1. Adding ignition time surely reduces power after a point
2. Your injectors should not be driven with more than 85% of their duty cycle.
3. You should test their cc/min either with a calibrated machine or by simple methods as it has been suggested in this forum by Mr. Croft himself. You could also check their spray pattern (if one of them is bad, you will observe black smoke)
4. Dwell settings are in milliseconds and have to do with discharge time, cranking dwell, running dwell etc. They have to do with the electrical characteristics of your coils, mainly.
5. Even with butterflies closed, some minimal quantity of air should go through. This amount of air actually is critical to the idle of ITB's. IT took me some time to find this out (by test and trial).
6. Maybe, if you could post some charts of your programming it could help, if Mr. Croft agrees. Together with a list of ignition parameters.
7. Yes, disconnect MAP completely (electrically)
8. Make sure there are NO spikes in your camshaft/crankshaft sensor for all your rpm range. This is a VERY typical issue and 99% of the times it is due to poor shielding of the cable and/or improper conductor thickness in relation to the overall length from sensor to ECU. Give us some numbers. I have solved such issues just by changing a cable (although they should be special).
9. Use widebands for tuning only. Take them out for normal running. You can have their readings fed to a gauge but do not send their data to the ECU. It is not that it would create you problems, but try to make troubleshooting as easy as possible. Also eliminate settings for use of lamda in the software
That is all from me for now. I am sure you can solve the problem, just go step by step.
Stay with FI, or go to Carbs?
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kpsig
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vandor
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Re: Stay with FI, or go to Carbs?
Rich,
Thank you for your comments. This system actually does not to regulate idle speed. There is an optional idle-air motor, but we are not using it. I had planned to have a small bypass valve that would increase air flow when the engine is cold and would automatically shut off at a certain engine temp, but we spent our time on other things. I will check anyways to see if the timing is changing at idle.
I did not think about removing the MAP sensor, I will do that to be sure it has no effect.
Guy,
The muffler is a MagnaFlow, I was not able to check if it is straight-through, I will need a strong flashlight. Their current designs are straight-through, but this one is a few years old, so it may not be.
I think the exhaust shop pressed the pipe to a smaller size so it will fit into the header collector, where the smaller pipe is not necessarily the same size as the collector ID, but even smaller. I think that would cause a lot of turbulence.
By noise test you mean dB meters at a racetrack? Or do they measure noise for road cars in Europe? What we are concerned with is ringing ears on long trips :-)
The throttle bodies are 40mm.
I agree, I think there is a bottleneck somewhere. The only thing that comes to mind is that with the old manifold we had to run a 3/8 spacer between the manifold and the head to gain clearance for the injectors. It was matched to the intake and the head, but the air did have to do a little s-curve (~1/8"), as the intake manifold bolts are not parallel with the port. The new intake is tilted to give more injector clearace, so the plate is not needed.
We had run the engine without the airbox (but with the very short velocity stacks that are inside the airbox), but it only gained ~2 hp, so the intake system is not a large restriction.
The cams came from international Auto Parts, I believe the only source of new cams in the US. They just publish specs, I doubt they ever dyno'd them.
CR is 10:1, valve size is 43mm/37.5mm in/ex. Yes, the head has been gasflowed by a shop with a flowbench. They did give us the flow results back when the head was done, I tried to compare them to yours, but they use different depression than you, so the numbers are not directly comparable.
Today was -8ºC, so other than adjusting cold start enrichment for that temperature, I did not do much. Right now the priority is still to get the car to idle reasonably, so I can do some tuning, go to the exhaust shop, and eventually to the dyno.
Thanks,
Csaba
Thank you for your comments. This system actually does not to regulate idle speed. There is an optional idle-air motor, but we are not using it. I had planned to have a small bypass valve that would increase air flow when the engine is cold and would automatically shut off at a certain engine temp, but we spent our time on other things. I will check anyways to see if the timing is changing at idle.
I did not think about removing the MAP sensor, I will do that to be sure it has no effect.
Guy,
The muffler is a MagnaFlow, I was not able to check if it is straight-through, I will need a strong flashlight. Their current designs are straight-through, but this one is a few years old, so it may not be.
I think the exhaust shop pressed the pipe to a smaller size so it will fit into the header collector, where the smaller pipe is not necessarily the same size as the collector ID, but even smaller. I think that would cause a lot of turbulence.
