Stock intercooler & piping really sucks! Here's proof!!!
 

Ok guys, I've been bored as of late so I decided to do some testing. I have always heard how terrible the stock intercooler & piping were when it came to efficiency. Curious, I accually wanted to see how much pressure loss there was between the turbo outlet and the manifold(were the boost gauge is usually connected).

What I did was drill a small hole in the black turbo outlet pipe(right at the first curve on the back manifold side of that pipe). I figured this would be a good location as when both turbos came online, I would get a good reading at that section. The nipple I used for the install came from the solenoid rack from my 20b(or you could use one of the "Help" assorted vaccum line fitings). I super glued the nipple into the black pipe. For a second gauge, I used a spare boost/fuel pressure gauge(from Autozone). After hooking up the other gauge, I went for a test drive.

Now before I continue, let me inform you guys about my car. My car is a 94 stock w/ 73k original miles running seqencial. I still have the stock vacuum lines. Only mods are a Pettit column mount boost gauge, downpipe, K&N in the stock air box, and a small hole cut underneath the box with ducting on the sides of the radiator(M2 style). My boost pattern in 11-7-11.

The test:................................

Because my boost gauges are differant, I switched them around during the test to make sure I got accuate readings. For the run I decided to do the 40-70 mph test in 3rd. With the boost gauge in the turbo outlet pipe section, I got 14psi on the primary and at transition 15psi max down to 14psi on the secondary. Wow I never thought the turbos were accually working that hard. Either way, thats 3lbs of pressure loss from the turbo outlet to the uim. Yep, the stock intercooler & piping really sucks. :)

Now for you guys with aftermarket intake & intercoolers, I would like some of you guys to try this yourselves so we can compare differant manufactures products and see how efficient their products really are. If your worried adout that hole thats drilled into the outlet pipe, just simply put on a vacuum nipple to plug it back off when not in use.

That's a great test. Nice of you to take the time to do that. It seems to me that I have seen similar data elsewhere, but I can't remember where.

Sorry, I won't be drilling any holes for testing with my Blitz smic.

Hey thx for the response. However, you wouldn't be drilling holes into the intercooler. It's the first angle part of the turbo outlet pipe between smog pump & uim. It would only be hard to do if you have the 99 spec y-pipe because it's metal not plastic.

Yep, that's why you should buy my ASP/M2 IC!!! :D

great test. you can also do this w/o drilling the hole in the pipe. from the stock y-pipe there is a larger metal nipple that you can use an extra piece of vaccuum hose and a brass "T" splitter to hook up your boost gauge to. if i have time later i will do this with my m2 ic and see how much pressure drop there is...

I read your post, and understood where you drilled the hole. I have an efini y-pipe (96 and later FD), and I still don't want to drill ANY holes ANYWHERE.

Alwan, I would like to see your results.

Adam

Yep I thought about using that nipple and "T" as well, but I wanted my nipple a little higher. I figured that location would give me the best reading because it's not exacty were the incomming air from both turbos is forced to together. Plus it's easier in the future to hookup a gauge for future testing if I upgrade.



Edit: Hey Adam C I read over your sig to fast and didn't see that you already had the upgraded Y-pipe. My bad....