typeR

... i think


so im reading stuff in the helms about what the ECU does to fuel cut ...it seems so simple ... only 2 possible issues does the ECU freak out if it senses or is told or what ever you wanna call it that its fuel cut didnt work ? ill releate this to my elimination of the VSA if you didnt manually turn VSA off but spun the wheels ud get a CEL because the desired result didnt happen ... not sure if the same will happen here ?

but essentially with the key in the ON II pos. ground is supplied to the primary fuel pump relay and for 2 seconds the secondary to energize the system and prime the injectors... after 2 sec.the ground is cut to secondary relay

at speeds above 7100 ground is cut to secondary relay by PCM ... so my idea is so simple and just may work ...pending CELs


jump ground from primary relay to secondary... only other down fall is we would not wanna leave the key in the ON II pos long


thoughts ?

aznboi2424

iTrader: (10)

But the key is in the ON II position whenever the car is on....

typeR

i should have been more clear on II but not running you know when u have the key all the way dash lit up but didnt crank the car ...i feel this is fine because how often will we ever be doing that ...

StreetKA

iTrader: (8)

i wouldn't do that because even if you succeed going around the limiter you risk potential damage to the valves... it was proven that power pick is at 6900-7000 and then it falls on its face...

i mean i give you if you succeed but the outcome may be not worth it without modifying heads

typeR

as we add things like headers etc it will allow the power curve to move up espcially when combined with freeer flowing exhaust ... im not running it to 8k here ...im basically doing this to avoid fuel cut and the pulled timing as a result of if u just blip it, and the lost power related to that ... im just looking to go 7500 at the most

civicdrivr

iTrader: (9)

The power from this engine starts to trail off after 6k rpms, whats the point of revving past 7100? Not only that, but is the stock ECU even programmed to properly control timing and fuel trims past the cut off? It seems very dangerous to me. If you want to raise your red line and actually control it properly, pick up an EMS.

fsttyms1

Here is another thought, would this bypass the top speed limiter. Im assuming the top speed limiter does the same thing as the rev limiter by cutting the ground to the fuel

fsttyms1

Another question. If the ground is ONLY supplied for a little bit how would grounding it to the 2ndary eliminate the cutoff. Wouldnt you need to ground the primary all the time so that the ECU cant cut the ground?


If the ground is only applied then cut after a few sec, how does the ECU cut the 2ndary again? Does it cut the primary?

CL-S progression 01

iTrader: (2)

i think ur onto something there OP but it definitely sounds like russian roulet with 6 pistons instead of 6 barrels

typeR

ur not following ... the ecu only cuts after 2 sec in the on pos... when running ground is supplied until 5500 in P N ... 7100 regaurdless of throttle pos. and 2 sec in the on II other wise ground is continuous durning normal op...


civic i doubt fuel tables just dissappear after 7100 again im talking 300-400 rpm just to avoid bouncing the limiter


if the car shifts at 6900 and falls to 4800


or shifts at 7500 and falls to 5000 where is there more usable power ?



by the way this should eliminate P/N 5500 fuel cut as well as top speed 149 gov

YeuEmMaiMai

valvetrain is only good for 7.5 TOPS (unless you do some work ot it) at that point you are going to get valve float and that spells DEATH to your motor.......Headers move the power peak up past the normal spot of 6.1K to about 6.6K with a peak of 290HP so 7.1K WOT shift point is still spot on......(this is what you can wind it up to using Sport Shift). In the 1st 3 gears you are gaining nothing as they are close together amd 4th is so tall that accelleration falls off drastically anyways. 5th is even taller yet.....

auto trans

1st max = 40
2nd max = 79
3rd max = 123
4th max = 148
5th max = 148.

Also defeating the high speed limitor is bad news for you as the car becomes extremely unstable above the fuel cut speed (per Acura interview with C&D some years ago the car will go airborne)

fsttyms1

I doubt it. It has more to do with the shitty tires from the factory. My car running at the 149 limiter is rock solid, doesnt float or lift as it drives. You can hold the wheel with 1 finger.

