View Full Version : Question!
Just removed the solenoid pipe gromit (thanks Adrian) and went out to see if any different.
Travelled about 8 miles before finding a stretch to open it up, so car was warm.
Set off from standing start reved the car to about 5500rpm in 1st and then into 2nd and car cut out at about 6000rpm and then kicked back in and reved through. went a little further and tried again in case the car wanted clearing out,and the same happened again at around 6000rpm.
Just as though the rev limiter had cut in early for some reason.The car has never done this before.
The car is standard apart from full Magnex pipe (decat and front pipe) and has done 3600 miles.
With the gromit removed there was a noticable difference in the acceleration, but I think it may be going back in for now!
Anyone any ideas ?
I believe your car will be overboosting, as the grommet is there to prevent this. If I recall from posts on the evo list on egroups.com the ecu recognises an overboost situation and corrects it. The advantage of removing the grommet is supposedly to give better boost/grunt mid-range.
No doubt the more technically minded members will be able to elucidate further http://www.ltregister.com/graphics/TooHappy.gif <!--e13-->
Just read some previous posts and I believe that indeed it sounds as though the ecu is cutting in to prevent overboost.
When I read the posts I thought that people had said that it only raised boost by about 2psi and therefore should not be a problem.
I also read that Ralliart remove the gromit on all their cars before delivery.
Anyone care to comment?
GROMIT, GROMMIT, GROMMET - You know what I mean Worsel,Worsell!!
I removed my restrictor and everything worked as I have described earlier.
Perhaps as suggested some other system is not happy with the lift in boost and is shutting you down. I really have no suggestions or insight into what may be happening to your car.
How much has boost raised? Has anyone else experienced this?
Absolutely positively overboost resulting in fuel cut.
Mine has done this once when flooring it from around 3k RPM (boost pressure should have still been building and not peaked at this point) but it hasn't happened again. If it does happens again I may have a prob. as my gromet went flying when I removed it. Oh well we'll wait and see.
Are you going to the Clitheroe cruise this weekend? Is it Friday or sat. night?
And there's thinking I was the only one to have this problem! I haven't removed my grommet, merely bored it out a little, but still get overboost (only now the weather's more turbo-friendly - muggy). Coordsport have posted something in response to someone's question about ECUs and have said that overboosting is not uncommon in cars with derestricted exhausts and induction systems. Answer is to drill out the vacuum pipe restrictor near the turbo. I'm (hopefully) off to BTR Prep to get mine sorted out next weekend so will let you know if that cures the problem. On the positive side at least the ECUs cutting the fuel to prevent damage to the engine!
I don't have a boost gauge fitted so have no clue as to what the boost has been raised to,
someone suggested it should have raised it to around 1.4. Would this be about right?
If so why should it detect 'overboost' ?
Adrian, re Clitheroe, I don't think so.
Bunch of 'youngsters' in their Nova's and GTI's doing handbrake turns and burnouts don't really impress me! (Just remind me of how stupid I used to be!!) when I was a 'youngster'
Mind you the Transit van with the £35000 'ice' system in was worth going for just to listen to that 'bass' sound.
Never heard anything like it!
and amp;gt; and amp;gt;just as though the rev limiter had cut in early for some reason
im 99% sure what you are experiencing is fuel cut ,
this is nothing to worry about !!!!
when the ECU detects boost beyond a specific level
(on most turbo'd cars about 3-4psi more than stock)
it will momentarily cut the supply of fuel to bring boost
back down to a reasonable level.
HKS, GReddy and others make a unit which allows you to bypass this
fuel cut , the HKS FCD (Fuel Cut Defencer) is approx £100.
If you are going to fit one of these units may I suggest
you get an EGT gauge fitted (Blitz £140) and a boost controller
(Apexi AVCR £450ish) and set boost at a level where EGT's stay
below 925-950, I tend to ignore boost pressure (within reason!)
and concentrate on EGT's when tuning my cars, making sure
I always keep EGT's below the detonation threshold.
Any guys here fitted water injection ??
