Wrapped my intake tubes with heat reflective tape.
08-18-2010, 01:50 PM
#91
Rennlist Member
exactly (again!)
there is nothing to be gained by insulating the intake tubes.
Yes, by doing water injection, you can increase the density of the intake air charge. Its been done in engine systems since world war II. My dad even put on a water injection system on his supercharged Corvar back in the 60s.
there is nothing to be gained by insulating the intake tubes.
Yes, by doing water injection, you can increase the density of the intake air charge. Its been done in engine systems since world war II. My dad even put on a water injection system on his supercharged Corvar back in the 60s.
I just don't get it... when did stock intake tubes become some great magical heat exchanger and the only way to keep the magic from happening is to wrap it up heat deflecting materials? Heat exchangers look like radiators, condensers, heat sinks, etc… lots of fins and surface area specifically designed to exchange heat.
Intakes are the opposite of this. They are round and smooth with a bunch of air rushing down the middle with very tiny fraction making contact with the outside wall for only a very short period of time. So even if that wall is close to 200 degrees that air rushing past it isn’t going to be touching it long enough to make any meaningful impact.
I think the the reason cooler air creates slightly more power is because it is slightly denser (contains more oxygen). More oxygen equals means more fuel equals more combustion equals more power. That's a pretty plausible argument to follow. Sure warmer air combusts more readily… if fact that’s why intercoolers are used on forced induction systems… because higher intake temps are more prone to early detonation.
I‘ll throw one out there that would be a fun riddle to contemplate. Why not put a water mister at the beginning of the inlet to allow for evaporative cooling? Plus water would induce more oxygen and allowing more fuel to burn. Now that would be interesting, but I’m guessing not plausible or it would have already been done.
Intakes are the opposite of this. They are round and smooth with a bunch of air rushing down the middle with very tiny fraction making contact with the outside wall for only a very short period of time. So even if that wall is close to 200 degrees that air rushing past it isn’t going to be touching it long enough to make any meaningful impact.
I think the the reason cooler air creates slightly more power is because it is slightly denser (contains more oxygen). More oxygen equals means more fuel equals more combustion equals more power. That's a pretty plausible argument to follow. Sure warmer air combusts more readily… if fact that’s why intercoolers are used on forced induction systems… because higher intake temps are more prone to early detonation.
I‘ll throw one out there that would be a fun riddle to contemplate. Why not put a water mister at the beginning of the inlet to allow for evaporative cooling? Plus water would induce more oxygen and allowing more fuel to burn. Now that would be interesting, but I’m guessing not plausible or it would have already been done.
08-18-2010, 01:50 PM
#92
Nordschleife Master
08-18-2010, 01:53 PM
#93
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Those who care about gas mileage for starters....
Not to mention heat soaking the hell out of your intake at cruise isn't all that great of an idea either.
Todd and I will easily have 10x's the amount of tuning for the cruise map versus WOT.
Considering your method of turning is "turning the adjustment **** on the fuel pressure regulator 1.5 turns" I don't expect you to agree with this.
Not to mention heat soaking the hell out of your intake at cruise isn't all that great of an idea either.
Todd and I will easily have 10x's the amount of tuning for the cruise map versus WOT.
Considering your method of turning is "turning the adjustment **** on the fuel pressure regulator 1.5 turns" I don't expect you to agree with this.
08-18-2010, 01:54 PM
#94
Rennlist Member
08-18-2010, 01:57 PM
#95
Rennlist Member
And this is why, your tests are completly worthless, unless you care about intake temps under part throttle conditions. I have no doubt you got the results you got with the fluke meter. I use a sunx sensor for pressure readings as well and have plotted the results from all over the car and intake.
what you have done is measure the air temp in the tubes while insulated and not insulated, right. and you have done this while you are driving around town, right? Do you see the flaw here in the test?
When under WOT conditions, where air density would be a factor, you will see very little change in air temp running over the air filter. try it and get back to us.
at any other point in the operation of our cars, air temp is really not a problem or an issue, so this solution of wrapping the intake tubes is a solution, LOOKING for a problem that it will not find.
what you have done is measure the air temp in the tubes while insulated and not insulated, right. and you have done this while you are driving around town, right? Do you see the flaw here in the test?
