Whats up with Ford ? cant they get anything right ever ?
Lots of people maybe raving about the new Boss, ok fine it beat the M3 on the track @ Laguna Seca..
Great job Ford...
Now for some other points for some pure Ford's awesomeness:
1] 2 keys ? Blue for regular use and Red for race/track mode:
My thoughts -
[a]LOL , whats up Ford ? copying BMW's M ideas /Honda's Vtec ?
- BMW always had an "M" button to switch between 2 maps for fuelling,ignition, throttle response, suspension etc
-Honda always had vtec , floor it and above 5800 rpm hell breaks loose, diff cam profile, fuelling and ignition curves..
.. I'd summarize this feature as "Yawn".. Ford u guys were always boring and no matter how hard u try u will never get the point.
[b]Another point of view these morons didnt consider - and this is my favourite..
Lets picture this - you are crusing along with the blue key, but along the way you encounter a nice hilly stretch of road with no traffic, naturally you'd want to flex the v8's muscles and see what its got; or another scenario where you'd want to kick a ricer's ass and need to show him who's the Boss .. If I was in a smarter engineered car I would press a button or floor the throttle or simple downshift to unleash power.
Hey but im in a Ford !! Guess what boys and girls what do the Boss owners do ?
Please raise your hands if u think u got the right answer:
Hahahah - Pull over, search for a spot to get off the expressway, switch of your engine and swap the keys or if you are brave or on medication you could attempt to put car in neutral and see if you switch off and swap keys ..
Nice idea - lots of thought must have gone into this awesome innovation.
Red key ..my ass ..morons.
2] Live rear axleC'mon guys, "free online suspension design lesson" for you - please write this down:
Good handling = Not live rear axle, anything but this.
Bad handling = Live rear axle
Guys we usually use some thing called a "independant suspension" on cars..please google it to get an idea of what it does.Hey even some offroaders are moving away from Solid axles to independant suspensions..
Hey who know we may need to do some rock climbing along with the jeeps ..probably would be useful there.
3] Quad pipes : Not buying this gimmick.
How did you design an exhuast header ? was it for the baffle plates closed or open ?
Did u design it with both in mind ?
total compromise of both low end and top end power..
I dont even want to think what happens to the velocity of the exhaust pulses when the baffles are opened ?
Turbulence - like a washing machine..
Exhaust/Header design lesson 1 - mantain exhaust velocity, turbulence = bad.
Unless you are out to design a rice machine..
Also it sounds like the exhaust is cracked/broken ..doesnt sound impressive at all.
4] Front splitter Guys - u are more rice than a mexican in a civic.
Front splitter which is like 1/2 a foot of the ground .. LOL
Even if you lower the car with adjustable shocks ..the overall truck lile aerodynamics are going to kill the whole point of the lowering + splitter etc.
Im now even more sure this car is for the posers/newbies wanting to buy a performance car out of the box..but will end up with a rice aerodynmic body kit.
My fav line - Front splitter ..my ass.
5] 380 lb/ft. @4,500 rpm Let me break this down into simplified terms and what it means to the driver while driving the car on a daily basis.
[1]Consider the gear ratios of the Boss302:
First 3.66
Second 2.43
Third 1.69
Fourth 1.32
Fifth 1.00
Sixth 0.65
[2]And a Final drive 3.73:1
[3] Tyre sizes as provided by the factory : 255/40R-19 or 285/35R-19
Now the most important question :
Considering the gear ratios and final drive with 19 inch wheels with 40 Profile can we really use that 380 lb/foot of torque at 4600 rpm.
--> 380 lb/ft = 514 NM in metric.
i.e 514 NM @ 4600 rpm
E.g normal road cars usually cruise at 2500 to 3500 rpm on freeways..
At these speeds the boss 302 engine is outside of its power band.
