Homer Posted January 16, 2007 Share Posted January 16, 2007 but intake temps at the filter would only be 10 deg higher in the engine bay max I would think and if you think about how hot the tubbies run (above 700deg) whether the air is going in to them at 20deg or 30deg the turbos would be that hot the air coming out of them into the intercooler will pick up serious heat either way and its then down to the outside air temp to keep the intercooler cold. Just my opinion but I would think even a 10 deg difference in air temp going into the tubbies it wouldnt be 10deg higher when it came out. they would probably be the same. The intake temp between the stock system and pod filter is much, much greater than that. Last spring I did some tests between the apexi and stock system, the stock intake temp was fairly a constant around 45deg at the filter (30deg@30mph), the Apexi showed up to 65deg (44deg@30mph), that’s an enormous difference. There wasn't any real noticeable power difference once out of traffic, but from a standing start and in-traffic, it was far more civilised to drive. Quote Link to comment Share on other sites More sharing options...
Homer Posted January 16, 2007 Share Posted January 16, 2007 umm, take a look at post 18, not sure myself. Post #18 is wrong though Quote Link to comment Share on other sites More sharing options...
Chris and Alana Posted January 16, 2007 Share Posted January 16, 2007 Why do you think its hundreds of degrees? Are you saying the air ingested at the turbo at approx 30deg is heated to 700deg by the turbo and the intercooler cools it back to 35-40deg by the time it reaches the intake? no not at all just that such a little differnce in temperature going into the tubbies (when they are so hot) shouldnt make the same difference when it comes out and into the intercooler Quote Link to comment Share on other sites More sharing options...
Matt H Posted January 16, 2007 Author Share Posted January 16, 2007 Why do you think its hundreds of degrees? Are you saying the air ingested at the turbo at approx 30deg is heated to 700deg by the turbo and the intercooler cools it back to 35-40deg by the time it reaches the intake? no not at all but thats beside the point, it doesnt matter to this discussion what the resultant temp is after the turbo, just the differance that the resultant temp is using both variations of air feed Quote Link to comment Share on other sites More sharing options...
Wez Posted January 16, 2007 Share Posted January 16, 2007 How would the airs velocity through the turbo affect this? If the air was in contact with a 700deg turbo for a long period of time its going to take on alot of radiant heat but at the rate its passing through the turbo I imagine its nothing like 700deg. Quote Link to comment Share on other sites More sharing options...
Pabs Posted January 16, 2007 Share Posted January 16, 2007 interesting to see a thread like this on here.... I have a thread going on the SEAT cupra forums at the moment along similar lines... I've got a CAI, with the filter in the passenger side wheel area, right down in the bottom of the bumper. Results are quite good. Standard airbox/feed gets around 170g/s air flow, with this i see 185g/s, and obviously more air is good. Intake temps are also slightly lower, although not hugely different. However, I'm going back to a standard airbox, just like most supra owners recommend. I'm doing this because the results are on par, if not better, when used with an uprated filter element (green filters, for example) and a larger air intake ducting/hosing. So long as the hose entry point is towards the front of the car, ie in the grille or down near a foglight, the results are as good, if not better. Also allow far easier access to clean/replace the filter. Doesn't LOOK as nice, but my car is not really a show car now as it's getting so worn, dented, and abused, with the 25k miles a year i do to work and back Quote Link to comment Share on other sites More sharing options...
Matt H Posted January 16, 2007 Author Share Posted January 16, 2007 Post #18 is wrong though fair enough! lol Quote Link to comment Share on other sites More sharing options...
Wez Posted January 16, 2007 Share Posted January 16, 2007 I would have thought the whole point of this was to reduce in the final intake temp, maybe I am missing something here Quote Link to comment Share on other sites More sharing options...
Matt H Posted January 16, 2007 Author Share Posted January 16, 2007 I have a thread going on the SEAT cupra forums at the moment along similar lines... I've got a CAI, with the filter in the passenger side wheel area, right down in the bottom of the bumper. Is the cupra a turbo? Quote Link to comment Share on other sites More sharing options...
Wez Posted January 16, 2007 Share Posted January 16, 2007 I am confused now If i get chance I will datalog the intake air with and without the headlight this weekend. Quote Link to comment Share on other sites More sharing options...
Chris and Alana Posted January 16, 2007 Share Posted January 16, 2007 The intake temp between the stock system and pod filter is much, much greater than that. Last spring I did some tests between the apexi and stock system, the stock intake temp was fairly a constant around 45deg at the filter (30deg@30mph), the Apexi showed up to 65deg (44deg@30mph), that’s an enormous difference. There wasn't any real noticeable power difference once out of traffic, but from a standing start and in-traffic, it was far more civilised to drive. So the temp of the air going into an open cone filter can be 20 deg's more than temp of the air that would flow through the original air box. I gues I was a bit out then but what difference does it make after the turbos have added their heat? surely the temps going into the intercooler arnt going to be 20 deg more aswell are they? you may expect a slight differnce but . . . . . arrrr, I dont know, might go to bed and watch the rest of shameless (I know its poo but its funny) Quote Link to comment Share on other sites More sharing options...
Wez Posted January 16, 2007 Share Posted January 16, 2007 I will think about this some more later Quote Link to comment Share on other sites More sharing options...
