Stroker with factory ECU's-will it work?
01-31-2008, 11:07 PM
#31
Three Wheelin'
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Nifty idea, "crimping" the ends of the tubes like that. So in effect the circle-to-oval transition is plenty gradual enough to focus rather than interfere with the pressure waves.
I bet that stroker is going be singing fairly loudly through the short stacks at high RPMS.
Thanks for sharing, Hammer!
~~~~~~~~~~~~~~~~~~~
I know suzuki used twin injectors on some of its more recent GSXR's and one injector was pointed at something like a 45 degree angle to the runner as this caused some sort of fueling anomality that they found best for power. I am sure they know allot more about this then i do that for sure.
Must be some funky swirl effect from bouncing the spray off the wall. Swirl is the magical power and efficency multiplier, as it creates more atomization which means better burning - as far as my research tells me.
At the stratospheric RPMS those bikes run, I wonder if the injectors ever have time to close.
I bet that stroker is going be singing fairly loudly through the short stacks at high RPMS.
Thanks for sharing, Hammer!
~~~~~~~~~~~~~~~~~~~
I know suzuki used twin injectors on some of its more recent GSXR's and one injector was pointed at something like a 45 degree angle to the runner as this caused some sort of fueling anomality that they found best for power. I am sure they know allot more about this then i do that for sure.
Must be some funky swirl effect from bouncing the spray off the wall. Swirl is the magical power and efficency multiplier, as it creates more atomization which means better burning - as far as my research tells me.
At the stratospheric RPMS those bikes run, I wonder if the injectors ever have time to close.
02-01-2008, 01:03 AM
#32
Three Wheelin'
Mark,
A 20% power increase will take a 44% fuel pressure increase if the increased fuel flow is to be accomplished by a fuel pressure change alone. Fuel flow changes as the sq root of pressure change.
A 20% power increase will take a 44% fuel pressure increase if the increased fuel flow is to be accomplished by a fuel pressure change alone. Fuel flow changes as the sq root of pressure change.
Let's see'em!
Btw, i going to put the stroker in the Holbert car and will probably not change the injectors. Im hoping 75psi on the fuel rails willl be ok.
I do remember, anderson having to go back to stock injectors when his stroker was running a little fat.
If i only expect 400rwhp, thats only a 80hp gain, or near 20%. I would think with a near 20% increase in fuel pressure over stock, it should be close.
Of course I'll do some easy testing on the dyno before i let'er rip.
Mk
Btw, i going to put the stroker in the Holbert car and will probably not change the injectors. Im hoping 75psi on the fuel rails willl be ok.
I do remember, anderson having to go back to stock injectors when his stroker was running a little fat.
If i only expect 400rwhp, thats only a 80hp gain, or near 20%. I would think with a near 20% increase in fuel pressure over stock, it should be close.
Of course I'll do some easy testing on the dyno before i let'er rip.
Mk
02-01-2008, 01:10 AM
#33
Three Wheelin'
Nice looking job. Congratulations! It's a long road. The stacks out the hood will be great. You'll likely need more than 30# injectors. These ITBs flow air really well. Consider using solid motor mounts as the motor will move quite a bit when the torque hits.
02-01-2008, 02:12 AM
#34
Rennlist Member
Is that one of those PV/nRT things???
so, if stock is 50psi, then 44% more fuel pressure would be 72psi. So, im right there. However, im there now. the question is, whether i need to be at 72psi, or are the injectors fighting back based on the pressure ????????(should be open loop, but is it?) I was cranking up the fuel pressure all along, through the years, and didnt see much change in mixture. I wonder why that was.
In any event, because Anderson was real rich at one point, i think he put some lower rated injectors at one time. I forgot what he is using now, but he is at 500rwhp. If 500rwhp (Joe fan) can be served by the 30lb injectors, can 400rwhp ( or really 385 hp is 20% more hp than my 320hp now) be served by 19lb injectors?? Now, on the other hand, if 30lb injectors can support 500hp, then at 20% less hp 416rwhp would require 21lb injectors (all other things being equal) .
since the MAF, really doesnt know the difference between high rpm and low rpm, I would imagine that the fuel could be regulated for a stroker, right up to the point where it cant. Im thinking along the lines of fuel injector duration, rpm, mass flow voltage, etc.