By noise test you mean dB meters at a racetrack? Or do they measure noise for road cars in Europe? What we are concerned with is ringing ears on long trips :-)
The throttle bodies are 40mm.
I agree, I think there is a bottleneck somewhere. The only thing that comes to mind is that with the old manifold we had to run a 3/8 spacer between the manifold and the head to gain clearance for the injectors. It was matched to the intake and the head, but the air did have to do a little s-curve (~1/8"), as the intake manifold bolts are not parallel with the port. The new intake is tilted to give more injector clearace, so the plate is not needed.
We had run the engine without the airbox (but with the very short velocity stacks that are inside the airbox), but it only gained ~2 hp, so the intake system is not a large restriction.
The cams came from international Auto Parts, I believe the only source of new cams in the US. They just publish specs, I doubt they ever dyno'd them.
CR is 10:1, valve size is 43mm/37.5mm in/ex. Yes, the head has been gasflowed by a shop with a flowbench. They did give us the flow results back when the head was done, I tried to compare them to yours, but they use different depression than you, so the numbers are not directly comparable.
Today was -8ºC, so other than adjusting cold start enrichment for that temperature, I did not do much. Right now the priority is still to get the car to idle reasonably, so I can do some tuning, go to the exhaust shop, and eventually to the dyno.
Thanks,
Csaba
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Guy Croft
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Re: Stay with FI, or go to Carbs?
well sorry I have no idea how good those cams are!
As for the ex system backpressure I suggest you tee into the pipe just downstream of the collector and put a pressure gauge on it at idle, see how many psi it gives right at the pipe wall (where the velocity is zero).
G
As for the ex system backpressure I suggest you tee into the pipe just downstream of the collector and put a pressure gauge on it at idle, see how many psi it gives right at the pipe wall (where the velocity is zero).
G
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vandor
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Re: Stay with FI, or go to Carbs?
Hello,
I have not worked on the car all week, as it has been too cold!
Guy, I assume the exhaust system backpressure needs to be measured at WOT and high RPM?
Kpsig,
Do you think the injectors need testing even if they are brand new?
I do know what dwell means, but I have no idea how to measure it on a distributorless system.
The ITBs have screws for air to bypass the throttle plates, so throats on the same TB can be balance to each other.
Are you saying these should be as closed as possible? Some people suggest all of these should pass some air, some say it's OK if some are closed.
I can post the parameters, I just need to get the current settings from the control unit. It would be a long post!
Supposedly if there are any spikes the control box would display an Error for that parameter, which would stay displayed until the unit is shut down. I haven't yet seen an Error message in over a year of playing with the system.
Yes, Lambda, or Closed Loop is turned off.
Thank you for your input!!!!
Csaba
I have not worked on the car all week, as it has been too cold!
Guy, I assume the exhaust system backpressure needs to be measured at WOT and high RPM?
Kpsig,
Do you think the injectors need testing even if they are brand new?
I do know what dwell means, but I have no idea how to measure it on a distributorless system.
The ITBs have screws for air to bypass the throttle plates, so throats on the same TB can be balance to each other.
Are you saying these should be as closed as possible? Some people suggest all of these should pass some air, some say it's OK if some are closed.
I can post the parameters, I just need to get the current settings from the control unit. It would be a long post!
Supposedly if there are any spikes the control box would display an Error for that parameter, which would stay displayed until the unit is shut down. I haven't yet seen an Error message in over a year of playing with the system.
Yes, Lambda, or Closed Loop is turned off.
Thank you for your input!!!!
Csaba
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kpsig
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- Location: Greece
Re: Stay with FI, or go to Carbs?
IF the injectors are brand new, well, no need to check them probably. Sorry, I had the idea they were second hand.
For the Dwell, just to give you an idea, in my (unique, not to be copied to your setup) setup I have minimum discharge time 1ms, cranking 3,4ms and running 4ms. I am on the safe side meaning that with those values I have good engine operation and minimum coil heating. Could you post the type of your coils?
ITB plates should be closed until you manage to have good idle when cold, meaning that there is an amount of air going by. You have to test and repeat many times and be sure that the TPS Sensor is not out of range.
Spikes are not logged as errors, typically in most ECUs. They just exist and confuse the ECU's algorithms.
Note that you could add a capacitor to your coils (typicall done in Zetec FOrd engines and Peugeot ones, easy to find how it is done with google) to eliminate noise from the operation of the coils. I have done this in my setup.
