COLD AIR INTAKE NEXT LEVEL OF PERFORMANCE?
12-13-2010, 09:16 PM
#151
Nordschleife Master
So true on a lot of counts but after really thinking about all of this there are varibles that are not absolute.
1. Never had the car Dyno'd.
2. The speedo. Im assuming its working correctly but who's to say? I never had it looked at for accuracy. The odo stopped working at 108K and that was 5 yrs ago.
3. The other thing is my stock air tubes, they were so ****ty I had to wrap them with duct tap to seal off the tears and holes Plus I only had two straps holding the air box cover down. Maybe at speed it lifted/bounced around and took in hot air from the motor?
Who knows. Most likely my car wasnt running at its true potential.
Either way, I think a cold air intake for any car is a great idea. Gains can be minimal or maybe they can be great. Its all good.
Happy trails brother ....
1. Never had the car Dyno'd.
2. The speedo. Im assuming its working correctly but who's to say? I never had it looked at for accuracy. The odo stopped working at 108K and that was 5 yrs ago.
3. The other thing is my stock air tubes, they were so ****ty I had to wrap them with duct tap to seal off the tears and holes Plus I only had two straps holding the air box cover down. Maybe at speed it lifted/bounced around and took in hot air from the motor?
Who knows. Most likely my car wasnt running at its true potential.
Either way, I think a cold air intake for any car is a great idea. Gains can be minimal or maybe they can be great. Its all good.
Happy trails brother ....
12-13-2010, 09:41 PM
#152
Rennlist Member
Well, there you go. now you are thinking! 
another proven science is that of air flow. turns and bends, are murder on flow. those 3 x 90 degree elbows only add one more 90 vs the stock stuff, but even that alone, without the use of inlet guide vanes, can have the effect of possibly 3-4 x the current distance. meaning if you have a 90 degree bend, you could have the same effect as if you had a 3ft long pipe and then a filter on it. There are formulas for most of thise in mechical eng. books and handbooks.
point is, we dont know what the dyno before or after was. you obviously feel it "woke up" so, its very possible, with tubes all beat up, leaks in the air box, paper filter, etc, you would feel some gains. how much, hard to tell. you really need a dyno to do this. (or a really controlled 60-100mph run)
the 60 to 100 run, Ive found to be able to detect 15-20hp losses.
another proven science is that of air flow. turns and bends, are murder on flow. those 3 x 90 degree elbows only add one more 90 vs the stock stuff, but even that alone, without the use of inlet guide vanes, can have the effect of possibly 3-4 x the current distance. meaning if you have a 90 degree bend, you could have the same effect as if you had a 3ft long pipe and then a filter on it. There are formulas for most of thise in mechical eng. books and handbooks.
point is, we dont know what the dyno before or after was. you obviously feel it "woke up" so, its very possible, with tubes all beat up, leaks in the air box, paper filter, etc, you would feel some gains. how much, hard to tell. you really need a dyno to do this. (or a really controlled 60-100mph run)
the 60 to 100 run, Ive found to be able to detect 15-20hp losses.
So true on a lot of counts but after really thinking about all of this there are varibles that are not absolute.
1. Never had the car Dyno'd.
2. The speedo. Im assuming its working correctly but who's to say? I never had it looked at for accuracy. The odo stopped working at 108K and that was 5 yrs ago.
3. The other thing is my stock air tubes, they were so ****ty I had to wrap them with duct tap to seal off the tears and holes Plus I only had two straps holding the air box cover down. Maybe at speed it lifted/bounced around and took in hot air from the motor?
Who knows. Most likely my car wasnt running at its true potential.
Either way, I think a cold air intake for any car is a great idea. Gains can be minimal or maybe they can be great. Its all good.
Happy trails brother ....
1. Never had the car Dyno'd.
2. The speedo. Im assuming its working correctly but who's to say? I never had it looked at for accuracy. The odo stopped working at 108K and that was 5 yrs ago.
3. The other thing is my stock air tubes, they were so ****ty I had to wrap them with duct tap to seal off the tears and holes Plus I only had two straps holding the air box cover down. Maybe at speed it lifted/bounced around and took in hot air from the motor?
Who knows. Most likely my car wasnt running at its true potential.
Either way, I think a cold air intake for any car is a great idea. Gains can be minimal or maybe they can be great. Its all good.
Happy trails brother ....
12-15-2010, 08:05 PM
#153
Rennlist Member
enjoying the read.
I do remember reading that in some cars you can get some pressurisation at the base of the windscreen. Thats one reason why cabin intakes are there.
