Will i be Running LEAN with Pivot Speed Meter?

[silviatub]

Hi Mates,

I got a JDM S15 Spec R with Pivot Speed meter SML-V installed to remove the speed cut...we went on a hard run yesterday on the highway and we managed to reach speeds upto 250 to 260km/h...when i was maintaining speeds above 200km/ to 250km/h, i noticed the water temp was more than half and it went up to a max of 3/4 of the stock water temp gauge:annoyed:...my cooling system is totally stock and there are no leaks so far...is this normal with the stock cooling system?

another school of thought told me that since i installed the Pivot Speed Meter, it actually fools the ECU to think that it is still running at 180km/h thus making AFR mixtures lean when exceeding speeds above 180km/h...as a result, this makes the EGT and water temp run pretty high ...is this assumption true mates?

i dont want to blow up my engine and any advice and guidance on this matter is highly appreciated...

:thumbs:

 

[Matt_S]

GET AN UPRATED RAD!

Seriously. The std temp gauge (if all the other S bodies are anything to go by anyway) are useless. You could be seeing well over 105 deg C (which was my personal max preferred level when drifting the S14) and the std gauge wouldnt move from centre line. SO for you to see it move to 3/4 - errrrrrrrrr, Id be backing off rather quickly! I dread to think what your temps were! THats when you start to cause damage. OIls really hot n thin, probably working outside its preferred temp range. If the oils thinner than it supposed to be, its not maintaining its protection and then things start to wear. Hello Big End failiure! :wack:

 

[gunner93]

Bro... if we are going for these kinda runs regularly, we need these :

1) Alu rad
2) New water pump
3) New termo
4) Oil cooler kit

My peak temp was 99 deg that night (temp gauge a tad over middle mark) and as you've noticed, I wasnt going all out since my engine check light was flickering when Diablo zoom passed me. :annoyed:

 

[silviatub]

Bro... if we are going for these kinda runs regularly, we need these :

1) Alu rad
2) New water pump
3) New termo
4) Oil cooler kit

My peak temp was 99 deg that night (temp gauge a tad over middle mark) and as you've noticed, I wasnt going all out since my engine check light was flickering when Diablo zoom passed me. :annoyed:

Bro,

For starters i will probably get the thermostat and aluminimum radiator...oil cooler will be much later when funds allow...

:thumbs:

 

[gunner93]

Another good quick fix is to replace your standard coolant with Water Wetter. It will run up to 5 degrees C cooler which will definately help.

 

[silviatub]

Another good quick fix is to replace your standard coolant with Water Wetter. It will run up to 5 degrees C cooler which will definately help.

Bro,

Will try that next time when i flush out my coolant...:wave:

 

[silviatub]

Hi Mates,

another school of thought told me that since i installed the Pivot Speed Meter, it actually fools the ECU to think that it is still running at 180km/h thus making AFR mixtures lean when exceeding speeds above 180km/h...as a result, this makes the EGT and water temp run pretty high ...is this assumption true mates?

i dont want to blow up my engine and any advice and guidance on this matter is highly appreciated...

:thumbs:

Mates,

Any feedback regarding the Pivot Speed Meter? is this making my car to run lean when im driving beyond 180km/h?

:thumbs:

 

[Matt_S]

Err, dont do high speed runs!

Its your right foot making it run lean, not the pivot meter :wack:

 

[StarletRick]

speed doesnt play any part of how the engine is running fuel wise.

the map for 2nd gear will be the same for 5th. the problem with hi speed runs is sustained high RPMs.

you need to be worrying about keeping the oil and water cool instead of the fueling.

 

[Matt_S]

speed doesnt play any part of how the engine is running fuel wise.

the map for 2nd gear will be the same for 5th. the problem with hi speed runs is sustained high RPMs.

you need to be worrying about keeping the oil and water cool instead of the fueling.

I dont agree with that mate. In 5th (6th) the loads are a lot higher than in 2nd :wack:
Its this load which (even on custom mapped cars) can cause issues. On one SXOC Top Speed Day (where we highed a 2.25 mile runway) we had about 10 cars die with melted pistons and mashed pistons/bores. One car even did all four plugs/pistons!

I decided there and then Id never attempt it in a car of my own. IMHO youre asking for trouble - especially on a hotter day. Revs will kill big end bearings and bolts but load will kill plugs and pistons.

 

[StarletRick]

the loads are higher ye. but the basic fueling and timing wont be different at a set rpm regardless of gear. the ecu doesnt have to know what gear you are in to run. all it knows is intake pressures, ignition, etc. cars dying at high speeds is overheating causing pinking, where the cooling stuff comes into play. this can be higher engine temps or the turbo blowing hotter air as its sitting at massive RPMs for a long period of time, or both. restrictive manifolds can even shag pistons on turbo cars where they hold the heat.

but in theory, an engine doing 6000 rpm needs x ammount fuel, regardless of if youre doing 30 or 150 mph.

 

[Matt_S]

WHAT!???!

Mate, if you cant give out sound advice I suggest you dont give it out at all!
Some of that you just posted is bollocks and contradicting.

the loads are higher ye. but the basic fueling and timing wont be different at a set rpm regardless of gear. the ecu doesnt have to know what gear you are in to run. all it knows is intake pressures, ignition, etc.

OK, so assumign the cars running MAF (he doesnt say) the ECU needs to know what volume of air is comign in (via voltage on the MAF), the throttle position (via the TPS) and where abouts the engine is in its cycle/what RPMs its doing (via the CAS). Once it knows all these, it adds fuel and sends the ignition timing as dictated my the lmap held within the std ECU.