In my car, spikes occuring at 4000 rpm and then 6000 rpm coming from crankshaft sensor, totally messed the fueling and ignition operation of my ECU, plus I was loosing power all over the range. I Fixed it with a properly shielded power cable with 4 conductors, paired at their ends (one pair for signal other for ground).
If I would like to give one starting point for your troubleshooting, it would be the crankshaft sensor (and cams, if you have one) cabling. MOst of the times, the cables given by the manufacturers of aftermarket ECUs are not properly working to every setup.
For the Dwell, just to give you an idea, in my (unique, not to be copied to your setup) setup I have minimum discharge time 1ms, cranking 3,4ms and running 4ms. I am on the safe side meaning that with those values I have good engine operation and minimum coil heating. Could you post the type of your coils?
ITB plates should be closed until you manage to have good idle when cold, meaning that there is an amount of air going by. You have to test and repeat many times and be sure that the TPS Sensor is not out of range.
Spikes are not logged as errors, typically in most ECUs. They just exist and confuse the ECU's algorithms.
Note that you could add a capacitor to your coils (typicall done in Zetec FOrd engines and Peugeot ones, easy to find how it is done with google) to eliminate noise from the operation of the coils. I have done this in my setup.
In my car, spikes occuring at 4000 rpm and then 6000 rpm coming from crankshaft sensor, totally messed the fueling and ignition operation of my ECU, plus I was loosing power all over the range. I Fixed it with a properly shielded power cable with 4 conductors, paired at their ends (one pair for signal other for ground).
If I would like to give one starting point for your troubleshooting, it would be the crankshaft sensor (and cams, if you have one) cabling. MOst of the times, the cables given by the manufacturers of aftermarket ECUs are not properly working to every setup.
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Guy Croft
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Re: Stay with FI, or go to Carbs?
The back pressure measurement only really needs to be done at around 1000rpm off-load, none is ideal but over 2.5psi and you've definitely got a problem.
If you do it thru the working range I'd be pleased to see the 'map' of pressure vs rpm at WOT.
G
If you do it thru the working range I'd be pleased to see the 'map' of pressure vs rpm at WOT.
G
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WhizzMan
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Re: Stay with FI, or go to Carbs?
When setting up a "new" EFI powered engine, idle is not really the first thing to look at. Try something in the middle of everything, say 3000 rpm at 50% throttle. It should be easy to get the engine to tick over and establish a stable A/F rating. Ignition timing isn't really critical at those loads and speeds, probably anything between 25 and 10 degrees advance will make the engine run. Once you have that working, you know all sensors and actuators are working properly. From there on, you can establish a "rough" fueling setup for other RPMs and loads. Once you get to the more extreme parts of your maps, adjust ignition accordingly, most engines don't actually differ that much, you know that you'll be fine at most RPMs with a static 10 degree advance so you can at least set up fueling more or less proper. After you have a more or less acceptable fuel map, you can work with the ignition to get better power output. Remember to keep on checking your fueling, since better power usually means the engine will flow more air per revolution, changing your fueling requirements. This is done best on a dyno that has provisions to keep your engine at a static speed and will merely adjust the load to correct for power output from the engine. Basically, you first tune for mixture, once that is okay, you tune for max torque without knocking at that specific rpm/load point. After all your statics are okay, you start tuning acceleration enrichment.
I would let the ECU use the variable motor/valve setup to control idle. I personally know only one system (Bosch L-Jetronic or LE-Jetronic) that doesn't use one on commercial vehicles. This is well known for rough idle running if you don't have your throttle vacuum and ignition perfectly in order. Keep in mind that this a system that is already fine tuned and it still messes up if only the slightest thing is wrong. I wouldn't have any hope for a system that has practically everything not set up yet to be able to control idle or even have the engine run at idle at all.
Yes, getting something to run on carbs is easier, if you have the correct carbs with the correct base setup for jets and everything. Most of that stuff is known for years and easy to find. Getting the same data for your EFI setup can be hard or impossible. It's not really that more difficult to get a really good result, it's just that it's a lot harder to get to the mediocre bit because the base setup isn't there already. Both systems have their merits and indeed, the last 10% power is rather expensive to get. Usually, some more track time, spending the money on suspension and tires will make you faster than the money spent on the dyno will. That being said, a lot of us are in this for the tech stuff and not for the fastest lap time. We want everything to be as good as possible with the materials provided. If that will cost money, a lot of people will spend it.