Some bonnet intakes point backwards on some cars as they got more air than facing the front .
I had a look at the photos in 'Project 928' showing the wool tuft tests and smoke to see if it showed anything that ight point to this.
MK notes that any small amount of reducing the negative pressure in the intake is a BIG bonus, so maybe there is a small benefit with the CAI placed where the heater unit should be.
ciao
I do remember reading that in some cars you can get some pressurisation at the base of the windscreen. Thats one reason why cabin intakes are there.
Some bonnet intakes point backwards on some cars as they got more air than facing the front .
I had a look at the photos in 'Project 928' showing the wool tuft tests and smoke to see if it showed anything that ight point to this.
MK notes that any small amount of reducing the negative pressure in the intake is a BIG bonus, so maybe there is a small benefit with the CAI placed where the heater unit should be.
ciao
12-15-2010, 09:40 PM
#154
Rennlist Member
I did these tests with a Sunx sensor. (very sensitive pressure /vacuum sensor).
I was able to determine that the pressure at the nose, front of the radiator area , is very close to what can be found at the base of the windshield. so, it stands to reason, that if you draw from both, as I do, you get the best bang for the effort. the entire idea is to optimize flow, (reduce pressure losses) and gain positive pressure at high speed, which by the way, is much less than people think. (i.e. .08psi at 80mph and near .36psi at 160mph or in otherwords, near 2.5% HP gain at 160mph from ram effect)
my tests have shown that the stock air box is pretty optimal. its wide KN filter, with toilet bowl entry to the MAF, is near ideal. in fact when I radiused the inlet in the airbox, and used a spacer to lift the air filter off the MAF, I lost 5 hp. there might be some heimholtz resonance to think about too. I also bolted on a straight 3.5" tube sticking straight out of the MAF (seemingly, and actually better than anything posted here as a CAI, and lost 4hp) put the stock air box back on (which is vented) and the power came back. The only reason Im not using one, is that so far, my tests have proved that the CAI doesnt work. again, if anyone doubts my tests or think that it does work, and manufacturers one, I will buy it if it works and pay double for it if it gives 15 to 20hp more.
most will not work better and have been seen to work better because the stock set up probably had a stock paper filter, AND was probably severely leaking anyway, via tubes and around the filter. I have yet to see a fair comparison of a stock airbox with KN (oiled properly) with any other version of an air filtration intake system.
Im ready to test if anyone wants me to go to the dyno and prove that it works or no.
Mark
I was able to determine that the pressure at the nose, front of the radiator area , is very close to what can be found at the base of the windshield. so, it stands to reason, that if you draw from both, as I do, you get the best bang for the effort. the entire idea is to optimize flow, (reduce pressure losses) and gain positive pressure at high speed, which by the way, is much less than people think. (i.e. .08psi at 80mph and near .36psi at 160mph or in otherwords, near 2.5% HP gain at 160mph from ram effect)
my tests have shown that the stock air box is pretty optimal. its wide KN filter, with toilet bowl entry to the MAF, is near ideal. in fact when I radiused the inlet in the airbox, and used a spacer to lift the air filter off the MAF, I lost 5 hp. there might be some heimholtz resonance to think about too. I also bolted on a straight 3.5" tube sticking straight out of the MAF (seemingly, and actually better than anything posted here as a CAI, and lost 4hp) put the stock air box back on (which is vented) and the power came back. The only reason Im not using one, is that so far, my tests have proved that the CAI doesnt work. again, if anyone doubts my tests or think that it does work, and manufacturers one, I will buy it if it works and pay double for it if it gives 15 to 20hp more.
most will not work better and have been seen to work better because the stock set up probably had a stock paper filter, AND was probably severely leaking anyway, via tubes and around the filter. I have yet to see a fair comparison of a stock airbox with KN (oiled properly) with any other version of an air filtration intake system.
Im ready to test if anyone wants me to go to the dyno and prove that it works or no.
Mark
enjoying the read.
I do remember reading that in some cars you can get some pressurisation at the base of the windscreen. Thats one reason why cabin intakes are there.
Some bonnet intakes point backwards on some cars as they got more air than facing the front .
I had a look at the photos in 'Project 928' showing the wool tuft tests and smoke to see if it showed anything that ight point to this.
MK notes that any small amount of reducing the negative pressure in the intake is a BIG bonus, so maybe there is a small benefit with the CAI placed where the heater unit should be.
ciao
I do remember reading that in some cars you can get some pressurisation at the base of the windscreen. Thats one reason why cabin intakes are there.
