , like the one from J&S electronics? Wouldn't it be nice to actually see if it was detonating?
I have run these on hondas for years (more than ten) - In fact when I first turbocharged my integra in '97 , it was the second thing I bought, I ran that car hard on the stock motor for years .

I can't wait to see the flames!!!
 
Well , I have to agree with Crescent ( and anyone else who knows what they are talking about)
EVERY car is different, even the same model of car with the same mods!
you could start with the same approximate settings, but proceed with caution , you NEED a wideband, and you need some knowledge of what is going on.

Thanks :D

There is a lot of widespread misconception the the "fmu" or "rrfpr" is a poor device , this couldn't be further from the truth, if it were then why would the "coveted" ctsc use it? even on their "hi-boost" kit? along with countless other commercially available sc/turbo kits , greddy/vortech/jackson racing/comptech/paxton - the list goes on.

I'd have to disagree with you on this statement :wink:

There are a number of reasons why this RRFPR is not the ideal fuel management for any type of forced induction. I'm not saying that it doesn't work - it certainly does do its job, its inexpensive, but its not the optimal solution by any means. Allow me to elaborate:

1) A RRFPR ramps up fuel pressure by a fixed ratio based on boost pressure. This can be potentially detrimental - again for a number of reasons. Stock injectors are usually sized from the factory for whatever NA application they are using it for and I've seen STOCK injectors on STOCK roms with 80-90% duty cycle with ZERO mods. (Talking specifically about Hondas, the Integra GSR/Type-R are perfect examples of this).

As most people know, injectors operate the most efficiently between 80-90% duty cycle and should never exceed 90% as they can lock (solenoid failing to open and/or close). By raising the fuel pressure, you are effectively raising the duty cycle. If the injector(s) doesn't fail altogether, it can result in improper atomization. Stock injectors (NA or FI), actually I'd almost say that ALL injectors, should only see a maximum WOT fuel pressure of around 50-60psi MAX. Otherwise, you have improperly sized injectors for your setup.

Also, in my experience, I've seen first hand, injectors fail at 80psi+. Stock *AND* aftermarket such as RC. What I mean by fail, is they will flow perfectly at their rated flow rate, but once they reached their fail point (I've seen as low as 80psi and as high as 108psi), they flowed ZERO cc's! Trust me on this one, luckily, I've only had one engine fail due to this problem, but it has happened on more than one occasion.

2) Most importantly, when you are tuning for a specific A/F ratio, in my experience 9 times out of 10, you will NEVER get a perfectly flat A/F using an FMU/RRFPR. The problem is inherently in its design. Since the RRFPR has a fixed ramp rate, during WOT operation the fuel pressure remains constant (provided boost remains constant) for the entire RPM range. Thus fuel delivery also remains constant at each RPM point through the RPM range at WOT.

This, again, will never give you a perfect A/F throughout the entire RPM range. Depending on the layout, flow characteristics, volumetric efficiency, cams, etc etc, you may need more (or less) fuel at specific RPM points to raise or lower the A/F ratio to meet your target A/F. This is absolutely unachievable with an FMU/RRFPR. That's why you'll see people talking about an 'average' A/F ratio where they are making adjustments (if the FMU is adjustable) to make the 'overall' A/F through the entire RPM range at an acceptable target A/F (Lean areas are richened up, at the sacrifice that other target A/F areas are now richer than optimal, and vice versa).

Simple piggy backs and full blown EMS that have RPM dependant fuel adjustments can fix these problem area easily. The FMU cannot.


So , what does all of this mean? One of the oldest sayings I can remember when dealing with cars? - KISS - keep it simple stupid.

True, however you're trading simplicity and cost at the sacrifice of an optimal tune.

Of all the turbo hondas I have seen (a LOT) the ones who have the most trouble are the ones running some kind of piggyback or standalone , larger injectors, etc...

In my experience, these people usually have an inexperienced tuner or installer which causes the runnability issues. (or parts that were recommended by an inexperience builder)

DON'T get me wrong , these have their place, but for most people who want to run less than 10psi it is (IN MY OPINION) an unnecessary and potentially troublesome solution

Again, an FMU/RRFPR works and does its job, but its certainly not the ideal solution and if your budget allows for it, always upgrade to a full standalone.