At 2500 Rpm the road speeds are calculated as :
1st gear :15mph
2nd gear :22mph
3rd gear :32mph
4th gear :41mph
5th gear :54mph
6th gear :82mph
Seems a bit slow, lets try 3500 rpm
1st gear :20mph
2nd gear :31mph
3rd gear :44mph
4th gear :57mph
5th gear :75mph
6th gear :115mph
Ok this seems reasonable, Im tying to cruise @ respectable speeds in CA..
I'm able to remain in 5th gear and do 75 mph @ 3500 rpm..not going to over drive coz I want to retain the capability to quickly overtake and change lanes ...
Observation - Im no where near the power band, Im not using the 512 NM as yet.
Now if I really wanted to use it I'd have to travel at 4500 rpm, so If I tap the throttle and climb to 4500 rpm what happens to my road speed?
Here are the figures with respect to gearing/final drive tyre etc etc
1st gear :26mph
2nd gear :40mph
3rd gear :57mph
4th gear :73mph
5th gear :96mph
6th gear :148mph
Oh no - dangerously into the speeding ticket zone.
So I will need to downshift to 4th to be able to ride the torque wave..
To understand what that feels like, just try and reach 4500 rpm in ur current car just to see how high that is..
..This makes it clear what this engine+gear bix+final drive +tyre combination means:
Its not a muscle car anymore,
Ford u got it wrong again - the Boss should be a torque monster not a screamer to carry its own heavy ass around.
With a kerb weight of 3600 pounds = 1632 kg = 1.6 tonnes ..
I need torque from down below from 1500/1800 rpm to haul this 1.6 tonnes of flab to respectable speeds and be able to cruise the way an "American muscle" car should.
Ideally a Muscle car = Heavy sedan/coupe with a massive V8 with a brutal bulldozer like shove of torque from way down in the rev range.and not a 7500 rpm screamer...
Hey V8s are not screamers ..leave the hi revs to the Wankels and Vtecs.
concentrate on width of power band instead of peak figures becoz the 302 is no agile/light wt sports car to simply point and shoot with the tacho at 6500 rpm.
Wake up guys and go back to the drawing board.
512 NM ..my ***
Thursday, 29 September 2011
Tuesday, 20 September 2011
cams :tappet clearance importance
Tappet clearance is a very important part of performance of an engine.
What is it and why is it so important ?
Taking example of a typical engine with a valve train having a SOHC, rocker arms, 4 valves..
To make the basics clear in this scenario : the cam follower i.e the rocker arm contacts the cam surface at one end and the valve at the other. The rocker is pivoted like a see-saw in the middle.
Since in the SOHC design there is a distance which has to be bridged between the cam lobe and the valve the rocker is usually long to account for this.
When the cam rotates the profile pushes the rocker arm up, this translates into the other end pushing the valve down.
Now there is a slight gap/clearance between the cam's surface and the follower.
Why this gap ?
Simple answer : To account for expansion of the valves while getting heated. If the valve expands it would not seat properly, it would be partially open
Due to expansion the valve end in contact with the rocker arm whose other end should be ideally touching the base circle of the cam would be partially pushed in. This is wrong as the valve should be closed and seated perfectly sealing the port during the time the follower is on the base circle of the cam.
But due to expansion due to heat this is not perfectly seated...its being pushed in and therefore partially open.
Now if we add some clearance between the follower and the cam(base circle portion) we will be able to allow this mechanism to expand for a few mm.
This simple problem was solved by a simple solution of providing a small clearance.. so far so good.
BUT doesn't this create a certain amount of wasted rotation of the camshaft to bring the surface of the lobe in contact with the cam follower ?
In more technical terms this gap would create some amount of delay in the time required for the follower to contact the flank.Here flank is that portion of the cam which provied the actual lift for a specific duration(note ..I always say duration and lift together)
Due to this clearance we introduced there will be a reduction of the time the follower would have spent in contact with the cam flank.
Just to exaggerate a bit to make this clear : say 30 degrees of the camshaft were spent in rotating the cam in bringing the flank closer to the follower and bridge the gap.
Since 30 degree of rotation was used up the follower gets a little less time in contact with the cam.