When under WOT conditions, where air density would be a factor, you will see very little change in air temp running over the air filter. try it and get back to us.
at any other point in the operation of our cars, air temp is really not a problem or an issue, so this solution of wrapping the intake tubes is a solution, LOOKING for a problem that it will not find. Eric,
Sorry I thought I answered your question. It is a Fluke sensor accurate to 1/2 deg. F, and at the time both were calibrated by our lab. The reading were done on a long mostly straight stretch of highway (60-65 MPH) about 10 and 20 miles into a 26 mile commute. The engine was fully up to operating temps and the readings did not vary much at all during a given 35-45 minute drive. Readings were taken at the same two landmarks as I passed them, approx. 10 miles and 15 miles from the starting location. The sensor was laying on top of the air cleaner directly above the MAF. It was snaked through the inlet on the LH side of the air cleaner housing and taped in place. The air box had previously been sealed with RTV, but the hoses were not taped or sealed to the air box, nor were the hoses sealed to the front air inlets. The hoses still had the holes for the cam gear/belt cooling.
I made every attempt to duplicate the conditions daily, the only variable was the actual ambient temps and on a few occasions traffic. The traffic (stop and go due to a accident) is when I saw the temps go above 170 degrees.
Sorry I thought I answered your question. It is a Fluke sensor accurate to 1/2 deg. F, and at the time both were calibrated by our lab. The reading were done on a long mostly straight stretch of highway (60-65 MPH) about 10 and 20 miles into a 26 mile commute. The engine was fully up to operating temps and the readings did not vary much at all during a given 35-45 minute drive. Readings were taken at the same two landmarks as I passed them, approx. 10 miles and 15 miles from the starting location. The sensor was laying on top of the air cleaner directly above the MAF. It was snaked through the inlet on the LH side of the air cleaner housing and taped in place. The air box had previously been sealed with RTV, but the hoses were not taped or sealed to the air box, nor were the hoses sealed to the front air inlets. The hoses still had the holes for the cam gear/belt cooling.
I made every attempt to duplicate the conditions daily, the only variable was the actual ambient temps and on a few occasions traffic. The traffic (stop and go due to a accident) is when I saw the temps go above 170 degrees.
08-18-2010, 01:58 PM
#96
Rennlist Member
Sub WOT load points are important, we aren't all racers.
08-18-2010, 02:05 PM
#97
Rennlist Member
Oh, now you are claiming the cooler cruise intake will give you better gas mileage? You are really reaching.
the point is, your intake will heat soak eventually anyway, only being kept cooler by the air running through it.
my tuning method was used to get a ball park of fuel adjusted to keep the engine safe, and at 11 to 12:1 over all, its safe, the plugs are clean and the engine is not detonating. sure, I would love to optimize, but for a car that drives perfectly smooth on the hyway, no flat spots, and runs strong WOT, with no issues, my mission has been achieved. The fastest 928 in the world, has done the same tuning .... Mark anderson...... fuel regulator pressure ONLY no other changes, 520rwhp
Do you think a clean air filter gives you better gas mileage too?
the point is, your intake will heat soak eventually anyway, only being kept cooler by the air running through it.
my tuning method was used to get a ball park of fuel adjusted to keep the engine safe, and at 11 to 12:1 over all, its safe, the plugs are clean and the engine is not detonating. sure, I would love to optimize, but for a car that drives perfectly smooth on the hyway, no flat spots, and runs strong WOT, with no issues, my mission has been achieved. The fastest 928 in the world, has done the same tuning .... Mark anderson...... fuel regulator pressure ONLY no other changes, 520rwhp
Do you think a clean air filter gives you better gas mileage too?
Those who care about gas mileage for starters....
Not to mention heat soaking the hell out of your intake at cruise isn't all that great of an idea either.
Todd and I will easily have 10x's the amount of tuning for the cruise map versus WOT.
Considering your method of turning is "turning the adjustment **** on the fuel pressure regulator 1.5 turns" I don't expect you to agree with this.
Not to mention heat soaking the hell out of your intake at cruise isn't all that great of an idea either.
Todd and I will easily have 10x's the amount of tuning for the cruise map versus WOT.
Considering your method of turning is "turning the adjustment **** on the fuel pressure regulator 1.5 turns" I don't expect you to agree with this.
08-18-2010, 02:08 PM
#98
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
"and who cares what your timing, or intake temps are during cruise."
If you don't think timing has any effect on cruise.....well that wouldn't surprise me.
You know, trying to carry on a conversation with you is about the same frustration level as teaching a handicapped child how to yodel.
08-18-2010, 02:11 PM
#99
Rennlist Member
Well, then its not an issue, if you are seeing intake temps of 170 degrees now is it? Its going to retard the timing and there is nothing you can do about it, unless you can drop the intake temps by 50 degrees, right Jim???
mk
mk
08-18-2010, 02:15 PM
#100
Nordschleife Master
Mark: a few degrees advance will give more power from the same gas, hence better mileage.
Eric: I didn't know you did that sort of volunteer work. Or are you a paid yodeling teacher?