Which brings me to the next topic, on a car with an engine as expensive as the nsx , why is no one running a knock control unit , like the one from J&S electronics? Wouldn't it be nice to actually see if it was detonating?
I have run these on hondas for years (more than ten) - In fact when I first turbocharged my integra in '97 , it was the second thing I bought, I ran that car hard on the stock motor for years .

Again, in my experience, if the engine is tuned correctly, it will not detonate. Thus knock detection is really only necessary during the tuning process - I prefer to use a detcan as my ears/brain can operate a lot faster and is far more trustworthy in detecting knock than any electronic device ;)

If you get a bad tank of fuel, or overboost are really the only conditions where you will 'introduce' knock on a well tuned setup (or run out of methanol/alcohol/water, etc on a setup that requires it).

Cheers!
 
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you guys know your things. so here's the question i have.
i am running a low boost whipple charger on my 96 nsx-T
i am thinking about doing the high boost set up, can you guys shine some light on me whats every thing that i will be needing, what fuel pressure i should set at what injectors i should be running or any thing that will make my life easier.
thanks
 
Reference Pics.
The Blue unit is from my Ancient 6 lb Low boost Whipple kit.
The Red unit is from Eds Newer 8 lb High boost Whipple kit.
The Blue Vortech has the optional bleed screw in it and I was told or thought it was in there to produce a slower or linear ramp up rate over the spring that is installed in it.
The Red one does not have this and has a machine screw type plug.
Both units can have their base idle pressure adjusted by the allen bolt and nut on the one end.
I took the plug out of the red one and installed it in the blue one and wow, it really jumps up that fuel pressure so much faster.
Trev
Actually the Blue one is called the:
SUPER FUEL MANAGEMENT UNIT (SFMU)
The Super Fuel Management Unit has all of the features of the Fuel Management Unit and also features 5 separate adjustments that can be used to ''shape'' the fuel pressure curve. These 5 adjustments are:
The main spring adjusting screw
The calibration ring & disc
The vacuum screw
The optional bleed screw
The boost screw
Here is a link or two:
http://www.vortechsuperchargers.com/product.php?p=30&cat_key=5
Manual here for the Vortech: http://www.vortechsuperchargers.com/download.php?dir=pdf/manuals&file=superfmuim.pdf

http://www.horsepowerfreaks.com/partdetails/Vortech/Fuel/Fuel_Management_Units/Universal/4594
 

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Which brings me to the next topic, on a car with an engine as expensive as the nsx , why is no one running a knock control unit , like the one from J&S electronics? Wouldn't it be nice to actually see if it was detonating?

If you are running the OEM ECU you are using a dual bank knock control system provided by Honda. This is a piezo transducer based system that uses a sensor to change the audible sound of knock into a voltage range that the ECU can understand. The factory ECU has a very aggressive knock sensor setup. On the OBD2 cars with a proper scan tool you can see the raw data from the knock sensor and the timing trims when they detect knock, very good tuning tools if you have an OBD2 car, if you have an OBD1 car you are sort of out of luck unless you add an additional knock sensor setup. These additional systems can be very difficult to setup.

If you are running the AEM ECU then you are in luck (sort of) as the AEM offers knock control using the original factory sensors if you know how to use it and set it up. Again this is not easy unless you have a frame of reference for what the knock sensors should be doing at any given RPM range and load range. I have seen a lot of tunes for the AEM and most (like 99%) do not have the knock control setup correctly or it is not even turned on.

Some tuners will tell you a proper tune does not need knock control, which is between you and your tuner to decide. I do know that the sensors are there to aid the ECU in keeping the engine alive when conditions are outside the norm. I also know that our stock cast pistons do not handle spark knock at all.

