Well guys the moment you have been waiting for has finally arrived but me not happy for now more on that later.
Sorry for the long POST.
A couple of weeks ago I booked the old girl in for its dyno run and cam timing adjustment.I was nervious and excited. All this money and time spent on my Falcon S pac to make it quicker had finally payed off or had it??
I rang up the dyno mob and asked how she went." you should be impressed" was the reply.Shy of relief. "You picked up a heap of torque when the cam was retarded 2 degrees, but lost alot of top end around 4000rpm was when it tapered off so I retarded it 2 degrees from standard and picked up more torque all the way through the rev range and ran out at 4500rpm. So what did I get at the wheels was my reply. "110 kw really good for an EA you should be happy".WWWWHHHAAATTT was my reply. You mean to say that I bolted on a set of HM's and had 107kw or 144hp(on different dyno) and now carried out head work Crow 825 cam and cam gear and gained 3 ****ING KW's.You've got to be joking.It turns out that they have just purchased a new dyno and are still trying to work out how to work it properly.He told me not to use the dyno figure as an overall reading, he said "You asked for your cam to be dialed in and that is what I have done and acheived good results".Which was true.I noticed the power range was alot better. Then he said "If you want horsepower reading or kilowatt output of your engine pull the engine out and we will dyno it for you,there are to many variences on a chassis dyno to get a good figure i.e diff gears,tyre pressures etc.A chassis dyno is only a tuning tool and that is what I have used it for"."It might not look alot on paper but the power curve that your motor made is more important then how many kilowatts you have acheived almost a flat power curve which will mean it will pull at almost any rpm.You can have 300kw but it all might be from 5500-6000 rpm useless for the street and even drag racing."Far enough,but WHY????
His reply was this " A couple of weeks ago we had an EA like yours had everything done bar variable camgear,instead it had a set of 3.7:1 diff gears and 2 1/2 inch exhuast including extractors it spat out 130kw at the wheels" YA ****ING WHAT.His reply "Well one it was on an old program of the dyno which we were having trouble with and since then we have up-dated it to the current program which we ran for your car." Um ok was my reply.His reply was "This is the weird part both my boss and I have driven both cars after the dyno runs and your car was much quicker and you have 3.45:1 diff gears." Ok short of feeling better. "I think these late model dynos take too many variables into account and stuff up the end result, but your car is by no means slow its quite quick"."Your car has a better power curve then the 130kw EA. His next question was what size exhaust do you have from the cat back. 2 1/4 was my reply. "**** that off and put a 2 1/2 on it come back and see me then it should make around 120-125kw on our new program".
I was let down but still had hope.I went immediately to my head guy and asked for "WHY". He looked at the dyno sheet and said "Very nice power curve indeed,but shit thats not right(kw output), there must be something not allowing it to breath properly, everything is done properly though,it should be making power all the way to 5000rpm someting is strangling it ". Next question was what size is your exhaust? Same answer 2 1/4."Well get rid of that and go 2 1/2 but there is something else,let me look at your intake box". So I poped the hood and he had a squizz."Remove your air box lid and drive it and see if there is any improvement".
So the first thing I did was go home and rip of my air box lid and take it for a spin boy did that make a difference,Bloody noisy but the tacho needle swung really quickly and the car was more responsive everywhere.Next day straight down to the wreckers for an airbox lid,came home and cut the top straight off it so all it did was clamp the air filiter in place.Next point of call was to take it back to where I got it dynoed with just the extractors and see if one I gained any kw by removing the airbox lid and two see if the other dyno was out.
Picked up the car and shore enough I gained 6hp with airbox lid off (around 3kw) to my disappointment the other dyno was not wrong I had a 148hp which is 110kw.I asked the same question "WHY". This guys reply was "Firstly your diff gears have been changed since last dyno which can change rear wheel horsepower,but secondly I have never seen a EA falcon pick-up 6hp with the air box lid off they usually get 0.5-1 hp, So the motor wants to make horsepower everything is done right there is something stopping it". He had a look under the car at the exhaust and told me there's your problem.Jacked the ass up and he pointed out that the 2 1/4 pipe over the dog leg (axle)is only 2 inch at max because it is not mandrel bent."Piss that exhaust off and then come and see me." He had checked the air fuel ratio and it was 13.5:1 so its not straving for fuel.Too much back pressure is occuring because of the restrictions in your system and also the bigger overlap in the new cam is allowing burnt exhaust gases to return to the combustion and you cant re-use burnt air.