Eric: I didn't know you did that sort of volunteer work. Or are you a paid yodeling teacher?
08-18-2010, 02:16 PM
#101
Craic Head
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Mark,
As Simon pointed out, here's the flaw in your potato analogy:
If the air tubes are the potato and the engine compartment is the oven, the big difference is that the air tubes are not completely enclosed within and under the hood (in the oven).
True enough if there were no outside factors, eventually the air inside the tubes (the baked potato) would reach the temp of the engine compartment (oven).
Instead a closer analogy would be to cut a hole in the front and back of the oven and put a 3" tube from one to the other and seal it off. Now blow air through that tube at different speeds.
Next insulate that tube and blow air through at different speeds.
I have no doubt that at WOT speeds you would read no difference in the outlet air but as Simon pointed out, the inside of the insulation will be closer to the air inside the tube and the outside of the insulation will be closer to the oven temp so at slow speeds, the air temps would probably remain colder coming out.
Otherwise, why do we insulate hot water pipes?
You're arguing that because you didn't see a difference at WOT, that there could be no gains at part throttle and that any gains at idle and part throttle are of no consequence.
Clearly they have improved the performance of the car (though not by adding peak HP) and John Speake has explained why.
Can we all agree that this mod doesn't add any HP but can still make the car run better (obviously, since the results have been demonstrated by those who have done it)?
As Simon pointed out, here's the flaw in your potato analogy:
If the air tubes are the potato and the engine compartment is the oven, the big difference is that the air tubes are not completely enclosed within and under the hood (in the oven).
True enough if there were no outside factors, eventually the air inside the tubes (the baked potato) would reach the temp of the engine compartment (oven).
Instead a closer analogy would be to cut a hole in the front and back of the oven and put a 3" tube from one to the other and seal it off. Now blow air through that tube at different speeds.
Next insulate that tube and blow air through at different speeds.
I have no doubt that at WOT speeds you would read no difference in the outlet air but as Simon pointed out, the inside of the insulation will be closer to the air inside the tube and the outside of the insulation will be closer to the oven temp so at slow speeds, the air temps would probably remain colder coming out.
Otherwise, why do we insulate hot water pipes?
You're arguing that because you didn't see a difference at WOT, that there could be no gains at part throttle and that any gains at idle and part throttle are of no consequence.
Clearly they have improved the performance of the car (though not by adding peak HP) and John Speake has explained why.
Can we all agree that this mod doesn't add any HP but can still make the car run better (obviously, since the results have been demonstrated by those who have done it)?
08-18-2010, 02:28 PM
#102
Rennlist Member
Hey, now this is just getting into a senseless argument.
Yes, I asked the question, and you gave the answer. yes, valid points. timing is important cruise. I'm interested in getting the best gas mileage while commuting to the track. The point is whether insulating the intake tubes will have a rats effect on intake temps, so that the timing DOES change in at cruise. as was said, the timing is reduced by 3 degrees when temps reach 120degrees. Jim also tested the insulated system and found his measurements of 30 degree temp drop. But, if he found temps at 170 degrees of the air entering the intake air filter, (which I have a hard time imaging , unless it was sitting in 105 degree stop and go traffic), then by lowering the intake temps by 30 degrees, you are still above the threshold where the timing is retarded.
You think there are no handicapped yodelers??
Yes, I asked the question, and you gave the answer. yes, valid points. timing is important cruise. I'm interested in getting the best gas mileage while commuting to the track.
The point is whether insulating the intake tubes will have a rats effect on intake temps, so that the timing DOES change in at cruise. as was said, the timing is reduced by 3 degrees when temps reach 120degrees. Jim also tested the insulated system and found his measurements of 30 degree temp drop. But, if he found temps at 170 degrees of the air entering the intake air filter, (which I have a hard time imaging , unless it was sitting in 105 degree stop and go traffic), then by lowering the intake temps by 30 degrees, you are still above the threshold where the timing is retarded.You think there are no handicapped yodelers??
You asked a very simple question:
"and who cares what your timing, or intake temps are during cruise."
If you don't think timing has any effect on cruise.....well that wouldn't surprise me.
You know, trying to carry on a conversation with you is about the same frustration level as teaching a handicapped child how to yodel.
"and who cares what your timing, or intake temps are during cruise."
If you don't think timing has any effect on cruise.....well that wouldn't surprise me.
You know, trying to carry on a conversation with you is about the same frustration level as teaching a handicapped child how to yodel.
08-18-2010, 02:32 PM
#103
Rennlist Member
I get this Glen, but the point is, is a cooler intake going to change the threshold of 120 degrees. (as was said), and was is it possible during cruise that you intake air at 55-65mph is over 120 degrees, if that is the threshold where timing is retarded 3 degrees?