This could mean lesser time spent in opening the valve
So if we designed a cam for x degrees to keep the valve open , it would be (x-30) degrees now due to this delay.
To account for this clearance the cams are designed accordingly - their base circle is chopped of slightly by = tappet clearance distance.
This way the flank begins to open a bit sooner instead of waiting to be contacted by the follower.
Now we understand that tappet clearance is very critical to the cam performance.
The best setting for clarance is specified by the manufacturer, if set perfectly the valve will be seated during the time the base circle of the cam is in contact and will open the valve as per the caculated duration just at the right time.
Too much clearance = reduction in opening of the valves,valves open late, the rocker arm with the follower comes in contact a bit later and in turn opens the valve later .Also it will create the characteristic noisy clatter after heating up almost similar to a diesel engine.
Too less clearance = valves remaining open for a longer time,loss of power.
Extremely tight = valves not closing completely during the base circle contact and allowing the hot gas to keep flowing and burning the valves.Intake valves can also get burnt like the Exhaust valves.
The behaviour/feel of the engine and the exhaust note will clarly indicate if you have got it right ..
A good test would be to let the car idle till it gets hot.
After getting hot this clearance begins to play a more significant role.
During idle:
-If the idle remains constant and smooth you are good to go.
-If the engine begins to stumble or the idle becomes rough it means you didnt leave enough clearance
During driving:
If the idle is smooth and there is no roughness it means we can now drive off and do another check.
-If there is loss of power felt then it means tappet is still a bit to tight, try for the next bigger (+ .0xx mm) gauge.
-If there is that noise again then it means you are still loose ; go for the next lower setting (-0.xx mm) gauge
I suggest you go for the setting in 2 stages :1st make sure the feeler gauge just fits and slides a bit tight, if this does not work then go for the next .00x setting but this time let it slide smoothly.
Also always remember to inspect with gauge again after tightening the locknuts just to make sure it didn't shift.
Once you get it right - note it down and try to set it to same.
Not necessary it will work on all cars with same setting but its a good place to start as a refernce point.
Each cars cam/rocker follower/tappet wear out differently and diff levels of carbon build ups therefore each engine may not respond in same way.
What is it and why is it so important ?
Taking example of a typical engine with a valve train having a SOHC, rocker arms, 4 valves..
To make the basics clear in this scenario : the cam follower i.e the rocker arm contacts the cam surface at one end and the valve at the other. The rocker is pivoted like a see-saw in the middle.
Since in the SOHC design there is a distance which has to be bridged between the cam lobe and the valve the rocker is usually long to account for this.
When the cam rotates the profile pushes the rocker arm up, this translates into the other end pushing the valve down.
Now there is a slight gap/clearance between the cam's surface and the follower.
Why this gap ?
Simple answer : To account for expansion of the valves while getting heated. If the valve expands it would not seat properly, it would be partially open
Due to expansion the valve end in contact with the rocker arm whose other end should be ideally touching the base circle of the cam would be partially pushed in. This is wrong as the valve should be closed and seated perfectly sealing the port during the time the follower is on the base circle of the cam.
But due to expansion due to heat this is not perfectly seated...its being pushed in and therefore partially open.
Now if we add some clearance between the follower and the cam(base circle portion) we will be able to allow this mechanism to expand for a few mm.
This simple problem was solved by a simple solution of providing a small clearance.. so far so good.
BUT doesn't this create a certain amount of wasted rotation of the camshaft to bring the surface of the lobe in contact with the cam follower ?
In more technical terms this gap would create some amount of delay in the time required for the follower to contact the flank.Here flank is that portion of the cam which provied the actual lift for a specific duration(note ..I always say duration and lift together)
Due to this clearance we introduced there will be a reduction of the time the follower would have spent in contact with the cam flank.
Just to exaggerate a bit to make this clear : say 30 degrees of the camshaft were spent in rotating the cam in bringing the flank closer to the follower and bridge the gap.
