Air con mod idea, increase bhp for free!!

[Digsy]

I would actually love to see the air con system you're going to plan to run to supply say for instance the 15,000 litres of air at 5,000rpm that your engine requires...........

 

That was my intitial thought (its not 15000 litres per minute at 5000RPM, though, its 7500 because its a two-stroke )

 

Thing is, the aircon doesn't have to supply the air - it just has to cool it. I knocked up the attached spreadsheet this morning when I first read the thread. It tells you the amount of heat that would have to be extracted from the intake air in order to drop the temperature on an NA from 35degC (about as hot as it gets in the UK) back down to 10degC. Its VERY simplified but there could (in theory) be a net gain of up to 11hp (extra fueling pro-rata'ed with air density). The cooling power isn't outlandish, either. IIRC most AC compressors are in the 5-7 kW range. I very strongly suspect that it won't be anywhere near as simple as this in real life, though, and I had to take a guess at the mechanical efficiency of the compressor. The effectiveness of the heat exchanger and the extra inlet depression it would create would also have to be taken into account.

 

In short, I reckon if this worked someone would have done it long ago

AC power.xls

[np89]

That was my intitial thought (its not 15000 litres per minute at 5000RPM, though, its 7500 because its a two-stroke :) )

 

Thing is, the aircon doesn't have to supply the air - it just has to cool it. I knocked up the attached spreadsheet this morning when I first read the thread. It tells you the amount of heat that would have to be extracted from the intake air in order to drop the temperature on an NA from 35degC (about as hot as it gets in the UK) back down to 10degC. Its VERY simplified but there could (in theory) be a net gain of up to 11hp (extra fueling pro-rata'ed with air density). The cooling power isn't outlandish, either. IIRC most AC compressors are in the 5-7 kW range. I very strongly suspect that it won't be anywhere near as simple as this in real life, though, and I had to take a guess at the mechanical efficiency of the compressor. The effectiveness of the heat exchanger and the extra inlet depression it would create would also have to be taken into account.

 

In short, I reckon if this worked someone would have done it long ago

 

 

 

AH yes right you are!lol my mistake!

[David P]

It does actually give more than it takes and was a naughty trick used by one of the Rally Teams before they were found out.

 

However, air con systems are nowhere near as efficient with post 95? safe gas.

 

 

It's not written in invisible ink on my laptop?

 

The induction system was lined with heat exchange pipes with the cold gas craftily plumbed in.

[stevie_b]

^^ Blank post here by David P, what's going on?

[mellonman]

so are we saying that you could make a metal air filter that is made of very smal air con pipes in the stock air box?

but even then its alot of work for little gain,

[David P]

The Rally class was to run with stock ancillaries and stock had air-con with the more efficient carcinogenic gas.

 

A fiddly job, but enough free naughty power to give them an edge until they were found out.

Edited August 19, 2013 by David P (see edit history)

[listy]

I think the idea is to create a cold air feed from the air con, onto the filter / into the air box.

In my eyes, it's a lot of work, for not much gain. Just create an air feed from a duct in the bumper. It's what I did, and on hot days, it did help (I went for a drive with it on, and without, and it helped create about 0.0 something of boost) and cost me all of around a tenner.

Money would be better spent on fabrication good ducting like Slutters did, which had proven gains, and drops in temperature.

 

Plus, as Digsy said, if it was worthwhile, then someone over the last 20 years of these cars being in existence, would have done it by now.

[Littler]

I think the idea is to create a cold air feed from the air con, onto the filter / into the air box.

In my eyes, it's a lot of work, for not much gain. Just create an air feed from a duct in the bumper. It's what I did, and on hot days, it did help (I went for a drive with it on, and without, and it helped create about 0.0 something bar of boost) and cost me all of around a tenner.

Money would be better spent on fabrication good ducting like Slutters did, which had proven gains, and drops in temperature.

 

Plus, as Digsy said, if it was worthwhile, then someone over the last 20 years of these cars being in existence, would have done it by now.

 

Wow that much boost

Edited August 19, 2013 by listy (see edit history)

[listy]

I know that was without a custom made airbox though, which I have in the pipeline (ssshhhhhhhhhhh ) I would expect better gains on warm days once the heat resistant box is in place, as the air will be cooler, as at the moment warm air still gets absorbed from the engine bay.

[Tricky-Ricky]

Had to have a little chuckle when I first read this, but I will make one comment, while cooling intake air undoubtedly has a beneficial effect, no amount of cooling will improve power levels if the charge cooling system is not efficient, IE the IC not doing a very good job of cooling, you could be putting air in at 0c but if the rest of the system isn't doing a good job then its totally wasted, my advice would be to all you can to cool the intake charge between the turbo and cylinders before even worrying about that side of the intake.

[Scott]

Just use a charge cooler with ice fill. Job done.

[Noz]

I think guys comparing the setup to others is a bit like saying don't use that turbo, get a better one when the question will the first component work isn't really addressed.

 

Had to have a little chuckle when I first read this, but I will make one comment, while cooling intake air undoubtedly has a beneficial effect, no amount of cooling will improve power levels if the charge cooling system is not efficient, IE the IC not doing a very good job of cooling, you could be putting air in at 0c but if the rest of the system isn't doing a good job then its totally wasted, my advice would be to all you can to cool the intake charge between the turbo and cylinders before even worrying about that side of the intake.

 

Dude your right. Not enough people compare their current setup. But I think we're just talking about if it would make any improvement at all. From ensuring all other components are working effectiveily, a good starting point perhaps but still this is an interesting point if it did work, even a little.

