air intake
#28
Since the average CAI makes no pretense of actually pressurizing the charge that seemed outside the scope of the discussion.
#29
Trying ot get enough pressure from a CAI to actually be worth speaking about will be pretty difficult. Trying to find a location for a scoop of some sort would be one problem, then building the scoop to allow the airflow to velocitize and smoothly enter the intake tubing would be another issue.
Personally, wrapping CAI piping or box with ceramic insulation would be easier to me. I suppose to lower the engine bay temps would be to cut / add vents in the hood.
Evil Aviator, I wouldn't say homemade CAI fail at getting pressure since most of them, including mine, are not designed to get pressure. They are designed to duct outside air into the engine. Now if you were desinging a CAI for pressure and you got nothing, then I would say it failed.
Personally, wrapping CAI piping or box with ceramic insulation would be easier to me. I suppose to lower the engine bay temps would be to cut / add vents in the hood.
Evil Aviator, I wouldn't say homemade CAI fail at getting pressure since most of them, including mine, are not designed to get pressure. They are designed to duct outside air into the engine. Now if you were desinging a CAI for pressure and you got nothing, then I would say it failed.
Last edited by RotaMan99; 09-27-07 at 07:08 AM.
#30
I have no way of measuring intake temps but I'd guess the difference would be very small.
Venting the hood would not only be at least as effective lowing the intake temps but also have the added benefit of lowering the coolant temps, assuming that the venting was designed to extract rad air outflow.
Hence my "more bang for the buck" statement.
#31
Certainly wrapping insulation is easier and I'd like to see what effect it might have.
I have no way of measuring intake temps but I'd guess the difference would be very small.
I have no way of measuring intake temps but I'd guess the difference would be very small.
Venting the hood would not only be at least as effective lowing the intake temps but also have the added benefit of lowering the coolant temps, assuming that the venting was designed to extract rad air outflow.
Hence my "more bang for the buck" statement.
Hence my "more bang for the buck" statement.
#32
Originally Posted by Evil Aviator
I assume that's because you think that the aluminum will cause massive heat transfer to the intake charge. In actuality, there is very little heat transfer because straight-wall metal doesn't transfer heat very well, and at the typical rotary engine's flow rate of 250-400cfm there is little time for the heat transfer to take place.
The temp difference in that test between plain sheetmetal and 1" thick insulated material was 4°F...over a 100 FOOT duct length.
Now, given the duct's poor heat transfer capability, the high airflow volume AND the short duct length what do you think the difference might be...a fraction of a degree?
By all means, go ahead and wrap your ducts...it certainly can't hurt but I'd be skeptical of any claims that it helps much.
#34
Evil Aviator, I wouldn't say homemade CAI fail at getting pressure since most of them, including mine, are not designed to get pressure. They are designed to duct outside air into the engine. Now if you were desinging a CAI for pressure and you got nothing, then I would say it failed.
4degF = about 1/2% hp difference
#35
Well that's exactly the problem. Everybody is so gung ho about lowering temperatures that they completely miss the point that pressure also has an effect on density. I am not talking about ram air, but rather what you guys would call a "restriction".
Originally Posted by Evil's Sig
Cold Air Intake = Long restrictive pipe that sucks in ambient (not cold) outside air.
4degF = about 1/2% hp difference
#38
#41
Evil Aviator, I wouldn't say homemade CAI fail at getting pressure since most of them, including mine, are not designed to get pressure. They are designed to duct outside air into the engine. Now if you were desinging a CAI for pressure and you got nothing, then I would say it failed.
Given that: The stock intake system already ducts outside air into the engine.
Your goal was: Duct outside air into the engine? That doesn't make any sense because it did that to start with.
Therefore, your actual goal was: Design a new intake system that ducts in the EXACT same temperature air as before, but with less pressure loss.
So, using your own reasoning, if you designed a CAI for colder temperature, and you got the exact same temperature as before, what have you hopefully gained?.... That's right, pressure.
Therefore, I say back to you, if you designed the CAI for pressure, and you got nothing, then I would say it failed. The dyno will prove this, because if the temperature remains constant, there will be absolutely no power gain if there is no gain in pressure.
#43
I can prove that you did in fact design yours for pressure
Your goal was: Duct outside air into the engine? That doesn't make any sense because it did that to start with.
Therefore, I say back to you, if you designed the CAI for pressure, and you got nothing, then I would say it failed.
Now removing the stock air box and building a CAI that is lower in restriction, is already a pressure increase, but thats the issue, I suppose you could say, everyone is building their CAI for increase in pressure because restriction lowers it and thats what people try to minimize is the restriction. Although, like you have said in the past, some CAI are so convoluded, they may not have gained anything at all.
#44
Now removing the stock air box and building a CAI that is lower in restriction, is already a pressure increase, but thats the issue, I suppose you could say, everyone is building their CAI for increase in pressure because restriction lowers it and thats what people try to minimize is the restriction. Although, like you have said in the past, some CAI are so convoluded, they may not have gained anything at all.
Now there is also the issue of momentum, but I won't go into that.
#45
Yes, that's exactly my point. Ironic, isn't
Now there is also the issue of momentum, but I won't go into that
so lets talk
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
09-16-18 07:16 PM
mulcryant
2nd Generation Specific (1986-1992)
10
09-09-15 05:24 PM