Heat exchanger

[87tpita]

I read on thirdgen.org that there was a small heat exchanger made for the sn series to cool the air charge down a bit but it doesnt lose psi. Has anyone heard of this?

[Michael]

This is the first I've ever heard of this. Would be interesting to see though.

Do you have a link to the discussion on thirdgen.org where you read this?

[speedytang]

I think they are confused and are talking about the transmission/heat exchanger coolant unit.

[87tpita]

Are you talking about the dipstick cooler upgrade? I looked on thirdgen but the only thread I found was about buying a heat exchanger and upgrading to the high flow impeller. Now Im not sure what site I read about the heat exchanger for the SNs that wont drop boost

[speedytang]

Yes I am talking about the dipstick cooler
I have been doing the Supercharger 'SN-VR4' for 20 years now and no such thing as a Free Lunch when it comes to cooling air without a pressure drop unless you Liquid Cool the intake charge.(Water/Meth).

[87tpita]

Well I just measured my crank and sc pulley and there, 6" and 3.25" so Im assuming its spinning at 46-47k,. The pulley spins fine by hand, no flat spots or such. My boost guage read 5-6psi at wot but its obviously spinning way to fast. Will the larger 4.5" sc pulley cool the aircharge down enough to make up for the boost Ill lose?The previous owner ran water/ meth and n2o but Im not interested in either.

Heres my setup,, 87 350 stock shortblock(9.3:1), 52mm or 48mm TB(not sure which to use), lpe superram intake heavily ported base with aluminum added aroung the ports, afr 190s full port, bowl blend w/2.05-1.60, full exhaust, comp 276 roller cam, accel gen6 DFI computer, 55lb low impedance injectors, 6al box and coil, 8.8 wires.

on another note the cylinder walls are scored so its being bored to a 355 or Ill buy a slightly used sbc already done up.

[speedytang]

If your producing 5psi with a 3.25" pulley, then with a 4.5" pulley your only going to be making about 2psi of boost at WOT. Larger the pulley the slower the unit spins and less boost you will make.

[87tpita]

something was up with the motor before I pulled it apart, the vacuum guage only showed 7" at idle and 16" max. Im not sure if it was rocker adjustment, timing, or vac leak. would any of these cause such low boost readings?

[speedytang]

All the above. If the timing was off the intake valve is not closing before the exhaust valve and all your vacuum and boost was going out the tailpipe.

[87tpita]

thanks for all the info, I really appreciate it.

[89LX]

www.frozenboost.com sells some small air to water to air aftercoolers with almost zero
drop in PSI and all the stuff needed to build a 500.00 after cooler system less the braided lines sold elsewhere. I'm building a new VR4 and am going to build the after cooler as well. Buying PMS should be quite the ride when done.

89LX, Todd