I would let the ECU use the variable motor/valve setup to control idle. I personally know only one system (Bosch L-Jetronic or LE-Jetronic) that doesn't use one on commercial vehicles. This is well known for rough idle running if you don't have your throttle vacuum and ignition perfectly in order. Keep in mind that this a system that is already fine tuned and it still messes up if only the slightest thing is wrong. I wouldn't have any hope for a system that has practically everything not set up yet to be able to control idle or even have the engine run at idle at all.
Yes, getting something to run on carbs is easier, if you have the correct carbs with the correct base setup for jets and everything. Most of that stuff is known for years and easy to find. Getting the same data for your EFI setup can be hard or impossible. It's not really that more difficult to get a really good result, it's just that it's a lot harder to get to the mediocre bit because the base setup isn't there already. Both systems have their merits and indeed, the last 10% power is rather expensive to get. Usually, some more track time, spending the money on suspension and tires will make you faster than the money spent on the dyno will. That being said, a lot of us are in this for the tech stuff and not for the fastest lap time. We want everything to be as good as possible with the materials provided. If that will cost money, a lot of people will spend it.
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robert kenney
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Re: Stay with FI, or go to Carbs?
Csaba
I may have missed this reading through the prior posts but where in the exhaust is the exhaust sensor and is it's telemetry used by the FI to map the injector duty cycle(pulse width)?
I may have missed this reading through the prior posts but where in the exhaust is the exhaust sensor and is it's telemetry used by the FI to map the injector duty cycle(pulse width)?
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Guy Croft
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Re: Stay with FI, or go to Carbs?
Thank you for joining Robert.
There have been numerous excellent and very informative/helpful posts by this time on this demanding and interesting thread.
With all due respect to Csaba who is in the 'frontline' and doing his best to fathom out what's wrong I want to take a little vote at this juncture, a 'sweepstake' with nothing to lose.
You vote for either:
1) it is a problem with the core engine (incl ex system)
or
2) it is a problem with the engine management, ie: the fuel injection/ignition system (in its entirety incl all hardware).
The winner is the person who IDs that (or those) fault/s (wherein: it/they, is/are then fixed & cured and the engine then runs like a dream and produces the right kind of power - which really should be well-over 165bhp & 148lbf ft torque). I would gamble a new GC book but most of you have got it and there may be several. Suitable ideas for prizes?
I vote 1).
Over to you. And don't let this stand in the way of constructive ideas to fathom out what is actually wrong BTW!
GC
There have been numerous excellent and very informative/helpful posts by this time on this demanding and interesting thread.
With all due respect to Csaba who is in the 'frontline' and doing his best to fathom out what's wrong I want to take a little vote at this juncture, a 'sweepstake' with nothing to lose.
You vote for either:
1) it is a problem with the core engine (incl ex system)
or
2) it is a problem with the engine management, ie: the fuel injection/ignition system (in its entirety incl all hardware).
The winner is the person who IDs that (or those) fault/s (wherein: it/they, is/are then fixed & cured and the engine then runs like a dream and produces the right kind of power - which really should be well-over 165bhp & 148lbf ft torque). I would gamble a new GC book but most of you have got it and there may be several. Suitable ideas for prizes?
I vote 1).
Over to you. And don't let this stand in the way of constructive ideas to fathom out what is actually wrong BTW!
GC
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TomLouwrier
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Re: Stay with FI, or go to Carbs?
hi guys,
My bike (yes, I know) has Weber-Marelli fuel injection (IAW P8, alpha-n type) with a throttle body very much like an IDF.
The instructions for setting up state very clearly that the air bleed screws are only for balancing flow between the two barrels. The one with the least vacuum (highest absolute pressure) in the inlet stays closed and the other is opened up a bit so that it gets the same value.
Idle is adjusted by opening the butterfly valves a bit, just like you would do on a carb.
Procedure is as follows:
- First close all bleed screws and fully close the butterflies.
- adjust the TPS so that it is in the correct working range (use Ohm-meter). The ECU should be able to recognize idle position.
- open up the butterflies a bit, start the engine and try to settle on a steady high idle
- synchronize the barrels by bleeding air into the one with the highest vacuum
- adjust idle mixture
- adjust idle downwards to specified revs
Repeat several times to get it all where it should be.
Of course this assumes an ECU that is already mapped correctly for the engine. In this case the mapping is probably still too far off, so you need to get into the ballpark first.