 

DEi make a co2 intake cooler which would in principle work in the same way. Everyone loves their turbo blankets right?

 

 

I think a comparison before and after would be needed. Ensuring all other sensible areas had been covered first (for the modification to be recommended for any other tuning purposes than to justify it did make a difference)

[Chris Wilson]

Some US company made a massive water to air heat exchanger for an after market turbocharged Ferrari and cooled the water using a truck sized air con compressor and ancillaries. They claimed it worked, but I note no manufacturers have taken this route. It's in one of the turbocharging books, with photos. The Ferrari was mid engined, so a conventional air to air heat exchanger (intercooler) would have the usual mid engined installation issues. On a front engined car a good air to air intercooler, properly ducted takes a lot of beating. KISS. A 3 litre engine at one bar boost has air inhalation similar to a six litre engine, there's no way a normal car air con unit could cool the sheer volume of air effectively. The air flow through a stock evaporator core to get impressive temperature drops is tiny compared to what a big engine ingests under boost, I would think. Air con usually works best on recirculate, with the windows shut, so the cool air get re-cooled further, too. Try that with an IC engine... I suspect the Ferrari was done for a Saudi prince or someone with far too much money, as an exercise in technical "over the topness"

Edited August 19, 2013 by Chris Wilson (see edit history)

[Ian C]

I can hear the laws of physics crying

[kill1308]

You could get a tanker full of liquid nitrogen to follow you around, with a pipe going from the lorry, in through the passenger window, then into the engine bay into a special cooling housing for the turbo

 

Full marks for the suggestion though, by all means try and post results before and after

Edited August 19, 2013 by kill1308 (see edit history)

[Chris Wilson]

I can hear the laws of physics crying

 

So can I, and I am as deaf as a post Without being unkind, when these good ideas come along on forums etecetera, bear in mind some of the best paid development engineers, worldwide, must have have missed the plot. OK, sometimes this happens, and progress is made, but 99% of the time it's vapour ware, excuse the pun.

[marc_p]

So much fail in this thread, you would be better to cable tie a bag of ice to the intake pipe for all the good it will do:D

[Ian C]

I see it as, on a hot day, powering a cooling fan via a pedal bike, and pedalling as fast as you can to cool yourself down.

[Tricky-Ricky]

I can see it now on ebay, miniature air-con units to plug into your intake, just like those little fans that give you turbo power:eyebrows:

[Digsy]

I see it as, on a hot day, powering a cooling fan via a pedal bike, and pedalling as fast as you can to cool yourself down.

 

Its not a First Law Of Thermodynamics violation, though

 

The relationship between the amount of cooling power required to drop the intake air charge and the amount of extra power you can extract from the combustion by stuffing more fuel in with the denser air isn't a direct one. In the same way that using an engine driven supercharger results in a net increase in output even though the supercharger itself requires considerable power to do work on the intake air to compress it. This is just way less efficient.

 

Incidentally, cooling fans only make you feel cooler but they increase the overall heat energy in the room

[Noz]

I can see it now on ebay, miniature air-con units to plug into your intake, just like those little fans that give you turbo power:eyebrows:

 

I'm on this

[Arron]

The simple fact remains as per initial thread guys.........

 

Those of you who have had the pleasure, displeasure of driving the Supra TT in summer will no doubt realise the crappy response and the sheer lack of adrenaline rush compared to winter response. And, if you're a technically minded person, you'll know the dreadful consequence of high intake temps under high boost....

 

Personally, I've had 5 TT Supra's in the past, 2 with air con and 3 without. Yes, if removed, the car will be lighter but come on how faster is losing a few kilos really going to be?? Just take the spare out and visit the loo before you drive ya car, that should off-set it lol

 

Fact, cooler intake charge temp increases bhp noticeably, just see the diff between winter and summer driving. This is why most people go for the FMIC. The mod, which I now have global rights on , will without a shadow of a doubt work. "I will give my Supra away if anyone can prove me wrong"

 

The FMIC coolers which peeps carry on about are only good for those of us who have 400+ bhp at the wheel otherwise the stock cooler is more than sufficient. The Japs are very clever people ;) No-one really uses the max bhp on a daily basis anyway. But this mod will make the 3000 rpm + rev ranges awesome.

 

Any takers for my car? lol

[Scott]

The simple fact remains as per initial thread guys.........

 

Those of you who have had the pleasure, displeasure of driving the Supra TT in summer will no doubt realise the crappy response and the sheer lack of adrenaline rush compared to winter response. And, if you're a technically minded person, you'll know the dreadful consequence of high intake temps under high boost....

 

Personally, I've had 5 TT Supra's in the past, 2 with air con and 3 without. Yes, if removed, the car will be lighter but come on how faster is losing a few kilos really going to be?? Just take the spare out and visit the loo before you drive ya car, that should off-set it lol

 

Fact, cooler intake charge temp increases bhp noticeably, just see the diff between winter and summer driving. This is why most people go for the FMIC. The mod, which I now have global rights on , will without a shadow of a doubt work. "I will give my Supra away if anyone can prove me wrong"

 

The FMIC coolers which peeps carry on about are only good for those of us who have 400+ bhp at the wheel otherwise the stock cooler is more than sufficient. The Japs are very clever people ;) No-one really uses the max bhp on a daily basis anyway. But this mod will make the 3000 rpm + rev ranges awesome.

 

Any takers for my car? lol

 

 

Can I have it on the basis that you are completely contradicting yourself?

[Arron]

Please Scott, elaborate

Can I have it on the basis that you are completely contradicting yourself?

[listy]