Since 30 degree of rotation was used up the follower gets a little less time in contact with the cam.
This could mean lesser time spent in opening the valve
So if we designed a cam for x degrees to keep the valve open , it would be (x-30) degrees now due to this delay.
To account for this clearance the cams are designed accordingly - their base circle is chopped of slightly by = tappet clearance distance.
This way the flank begins to open a bit sooner instead of waiting to be contacted by the follower.
Now we understand that tappet clearance is very critical to the cam performance.
The best setting for clarance is specified by the manufacturer, if set perfectly the valve will be seated during the time the base circle of the cam is in contact and will open the valve as per the caculated duration just at the right time.
Too much clearance = reduction in opening of the valves,valves open late, the rocker arm with the follower comes in contact a bit later and in turn opens the valve later .Also it will create the characteristic noisy clatter after heating up almost similar to a diesel engine.
Too less clearance = valves remaining open for a longer time,loss of power.
Extremely tight = valves not closing completely during the base circle contact and allowing the hot gas to keep flowing and burning the valves.Intake valves can also get burnt like the Exhaust valves.
The behaviour/feel of the engine and the exhaust note will clarly indicate if you have got it right ..
A good test would be to let the car idle till it gets hot.
After getting hot this clearance begins to play a more significant role.
During idle:
-If the idle remains constant and smooth you are good to go.
-If the engine begins to stumble or the idle becomes rough it means you didnt leave enough clearance
During driving:
If the idle is smooth and there is no roughness it means we can now drive off and do another check.
-If there is loss of power felt then it means tappet is still a bit to tight, try for the next bigger (+ .0xx mm) gauge.
-If there is that noise again then it means you are still loose ; go for the next lower setting (-0.xx mm) gauge
I suggest you go for the setting in 2 stages :1st make sure the feeler gauge just fits and slides a bit tight, if this does not work then go for the next .00x setting but this time let it slide smoothly.
Also always remember to inspect with gauge again after tightening the locknuts just to make sure it didn't shift.
Once you get it right - note it down and try to set it to same.
Not necessary it will work on all cars with same setting but its a good place to start as a refernce point.
Each cars cam/rocker follower/tappet wear out differently and diff levels of carbon build ups therefore each engine may not respond in same way.
Sunday, 18 September 2011
Morons always reverse and park their cars facing outwards
I'm trying to find a parking spot in a busy downtown shopping mall.
I could see some spots open but then what's up ?whats holding up the queue ahead ?
Its the smart ass trying to park his car facing the right way!!
I just dont get it.. whats the point ?
It is tougher to park in reverse, it takes up more time, it holds up people and blocks both lanes.
While parking into the slot : (1)The driver will 1st go forward and into the opposing lane instead of simply turning into the slot.This will hold the opposite lane as well as your own lane. Nice job smart guy.(2) Now the driver will reverse into the slot, its slower and tougher to back into a slot going backwards u stupid moron.Reversing into an open area is easier then reversing into a limited parking slot..get it ?
So by now car is parked. (3)Here are the additional disadvantage I can see - if you have a wall then your boot is now close to it..try and load stuff into your boot after you come back from shopping.
But hey who cares this guy will load stuff into his boot while holding up traffic again..
While getting out of the slot :
(1)Its the same while getting out. Since the steerable wheels are now facing outside the turning radius is reduced. The car will have to travel slightly further to get the tail end of the car out of the slot before being able to turn the steering to full lock and drive away.(2)So now this guy will go into the opposing lane and then start turning which will take more space.
Morons dont get it ? If you face the road doesn't mean its faster to get in or out.
Its like that Ostrich thingy where these birds think they are safe by burying their head in the sand.. vaguely similar analogy - these retards face the exit so they think its faster/convenient ? or fun ?whatever..
Other technique used by 99% of the normal people - find a slot, simply drive into it.To leave : back out till you can get your front wheels turned just enough to face the right way. Now drive off.
I could see some spots open but then what's up ?whats holding up the queue ahead ?