Any guys here using decent fuel additives ??
Tolloline is the dogs but don't get caught and I think Richard Lamb at ERL did a water injection but with exhaust temps in the regeon you mentioned I would be suprised if it made much difference.
The same thing has happened to me although the cut is more harsh that the rev limiter.
I have two questions:
1. Has anyone got an answer to this?
2. Has anyone got the part-number of the grommet as I too lost mine when it pinged across the engine bay?
Grommet No: W3NSL33 DAL3 CH33S3
Best of luck.
http://www.ltregister.com/graphics/Happy.gif <!--e1--> http://www.ltregister.com/graphics/Happy.gif <!--e1--> http://www.ltregister.com/graphics/Happy.gif <!--e1-->
For future reference, the best way to extract/re-insert the grommet is to use a self-tapping screw http://www.ltregister.com/graphics/TooHappy.gif <!--e13-->
Does this mean you've taken yours out?
Grommet I mean!
Are you having similar problems or have you found a way of solving the problem?
I must say that I'm impressed with the way the car is performing at the moment with it taken out. I think if I do get the induction kit which is on order, I'll have to replace it, because then it will overboost even more.
If there is an easy cure for this would someone please let us know
I do not have a great understanding of the mechanism for triggering fuel cut. I did not experience it with my E5 GSR.
If you have lost your grommet you can use an inline needle valve to replace the restriction. By making adjustments to the valve you may be able to find a point where you still enjoy performance gains without reaching fuel cut. Increasing the restriction reduces boost.
The real performance solution is to replace the ECU with one where Big Brother is not telling you what to do. Granted you will loose your warranty but from what I hear it is of questionable value anyway.
Great gains can be made with fueling and ignition timing let alone lifting boost. Take the time to understand your car and gently discover what it is capable of. I have fitted Lambda and knock gauges to let me know when I am asking more of the engine than conditions allow. The capabilities of this stock engine continue to amaze me!
I have just reviewed earlier post and am wondering about the wisdom of MMC inducing “fuel cut”. The whole point of this is to prevent damage to the engine right. If you are approaching the practical level of what Mitsubishi feels to be the safe limits of the engine, is cutting of the fuel and at least temporarily leaning out the fuel mixture sensible? At the limits of performance leaning an engine will encourage detonation. Detonation is what bends connecting rods, melts and knocks holes in pistons. Bad, very bad! Perhaps ignition cut would be a better idea. I would be somewhat cautious if you are getting fuel cut.
When the ECU senses overboost does it kill the ignition or fuel? As you say an ignition cut would be far more sensible.
I have been told by DP motorsport that a solution to the problem is to raise the fuel pressure and then use the AFC I've got fitted to tell the ECU that less air is coming in. ie make the ecu run leaner but increase the fuel pressure to compensate. thus the overboost will not cut in because of the apparent reduction in airflow.
I can see that an upgraded ECU may be a neater way of doing things but as I've already got the AFC fitted it makes sense to give this a go.
I am fairly certain that fuel cut it is. I believe that MMC also use fuel cut to control rpm overrun.
Your guys at DP seem to have a reasonable approach to fooling the ECU.
The only problem I can see is that airflow and rpm are probably the main determinants for many system maps in the ECU. If you are modifying the signal for airflow it may change the ignition timing and fuel mix for that load level. Adding fuel will help compensate for the higher engine true rpm but the ECU may also be setting too much ignition advance.
When I went shopping for enhancements to my car I considered retaining the stock ECU and using add-ons to fool it. By the time I had added all I felt I needed it was costing more than an ECU implant.
Bottom line , it is overboost fuel cut by the program in the ECU. I did this to my VI with same result. The cut is brutal on full throttle so don't make a habit of it , it will result in damage to the drive train over time. It isn't just more boost pressure , it's also the rate of pressure rise , when the ECU see's the combination of both exceeding the map the result is fuel cut to prevent engine destruction. The reason for destruction would be the inadequate standard fuel pressure setting and standard fuel pump delivery resulting in weak mixture and BANG !! Go to Power engineering , get thier remap to the STANDARD ECU , get more power AND run on 95 RON fuel without problems.