There, thats all the guesses i could come up with . If it required 30lb injectors, that shouldnt be too much of an issue to fix. (other than, who makes them, do they plug right in, where do we buy them, etc)
Thanks Louie!
Mark
Edit: a few changes to correct some of my math errors above.
so, if stock is 50psi, then 44% more fuel pressure would be 72psi. So, im right there. However, im there now. the question is, whether i need to be at 72psi, or are the injectors fighting back based on the pressure ????????(should be open loop, but is it?) I was cranking up the fuel pressure all along, through the years, and didnt see much change in mixture. I wonder why that was.
In any event, because Anderson was real rich at one point, i think he put some lower rated injectors at one time. I forgot what he is using now, but he is at 500rwhp. If 500rwhp (Joe fan) can be served by the 30lb injectors, can 400rwhp ( or really 385 hp is 20% more hp than my 320hp now) be served by 19lb injectors?? Now, on the other hand, if 30lb injectors can support 500hp, then at 20% less hp 416rwhp would require 21lb injectors (all other things being equal) .
since the MAF, really doesnt know the difference between high rpm and low rpm, I would imagine that the fuel could be regulated for a stroker, right up to the point where it cant. Im thinking along the lines of fuel injector duration, rpm, mass flow voltage, etc.
There, thats all the guesses i could come up with . If it required 30lb injectors, that shouldnt be too much of an issue to fix. (other than, who makes them, do they plug right in, where do we buy them, etc)
Thanks Louie!
Mark
Edit: a few changes to correct some of my math errors above.
Last edited by mark kibort; 02-01-2008 at 02:31 AM.
02-01-2008, 02:18 AM
#35
Rennlist Member
Its cool seeing all the different ITB iterations. I believe Louie's designed his with three things in mind 1) low profile to fit under the hood 2) getting the throttle plates as close to the intake ports as possible for better throttle response 3) short stacks to dump low rpm torque.
I've got Loiue's set up, so the throttle plates are close to the intake ports. I believe the BMW M5's use 50mm throttle bodies. My intent was to use the M5 stacks as they are longer then Louie's and should produce more bottom end. Since the stacks are taller my airbox will also have to be taller than Louie's and will come through the hood. It won't be a shaker like Hammers though. The plenum box will be like Louie's, basically a sealed box with a snorkel running to a filter in front of the rad. The difference is that my snorkel will have a supermaf hotwire sensor to run the stock LH/EZK. That's the plan anyway, we'll see how it all works out.
It's going to be cool to see how much difference there is in the powerbands of these strokers with their slightly different intake set ups.
Looks rockin' Hammer!
02-01-2008, 03:10 AM
#36
Three Wheelin'
Hi Mark,
The fuel flow change being the sq root of the pressure change is one of the formulas you use. I don't know it's origin. Maybe Archemedes figured out you need 4 times the pressure to squirt twice as much liquid out a hole.
Since you (I think) plan on running your car on the street as well as on the track you might do some research on fuel system requirements for an engine with quite broad dynamic power range. Sure, you can fudge most anything to run over a narrow power band by bumping fuel pressure, but it won't run well at both ends.
There are formulas to figure this all out and they are pretty close to actual. Your engine should make between 430 and 460 rwhp with the top end, and cams, you have now if you use 968 intake valves. With the S4 valves I guess around 400. However, it will have a lot of torque below about 4200 rpm. I don't really see how you can use the 19# injectors at the high fuel pressure and still have it idle. The math doesn't support it assuming stock fuel map in the LH. You'd be better off to use 36#, or maybe 42# injectors, stock fuel pressure and sharktune it until it was optimum. 30# injectors might be a little on the thin side. That does depend on how the top end breathing is though. Strangled with little valves, the 30# may work.
Could be you didn't see much mixture change with increasing fuel pressure because it takes a big pressure increase to make much flow difference. Don't know the situation though.
You can get Bosch/Ford injectors from eBay. Often the O ring seals on the bottom won't be big enough for the 928 manifold when the injectors are for a Ford engine. Get the right O rings at any injector service place.
The fuel flow change being the sq root of the pressure change is one of the formulas you use. I don't know it's origin. Maybe Archemedes figured out you need 4 times the pressure to squirt twice as much liquid out a hole.
Since you (I think) plan on running your car on the street as well as on the track you might do some research on fuel system requirements for an engine with quite broad dynamic power range. Sure, you can fudge most anything to run over a narrow power band by bumping fuel pressure, but it won't run well at both ends.