Some bonnet intakes point backwards on some cars as they got more air than facing the front .
I had a look at the photos in 'Project 928' showing the wool tuft tests and smoke to see if it showed anything that ight point to this.
MK notes that any small amount of reducing the negative pressure in the intake is a BIG bonus, so maybe there is a small benefit with the CAI placed where the heater unit should be.
ciao
12-30-2010, 10:18 PM
#155
Burning Brakes
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Finished the air intake system up.
Looked into the motors looks like they will test out around:
High Amps:.......119 each
High Watts:......(4400 each unit)
RPMs:..............34000+
Thrust:............10lbs+ each unit
Theres alot more involved
WOT switch
Relay that can handle minimum of 250 continous amps
Servo tester which will adjust fan speed when WOT
ESC's
Programming ESC's
Battery packs
Lots of wiring
A good place to mount it all
Hopefully will have some of the stuff ready to work on in spring.
For now the air intake is setup with the units.
Still reading,searching and asking questions its a learning process.
Looked into the motors looks like they will test out around:
High Amps:.......119 each
High Watts:......(4400 each unit)
RPMs:..............34000+
Thrust:............10lbs+ each unit
Theres alot more involved
WOT switch
Relay that can handle minimum of 250 continous amps
Servo tester which will adjust fan speed when WOT
ESC's
Programming ESC's
Battery packs
Lots of wiring
A good place to mount it all
Hopefully will have some of the stuff ready to work on in spring.
For now the air intake is setup with the units.
Still reading,searching and asking questions its a learning process.
Last edited by inactiveuser1; 05-06-2013 at 12:25 AM.
12-31-2010, 08:02 PM
#156
Burning Brakes
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Checked fit on the car today.
Front,top and side view.
Side view shows how short they are they look alot longer in other views.
Overall they are 8inches which includes 1 inch on each end for clamping into the rubbers.
Front,top and side view.
Side view shows how short they are they look alot longer in other views.
Overall they are 8inches which includes 1 inch on each end for clamping into the rubbers.
Last edited by inactiveuser1; 05-06-2013 at 12:25 AM.
12-31-2010, 08:37 PM
#157
Nordschleife Master
Your list of stuff to do doesn't include injectors? The stock injectors don't have a lot of headroom before the engine will start to run lean.
12-31-2010, 09:25 PM
#158
Burning Brakes
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You need a fitting to connect and measure pressure - if those things succeed in pressurizing the intake, you need to know how much. Then just plug them in and see what you read with the engine off
Your list of stuff to do doesn't include injectors? The stock injectors don't have a lot of headroom before the engine will start to run lean.
Your list of stuff to do doesn't include injectors? The stock injectors don't have a lot of headroom before the engine will start to run lean.
Was looking at Tim's stage 1 and didn't see anything on injectors till the stage 3 so wasn't sure if he is using
stock ones or if it would need them as this won't make as much power as a stage 1 and who knows what it will do yet.
You're right on the connection for pressure and have thought of it,would like to hear from some of the guys
who are running the superchargers to see different setups on the gauges,example what they used etc.
Once I get some ideas will ad it in.
I still have to make tie bars on the front and rear units so they don't blow apart.
Will weld a nut onto each unit and put a tie bar on them.
Last edited by inactiveuser1; 01-06-2011 at 08:30 PM.
01-01-2011, 01:59 AM
#159
Rennlist Member
They look awesome and should work well. Looking forward to the test results.
as far as measuring pressure , statically and dynamically, a Sunx sensor can do this very easily and it is a very sensor. (under $100)
as far as measuring pressure , statically and dynamically, a Sunx sensor can do this very easily and it is a very sensor. (under $100)
01-08-2011, 03:16 PM
#160
Burning Brakes
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Mark,
The fans were tested outside the system at alittle over 10lbs thrust each.
The one place claimed that the real big units(Twin fans) generates about 3800 CFM and 52 pounds of thrust when using two 15S setups.
On a lower end system like a 12S battery setup which would be close to what I would fit in the car but with 10lbs thrust each.
42v (low-end 12S setup) in order to produce 15 pounds of thrust (per fan). The CFM would be around 2100 total.
That is 30 pounds thrust with 2larger units,smaller motor and batteries but still too big to fit on the car.
2100cfm/30lbs thrust=70cfm per 1 pound thrust?Does that sound right?
Looking at the top numbers 3800cfm/52lbs thrust=73cfm per 1 pound of thrust.