CL-S progression 01

iTrader: (2)

i wish i had enough road to top my car out. I have been waiting for the day... :-(

phee

iTrader: (5)

My 99 was stable to 156 on the fl turnpike. This was before I went to the type-s Ecu.

Is there still spark during the fuel cut?

typeR

yet to be determined but it sounds like it from the helms

civicdrivr

iTrader: (9)

Track. Not road.

typeR

http://s1193.photobucket.com/albums/...current=TL.mp4


take special note of whats demonstrated and said at around the 4.40 spot in video

Karanx7

iTrader: (2)

Interesting.

A418t81

iTrader: (1)

Haha, that looks like a freaking megasquirt he's running in line with the ECU.

CL-S progression 01

iTrader: (2)

there is no track in this country with enough rd to top out an auto cls

typeR

it is

OperationDarkie

iTrader: (1)

I would be careful with that, stock valve wont like those RPM's for very long unless you are running valve springs and retainers, are you trying to move the powerband up or something?

phee

iTrader: (5)

I don't think the idea is to rev that high purposely. It just gives us a buffer to shift during the 1/4. But type-r u may have a bigger issue on your hands with an auto cl-s since the Ecu shifts automatically during 1-2

fsttyms1

Doesnt if you are gate shifting

B+O

Has this been tried yet?

I was looking at the wiring diagram for my car and it looks as though the ECU grounds both the Ignition and Fuel Pump circuits...


FR1 is grounded and if you follow the current through the diagramatic "relay" switch of the Main PGM-FI relay, you can see that there's essentially 2 Circuits embedded in the Relay with pins dedicated to the ECU...


one circuit controls ignition, it looks like, the other controls the fuel pump...

It's too rudimentary to actually do a hard stop with fuel injectors and line pressures being that high. I do think Honda stopped the fuel pump from over pressuring the injection system, Hence the FLR1 circuit which cuts power to the Main PGM-FI relay. FLR2 cuts ground to the Fuel Pump Relay (and that's what happens when the ignition is on II for 2 seconds it cuts ground to the fuel pump relay itself and I assume the Ignition circuit (FLR1 pin).

Both of those scenarios cause a 'open circuit' in the fuel pump which stops it's action... the question is, when does the ECM cut ground to the fuel pump itself, and when does it cut ground to the PGM-FI relay??

As far as the ignition part of the PGM-FI relay...

It' looks as though there's a ground and a Power for this... the ECU provides two grounds and 2 powers for this circuit. not sure of its importance in the system other than to provide a switched 12volt feed to the ECU (uses 2 power wires and 2 ground wires)

That's my take atleast.

BTW, I have a 2004 3.5RL but it seems like all honda ECUs have roughly the same "design structure"

YeuEmMaiMai

It's what acura told C&D when they asked............and the 3rd gen TL only goes a few MPH faster (155 vs 147) thus getting Z rated vs V rated tires...

fsttyms1

It may be but its not what i have observed (up to 150) and i dont believe it would get any worse at 160-165 if the car were to be able to get there. (i would be more than happy to test it if i could to prove and show that the car is stable)

yungone501

iTrader: (4)

Wow I really hope this thread (nor some of the people in it) isnt saying that fuel cutoff is done by dropping a ground circuit from the fuel pump relay...is it?

Somebody a few responses above actually gave a response based off logic and was able to understand why this WOULD NOT work by saying that fuel pressure wouldnt fall fast enough to protect the motor in the event of an over rev.

The truth is that the ECM performs "fuel cutoff" by dropping an electrical pulse (ground actuated) to the fuel injectors. Here is an explanation taken from AllData as to what it is also:
"Fuel Cut-off Control
During deceleration with the throttle valve closed, current to the injectors is cut off to improve fuel economy at speeds over 1,100 rpm .
Fuel cut-off action also occurs when engine speed exceeds 6,600 rpm , regardless of the position of the throttle valve, to protect the engine from over-revving. When the vehicle is stopped, the PCM cuts the fuel at engine speeds over 5,000 rpm ."