So it was off to the exhaust shop for a 2 1/2 inch system.Turned out my extractors had a 2 1/4 in entry into the cat and around 2 inchs out when it was made up to the flange to bolt to the standard size system.Resriction number one. It performed well for a standard car not flowing alot of air but not for mine not anymore.So it was modified with 2 1/2 entry into the cat and 2 1/2 out.A 2 1/2 inch mandrel bent system was then fitted with 2 resenators and 1 straight through muffler.On the way to the dyno run I noticed it straight away it had more pull in every gear and did it so easily.
Then the dyno.Ran it up and it went to 164 hp or 122kw which made me more happy, real happy.Then I confronted another problem it's running too Lean 14.2:1 at 4500 and 14.8:1 at 4800. ****. My dyno guy said it should be making power all the way to 5000rpm now it can breath better, instead of max a 4500 which was 164,then at 4800 it went to 142hp losing power.Me thought got rid of the restriction and increased air flow so thats why it's lean.So I asked him what he thought.I was also hoping that this is why its not making power to 5000 rpm. He said "Your motor is working too well, now the engine can breath its flowing a lot more air then normal,your fuel system does not know you have increased air speed and volume so it can't put enough fuel to match the air flowing in." " Its working really well as an air pump which is what an engine is, just that its not getting enough fuel to make use of the increased air flow." This is good and bad. Good because there is more power to be made by making it richer and explains why 500 rpm short of where max power should be, but bad if I don't as I could burn out valves or melt a piston.
I got a couple of ops:
1) Check my fuel flow,pressure and reg for correct operation,Will do.
2) Chip,Dear
3) Adjustable fuel pressure regulator,Cheapy
4) Programable ECU. XXEE
The cheapest would be the Regulator for starters.To see if it makes any difference but then I am running higher fuel pressure so more load on the fuel pump and hoses.So I'll check my fuel system over thoughly and then make a decision I'll keep you guys infromed.
Wish me luck.
From what I have experienced if you want your car to be quicker but don't want to spend alot of money,fit 3.45 diff gears,good set of extractors 2 1/4 system if you are going to leave it standard interms of camshaft and head but 2 1/2 if you intend on modifing it later.By bloting on a 2 1/2 system you will probably not gain as much as I have due to the fact that a standard motor is not flowing as much as a motor with head and cam mods.But it will help.
If you want to spend money and make it quicker then every mod you carry out compliments the other such as camshaft head,chip and intake. Up to you.
Sorry for the long POST.
A couple of weeks ago I booked the old girl in for its dyno run and cam timing adjustment.I was nervious and excited. All this money and time spent on my Falcon S pac to make it quicker had finally payed off or had it??
I rang up the dyno mob and asked how she went." you should be impressed" was the reply.Shy of relief. "You picked up a heap of torque when the cam was retarded 2 degrees, but lost alot of top end around 4000rpm was when it tapered off so I retarded it 2 degrees from standard and picked up more torque all the way through the rev range and ran out at 4500rpm. So what did I get at the wheels was my reply. "110 kw really good for an EA you should be happy".WWWWHHHAAATTT was my reply. You mean to say that I bolted on a set of HM's and had 107kw or 144hp(on different dyno) and now carried out head work Crow 825 cam and cam gear and gained 3 ****ING KW's.You've got to be joking.It turns out that they have just purchased a new dyno and are still trying to work out how to work it properly.He told me not to use the dyno figure as an overall reading, he said "You asked for your cam to be dialed in and that is what I have done and acheived good results".Which was true.I noticed the power range was alot better. Then he said "If you want horsepower reading or kilowatt output of your engine pull the engine out and we will dyno it for you,there are to many variences on a chassis dyno to get a good figure i.e diff gears,tyre pressures etc.A chassis dyno is only a tuning tool and that is what I have used it for"."It might not look alot on paper but the power curve that your motor made is more important then how many kilowatts you have acheived almost a flat power curve which will mean it will pull at almost any rpm.You can have 300kw but it all might be from 5500-6000 rpm useless for the street and even drag racing."Far enough,but WHY????
His reply was this " A couple of weeks ago we had an EA like yours had everything done bar variable camgear,instead it had a set of 3.7:1 diff gears and 2 1/2 inch exhuast including extractors it spat out 130kw at the wheels" YA ****ING WHAT.His reply "Well one it was on an old program of the dyno which we were having trouble with and since then we have up-dated it to the current program which we ran for your car." Um ok was my reply.His reply was "This is the weird part both my boss and I have driven both cars after the dyno runs and your car was much quicker and you have 3.45:1 diff gears." Ok short of feeling better. "I think these late model dynos take too many variables into account and stuff up the end result, but your car is by no means slow its quite quick"."Your car has a better power curve then the 130kw EA. His next question was what size exhaust do you have from the cat back. 2 1/4 was my reply. "**** that off and put a 2 1/2 on it come back and see me then it should make around 120-125kw on our new program".