Please forgive my skepticism but I doubt the wisdom of asking the engine to do more with less. Octane is a complex measurement of a fuels resistance to detonation. More power is usually achieved by increasing ignition timing advance and lifting boost. Adding fuel enrichment can help suppress detonation but why use a fuel that is essentially unsuited to high power engines? Won’t you then simply exhaust the capacity of the stock fuel system earlier?
My understanding is that the stock ECU performs fuel cut when it sees more air entering the engine than it is programmed to allow. MMC uses airflow to infer engine load. Fueling, timing and boost are determined at all load points in relation to RPM. When it sees more air than it expects it assumes that something is wrong and stops the engine briefly by shutting off the injectors.
Experience tells me that the stock fuel pump and injectors are more than adequate for quite a bit more power than pulling out the grommet can ask of the engine. It seems to me that the ECU for the E6 may be less tolerant of boost lift than that supplied with the E5. Has anyone found fuel cut when removing the grommet on an E5?
I have read posts from other group members to the effect that a “Fuel Cut Defencer?” will stop the ECU from performing this somewhat antisocial act. Without knowing anything of the methodology for stopping fuel cut perhaps this is the most appropriate step.
Please forgive me, and no i'm not taking the p*** either,but what sort of performance gains are we talking here?
Sounds pretty hairy to me!, do the gains justify the means? and the risk?
Spoke to Ralliart rep at Oulton Park earlier in the year and mentioned improved fuel pumps and pressures.
His reply was that the Evo 6 does not need any replacement/improved fuel pumps because the stock one is more than adequate for major power gains.
Many companies start with this and it really is not necassary unless you are going for major bhp mods, ie 360-450bhp
Please, DON'T shoot the messenger!!
I have called Ralliart and a Mitsubishi dealer with the part number, but they don't recognise it.
Where did you find the number and please could you confim it is right?
Sorry, it was meant to be a joke.
Substitute E for 3 and amp; S for 5 what do you get?
Sean [Wallace and amp; Grommet's mate http://www.ltregister.com/graphics/Happy.gif <!--e1-->]
Cracking Cheese, Grommit!
I noticed, but then I am l33t http://www.ltregister.com/graphics/Happy.gif <!--e1-->
How stupid do I look? - Almost as stupid as when I pulled out to overtake a family hatchback on its way to do a weekly shop and got the engine cut!!!
I've been down to the Mitsubishi dealer and he couldn't locate the part. Does anyone know what this pipe connectes to, and what the solenoid does. The guy in the parts department can't find it without more info.
Glad to see you've got a good sense of humour http://www.ltregister.com/graphics/Happy.gif <!--e1-->
Dragon Autosport do a fuel cut defencer for £80.00.
The part number for this vacuum solenoid valve is MR161743. It comes with the grommit, but costs £71 delivered. (grommit not available separately)
It's not that I'm tight, but seventy quid when all I want is the grommit?
I'd really like a few of these little bits of plastic so that I could drill them to different diameters so if anyone has any ideas on a suitable replacement or an adjustable gadget to go onto the pipe, then I would be extreamly interested.
Naunt (off to purchase some Lego or something!!)
Think someone mentioned this earlier,what about carburetor jets, these come in various diameters, but would they fit in the solenoid ?
Maybe worth a try
It would seem that I've caused quite a few problems for some people (myself included). All info supplied was in good faith and I am very sorry if its caused problems. My car has only cut out 3 times since removing the gromit, all three occasions were at about 3-4k RPM not at high revs.
I'm going to order an HKS fuel cut defencer and see if it sorts the problem out. Alternatively how about buying some small bore ally pipe from a model shop.
I'll let you all know how it goes.
Just to elaborate on the grommet thing, when I removed mine (VI) power was definately increased , however engine characteristics were deteriorated , throttle response was abrupt etc . PE's remap not only gave even more power but also improved even the standard engine personality . More than one source I have spoken to about injectors and fuel pumps has found the standard items to be inadequate above 350 BHP.