typeR

i think you're gonna wanna re check that info from all data ... and or the model theyre refering to , maybe a base CL ... but fuel cut on a type S is 7100 and 5500 in neutral/ park not 6.6 and 5



long and short reguardless of how and where it has been disscussed for years on defeating 7100 rpm fuel cut... what ive said for years is figure out where the signal is coming from and being delivered to the ECU and trick it via some kind of voltage clamp... like i did with eliminating my VSA ....i made the ECU thinks it still sees it connected ... how then do we trick the ecu into thinking it has not yet seen 7100 rpms ?

typeR

i think the top speed is 147 not 9 but either way i believe the airborn thing... i hit it once on long stretch toll rd in the late night hours with zero cars for hours and i still get bad flash backs of the feeling of about to go air born and how dead i was gonna be

Re and Cheryl

This is true, and as such the defeating of the rev limiter is not possible without reprograming the ECM, which is not possible on these. I also see no need to increase the top speed limiter beyond stock. These cars are not safe at those speeds anyway. Even with better suspension and tires, your just looking for an accident.

Re'

Karanx7

iTrader: (2)

Got any evidence on these cars not being safe beyond 150? Car seems rock solid at 145. With proper tires, I'd imagine it would be safe for much higher than that.

fsttyms1

Agree, i have had mine there many times and it is very stable (with upgraded suspension and tires). Even with the stock suspension it handled the speed well.

yungone501

iTrader: (4)

Yes, the info I gave was from a base TL, but the same applies to the Type S in regards to how fuel cut off occurs. In terms of the fuel cut off, because the ECM bases the limit on what the cam/crank sensors are telling it, it would be almost impossible to change the limit without affecting the engines fuel/ignition map. In other words, unless the programming configuration is changed internally with the ECM, manipulating redline is impossible.

As for modifying the limit on top speed, the VSA/Traction system has nothing to do with this limit at all. As a matter of fact, you could completely remove/disconnect the ABS module and still have the same top speed limit. The ECM uses two sensors on the transmission (countershaft and main shaft speed sensor) to determine vehicle speed for shifting purposes as well as the signal to the speedometer. This same signal is the used for top speed cut. Because both sensors are literally wired in parallel with other engine sensors and one sensor monitors the other, you would have to intercept each of their signals back to the ECM and modify them EQUALLY so that one of the two doesn't detect a fault. Sounds, to me, like a major PIA unless you REALLY know what you're doing. Especially just to go faster in a car that wasn't really designed to handle anymore speed than....well, how fast than it was designed to go. It's not like we're working on Ferraris and Busas here.

Re and Cheryl

Defeating the top speed limiter on an automatic trans car would be impossible because the trans will not shift without a speed signal. Defeating it on a manual trans vehicle could be as simple as killing the vehicle speed signal to the ECM. I'm sure you would get the SES light illuminated though.

Although I will not debate the need to drive this fast, I can tell you I have driven much better cars at speeds over 145mph on the autobahn in Germany and felt nervous. And roads in Germany are much better than roads in the US and in many places you are actually allowed to achieve these speeds legally. Our cars are high priced Accords, no way I'm taking an Accord that fast.

Re'

yungone501

iTrader: (4)

^^^
Lmao, agreed.

I ride a 2007 R1 and when I first bought the bike, with factory gearing I was able to get it up to 187mph...or atleast that's what the speedo said. Even on a machine that's specifically built and designed to go that fast, it's nerve racking. I did that one time and ONE TIME ONLY, then I geared it to a top speed of about 155-160mph. Now my problem the front end lifting off the ground in almost every gear except 6th. But THAT puts a smile on my face. :-)

fsttyms1

There is a big difference going that fast between 2 wheels and 4 wheels I feel a lot more stable and safe in my TL doing 150 than i did/do on my old zx6r and cbr1000rr (which were both designed to go that fast)

Either way, the debate isnt whether the car can handle it, its how to make it achieve it. The only real way is with a full standalone

typeR

btw i dont want to do this to go above 147 ... its that i always felt there were a couple hundred more rpms of power remaining and that just blip fuel cut on the 1-2 and 2-3 in the quater results in the pulling of timing

fsttyms1

I would like a little more rpm as well. Springs are the limiting factor from what i have seen and read. There are springs available that are better. With a little tunning i know we could get more out of this motor with a few hundred bump in rpm. Especially with a set of cams.