I was let down but still had hope.I went immediately to my head guy and asked for "WHY". He looked at the dyno sheet and said "Very nice power curve indeed,but shit thats not right(kw output), there must be something not allowing it to breath properly, everything is done properly though,it should be making power all the way to 5000rpm someting is strangling it ". Next question was what size is your exhaust? Same answer 2 1/4."Well get rid of that and go 2 1/2 but there is something else,let me look at your intake box". So I poped the hood and he had a squizz."Remove your air box lid and drive it and see if there is any improvement".
So the first thing I did was go home and rip of my air box lid and take it for a spin boy did that make a difference,Bloody noisy but the tacho needle swung really quickly and the car was more responsive everywhere.Next day straight down to the wreckers for an airbox lid,came home and cut the top straight off it so all it did was clamp the air filiter in place.Next point of call was to take it back to where I got it dynoed with just the extractors and see if one I gained any kw by removing the airbox lid and two see if the other dyno was out.
Picked up the car and shore enough I gained 6hp with airbox lid off (around 3kw) to my disappointment the other dyno was not wrong I had a 148hp which is 110kw.I asked the same question "WHY". This guys reply was "Firstly your diff gears have been changed since last dyno which can change rear wheel horsepower,but secondly I have never seen a EA falcon pick-up 6hp with the air box lid off they usually get 0.5-1 hp, So the motor wants to make horsepower everything is done right there is something stopping it". He had a look under the car at the exhaust and told me there's your problem.Jacked the ass up and he pointed out that the 2 1/4 pipe over the dog leg (axle)is only 2 inch at max because it is not mandrel bent."Piss that exhaust off and then come and see me." He had checked the air fuel ratio and it was 13.5:1 so its not straving for fuel.Too much back pressure is occuring because of the restrictions in your system and also the bigger overlap in the new cam is allowing burnt exhaust gases to return to the combustion and you cant re-use burnt air.
So it was off to the exhaust shop for a 2 1/2 inch system.Turned out my extractors had a 2 1/4 in entry into the cat and around 2 inchs out when it was made up to the flange to bolt to the standard size system.Resriction number one. It performed well for a standard car not flowing alot of air but not for mine not anymore.So it was modified with 2 1/2 entry into the cat and 2 1/2 out.A 2 1/2 inch mandrel bent system was then fitted with 2 resenators and 1 straight through muffler.On the way to the dyno run I noticed it straight away it had more pull in every gear and did it so easily.
Then the dyno.Ran it up and it went to 164 hp or 122kw which made me more happy, real happy.Then I confronted another problem it's running too Lean 14.2:1 at 4500 and 14.8:1 at 4800. ****. My dyno guy said it should be making power all the way to 5000rpm now it can breath better, instead of max a 4500 which was 164,then at 4800 it went to 142hp losing power.Me thought got rid of the restriction and increased air flow so thats why it's lean.So I asked him what he thought.I was also hoping that this is why its not making power to 5000 rpm. He said "Your motor is working too well, now the engine can breath its flowing a lot more air then normal,your fuel system does not know you have increased air speed and volume so it can't put enough fuel to match the air flowing in." " Its working really well as an air pump which is what an engine is, just that its not getting enough fuel to make use of the increased air flow." This is good and bad. Good because there is more power to be made by making it richer and explains why 500 rpm short of where max power should be, but bad if I don't as I could burn out valves or melt a piston.
I got a couple of ops:
1) Check my fuel flow,pressure and reg for correct operation,Will do.
2) Chip,Dear
3) Adjustable fuel pressure regulator,Cheapy
4) Programable ECU. XXEE
The cheapest would be the Regulator for starters.To see if it makes any difference but then I am running higher fuel pressure so more load on the fuel pump and hoses.So I'll check my fuel system over thoughly and then make a decision I'll keep you guys infromed.
Wish me luck.
From what I have experienced if you want your car to be quicker but don't want to spend alot of money,fit 3.45 diff gears,good set of extractors 2 1/4 system if you are going to leave it standard interms of camshaft and head but 2 1/2 if you intend on modifing it later.By bloting on a 2 1/2 system you will probably not gain as much as I have due to the fact that a standard motor is not flowing as much as a motor with head and cam mods.But it will help.
If you want to spend money and make it quicker then every mod you carry out compliments the other such as camshaft head,chip and intake. Up to you.