Regarding fuel , the standard engine is well overfuelled , as the bloody fuel consumption will testify , the remap sorts this and makes more use of the correct amount of fuel and as far as what I saw on the power run at PE plus my experience of the car so far it is fine on 95 RON with better fuel economy.
Which is nice!!
There's no hard feelings from this end, after all it was me who dropped the tiny bit of plastic on the gravel drive http://www.ltregister.com/graphics/Happy.gif <!--e1-->
I've posted a message onto the CoOrd Sport web site and Peter Collinson has sent me a replacement grommet FOC (He's a very nice man)
The one he's sent me is brass where as the old one was plastic, but I guess the important thing is the size of the hole (no funnies please).
I'll fit the jet this week end and also measure the hole with a small drill bit. I'll post back and hopefully someone can confirm the size?
I've ordered a fuel cut defencer from dragon Autosport £80 |PLS| VAT. hopefully it will be here early next week. Apparently it comes with instructions and is simple to fit. Hopefully it will solve the problem and can still be set to cut fuel if silly boost pressures are reached. ie. just up the standard boost cut level. ( Think I may buy a boost gauge as well so I can keep an eye on things)I'll let you all know how it goes.
P.S. Naunt I've got a block paved drive and still cound't find the damn thing.
Well the jet arrived and I went to install it at the weekend and.........
I dropped it!!!!!
It was just as well I had a blanket under the car http://www.ltregister.com/graphics/Happy.gif <!--e1-->
Anyway after finding the jet and trying again, I discovered it didn't fit, So I have ordered the whole valve @ £70 http://www.ltregister.com/graphics/Sad.gif <!--e2-->
Once I get the grommet, I'll try to find a set of jets with various internal diameters and post back with the info.
Where the jet goes is not that critical once it presents a restriction to the outlet from the solenoid. Try stuffing it in the tube that attaches to the solenoid where you removed the original restrictor.
There is two valves in the turbo pipes, the one in the solenoid is plastic the other is near the turbo, this is brass. Be careful as over boost will cause damage and overboost problems.
Have you ordered the solenoid? I might be able to get one.
Yup, the deed has been done, but thanks for the offer.
Adrian also lost his grommet, so he may be wanting one.
Ralliart Geeza, is it true that Ralliart take the so called grommet out on all of their Evo VI cars ?
If so what is the solution to the overboosting problem that we are now getting ?
Any help would be appreciated.
The ECU cuts fuel when the boost exceeds the parameters of the ECU. This is a SAFETY feature designed to prevent the engine running LEAN at high boost levels, and dettonation occuring because the ignition is too advanced for the higher boost.
An FCD fools the ECU into thinking it's running less boost, and prevents it cutting the fuel. Whilst this is a popular method of tuning in Japan, they do this in conjunction with electronic boost control, and also controllers for fuel, and ignition.
PLAYING with restrictors, FCD's, etc', is asking for trouble, and unless you know what you are doing, or can monitor det', boost, and AFR's, it's only a matter of time...........
If you do decide to experiment, at least pay for some time on a well run rolling road, where it can be done reasonably safely.
At this point I'll make an offer here...
If someone can knock up a drawing of this bit, showing the internal (hole size) and external dimensions, I'll make a load of these (I've got a machine shop) out of brass with various different hole sizes (again, let me know what you want to try), and supply whoever wants them with a bag containing as many varying hole sizes as you want in each kit . Nominal charge for material and minimal labour only (CNC Machinery...don't ya love it) and you certainly won't have to spend anything like the cost of the Solenoid.
Let me know [img]http://www.ltregister.force9.co.uk/graphics/Happy.gif border|EQU| 0 align|EQU| middle >
Alan (just trying to be a helpful Evo owner...NOT trying to make money here...)
TO ALL EVO4-5-6 OWNER.
