Splitpin

What "funny sounds" were you expecting?

Again, what's this apparent preoccupation with sounds? The bottom line is that you have no idea how safely (or otherwise) the engine is running right now, and, as Harvey has said, you've clearly driven it foot-down. If it is running wrong, you won't be able to hear a problem until it is too late. Still, it is your engine.

As I explained earlier, the significant increase in inlet tract volume between the turbo and throttle body/cylinders will affect the functioning of the engine system in a number of areas. The longer, metal pipes, for example, create much more opportunity for pressure waves to form. This will affect both boot control and issues like the noise you hear from the dumpvalve.

Tazman861

iTrader: (2)

To all posters thanks for the (varied and different inputs)

Harvey, you sound upset but I needed to know that everything was installed and working correctly - no good waiting for the mapper to arrive and find a problem with the install !! You may have done several and be confident that you can install one and all is well but its my first and you can't exactly ask anyone to check!

Splitpin, When I say funny noises I was not actually wanting to hear any and I didn't. When you install something to your car you are hoping it all goes to mplan but with a FMIC they are all a bit different and as this was/is my first FMIC install I wanted to make sure nothing rubbed or pipes knocked against their surrounds etc. I also needed to ensure there were no leaks - there are several joints in the inlet tract!!

Anyway I have tested it to max boost and all is well, If I need to use the car before the remap it wont use full boost and kept off any boost as much as possible.

harvey

iTrader: (48)

What makes you think it is over fuelling to death and where abouts in the rev range and against what boost?
Remember that the problem will be more prevalent with an efficient intercooler system. Other things that cause a car to over fuel could be a problem with the water temperature sensor or even a clogged air filter or too small an air filter.

Stealth, as long as you got something useful out of it I am happy.

harvey

iTrader: (48)

Not at all Tazman but I am amused that someone who worked out running the car hard was a bad idea then proceeded to do just that. When the engine is run on boost with a lack of fuel ie. weak AFR, it only takes a few seconds for the damage to be done. The only time I have damaged one of my own engines was after I fitted an APS CAK. In those days I was new to Subarus and these pieces of junk were the rage. If you didn't have one you were nobody. APS did not give a warning that fitting one of these CAKs should be done with the minimum of a MAF rescaling. Even after the event and pointing out to them what the problem was and why they happily turned out these CAKs with no warning for a further three years.
Anyway, having fitted the APS CAK and let the car warm up gently over several miles I was back in the yard with number 2 piston picked up in the bore with 11 miles total journey. I guess I had two or three goes at WOT and not one of them would have lasted for more than 500 or 600 metres on a very twisty road so it is very easy for the unwary to pick up a piston in the bore if their AFRs are too weak and it happens in next to no time.
This is why you occasionally see a mapper jumping about in the passenger seat very perplexed when the vacuum pipe detaches from the fuel pressure regulator and it takes you two seconds to react.

Splitpin

How do you know it is "overfuelling to death"? Are you monitoring it with a wideband AFR meter?

If you're not, it is difficult to understand why you know it is overfuelling, and, seemingly, eminently possible that you are mistaken.

"Progressive learning from maf"? What exactly do you think that is? These ECUs are incapable of relearning their mass airflow scaling because they don't have any sensors capable of providing feedback.

As I wrote in post #22, your ECU is incapable of "adjusting" in any respect to these modifications, let alone doing it "too well" (or not enough). The only self-learning capability it has is in respect to things like closed loop fuelling adjustment (which is inoperative under boost), knock correction (with its limited ignition and fuelling trims), stuff like that.

The idea of "MAF learning" is non-sense. If your engine is chronically overfuelling, the usual cause of something like that is a broken/stuck injector, or, commonly, someone changing to larger capacity injectors without recalibrating the ECU to suit. A fuel pressure regulator altering its settings is another possible cause, although there you would normally expect rail pressure to drop rather than increase.

Again though one wonders what makes you so sure it is overfuelling. Even if it is, btw, the consequences of "overfuelling to death" might well mean death for the engine. Bore wash and consequent accelerated wear is one of the first results.

sponners

iTrader: (4)

what sort of AFR change are we talking about on average going from a top mount to a fairly decent front mount?

(the standard map runs fairly rich also)

if the car is running slightly lean after fitting a front mount then surely this will be picked by the fuel trims and the long term trim transfered over to open loop anyway?



really cant see a fmic having a dangerous effect on the standard map (but it is pointless fitting a fmic without a remap to reap the benefits from the cooler charge)

harvey

iTrader: (48)

What ECUs are you aware of that have fuel trims and long term trim?
I am not aware of any ECUs commonly used on Subarus that have the properties that you describe above that have any relevance to fitting a front mount or any other modification that dramatically alters running conditions.
There is a degree of latitude within the map to take care of changes in normal running condition in closed loop. The car will attempt to achieve stoich in closed loop but you are not in closed loop when you are on boost or above particular revs which in many cases is 4000 rpm. Please read what Splitpin wrote previously.
If you can't see why a front mount has a dangerous effect on the OE map then I do wonder if you have read what has gone before in this thread.

wylie1

hi mate i have the same mods and pretty sure its not remaped as ive only just brought it and mine is overfueling bigtime

sponners

iTrader: (4)

to be fair I'm going off a evo ecu regarding the LTFT that does apply to open loop.


regardless of all that what is the typical AFR change you would expect after fitting a front mount?

bluenose172

iTrader: (2)

^ The OEM Subaru ECU has a LTFT that applies to Open Loop fueling.

bluenose172

iTrader: (2)

Not read the whole thread, but I assume that the consensus is that the fitting of the FMIC will indirectly affect the AFR due to having to change the intake.

sponners

iTrader: (4)

I assumed it had (never done any tuning on a subaru ecu) but after Harveys reply of "What ECUs are you aware of that have fuel trims and long term trim?" I thought I got it wrong.

sponners

iTrader: (4)

yeah thread is basicaly about whether the car is likely to be safe or not after fitting a front mount.

Myself and a few others are saying yes and some are saying no it wont be safe at all.

Splitpin

Which "OEM Subaru ECU" are you talking about? There are a good five or six different types in use across the various turbocharged Imprezas.

The classic ones, for example, can only alter their fuelling in open loop mode in response to knock detection, which is not the same as a proper fuel trim.

Splitpin

You're forgetting those of us who've said that it is impossible to predict whether any given car will be "safe" or not, and that the only way to tell for certain is to get it checked out.

However, the bottom line is that if you want to bolt on mods like that and make the most out of them, the only way to do that is to get it tuned properly. If you just bolt an FMIC on without mapping, even if it's "safe" it'll probably drive worse than it did prior to modification.

You may have.

bluenose172

iTrader: (2)

Newage, 2001-2007, haven't worked/looked with earlier or later ones.

dynamix

iTrader: (3)

Yep - built using an assumption that any trims at the top end of the closed loop range 'should' be carried forward into open loop.

If there is an induction kit involved then the closed loop fuel trims will probably be out of kilter anyway and potentially skewed. This would then be skewed into open loop even though the flow characteristics of an induction kit could differ from the std airbox.

There are so many variables that really I dont understand why people want to fit these kinds of modifications and not map them. You really will get no benefit from them without mapping and quite often a distinct issue if not mapping them.

Obviously if someone wants to risk their engine for the sake of it then please feel free but as Harvey says there is enough information in here that should be pointing you to the right conclusion - ie fit and map or dont fit.

harvey

iTrader: (48)

There is no typical figure because each car is different. This is the whole point. Some cars will get away with it but others will not, particularly if the FMIC fitted is efficient. If an FMIC is fitted and there is no need to add fuel then you have wasted your time as you have not picked up power. (other than utilise any excess fuel that may have been present before you started) Depending on how much fuel and where it is added will give an indication of how much at risk your engine would have been.
Once a front mount has been fitted DET is a real possibility because of the changes that have taken place and even without DET if the AFR is sufficiently weak there is the possibility of nipping a piston.

Quite simple. I sell Hybrid FMICs and I will always advise a remap is necessary when one of these front mounts is fitted. This may reduce or delay the ultimate number of sales but I have been involved in fitting and mapping Hybrid front mounts for years and my advice is based on experience and observations over these years. I would rather not sell one of my front mounts than be partially responsible for an engine mishap. If anyone has mapped a similar number of cars with these front mounts fitted and has a contrary view, let us have it. It is not going to happen. We are talking about efficient front mounts predominantly fitted to Classic cars.