If the car is on more load, the ECU will prob run less ign advance to avoid det. As it IS on more load at the time of a High speed run (say 6500rpm+ in 6th gear), the load site will be higher on the map (than it would do at say 6500rpm in 3rd gear) and therefore the ECU will compensate with more fuel and less ign advance than it would do at the lower speed/load.

cars dying at high speeds is overheating causing pinking, where the cooling stuff comes into play. this can be higher engine temps or the turbo blowing hotter air as its sitting at massive RPMs for a long period of time, or both. restrictive manifolds can even shag pistons on turbo cars where they hold the heat.

WRONG! Thats a very old wives tale outlook on it mate (although I tend to agree a bit about the manifolds). Sure, the massive increase in oil and water temps cause issues and the coolers could help. The main issue is that the fuelling can go out due to the engine running hotter than normal. The plugs - normally OK at the 'quick blast up the road' get to hot, cant dissipate the heat away quick enough, cant give a proper spark then let go, giving you lumps of ceramic in the bores :wack:
Plus, this guy doesnt say he has a FMIC - which is another no no. Saturation of the std FMIC is easy on long maintained runs. Especially flat out!

The clue was in the original post as to what he wanted:

Hi Mates,

I got a JDM S15 Spec R with Pivot Speed meter SML-V installed to remove the speed cut...we went on a hard run yesterday on the highway and we managed to reach speeds upto 250 to 260km/h...when i was maintaining speeds above 200km/ to 250km/h, i noticed the water temp was more than half and it went up to a max of 3/4 of the stock water temp gauge:annoyed:...my cooling system is totally stock and there are no leaks so far...is this normal with the stock cooling system?

another school of thought told me that since i installed the Pivot Speed Meter, it actually fools the ECU to think that it is still running at 180km/h thus making AFR mixtures lean when exceeding speeds above 180km/h...as a result, this makes the EGT and water temp run pretty high ...is this assumption true mates?

i dont want to blow up my engine and any advice and guidance on this matter is highly appreciated...

:thumbs:

He knows it already and just wants reassurance. There is a good chance that the AFRs are way out when he does these runs over the OEM speed limit. HKS Spped cuts were similar and quite frowned upon without some kind of SAFC type fuel compensation/map/tweak.

but in theory, an engine doing 6000 rpm needs x ammount fuel, regardless of if youre doing 30 or 150 mph.

OK, gimme £10 worth of fuel. I bet I burn it up easier at 6k in 6th than 1st! Thats just physics! (apart from the fact the engien will go pop due to airflow and load etc in 1st :wack: )
Friction/airflow etc all go further in hand at 150, so it stands to reason you gotta put out more energy to get the result.

 

[StarletRick]

im going to have to agree to disagree here as youre not really listening to what im trying to say.

heat is the main problem at hi speeds. it causes 95% of the problems when it comes to det. everything is working harder and getting hotter, hotter air temps etc cause det.

pinking and running lean are 2 different things.

 

[Matt_S]

im going to have to agree to disagree here

SEE! We agree on something!

 

[silviatub]

WHAT!???!

Mate, if you cant give out sound advice I suggest you dont give it out at all!
Some of that you just posted is bollocks and contradicting.



OK, so assumign the cars running MAF (he doesnt say) the ECU needs to know what volume of air is comign in (via voltage on the MAF), the throttle position (via the TPS) and where abouts the engine is in its cycle/what RPMs its doing (via the CAS). Once it knows all these, it adds fuel and sends the ignition timing as dictated my the lmap held within the std ECU.

If the car is on more load, the ECU will prob run less ign advance to avoid det. As it IS on more load at the time of a High speed run (say 6500rpm+ in 6th gear), the load site will be higher on the map (than it would do at say 6500rpm in 3rd gear) and therefore the ECU will compensate with more fuel and less ign advance than it would do at the lower speed/load.




WRONG! Thats a very old wives tale outlook on it mate (although I tend to agree a bit about the manifolds). Sure, the massive increase in oil and water temps cause issues and the coolers could help. The main issue is that the fuelling can go out due to the engine running hotter than normal. The plugs - normally OK at the 'quick blast up the road' get to hot, cant dissipate the heat away quick enough, cant give a proper spark then let go, giving you lumps of ceramic in the bores :wack:
Plus, this guy doesnt say he has a FMIC - which is another no no. Saturation of the std FMIC is easy on long maintained runs. Especially flat out!

The clue was in the original post as to what he wanted:


He knows it already and just wants reassurance. There is a good chance that the AFRs are way out when he does these runs over the OEM speed limit. HKS Spped cuts were similar and quite frowned upon without some kind of SAFC type fuel compensation/map/tweak.



OK, gimme £10 worth of fuel. I bet I burn it up easier at 6k in 6th than 1st! Thats just physics! (apart from the fact the engien will go pop due to airflow and load etc in 1st :wack: )
Friction/airflow etc all go further in hand at 150, so it stands to reason you gotta put out more energy to get the result.

Hi Mate,

I do have a Greddy Spec M intercooler kit installed...so looks like its true after all the car runs lean with the Pivot Speed Meter :annoyed: if its above the OEM speed...can an adjustable fuel regulator help to cure this problem or do i still need a PowerFC or other piggyback ECUs mate?

:thumbs:

 

[Matt_S]

Adj FPR wont help. Probably best bet is a Power FC or a HD Chip. Fuel pump migh thelp tho.

 

[silviatub]

good advice there mate...thanks

:thumbs: