Generally they say a 4wd car will lose approx 30% through the drivetrain. Your losses seem very low. A friend had a GT4 which had 329BHP @ flywheel at power engineering , which only translated to 235bhp @ wheels. This was just a tad over 6000 rpm. I think that using different gears can make the rollers perhaps see a varying amounts of power, and different rolling roads can vary too.... It would of course be interesting to see what sort of power the car would have with the standard sti intercooler in place with some good cold air blown onto it, as a better back to back test of actual power gains, or maybe charge air temp improvements.
Anyway, It appears to be a good result
What sort of boost pressure are you running??

 

BTT for Jonny Gav

I have now modified the original air con rad for the water cooler. The end tanks have been extended to make the rad a single pass unit. The standard air con rad is 3 pass and quite restrictive.

The water pump is a very high flow rate Davies Craig 80 ltr/min.

All the pipework is 1" bore to keep the circulation rate up.

I monitored the air charge and circ water temps. On an 17 degree day I hit a max charge temp of 42C that was after six full bore acceleration runs up to 120 mph from standstill using 24 psi boost

The circ water slowly increased from 17 to 23 deg C. A short cruise (3 - 4 min) at 70 mph had the circ water back down to 18 C.

With the TMIC if I tried six runs back to back my temps would have been in the 60's and my knocklink would be winking at me

Not sure how it would cope with track use ? although most tracks only have around 50% full throttle use. Obviously, the warmer the water gets, the more efficient the rad becomes at removing the heat so equilibrium point would vary by use.

While I don't claim this is as temperature efficient for track use as some of the better FMIC's, it does have it's advantages. One of which is retaining the instant throttle response associated with TMIC's whilst eliminating the heatsoak problems.

Andy

 

Modified air con rad used as chargecooler water cooler

 

Looks like the rad is the weakest link in the setup then. You might get better results with a dual pass rad, if it still maintains good flow rates the higher speed in the pipes increases turbulence, encouraging better heat transfer from the bulk fluid to the tube wall.

The rad on my Legacy is not as big, but might be a little deeper from memory.

Do you use water wetter in the setup? Any comparison with/without?

Cheers

Paul

 

Andy: Very impressed. Is heat from the cooling radiator an issue. I assume you have retained its position.
Pitty fridges draw so much power. 12v immersion unit?

 

I've not tried water wetter yet, will do later though

The problem any radiator is going to have is the low delta T from circ water to air. The air con rad is designed to give a low end temperature to the refrigerant, whereas a normal car rad is designed to operate circa 85 C.
Then you need to balance the weight issue, being an RA I want to keep it as light as possible.

The bonnet scoop still directs air on to the water jacket to further assist with cooling. At motorway speeds I can switch off the circ pump without an increase in charge temp.

 

Harvey

Doesn't seem to be causing any temp rise. Whilst you are moving the air con rad gets the air first. If the car is stationary for any length of time the fans come on and pull cold air through both rads. I may fit a switch on the fans so I can run them manually, this is what the air con system done.
Could possibly fit waterspray too ??

 

Radiator looks good, It is a lot bigger than that fitted to the legacy. The legacy unit is a pretty small 2 pass jobbie, although I think the chargecooler unit itself is reasonably good. Do these watter wteer things actually work?? I have tried them on occation, and have bever noticed any difference, although not monitoring temps at the time. From anything I have read ( where people arent actually trying to sell something at the same time ) Pure water is the best coolant. A friend who races karts actually uses bottled water! The karts have standard rad size, and no pump, so temp monitoring can be very important. It does run approx 3-4 degC cooler with bottled as opposed to tap water. Possibly pure/de-ionised water may be better again? With just a little anti-freeze added purely for anti corrosion properties.

 

In the future, if intake temps become an issue, I might try adding a second charge cooler rad to the legacy.

Paul

 

btt

hehe

 

why paul?

 

well, someone asked about a chargecooler somewhere, so I dug this up, but lost the other thread.

Just thought it was historically interesting.

as many of the old threads are, which seem to re-invent themselves every few months, except yours of course.

Tubular headers thread...
Mellow asking about replacing a TD04...
John Banks first hybrid turbo of many...
Christian's pig ugly spoiler for sale...

all good stuff

P

 

24psi boost

[Edited by ScoobyDuck - 8/29/2002 1:46:46 PM]

 

Would moving the headlamp washers to the front of the bumper so the sprays can be directed at the rad be of any use, or am I talking p*sh ?

 

ahh I understand... I thought you had some inside knowledge

 

the inside of what?

 

new home?

 

No, Ian (UkLegacyT) had It, I was going to buy it, but chickened out, silly me!

 

Thought this thread was worthy of a reserectuon, Andy you got any pictures of the original diy chargecooler?

 

You'd be best off on 22b mate or Facebook, he doesn't frequent these pages much anymore afaik