Dave
 
you guys know your things. so here's the question i have.
i am running a low boost whipple charger on my 96 nsx-T
i am thinking about doing the high boost set up, can you guys shine some light on me whats every thing that i will be needing, what fuel pressure i should set at what injectors i should be running or any thing that will make my life easier.
thanks

I just setup a 95 OBD2 BBSC car with the AEM F/IC. I would go this route if I owned an OBD2 car. The tuning was surprisingly easy, and much easier than a full stand alone, your tuner will have full control over fuel and timing referenced to boost and RPM. You will not have any emissions issues if your state has the plug in style check. You will not loose any OEM ECU functions (Drive by wire, knock control, traction control, check engine light, OEM drivability)

Here is a basic list of things that need to be changed to make use of the F/IC:
1. AEM F/IC (this is a NSX specific unit using a special firmware)
2. Boomslang wire harness
3. larger injectors (550cc is a good size for the high boost CTSC)
4. change the CTSC FMU to a 1:1 FPR, AEM makes a nice unit but there are many to pick from
5. remove the CTSC boost-a-pump and rewire the fuel pump back to stock operation
6. optional but recommended - upgrade the fuel pump (if you upgrade the fuel pump bypass the OEM two stage fuel pump system.
7. replace your fuel filter prior to tuning
8. Titanium Dave's belt tension thingy
9. Add a wideband and fuel pressure gauge for piece of mind
10. tune on dyno for both closed loop and open loop AFR, and timing

I do not work for AEM, yadda yadda yadda, I just happen to use this piece to good results, and after setting up my AEM ECU stand alone this thing is a breeze to setup.

Dave
 
If you are running the OEM ECU you are using a dual bank knock control system provided by Honda. This is a piezo transducer based system that uses a sensor to change the audible sound of knock into a voltage range that the ECU can understand. The factory ECU has a very aggressive knock sensor setup. On the OBD2 cars with a proper scan tool you can see the raw data from the knock sensor and the timing trims when they detect knock, very good tuning tools if you have an OBD2 car, if you have an OBD1 car you are sort of out of luck unless you add an additional knock sensor setup. These additional systems can be very difficult to setup.

If you are running the AEM ECU then you are in luck (sort of) as the AEM offers knock control using the original factory sensors if you know how to use it and set it up. Again this is not easy unless you have a frame of reference for what the knock sensors should be doing at any given RPM range and load range. I have seen a lot of tunes for the AEM and most (like 99%) do not have the knock control setup correctly or it is not even turned on.

Some tuners will tell you a proper tune does not need knock control, which is between you and your tuner to decide. I do know that the sensors are there to aid the ECU in keeping the engine alive when conditions are outside the norm. I also know that our stock cast pistons do not handle spark knock at all.

Dave


Yes , you are correct the factory ecu contains some form of knock control.
The only problem with the stock knock control is , a) it is slow to respond(it does not really need to be very responsive on a stock engine b/c a small amount of detonation will probably not spike the cyl. pressure enough to cause immediate damage and ,b) the factory knock control doesn't have the ability to pull enough timing to stop the detonation from occuring at times. And ,c) an effective system needs to be able to pull timing based on which cylinder is pinging and put it back by the next rotation .

I think quite a few nsx owners have proven that the factory knock control is insufficient for use in f/i applications as evidenced by various blown head gaskets,pounded rod bearings ,cracked ring lands, ect.,etc.

Yes the aem has a decent knock control feature ,and yes it is very difficult for most people to set up , the hardest part , I have found , is trying to get the operation to be "seamless"
whereas with the other unit I mentioned, ( http://www.jandssafeguard.com/tech.html )is really simple to set up , and actually does exactly what it says it will do , also the aem does not have a provision for a knock display , many other units are available but they are passive devices, a/f knock amp , safcII and such...

The stock honda knock sensors seem to be frequently very noisy , making it hard to tell detonation from just noise, a better sensor (I've used the 2g eclipse one) will give way better results (needs to be roughly the same freq. range as the honda one) and make setting up the knock control easier.

Detonation must be the #1 cause of engine failure in a f/i engine avoiding/curbing it should be the 1st. priority , it causes damage by spiking cylinder pressure, and has a tendency to perpetuate itself, if you can stop the ping by the time the cylinder comes around again , the damage will be much more likely to occur, I don't think the factory knock control is capable of retarding each cylinder individually - this is what is needed .
 
