Contour Enthusiasts Group Archives Forums Modifications Forced Induction 70mm TB re-installed; Intercooler pressure drop?

I put the 70mm TB back on, let me tell you the butt dyno says more power! The car went crazy fast and the tires have a little less grip in 1st and second now despite the ATB differential!
The turbo really likes it, I can really tell a difference under acceleration.
BTW unrelated, but I think I figured out why my dyno runs were all at 5.75 psi instead of the 6.5psi that I had before that. The wastegate spring is set at 6.5psi stock but I have the intercooler in there now and I'm sensing my boost pressure at the vacuum ports in the manifold.
This probably means that there is a 0.75psi pressure drop across the intercooler now that it is installed. According to the book MAximum Boost, IIRC it says that intercoolers with a pressure drop of 1 psi or less are good, obviously with less being better for racing cars. I think 0.75 is pretty good for a street car.

The intecooler I have is a spearco made unit from another car that I picked up used. Keith at streetflight helped me figure out the best way to fit it and then he did all the welding on it. It looks quite good I think. I will take some pictures tonight, but again, I have no way to host them right now so I'll email some on request for those of you looking for ideas or just curious.
Next step is to design&build, or buy a boost pressure regulator to up the boost.
I'll eventually be starting to add little goodies to my system to make it better and better.

Looks like someone will host pics for me, so they should be up later on.

pics are big so here are the links....

Pic 1

Pic 2

Pic 3


Very cool!

Looks pretty to me

Looks quite good!

Have you thought about doing any temperature testing before and after the IC to see what sort of efficiency you are getting?

Tom I would second Rara's question for cooled temps. I want a IC bad but don't have the room in my hatch for a tank. I would love to get away with one up front just has you have set-up. I assume yours will not cool as eficiently as one with a tank in the back, but if were talking 10 degrees difference that is no big whoop to me Looks nice, tell Kieth he is a h*ll of a welder! Those beads are perfect.

Thumb???

No thats just my middle finger, its a bit distorted from the editing.

This morning I posted some results but the post isn't here??
Oh well, here it is again with less description since I'm on my lunch hour.

Yesterday I measured intercooler temps morning and late afternoon, both times with the car at operating temp and the intercooler pump off long enough for the temperature to be stabilized. This is as effective as measuring before the cooler because the cooler is so close to the turbo and with the pump off there is no circulation so no cooling effect.
Results:

Morning, ambient ~68-70 F, car idling pump off, IAT = 91 F
Pump on, 30 seconds later the temp stabilized, IAT = 88 F
3 deg F temperature drop just from circulation.

Afternoon, ambient ~80-85 F, car idling pump off, IAT = 134 F
Pump on, 30 seconds later the temp stabilized, IAT = 129 F
5 deg F temperature drop from the circulation.

In Phoenix when we did the first dyno run (300HP) the ambient was ~88 (night time), there was a strong fan in front of the car blowing on the intercooler heat exchanger.
The car was not hot yet, but FWIW the IAT hit only 114 F.
Before the intercooler was on the car, 3rd gear pull on the freeway so it had plenty of fresh air coming in. Ambient was at least 85F; IAT read 169F right when I let off.

So with these preliminary tests it looks like the intecooler is pretty efficient.

Kinger, the only benefit to the trunk mounted tank is that it can be bigger and hold ice. It is the heat exchanger in the front that determines the cooling efficiency. Without ice, the liquid will heat up to the same temperature as mine does and will then perform identical assuming the intercooler cores were identical. All the extra water does is give it more mass to heat up, so it takes longer for the liquid temp to rise. For the track, ice is a huge benefit though for everyday driving it isn't practical. That is why I went with this smaller front mounted reservoir. I didn't loose any usable space and I can still plumb in a second trunk mounted tank for iced water for track days. In the meantime I loose no trunkspace for daily driving.

Tom

PS: Most of the welds you see were done at spearco though where the blow-off valve and the intake pipe are welded on is what Keith did. I think he did a great job too.

Mmmmm...I N T E R C O O L E R.....

My iat can see 160 when idling on a 79 degree day! I can't imagine what it will see on a 100 degree day with 7 psi!

warmonger, to determine any meaningful efficiency numbers, you need to get the air temp after the turbo but before the IC, and also after the IC, all while under boost.

The air temp will be quite different between on and off boost.