FIRST I WILL LIKE TO CLARIFY THAT THE ENGINE DETERMINE OVERBOOST BY THE VOLUME OF AIRFLOW IT SEE AND THE DENSITY OF THE AIR (AIR TEMP/COLD AIR |EQU| HIGH DENSITY). THAT EXPLAIN WHY SOME OWNER ONLY OCCASSIONALLY SEE OVERBOOST SHUT OFF. EG. DRIVING THE CAR IN THE EARLY WINTER MORNING WHEN ENGINE HAS JUST WARMED UP , WHEN THE EGINE BAY IS NOT SO WARMED WITH PLENTY HIGH DENSITY CAR AIR, IS THE MOST COMMON TIME FOR BOOSTCUT TO HAPPEN. BY REMOVING THE GROMMET WILL RAISED THE BOOST LEVEL (ON EVO6)FROM 1.05 BAR TO 1.20 - 1.25BAR, AND ON STD CARS THE BOOSTCUT SEEMS THE HAPPEN AT 1.25-1.30 BAR. IT SEEMS TO ME EVO 4 AND 5 HAVE A HIGHER BOOST CUT LEVEL THAN EVO 6.
I HAVE SOLVED THE PROBLEM BY LEANING THE CAR OFF BY APEX-I SUPER AFC. THE S-AFC LEANS THE CAR OFF BY FOOLING THE AIR FLOW SIGNAL TO THE ECU, THUS MAKING THE ECU SEE A LOWER VOLUME OF AIR ENTERING THE ENGINE. BY DOING THIS THE ENGINE RUNS LEANER WHICH IS GOOD FOR FUEL CONSUMPTION AND POWER. THE STD. CAR SEEMS TO RUN FAR TOO RICH, AFTER LEANING OFF THE FUEL MIXTURE THE ENGINE PULLS MUCH STRONGER AND REV MORE FREELY. MORE IMPORTANTLY YOU CAN RUN MORE BOOST! I HAVE SETTED MY CAR UP ON THE ROLLING ROAD AND ON THE ROAD WITH THE AID OF A AIR/FUEL RATIO GAUGE AND EHAUST GAS TEMP. GAUGE, RUNNING 1.4 BAR BOOST ON THE STD ECU WITH 95 RON FUEL. I HAVE ALSO USED AN S-ITC TO RETARD THE IGNITION TIMING ABIT TO PREVENT ANY PINKING. SINCE THIS SETUP I HAVE COVERED 20,000 MILES AND THREE TRACK DAYS RUN BY THE CLUB.
THE STD INJECTORS AND FUEL PUMP SEEMS TO MAX OUT AROUNF 340BHP. THE STD FUEL PUMP IS WIRED UP SO THAT IT ONLY GETS AROUND 9.0V WHEN YOU ARE DRIVING OFF BOOST AND 12.8V WHEN ON BOOST. YOU CAN INCREASE THE FLOW OF THE FUEL PUMP BY WIRING IT UP TO SEE 14.3V ON BOOST. MOST OF OUR ELECTRIC GOODS IN OUR CAR SEE THE FULL VOLTAGE OFF OUR BATTERY (AROUND 14.3V) EG. HEADLIGHT CD PLAYER ETC. BY DOING THIS YOU ARE ICREASING THE FLOW RATE OF THE PUMP BY 30% THUS MAINTAING A BETTER FUEL PRESSURE UNDER HIGH SPPED HIGH BOOST CONDITIONS.
Max, Sshhhh... I had an xmas do last night, 6am shot and my poor head needs some tlc http://www.ltregister.com/graphics/Happy.gif <!--e1-->
Thanks for posting your experiences here. I also have been looking for more from my stock E5 GSR engine than most people seem to think safe.
I agree that the E6 ECU seems to allow less boost than earlier models.
It is interesting to hear of your approach of lifting boost and retarding ignition. I have increased both boost and ignition and suppressed detonation by over fueling on 97 RON. Fuel consumption is abysmally poor but oh my, what power!