Its the smart ass trying to park his car facing the right way!!
I just dont get it.. whats the point ?
It is tougher to park in reverse, it takes up more time, it holds up people and blocks both lanes.
While parking into the slot : (1)The driver will 1st go forward and into the opposing lane instead of simply turning into the slot.This will hold the opposite lane as well as your own lane. Nice job smart guy.(2) Now the driver will reverse into the slot, its slower and tougher to back into a slot going backwards u stupid moron.Reversing into an open area is easier then reversing into a limited parking slot..get it ?
So by now car is parked. (3)Here are the additional disadvantage I can see - if you have a wall then your boot is now close to it..try and load stuff into your boot after you come back from shopping.
But hey who cares this guy will load stuff into his boot while holding up traffic again..
While getting out of the slot :
(1)Its the same while getting out. Since the steerable wheels are now facing outside the turning radius is reduced. The car will have to travel slightly further to get the tail end of the car out of the slot before being able to turn the steering to full lock and drive away.(2)So now this guy will go into the opposing lane and then start turning which will take more space.
Morons dont get it ? If you face the road doesn't mean its faster to get in or out.
Its like that Ostrich thingy where these birds think they are safe by burying their head in the sand.. vaguely similar analogy - these retards face the exit so they think its faster/convenient ? or fun ?whatever..
Other technique used by 99% of the normal people - find a slot, simply drive into it.To leave : back out till you can get your front wheels turned just enough to face the right way. Now drive off.
Saturday, 17 September 2011
Blood group or Octane rating ?
Really how much of petrol content do you have in your blood ?
Not much ?quite a lot or you actually have an Octane rating instead of a Blood group to be relevant?
Do you get all upset if the engine didnt feel right today ? was it the heat was it the bad fuel or was it the ignition or the tappets ?
Love the way the exhaust sounds and not one opportunity is missed to hear that exhaust growl or lazily burble/pop on the over run?
Crazy enough to do a "down-shift syncro rev match" in city driving...?
Gear shifts are timed perfectly with tacho or the feel of the car..
Missing a doctor's apointment or a meeting is ok..hey shit happens. BUT never a car servicing schedule.
If the oil is a .5 mm higher than the upper mark on the dip stick its a crime ?
Who cares how long the destination is or how beautful the scenery is as long as the engine remains in the power band..
Pinging/knocking will trigger a heart attack.. and worse if its your own engine ..
You know what your clutch smells like and of course burnt rubber ..
Nothing sounds better than an overlapping cam trying to breathe at idle..
Statistics like rod-stroke ratio, gear ratio, drive ratio, air-fuel ratio mean more then what mileage can be derived from tankful then u are on the right track..
If you can still relate to stuff here and are guilty of some or all of the above u know its too late ..you are addicted. The car Gods will be happy..
Not much ?quite a lot or you actually have an Octane rating instead of a Blood group to be relevant?
Do you get all upset if the engine didnt feel right today ? was it the heat was it the bad fuel or was it the ignition or the tappets ?
Love the way the exhaust sounds and not one opportunity is missed to hear that exhaust growl or lazily burble/pop on the over run?
Crazy enough to do a "down-shift syncro rev match" in city driving...?
Gear shifts are timed perfectly with tacho or the feel of the car..
Missing a doctor's apointment or a meeting is ok..hey shit happens. BUT never a car servicing schedule.
If the oil is a .5 mm higher than the upper mark on the dip stick its a crime ?
Who cares how long the destination is or how beautful the scenery is as long as the engine remains in the power band..
Pinging/knocking will trigger a heart attack.. and worse if its your own engine ..
You know what your clutch smells like and of course burnt rubber ..
Nothing sounds better than an overlapping cam trying to breathe at idle..
Statistics like rod-stroke ratio, gear ratio, drive ratio, air-fuel ratio mean more then what mileage can be derived from tankful then u are on the right track..
If you can still relate to stuff here and are guilty of some or all of the above u know its too late ..you are addicted. The car Gods will be happy..
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