There are formulas to figure this all out and they are pretty close to actual. Your engine should make between 430 and 460 rwhp with the top end, and cams, you have now if you use 968 intake valves. With the S4 valves I guess around 400. However, it will have a lot of torque below about 4200 rpm. I don't really see how you can use the 19# injectors at the high fuel pressure and still have it idle. The math doesn't support it assuming stock fuel map in the LH. You'd be better off to use 36#, or maybe 42# injectors, stock fuel pressure and sharktune it until it was optimum. 30# injectors might be a little on the thin side. That does depend on how the top end breathing is though. Strangled with little valves, the 30# may work.
Could be you didn't see much mixture change with increasing fuel pressure because it takes a big pressure increase to make much flow difference. Don't know the situation though.
You can get Bosch/Ford injectors from eBay. Often the O ring seals on the bottom won't be big enough for the 928 manifold when the injectors are for a Ford engine. Get the right O rings at any injector service place.
Is that one of those PV/nRT things???
so, if stock is 50psi, then 44% more fuel pressure would be 72psi. So, im right there. however, im there now. the question is, whether i need to be at 72psi, or are the injectors fighting back based on ????????(should be open loop, but is it?) I was cranking up the fuel pressure all along and didnt see much change in mixture. I wonder why that was.
in any event, because Anderson was real rich at one point, i think he put some lower rated injectors at one time. I forgot what he is using now, but he is at 500rwhp. If 520rwhp (Joefan) can be served by the 30lb injectors, can 400rwhp ( or really 385 hp is 20% more hp) be served by 19lb injectors?? Now, on the other hand, if 30lb injectors can support 500hp, then at 20% less hp 416rwhp would require 21lb injectors (all other things being equal) .
since the MAF, really doesnt know the difference between high rpm and low rpm, I would imagine that the fuel could be regulated for a stroker, right up to the point where it cant. Im thinking along the lines of fuel injector duration, rpm, mass flow voltage, etc.
There, thats all the guesses i could come up with . If it required 30lb injectors, that shouldnt be too much of an issue to fix. (other than, who makes them, do they plug right in, where do we buy them, etc)
Thanks Louie!
Mark
so, if stock is 50psi, then
so, if stock is 50psi, then 44% more fuel pressure would be 72psi. So, im right there. however, im there now. the question is, whether i need to be at 72psi, or are the injectors fighting back based on ????????(should be open loop, but is it?) I was cranking up the fuel pressure all along and didnt see much change in mixture. I wonder why that was.
in any event, because Anderson was real rich at one point, i think he put some lower rated injectors at one time. I forgot what he is using now, but he is at 500rwhp. If 520rwhp (Joefan) can be served by the 30lb injectors, can 400rwhp ( or really 385 hp is 20% more hp) be served by 19lb injectors?? Now, on the other hand, if 30lb injectors can support 500hp, then at 20% less hp 416rwhp would require 21lb injectors (all other things being equal) .
since the MAF, really doesnt know the difference between high rpm and low rpm, I would imagine that the fuel could be regulated for a stroker, right up to the point where it cant. Im thinking along the lines of fuel injector duration, rpm, mass flow voltage, etc.
There, thats all the guesses i could come up with . If it required 30lb injectors, that shouldnt be too much of an issue to fix. (other than, who makes them, do they plug right in, where do we buy them, etc)
Thanks Louie!
Mark
so, if stock is 50psi, then
02-01-2008, 04:15 AM
#37
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Keeping stock pressure sounds like a good idea anyway so 42's and Sharktuner is the way to go. 430+ rwhp sounds really good. Was hoping for 450 at crank.
02-01-2008, 06:06 AM
#38
Under the Lift
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02-01-2008, 06:23 AM
#39
Rennlist Member
If you are running closed loop with O2 sensor, then the loop can adjust pulse width +/= 20%. When the loop gets to the end of the range it defaults rich.
02-01-2008, 10:30 AM
#40
Rennlist Member
Thread Starter
Yo.
Its cool seeing all the different ITB iterations. I believe Louie's designed his with three things in mind 1) low profile to fit under the hood 2) getting the throttle plates as close to the intake ports as possible for better throttle response 3) short stacks to dump low rpm torque.