Spikes or rogue signals are a very common cause for confusing the ECU. Quality of cables, shielding and mass should be at least on par with what you expect to find on a recent, mass produced car. Also make sure that the power supply to the ECU is free of noise signal. Use a scope if available.
I'm not entering my vote yet in the poll...
regards
Tom
My bike (yes, I know) has Weber-Marelli fuel injection (IAW P8, alpha-n type) with a throttle body very much like an IDF.
The instructions for setting up state very clearly that the air bleed screws are only for balancing flow between the two barrels. The one with the least vacuum (highest absolute pressure) in the inlet stays closed and the other is opened up a bit so that it gets the same value.
Idle is adjusted by opening the butterfly valves a bit, just like you would do on a carb.
Procedure is as follows:
- First close all bleed screws and fully close the butterflies.
- adjust the TPS so that it is in the correct working range (use Ohm-meter). The ECU should be able to recognize idle position.
- open up the butterflies a bit, start the engine and try to settle on a steady high idle
- synchronize the barrels by bleeding air into the one with the highest vacuum
- adjust idle mixture
- adjust idle downwards to specified revs
Repeat several times to get it all where it should be.
Of course this assumes an ECU that is already mapped correctly for the engine. In this case the mapping is probably still too far off, so you need to get into the ballpark first.
Spikes or rogue signals are a very common cause for confusing the ECU. Quality of cables, shielding and mass should be at least on par with what you expect to find on a recent, mass produced car. Also make sure that the power supply to the ECU is free of noise signal. Use a scope if available.
I'm not entering my vote yet in the poll...
regards
Tom
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kpsig
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- Location: Greece
Re: Stay with FI, or go to Carbs?
Well I am entering my vote.
It is 2) and more specifically, some electrical noise from
a)crankshaft/cam sensor
b)coils (ignition circuit)
c)injector themselves
FOr all cases, if ECU does not offer logging, you could check it with an osciloscope.
Remedies: a) cabling, new one with proper shielding
b) the same, also add a capacitor
c) if you could post the exact part numbers of the injectors, I could tell you more.
Also use the shortest possible cabling.
The spikes/noise you have cannot be damped with software and/or hardware modifications (eg filters).
It is 2) and more specifically, some electrical noise from
a)crankshaft/cam sensor
b)coils (ignition circuit)
c)injector themselves
FOr all cases, if ECU does not offer logging, you could check it with an osciloscope.
Remedies: a) cabling, new one with proper shielding
b) the same, also add a capacitor
c) if you could post the exact part numbers of the injectors, I could tell you more.
Also use the shortest possible cabling.
The spikes/noise you have cannot be damped with software and/or hardware modifications (eg filters).
-
vandor
- Posts: 108
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- Location: Texas, USA
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Re: Stay with FI, or go to Carbs?
Hello,
I just had a little time today, so I disconnected the 4 vacuum hoses and put caps on them, to eliminate any possible vacuum leaks in the hoses. No change in behavior at idle, the mixture is still all over the place.
Tomorrow I will spend more time diagnosing things, and will also do a compression check.
Kpsig,
The coils that this FI system uses are from a General Motors product (Buick, Chevrolet, etc). They came mounted on a box that has some electronic in it (not the ECU). You can see them on the bottom of the second pic. The reason I included the pics is to show that with the new coil location the plug wires are very long. We moved the coils to try and stay away from the heat of the headers.
The FI system manufacturer stated that if any inputs were out of range it would register as an error, but I do not know if it is true for momentary spikes.
Thanks for the capacitor idea, I will have to do that to eliminate that possibility.
Do I have to totally replace the crank sensor cabling, or is there a way to shield it? How do I know if it is a good quality shielding cable?
I will see if I can find any part numbers on the injectors.
Guy,
Thanks for the exhaust info, we'll have to do that next time we are on the dyno.
As far as the sweepstakes, I think the idle problem is something relating to the FI, but the power maxing out at 6000 has to do with a bottleneck in the flow somewhere.
WhizzMan,
This is not a new engine. It was idling fine, and running OK (although probably making less power than it should) before we rebuilt the engine, replaced the intake manifold, went to smaller injectors, and moved the coils. Since it was working before, it is likely that one of the things we changed has an undesired effect.
Robert,
The oxygen sensor is just after the 4-1 collector of the header. I will take a pic tomorrow. Closed Loop is turned off, so it is not used by the ECU.