Matt H Posted January 16, 2007 Author Share Posted January 16, 2007 I would have thought the whole point of this was to reduce in the final intake temp, maybe I am missing something here Yeah that corrects, I don’t disagree that there will be an effect on final temperature, but that effect, albeit it being affect to me seems almost a pointless affair to be chasing. we are all speculating at the moment tho, I could be hugely wrong, but logic tells me that the difference will be almost negligible, or if not negligible, not worth the cost? If you can afford the time and build you own feed then why not, but I don’t think anyone could justify buying say a headlight with the hole in it. Not exactly sure but isn’t Joh selling them for over £100? Not value for money unless your after that race car look? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 16, 2007 Share Posted January 16, 2007 umm, take a look at post 18, not sure myself. I see your point, but i wonder in reality if the actual air temp just after the turbo is that high? in fact if i can find a way to get a thermocouple into the outlet side of the turbo i'll check it. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 16, 2007 Share Posted January 16, 2007 umm, take a look at post 18, not sure myself. Sorry double post! Quote Link to comment Share on other sites More sharing options...
Matt H Posted January 16, 2007 Author Share Posted January 16, 2007 Yeah me too, good discussion tho chaps, im gona go and watch the second series of lost i bought yesterday Quote Link to comment Share on other sites More sharing options...
Pabs Posted January 16, 2007 Share Posted January 16, 2007 Is the cupra a turbo? yes mate. 1.8 20VT with a k03s turbo. I'm roughly running 218bhp/240lbft, with a boost pressure of about 20psi peak. Standard boost level is about 9psi. Quote Link to comment Share on other sites More sharing options...
Homer Posted January 16, 2007 Share Posted January 16, 2007 So the temp of the air going into an open cone filter can be 20 deg's more than temp of the air that would flow through the original air box. I gues I was a bit out then but what difference does it make after the turbos have added their heat? surely the temps going into the intercooler arnt going to be 20 deg more aswell are they? you may expect a slight differnce but . . . . . arrrr, I dont know, might go to bed and watch the rest of shameless (I know its poo but its funny) Its a good question, the only way is to check the air temp pre and post IC (also a good measure of IC performance). Post IC is the one that really matters but without the other measurements of Air intake temp its not going to be comparible. I have the equipment to do this, but no longer the car! However, lower intake air can only be a good thing, it's not like its going to get any cooler! Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 16, 2007 Share Posted January 16, 2007 I already have a thermocouple in the plenum, which is the actual intake charge temp, as it gets a little re heated due to the metal temp, so if i can get one into the turbo side i will, should make a good comparison. Just a side note, on my old S14 i had a very good cold air inlet straight to the filter/AFM and i got very low charge temps both befor the turbo and in the plenum, even in hot weather. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 16, 2007 Share Posted January 16, 2007 I don't know if you'll believe this or not but the output from a high boosting moderate sized turbo can be eighty to ninety degC higher than ambient temps. Also, on a nice hot day in France, I measured a balmy 75 degC in my engine bay near the engine. So if it's A) 30degC outside you can get 120degC out the turbo if you pick up ambient air temps. B) Get it from the engine bay and it'll spit out say 160degC. If you've got an 80% efficient intercooler, it'll pull 80% of (120-30) out of scenario A. Which is 72degC off 120degC = 48degC In scenario B you get 80% of (165-30) (yes, still 30, we aren't using in-bay air through the intercooler) which is 108degC off 165 = 57degC. That's almost 10degC higher intake temp in the plenum. So its not as bad as it initially looks providing your intercooler is doing its job. However on top of the power loss due to the hotter air, you've also got the more anaemic air you've drawn in in the first place. Boost works on pressure and hotter air = more pressure so your A-scenario 1 bar of boost at 120degC is more powerful, like for like, than scenario B's 1 bar of boost at 165degC. It's not all about power either, hotter intake temps are the number one cause of detonation. You know why you have to run rich at high boost? The extra fuel acts as a coolant, like water injection. Yes, we need it for the power, but we need it more for the cooling. Add 10degC onto your intake charge and you'd better run more fuel with it. And you know what an even richer mix means? Less power And speaking of your intercooler doing it's job, what if you've booted it and got on boost while there isn't much flow over your 'cooler? Nasty. That's the big wheezy feeling you get from a pod filter setup when stuck in traffic in high heat and then booting it from a crawl/standstill. It gulps in 70degC air, compresses it a bit and then can't cool it. So yes, it does matter somewhat, I reckon For the sake of a shield (doesn't have to be hermetically sealed, just a shield from the engine fan and it's ambient air) and a duct that can be left in from the stock setup, you get nothing but benefits... -Ian Quote Link to comment Share on other sites More sharing options...
TLicense Posted January 16, 2007 Share Posted January 16, 2007 Quote Link to comment Share on other sites More sharing options...
hadyn Posted January 16, 2007 Share Posted January 16, 2007 Ultimately though on a stock set up, if you fit an aftermarket cone filter you will lose power/not make any power compared to the stock airbox and filter? Quote Link to comment Share on other sites More sharing options...
Wez Posted January 17, 2007 Share Posted January 17, 2007 Great post Ian, just the answer I was hoping to read Quote Link to comment Share on other sites More sharing options...
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