08-18-2010, 02:43 PM
#104
Rennlist Member
Yes, and I agreed with you . the insulation really effects the rate of change of temps. I get this. I also agree this is why, at slow speeds you could see some improvement. 30 dgrees though? I dont know, but I tend to trust Jim's results, but not sure when they were measured. (he was talking driving around at all different speeds) I woudlnt think you would see a 30 degree drop at 55mph or faster, but thats my guess. pretty simple test though to check. Im glad you agree that under WOT that there really wouldnt be any gains or expected temp drops.
as far as the last part of your reply, I dont believe that the car will run better with insualtion for the reasons I mentioned. my car runs the same in the cold as it does in the hot and I run at the race track in near 105 temps, with track temps of over 130 degree F. I never notice any difference, besides a slight lack of power due to the heat its always much faster when its 40 degrees outside and it runs the same. Also, my gas mileage is near the same too from what Ive measured. maybe the thicker air when cold counteracts any of the gains of the colder air in combustion. (ignoring any timing changes possible)
Anyway, to get back on track. my only position is that insulating the tubes dont help HP at WOT, and Ill leave it at that. " responsiveness", etc, to me, equal HP. If you are talking you have to push the throttle a little further down to get the same power, then thats really not a performance change in my book. I would like to see the top of air filter temp results for Jims tests though. Highway, vs around town, at a stop light, at high rate of speed, and then of course, WOT!
as far as the last part of your reply, I dont believe that the car will run better with insualtion for the reasons I mentioned. my car runs the same in the cold as it does in the hot and I run at the race track in near 105 temps, with track temps of over 130 degree F. I never notice any difference, besides a slight lack of power due to the heat its always much faster when its 40 degrees outside and it runs the same. Also, my gas mileage is near the same too from what Ive measured. maybe the thicker air when cold counteracts any of the gains of the colder air in combustion. (ignoring any timing changes possible)
Anyway, to get back on track. my only position is that insulating the tubes dont help HP at WOT, and Ill leave it at that. " responsiveness", etc, to me, equal HP. If you are talking you have to push the throttle a little further down to get the same power, then thats really not a performance change in my book. I would like to see the top of air filter temp results for Jims tests though. Highway, vs around town, at a stop light, at high rate of speed, and then of course, WOT!
Mark,
As Simon pointed out, here's the flaw in your potato analogy:
If the air tubes are the potato and the engine compartment is the oven, the big difference is that the air tubes are not completely enclosed within and under the hood (in the oven).
True enough if there were no outside factors, eventually the air inside the tubes (the baked potato) would reach the temp of the engine compartment (oven).
Instead a closer analogy would be to cut a hole in the front and back of the oven and put a 3" tube from one to the other and seal it off. Now blow air through that tube at different speeds.
Next insulate that tube and blow air through at different speeds.
I have no doubt that at WOT speeds you would read no difference in the outlet air but as Simon pointed out, the inside of the insulation will be closer to the air inside the tube and the outside of the insulation will be closer to the oven temp so at slow speeds, the air temps would probably remain colder coming out.
Otherwise, why do we insulate hot water pipes?
You're arguing that because you didn't see a difference at WOT, that there could be no gains at part throttle and that any gains at idle and part throttle are of no consequence.
Clearly they have improved the performance of the car (though not by adding peak HP) and John Speake has explained why.
Can we all agree that this mod doesn't add any HP but can still make the car run better (obviously, since the results have been demonstrated by those who have done it)?
As Simon pointed out, here's the flaw in your potato analogy:
If the air tubes are the potato and the engine compartment is the oven, the big difference is that the air tubes are not completely enclosed within and under the hood (in the oven).
True enough if there were no outside factors, eventually the air inside the tubes (the baked potato) would reach the temp of the engine compartment (oven).
Instead a closer analogy would be to cut a hole in the front and back of the oven and put a 3" tube from one to the other and seal it off. Now blow air through that tube at different speeds.
Next insulate that tube and blow air through at different speeds.
I have no doubt that at WOT speeds you would read no difference in the outlet air but as Simon pointed out, the inside of the insulation will be closer to the air inside the tube and the outside of the insulation will be closer to the oven temp so at slow speeds, the air temps would probably remain colder coming out.
Otherwise, why do we insulate hot water pipes?
You're arguing that because you didn't see a difference at WOT, that there could be no gains at part throttle and that any gains at idle and part throttle are of no consequence.
Clearly they have improved the performance of the car (though not by adding peak HP) and John Speake has explained why.
Can we all agree that this mod doesn't add any HP but can still make the car run better (obviously, since the results have been demonstrated by those who have done it)?