Not directly related to this thread but something else that should be taken in to account is the fact that the FMIC usually comes after a few other significant modifications are done on the car. The remapping at the time the front mount is fitted often takes in to account the fact that other modifications have been done.
Also pointed out is the fact that if you fit a front mount, even if you do get away with it you are not getting the best out of the modification if your engine is not mapped for the new conditions.

I am predominantly referring to Classics which is why I asked what ECUs were being referred to. The ability of the Subaru ECU has improved throughout the development of the car but as far as I am aware no Subaru ECU is capable of making fuel adjustments to cater for the fitting of a front mount. The main benefits from the front mount take place well beyond the area where the FMIC can operate in closed loop and the ultmate benefit is at WOT. The Classic ECU only adjusts fuel on closed loop. Obviously the ignition has a learning capacity but both perameters can only adjust within a certain percentage range. New Age ECUs, particularly the later cars, have more learning ability but this is not to cater for the fitting of a front mount and Duncan has touched on how the fuel adjustment operates.

harvey

iTrader: (48)

No. You have to read the thread if you are interested.
Fitting a front mount will directly affect the AFR because of the substantial temperature difference in the air charge temperatures. There canl also be differences if the induction system has been changed and there will be dynamic boost changes.

bluenose172

iTrader: (2)

I'm in no way in the 'doesn't need a remap' camp, there are too many variables to say for sure. I thought you couldn't fit a fmic to an impreza without changing the intake tract at some point, so that would be the primary reason I would advise a remap.

I also don't for one minute think the learning abilities of the ecu can accommodate this, I merely pointed out that there was a trim applied to open loop on newage cars.

harvey

iTrader: (48)

No way did I conclude you were in the no remap camp and sorry if you picked up that conclusion. There is a lot in this thread and my hope is that it will lead to a better understanding as to why a remap is very strongly advisable when fitting an FMIC.
Some people already have an induction kit before they go down the FMIC route and the change in induction kit is only a part of the equation that necessitates a remap. With an efficient FMIC the car can probaly enter areas of the map that were not previously mapped.

harvey

iTrader: (48)

Just to add,............ because the car can now run air charge temperatures fairly close to ambient, which was not the case previously and because the differences at WOT can be substantial, then the need for additional fueling is great.

jura11

iTrader: (7)

Hi Harvey i have question about the Hybrid GT FMIC what you are selling,will Hybrid GT FMIC fit on Hawkeye?
My friend have Hawkeye,but cheapest FMIC cost 1000£

sponners

iTrader: (4)

thats what I said in my first posts, .....after any breathing mods its always best to check AFR/det just to be on the safe side and gains wont be had until the car is remapped to utilise the mods.


I still stand by saying fitting a fmic with a standard map will be safe.

sponners

iTrader: (4)

different story when it comes to induction kits as they can really can alter things.

(cant see why a induction kit would throw out the idle trims though???the lambda will still be aiming for stoich)

sponners

iTrader: (4)

The only reason I've heard so far as to why it would be dangerous is because of the AFR leaning out.

I'm gueesing you wouldn't see a AFR change of more than 0.2 which is tiny. (remembering the standard map is very rich anyway)

You mentioned if there is no need to add fuel after fitting a front mount then your wasting your time?
what do you do when you remap the car to make more power? (generally speaking) you remove fuel - not add.


.....I'll repeat in saying as you have that it is pointless fitting these without a remap as there will be no gain.

harvey

iTrader: (48)

You won't take the Hybrid GT2 out the box and fit it to a Haweye, that is for sure. I am sure it would be possible for us to do if we had a Haweye in our workshop, (afterall we fitted a Hybrid GT to my wife's deisle Vectra recently. 1.9 CDTi SRi 225-230 bhp and 325-340 lbs ft.)e would have to use additional pipework, either silicon or aluminiu, to make it fit.
I have a preproduction Hybrid Hawkeye kit here that I am looking for a Hawkeye to fit it to. The kit stands me £550. It will have to be fitted here in Darlington. It will be the first one we do so it is not drive in drive out and it could take several days subject to what we find. Fitting would at a guess be in the order of £200 or a little over.

jura11

iTrader: (7)

Hi Harvey
i'll pass to my friend which i need FMIC for his hawkeye .
Jura

Splitpin

Are you prepared to support that comment by agreeing to pay for the repairs to any engine that fails after a front mount intercooler is fitted, sans remap?

The trouble with your stand is that while you will no doubt be right a significant percentage of the time, you don't have to be wrong too often to end up sounding like a bit reckless (with other people's engines).