Tom,
Thanks for the info!
Thank you all!
Csaba
I just had a little time today, so I disconnected the 4 vacuum hoses and put caps on them, to eliminate any possible vacuum leaks in the hoses. No change in behavior at idle, the mixture is still all over the place.
Tomorrow I will spend more time diagnosing things, and will also do a compression check.
Kpsig,
The coils that this FI system uses are from a General Motors product (Buick, Chevrolet, etc). They came mounted on a box that has some electronic in it (not the ECU). You can see them on the bottom of the second pic. The reason I included the pics is to show that with the new coil location the plug wires are very long. We moved the coils to try and stay away from the heat of the headers.
The FI system manufacturer stated that if any inputs were out of range it would register as an error, but I do not know if it is true for momentary spikes.
Thanks for the capacitor idea, I will have to do that to eliminate that possibility.
Do I have to totally replace the crank sensor cabling, or is there a way to shield it? How do I know if it is a good quality shielding cable?
I will see if I can find any part numbers on the injectors.
Guy,
Thanks for the exhaust info, we'll have to do that next time we are on the dyno.
As far as the sweepstakes, I think the idle problem is something relating to the FI, but the power maxing out at 6000 has to do with a bottleneck in the flow somewhere.
WhizzMan,
This is not a new engine. It was idling fine, and running OK (although probably making less power than it should) before we rebuilt the engine, replaced the intake manifold, went to smaller injectors, and moved the coils. Since it was working before, it is likely that one of the things we changed has an undesired effect.
Robert,
The oxygen sensor is just after the 4-1 collector of the header. I will take a pic tomorrow. Closed Loop is turned off, so it is not used by the ECU.
Tom,
Thanks for the info!
Thank you all!
Csaba
- Attachments
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Guy Croft
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Re: Stay with FI, or go to Carbs?
FWIW I just want to stress that the cam profile could well be the culprit..
What you're seeing is exactly what regrinds do on the 8V TC and I have seen some billets that are not much better.
GC
What you're seeing is exactly what regrinds do on the 8V TC and I have seen some billets that are not much better.
GC
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vandor
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Re: Stay with FI, or go to Carbs?
Hello,
I did some work on the car on Sunday. Below see pics of the oxygen sensor location.
First I did a compression check, to check the basics, and all cylinders were at 170-175 psi. Then I moved the cable for the crank sensor pickup, as it was passing just inches from the coils. However, the idle mixture problem is still there,
it still varies from full rich to full lean.
I also checked the static timing with a timing light by setting all values to zero, to see if if the crank sensor was mounted in the exact same place it was before. Amazingly the engine did not stall with the retarded timing, so I dialed in less advance at idle (than originally) when I set things back to normal. The mixture is still all over the place, but the engine does not stall.
I have emailed the FI manufacturer for instructions on how to wire a capacitor to the coils.
Guy, when you say the cam profile could be the culprit, do you mean of the low powerband, or the idle mixture problem?
I assume the former.
Thanks,
Csaba
I did some work on the car on Sunday. Below see pics of the oxygen sensor location.
First I did a compression check, to check the basics, and all cylinders were at 170-175 psi. Then I moved the cable for the crank sensor pickup, as it was passing just inches from the coils. However, the idle mixture problem is still there,
it still varies from full rich to full lean.
I also checked the static timing with a timing light by setting all values to zero, to see if if the crank sensor was mounted in the exact same place it was before. Amazingly the engine did not stall with the retarded timing, so I dialed in less advance at idle (than originally) when I set things back to normal. The mixture is still all over the place, but the engine does not stall.
I have emailed the FI manufacturer for instructions on how to wire a capacitor to the coils.
Guy, when you say the cam profile could be the culprit, do you mean of the low powerband, or the idle mixture problem?
I assume the former.
Thanks,
Csaba
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Guy Croft
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Re: Stay with FI, or go to Carbs?
The fact that the peak power is at almost the same place as a standard cam would give bothers me, sure.
As for weird idle yes the cam can do that too.
You see I have no idea what this cam setup really is, ie: it's an unknown for me.
To determine the effectiveness and characteristics I'd need the lift-degree map with flat follower.
G
As for weird idle yes the cam can do that too.
You see I have no idea what this cam setup really is, ie: it's an unknown for me.
To determine the effectiveness and characteristics I'd need the lift-degree map with flat follower.
G
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