Just a quick note, you do not need to "replace" the Comptech FMU, just remove it from the system. The factory NSX FPR is already 1:1 ;)

You remove the factory FPR when you install the CTSC fuel rails, I am not sure if it can be installed on the CTSC fuel rail or not (have never tried). I guess you can get some sort of fuel line adapter to make it work, but with the price of AN fittings it may make more since to use the lines in the CT kit and replace the FMU. You really do not need to remove the CT-FMU, but you will spend a little more time dialing in your tune on the F/IC and will have to spend more time on the dyno working through the different RPM and load ranges to get it right. There may also be some non-linear changes needed to the O2 offset table to allow for the higher rate of the CT-FMU.
 
The only problem with the stock knock control is , a) it is slow to respond(it does not really need to be very responsive on a stock engine b/c a small amount of detonation will probably not spike the cyl. pressure enough to cause immediate damage and ,b) the factory knock control doesn't have the ability to pull enough timing to stop the detonation from occuring at times. And ,c) an effective system needs to be able to pull timing based on which cylinder is pinging and put it back by the next rotation .

I am not sure if the Honda sensors are all that bad, I have been watching mine on the AEM ECU for a little over two years now and they seam to be right in line with others that I have logged. I do believe the Whipple and maybe the Autorotor could be responsible for adding noise to the knock signal as any mechanical device added to the engine could do but the placement of the blower directly on top of the two sensors may make it more prevalent.

I think quite a few nsx owners have proven that the factory knock control is insufficient for use in f/i applications as evidenced by various blown head gaskets,pounded rod bearings ,cracked ring lands, ect.,etc..

Keep in mind the OEM ECU is pulling timing and adding fuel based on tests from a NA engine, if you use the F/IC or any other method to retard timing based on boost. Then when a knock condition is heard the amount of timing being removed is added to the already retarded timing (assuming the knock condition happened while in boost).

These numbers are made up and are just here for the ease of the math.

Lets just say with a NA NSX engine at Wide Open Throttle and 6k RPM the ECU is commanding 22 degrees of timing, and a knock event happens at 0 boost then the ECU would pull 4 degrees of timing, bringing the commanded timing down to 18 degrees of timing.

For a boosted NXS running say 7lbs of boost at the same 6k RPM and at WOT, the timing should be retarded to something closer to 16-18 degrees under these conditions to begin with, then after a Knock event is heard the timing would be reduced by 4 additional degrees to 12-14 degrees, that should be enough to prevent the next knock condition.

I think we can agree the system in place was not programmed for F/I, but that is why you would add something like the F/IC, to give you control of the conditions that the factory tune was not programmed for. The J&S Safeguard system you linked to earlier make use of the factory knock sensor to only adjust the timing after a knock event. Same Honda sensor and only reacts to the condition and does nothing to prevent the first knock condition. The display may give the driver information about the event but it already happened.


I don't think the factory knock control is capable of retarding each cylinder individually - this is what is needed .

I am not sure either, but I would be surprised if it did not, the ECU has all the needed information to determine the cylinder that the knock conditioned occurred in. You should be able to determine the event based on the knock sensor and the crank position sensor, the rest is math to work out the exact cylinder the event happened in.

Angus, please do not think I am picking on you, you are bringing up very good points ones I asked myself many times while looking for the best solution to my quest for the safest HiBoost setup I could put on my car. At the time I set my car up the F/IC did not exist, and while a stand alone ECU can be a perfect solution for some guys it is not for everyone (really most people). The F/IC is a good solution for the guy that wants the OEM Tune to handle all the drivability issues it was programmed for and still have control in the part of the tune that the OEM ECU was never programmed to handle. Sort of the best of both worlds.

Dave
 
Dave, Please pick on Angus, he uses such big words and makes us other guys look unintelligent, if thats a word!!! lol
Nice amount of information guys.
Love it!
Trev
p.s. So me cracking open the timing pot and cranking in 2 more degrees on my 91 low boost whipple with 9.6:1 coated pistons was a good thing?
Boom
 
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