I've got Loiue's set up, so the throttle plates are close to the intake ports. I believe the BMW M5's use 50mm throttle bodies. My intent was to use the M5 stacks as they are longer then Louie's and should produce more bottom end. Since the stacks are taller my airbox will also have to be taller than Louie's and will come through the hood. It won't be a shaker like Hammers though. The plenum box will be like Louie's, basically a sealed box with a snorkel running to a filter in front of the rad. The difference is that my snorkel will have a supermaf hotwire sensor to run the stock LH/EZK. That's the plan anyway, we'll see how it all works out.
It's going to be cool to see how much difference there is in the powerbands of these strokers with their slightly different intake set ups.
Looks rockin' Hammer!
Its cool seeing all the different ITB iterations. I believe Louie's designed his with three things in mind 1) low profile to fit under the hood 2) getting the throttle plates as close to the intake ports as possible for better throttle response 3) short stacks to dump low rpm torque.
I've got Loiue's set up, so the throttle plates are close to the intake ports. I believe the BMW M5's use 50mm throttle bodies. My intent was to use the M5 stacks as they are longer then Louie's and should produce more bottom end. Since the stacks are taller my airbox will also have to be taller than Louie's and will come through the hood. It won't be a shaker like Hammers though. The plenum box will be like Louie's, basically a sealed box with a snorkel running to a filter in front of the rad. The difference is that my snorkel will have a supermaf hotwire sensor to run the stock LH/EZK. That's the plan anyway, we'll see how it all works out.
It's going to be cool to see how much difference there is in the powerbands of these strokers with their slightly different intake set ups.
Looks rockin' Hammer!
I wanted longer runners to help my torque. It will come in handy with a 2:20 rear cog. I'm planning the same MAF setup. John Speake is working with me on that. My Super MAF "venturi" will be in an oval tunnel in the scoop behind an air filter with the MAF electronics box mounted remotely off to the side of the airbox. I also think it will be interesting for us to compare notes on the effects of each of our designs. Lookin' forward to it.
Hammer
02-01-2008, 10:37 AM
#41
Rennlist Member
Thread Starter
[QUOTE=JEC_31;5052968]Nifty idea, "crimping" the ends of the tubes like that. So in effect the circle-to-oval transition is plenty gradual enough to focus rather than interfere with the pressure waves."
That was precisely my thinking! You read my mind........SCAREY thought!
Louie,
I've thought about the solid mounts but I may just install a torque limiter. After all, I do want the shaker to shake!
Thanks for the injector advice.
Hammer
That was precisely my thinking! You read my mind........SCAREY thought!
Louie,
I've thought about the solid mounts but I may just install a torque limiter. After all, I do want the shaker to shake!
Thanks for the injector advice.
Hammer
02-01-2008, 11:12 AM
#42
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Great, need to invest $$$ for 42's. I was hoping 30 would be enough with 6.5L, 968 intake valves in slightly ported head, modified S3 cams with 0.5mm more lift than stock, 3" headers and exhaust. In reality I knew 30 would be too small but they were practically free. Keeping stock pressure sounds like a good idea anyway so 42's and Sharktuner is the way to go. 430+ rwhp sounds really good. Was hoping for 450 at crank.
Keeping stock pressure sounds like a good idea anyway so 42's and Sharktuner is the way to go. 430+ rwhp sounds really good. Was hoping for 450 at crank.
02-01-2008, 12:33 PM
#43
Three Wheelin'
I was assuming Mark was adjusting fuel pressure on the dyno at WOT. Therefore no closed loop.
02-01-2008, 12:53 PM
#44
Three Wheelin'
The limiters I have run across cut spark to some cylinders to limit wheelspin. I've been reluctant to try that because of the strain on the drivetrain due to uneven power pulses. The spaghetti driveshaft won't take the violent twist/untwist action very long. Maybe ok with a big mass flywheel at the front. Did you have something else in mind? I've thought of a solenoid activated throttle stop to limit full throttle travel in 1st and 2nd gear. 3rd doesn't break loose too much except around the torque peak range.
02-01-2008, 01:11 PM
#45
Rennlist Member
Thread Starter
Torque limiters are a drag race thing. It's a device on the drivers side to allow the engine to lift up to an extent under hard acceleration then has a positive stop at some point. If spring loaded it's easy on the drive train. Works well on street/strip cars. Allowing normal operation under street driving but transfers power to the chassis in competition situations.
My car is an automatic btw.
Hammer
My car is an automatic btw.
Hammer