Though I have not installed an exhaust temperature gauge I have fitted a knock alert that I have tuned to alarm at a lower level of knock than the stock ECU used to allow. At 20 PSI I still have no signs of detonation. This is all managed with an implant ECU that gives fuel pump voltage control and many other functions to numerous to list here. To date I have not exhausted the capacity of the stock fuel system.
Are you still using stock internals in your engine? I have changed the final drive ratio for the very tight and short road conditions locally. Up rated clutch muffler and induction have all helped. Changing the suspension helped the handling immensely.
Thanks again for sharing your experience, 20K and no problems are most encouraging. Keep up the good work!
Chunky serves you right!
DEAR CHUNKY AND OTHERS
MY EVO6 GSR SPEC.:
5ZIGEN MAX304 EXHAUST
HKS FRONT PIPE |PLS| HKS STAINLESS STEEL LAMDA HOUSING
HKS KANSAI INTERCOOLER PIPE KIT
HKS KANSAI FILTER RELOCATION KIT
TEIN HEIGHT AJUSTABLE SUSPENSION
OIL BREATER KIT
EXTRA OIL COOLER
I AM GETTING 95-98% INJECTOR DUTY CYCLE. THAT MEANS I AM MAXING OUT MY INJECTORS. I AM GOING TO GET ADJUSTABLE FUEL REG.,HOPING TO RE-SOLVE THE PROBLEM.
DO YOU HAVE ANY PROMBLEM WITH YOUR OIL TEMP.?
BEFORE ADDING EXTRA OIL COOLER I AM GETTING 130 C'
Your oil temp , does it run at 130 deg c continuously (after warm up) or is that a peak temp . Does the ambient temp have any influence , and does road speed affect temp and amp; if so how ? What oil do u run . What is yr oilcooler upgrade ? Excuse the interrogation but I'm curious.
There is a cheap and simple but more difficult to adjust way to lean out your car than using a super AFC or other means. The MAF (airflow meter) has a screw on the bottom of it that is covered with silicone. If you dig off the silicone you can back the screw out. The more you back it out the leaner the car will run as you are allowing more air to bypass the part of the MAF that counts the air.
To back up what others were saying, if you are going to fool around with boost controllers, super AFCs, FCDs or other such devices make sure you first fit a boost gauge and definitely an EGT gauge so you can monitor what is happening. If you don't, sooner or later your engine will blow.
NO, MY EVO6 USUALLY RUN 90-100 C' OIL TEMP. BUT WHEN I FIRST HAD THE CAR (STILL STD.)I RAN IT AT CADWELLPARK AND I SAW ABOVE 130 C'. FROM THEN I KNOW IF I WHAT TO MOD MY CAR I NEED LOWER OIL TEMP. FROM THE MODEL DEVELOPMENT FROM EVO4 TO 6.5, MITSUBISHI HAVE ALWAYS INCREASED THE OIL COOLER CAPACITY, THAT TELLS ME OIL TEMP IN THESE ENGINE IS AN ISSUE.
I FOUND THAT HKS DO AN UPGRADE OIL COOLER, WHICH I SEEN FITTED TO AN EVO4 (JOHNATHAN'S CAR). I BELIEVE IT WORKS VERY WELL BECAUSE IT INCRESED THE CAPCITY BY 60% AND HAVE FINS TO DIRECT THE AIR TO IT.
I HAVE CHOOSEN A CHEAPER OPTION, I ADDED A MOCAL OIL COOLER CORE TO THE EXISTING OIL COOLER. RUNNING IN LINE, THAT MEANS HAVING TWO OIL COOLER. IT SEEMS TO LOWER MY OIL TEMP. BY 10 C' AT HARD USE (TRACKDAYS). THE WHOLE THING COSTED ME AROUND £150.00 |PLS|VAT FITTED. R.E. PERFORMANCE AT BURY HAD DONE THE JOB (ASK FOR KEN) 0161-7611177
Are you near to Bury?
There are a few of us who go out on the first Sunday of the month for a drive and lunch, your more than welcome to come next month. I'm in Burnley and have also used RE performance in the past. (I'm also responsible for Ian (peeley) starting this thread)
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