Trying to get an idea of what thrust is equal to in cfm from looking at the info they had.
What have you found on thrust compared to cfm in an open area as in cfm to thrust?
The fans I will be trying later on were alittle over 10lbs thrust each (20 lbs*70cfm=1400cfm) in an open area?
That is 1400cfm in open air thou.
So what have you found on the larger motors v8 on cfm flow once in the intake system compared to being outside in open?
Are you using anything in the intake now to test airflow and if so is it in cfm?
On stock injectors what amount of horsepower can be added before going to larger ones?
If this all works out then would think of making the center section alittle larger for bigger motors and 11 bladed carbon fan
blades instead of 7.
The fans were tested outside the system at alittle over 10lbs thrust each.
The one place claimed that the real big units(Twin fans) generates about 3800 CFM and 52 pounds of thrust when using two 15S setups.
On a lower end system like a 12S battery setup which would be close to what I would fit in the car but with 10lbs thrust each.
42v (low-end 12S setup) in order to produce 15 pounds of thrust (per fan). The CFM would be around 2100 total.
That is 30 pounds thrust with 2larger units,smaller motor and batteries but still too big to fit on the car.
2100cfm/30lbs thrust=70cfm per 1 pound thrust?Does that sound right?
Looking at the top numbers 3800cfm/52lbs thrust=73cfm per 1 pound of thrust.
Trying to get an idea of what thrust is equal to in cfm from looking at the info they had.
What have you found on thrust compared to cfm in an open area as in cfm to thrust?
The fans I will be trying later on were alittle over 10lbs thrust each (20 lbs*70cfm=1400cfm) in an open area?
That is 1400cfm in open air thou.
So what have you found on the larger motors v8 on cfm flow once in the intake system compared to being outside in open?
Are you using anything in the intake now to test airflow and if so is it in cfm?
On stock injectors what amount of horsepower can be added before going to larger ones?
If this all works out then would think of making the center section alittle larger for bigger motors and 11 bladed carbon fan
blades instead of 7.
Last edited by inactiveuser1; 01-08-2011 at 03:36 PM.
01-08-2011, 07:35 PM
#161
Rennlist Member
The Murf Stage 1 &2 do use the stock 19# injectors, but with an FMU to increase fuel pressure andhence flow when under boost.
Stage 3 uses 42# witrh stock FPR.
Stage 3 uses 42# witrh stock FPR.
01-09-2011, 01:06 AM
#162
Burning Brakes
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John,
Thanks for answer on the different stages and injector sizes with FMU.
Was looking at DR's test seen 30# injectors with stock fuel pressure but with shark tune
that was with 6.9psi boost not sure what is more up to date thou on the setup that was from 2006.
http://www.928gt.com/productspecs/40357.htm
Thanks for answer on the different stages and injector sizes with FMU.
Was looking at DR's test seen 30# injectors with stock fuel pressure but with shark tune
that was with 6.9psi boost not sure what is more up to date thou on the setup that was from 2006.
http://www.928gt.com/productspecs/40357.htm
01-09-2011, 06:01 AM
#163
Rennlist Member
I believe that spec for DR's twin screw system is still current. Yes, he uses 30# with stock fuel pressure (no FMU) and Sharktuned.
Murf Stage 3 with 42# also is Sharktuned. John Kuhn's Twin turbo uses 42# with ST. Tuomo's Kuhn TT is fitted with 64# and ST.
If you make any useful boost with your fans you will need to think how to get more fuel into the engine. As has been said, the 19# are pretty well max'd out even with the stock engines.
A 5 litre engine at 6500 rpm would use 578 cuft/min if it were 100% efficient from my calcs. No sure what the efficiency of the 928 engines are, but 80% might be a useful starting point.
Murf Stage 3 with 42# also is Sharktuned. John Kuhn's Twin turbo uses 42# with ST. Tuomo's Kuhn TT is fitted with 64# and ST.
If you make any useful boost with your fans you will need to think how to get more fuel into the engine. As has been said, the 19# are pretty well max'd out even with the stock engines.
A 5 litre engine at 6500 rpm would use 578 cuft/min if it were 100% efficient from my calcs. No sure what the efficiency of the 928 engines are, but 80% might be a useful starting point.
01-09-2011, 03:50 PM
#164
Burning Brakes
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If going up on injectors of 24lbs,how would the car be at an idle without FMU?
Is anyone running 24lb injectors just with minor mods or with an Cold air intake?
Is anyone running 24lb injectors just with minor mods or with an Cold air intake?