The Supercharged NA is pushing 10 psi finally........

[douglas vincent]

but it has been a long time in coming. I must have 70-80 hours now working on the stepper pulley setup, with two complete failures until this last attempt. I finally mounted the stepper pulley by boring a center hole large enough to press fit a timing belt idler into it, and bolting this to where the power steering pump used to be. I had some annoying belt slip issues, and still do to some degree, but I am now sure i can overcome the last of them.

I was also having some boost leak and I think my recirculating BOV was leaking so I removed it so now i just plain dont have a BOV.

But I had a rather depressing evening with it though. I took it to the drag strip for some runs. Last week, on 7 psi and bad clutch, I was consistantly getting 15.2-15.4 at 88-89 mph. I expected to do at least this. Nope, my best was 15.6 ONCE, with an average of 16 sec. The damn wagon just felt freaking boggy. You would lean forward in anticipation of the boost surge and end up just leaning forward. Occasionally, and infrequently to boot, the engine would just suddenly have alot more power, but this seemed random.

This was before I removed BOV. The PSI would start at about 9 and just leak down to about 5. I was sad. I figured it could be bad gas and/or combined with that gallon of Xylene I through in, or the parisitic loss of the supercharger, combined with the boost leak, was just eating up the power.

So i called it an early night and drove back to the shop to stare at the engine and have a beer or two.

This is where I decided to remove the BOV. Since the belt seemed pretty damn tight, I decided to forgo building a new tensioner as I just didnt have time to do that tonight.

I was so tempted to go back to the 7psi pulley setup but while I was thinking about this, I wondered if the spark plug switch I did when I installed the stepper pulley may be to blame for the bogginess.

Well I stuck the stock plugs back in (I had stuck 1 step colder plugs in), but most importantly, the Magnecor wires seemed once again to not be on the plugs correctly. So I stuck some "old" new wires on and off I went for a test drive.

Other than some belt slip that now only allows the PSI to fall to about 7 (sometimes) I suddenly have a powerful engine now. Spark plugs and spark plug wires just seem to have a say in all of this I suspect.

It was too late to head back out to the drag strip but I am pretty damn confident I would be hitting a 15.0 if not better now that the engine actaully is firing correctly. It has some serious pull now. It also has some serious need for 94-95 octane gas with this high of boost and compression ratio.


My next goal? (after fixing the belt slip of course) is to get a 13.99. Nitrous of course.

[-K-]

Good stuff, I hope you find a cure for the belt issue.

[skid542]

You're crazy but damn I love what you've been doing. Glad to hear you finally got your 10 psi.

[Nomake Wan]

I'm really loving your progress... supercharging the engine is awesome. I also hope that you find a cure for the belt slippage.

Good luck!

[douglas vincent]

But tonight I put it back to the 7 psi. The stepper pulley setup just have too many problems that money (ie lack of) could not fix. The belt slipped, the boost wobbled, the engined detonated, the power was way less than the 7 psi setup. It just didnt seem to work that well, even thought the boost guage was definately 10 psi straight up.

Basically, I suspect that I was/am suffering the dreaded parisitic loss of the SC when using the stepper pulley. When I get the money, I will eventually just get a bigger crank pulley made that will give me 10 psi and I suspect that I will not have any of the above problems. Anyone want to buy a stepper pulley?!