In practice, and taking your comment exactly as it is written, you are probably right. Simply changing from a TMIC to an efficient FMIC on a totally standard car should keep things within safe limits the majority of the time.

The problem is that, in practice, when you fit a front mount, you have to fit an induction kit. The front mount may not push the engine beyond safe margins but the combination of FMIC + MAF scaling changes can do so quite easily, with or without a bit of underlying engine/sensor wear.

Given that you're not going to see the benefits of these types of mod without having the engine tuned properly, as has now been said a number of times, there is, in practice, no point fitting them unless you're going to have them mapped in. You may as well leave the thing standard - it'll probably work better that way then modified but unmapped.

harvey

iTrader: (48)

Spooners : This is getting very complex and atleast we both agree there is no point fitting an FMIC without a remap, however, we fundamentally disagree that it is unsafe to do so and my position is quite clear. It is not safe to fit an efficient FMIC without a remap as you are at risk of DET or nipping a piston and this is not theory but practical experience. The least that can be done is to have a check ride and look at the AFRs throughout all operating perameters likely to be encountered. Only then will you be sure if a remap is unnnecessary for safety reasons. If it is not necessary for safety reasons then the need for a remap for performance reasons will be prety obvious providing the FMIC was an efficient design. Many are not so AFRs may not be effected to the same extent.
I have never specifically measured the change so I cannot give you a specific figure for it and it will vary from car to car. A professional mapper may have observations on the actual figure.(which will vary, car to car for many reasons)
You seem to be assuming the FMICs are fitted to cars that have not been mapped before. Obviously if it has been subject to a previous remap it will not be running very rich anyway
As a rule, the FMIC is down the list of modifications. The car may already have been mapped or the existing modifications may have gone a long way to utilising any excess fuel from the factory map. Furthermore and very importantly, the car may not be on the O/E ECU. In my experience, the FMIC is usually the last mod before a remap becomes essential and not an option.
If the car was properly mapped before the FMIC was fitted that is exactly correct. To take into account the car may have been running very rich in the first place I will clarify that to make it exact and clear. There is no point fitting an FMIC if it does not add power and give added safety.
Determining when the point at which a front mount is needed is the key.
Perhaps on the first remap on a standard ECU but not if the car was properly mapped in the first place. A good way to determine if a modification has been successful and before going anywhere near a rolling road or relying on your butt dyno is to see how much fuel has been added and where.
If the car was properly mapped in the first place and you remap to maintain the same AFR targets, more fuel = more power, less fuel = less power. Laws of physics I expect.


Taking what you have said already this is a bit contradictory. If the car is already rich before the FMIC is fitted and if ACTS are already sufficiently out of control to warrant an efficient FMIC then fitting the FMIC on its own will clearly show power gains, simply from the reduced charge temperatures. Again down to the laws of physics. Whether it is a safe gain or not has to be at the very least checked.

Elsewhere and when it was not contentious I gave an example of a car mapped with an STi 8 top mount. The car was specifically mapped to see what it could do. 392 bhp. It returned to the same rollers with a Hybrid GT fitted. No other modifications. It then ran 401 bhp. Following a full remap it was left with a safe map at 410 bhp. It was also noted that on a slightly warmer day, ACTs had dropped by over 20 deg C above ambient.
Running that car without a remap would have been foolhardy IMHO despite the fact there was only a 9 bhp gain before the map was attended to properly. The car is fitted with permanent EGT, wideband AFR and knock detection.

Anyway we clearly have lots of variables. What ECU O/E or aftermarket, what model and year and obviously how efficient the intercooler is as that has a big effect but here are some other considerations.
Is the ECU on MAF or MAP? On MAF I suspect the AFR will be less effected than on MAP. Also on MAF you may see a rich spike at the point the turbo spools.
On an MAP system the fueling is fixed to each load cell although there is as a rule an ACT correction table. Unless that correction map is properly scaled then your AFRs are out the window anyway.
Also, if the MAF Sensor is repositioned (as it is on all New Age Hybrid FMIC kits) then there can be a considerable effect on AFRs. I am not saying weak or rich, just that the AFRs can vary substantially.

So for several reasons it is unwise to fit an FMIC without a remap. In a percentage of cases I.M.H.O. it will result in engine damage in a worst case senario and at best reduced engine performance and efficiency. Your engine, your choice.