I recently installed (with the help of my local shop) a 96-98 d16y8 supercharger on my 99 Acura EL (some custom fabbing was required, made for a sweet 14 hour day) and everything seemed to go smoothly.
When I gave it a test run, I found that I am only making 4psi (closer to 5 at redline), and the pulley is an 8psi setup. I searched the web for some answers, and the following things came up as potential issues:
- screwed up gauge
- timing
- vaccuum leak
- bypass valve
- belt slippage
I have faith in my brand new Faze gauge (appears to be accurate). The belt does not appear to slip, and I've applied some belt dressing to the (brand new) belt just in case. Timing has been set at the dizzy to 10* BTDC. I have no clue how/where to check for leaks in either vaccuum or the bypass valve, but my boost gauge reads -20 at idle, -25 with the throttle closed and decelerating. That bypass valve seems to jump out at me as the potential problem, but i don't know how to test it (or the vaccuum system, for that matter). Idle is normal, but dips really low (100-200rpm) in stop-and-go maneuvers before the car warms up.
it could be a vacuum leak but more than likely it's the pulley size/belt length. Just because it's 8 PSI on a D16Y8 doesn't mean it will give you 8 PSI on your engine. Different blowers use different sized pulleys to get the same boost ratings.
Both engines are D16Y8, it's just the "accessories" that changed between the revisions. but I agree, I'm starting to suspect the crank pulley is not as advertised. I'll lift the car tonight and measure both the crank and the super pulley and see if they match the stock specs.
well the pulley seems to be the right size.. damn, i was hoping that was the problem.
I'm back at the bypass valve, only because I know my shop had to take it off , repair it, and put it back on during the installation because of a broken nib (the one the vacuum hose connects to).
Can someone post a pic of their bypass valve, particularly the butterfly valve that connects to the intake manifold. i have a feeling that isn't seated properly...
IIRC, the butterfly valve never really closes perpenticular to the valve body. When closed, instead of being like |_|, it's kindof more like |/| but not so steep of an angle.
As an answer to how to check for vaccum leaks, a smiple way is to use a propane bottle with a blowtorch attachment. It should have a control knob so you can turn it on just a wee bit, just enough that you can hear/smell it, too much and you'll blow up your engine. If you have it, get a length of black hose to attach to the end of the blowtorch nozzle to make the detection process easier.
With the engine running, move the hose around certian areas of the engine such as the intake manifold and any other vaccum lines that would be sucking air if it weren't attached properly. If that doesn't show you anything another trick of the trade that works fuckin' awesome for detecting exhaust leaks is to take a cup of clean brake fluid and with the engine running disconnect the fuel pressure regulator hose, that goes from the intake to the regulator, off of the regulator. Use the hose to suck up just enough brake fluid that the engine doesn't die. Let it suck up a fair amount of brake fluid, about a cup or so is what I do.
This process smokes like hell just to warn you, and it will take some time of driving to burn off all of the fluid so don't take it on any public roads where there might be pigs.
The brake fluid not only smokes like hell so you can see any leaks in the exhaust system, it also cleans most of the carbon off the inside of the engine, the brake fluid latches onto the carbon build up, and is subsequentialy burned off as the engine runs.
On my D16Y8 I had a cracked exhaust manifold, but I didn't know it because the computer was compensating for it so well, and visually the heat shield covered up the mani so I didn't see it untill we used the brake fluid. Smoke was billowing out of the front of the engine like no other. Took about an hour for all of the smoke to burn off but once it did there was a noticable difference from before and after.
Hope this helps anyone who searches for vaccum leaks.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
problem with JRSC: losing 4 psi on 8 psi pulley
Linear Mode
