Spent a full day at the dyno with a handfull of different intercoolers - some new and some old. We wanted to see what kinds of differences there are between them in terms of power output capability as well as get some thermo information on them too. What we found was pretty interesting.
Here's the lineup:
UAS FrontMount Intercooler
New Z1 Sidemount Intercoolers
Stillen Intercoolers
Stock Intercoolers
Prototype Z1 Water-Air Sidemount IntercoolersUnfortunately we did not have a pair of Greddy Intercoolers to take with us for comparison, but the data suggests that we probably aren't missing much.
Here are the results:
The notes below the chart have the details of the pulls and the temperature of the air both before and after the intercooler for each setup. Two "T" type thermocouples were used with a fluke dual-input meter for monitoring temps. All pulls were made when the inlet side of the intercooler was at 145 degrees F and the outlet side was between 90 and 95 degrees F. Three pulls were made for each setup and cool-down time was observed between pulls to allow the powerplant components to drop back down to 180F as per the coolant temperature.
In the notes below the chart, you can see the last line entry for each pull which tells the name of the intercooler used, inlet temperature before pull, and MAX values showing the peak temperature of the air just before the core and just after the core. The donor car belongs to Lorca Divale, a PE1420 powered TTZ with downpipes, testpipes, cat-back exhaust, dual intake, 555cc injectors, Z1 built engine with Wiseco forged pistons (88mm), stock camshafts, mild portwork, and a Blitz SBC-ID boost controller. Boost was set to 60% duty cycle for all runs and the gain setting was set to 15. We did not modify these parameters for any runs to allow us to monitor the difference in boost pressure. You cannot easily monitor pressure-drop with an intercooler and it is impossible to measure it on the Z due to the idle air hose which connects the manifold to the turbo outlet pipe - this causes a pressure balance on both sides of the intercooler and you would have no luck measuring a difference. However, the difference we see from one intercooler to the next gives us a valuable piece of information - the difference in peak pressure is related to pressure drop since we are measuring boost pressure at the intake manifold.
 We began at noon and as the day progressed the ambient temperature went up four degrees. It appeared that each degree of temperature increase ambient resulted in about a 4HP loss of power - definately a rough estimate since this observation was spread across the testing of each intercooler -- but the fact that they all made just about the same power with slight decline in power as the ambient temperature went up, it was our conclusion that there just wasn't much difference between the aftermarket intercoolers and the only clear distinction was with the stock intercoolers having ~20HP less.
It is far too easy to say "with all things being equal, 'x' intercooler is the clear winner", but the fact of the matter is that it is near impossible to keep your test environment static with the exception of what you intend to change. In our tests, the temperature went up a few degrees and the power output varied a few horsepower and ft/lbs between the different intercoolers, but it is hard to say if the lower power had more to do with intercooler design or with ambient temperatures. *shrug* I guess when things get this close though, you can probably just rest and say that they are all pretty much the same. And some video for you bandwidth kings. After further tuning of Lorca's PE powered TT and increase in boost pressure to 24.4psi, we produced these dyno results:
 A note on the prototype water-air intercoolers:
This is a design we wanted to entertain to see what we could get out of them but based on the results we feel that they need to be further engineered. They were tested during the hottest part of the day and while they yielded the smoothest power curves, they actually produced the least power, 9hp less than the UAS, 7HP less than the Z1, and 4HP less than the Stillen. The Z1 sidemount intercoolers will be released this wednesday. Stay tuned..
AIM: EricTTZ |
