hacker-pschorr

As Jim Bailey likes to say, the best performance upgrade for a 928 is everything working as the factory intended.

In case you did not know, Tim Murphy, Z, Todd, Jim Page and I have been working on a 1986.5 for Shane he purchased locally in Green Bay. We are using this car as the test bed for a stage 3 supercharger system.
Part of this process is making sure everything is 100% before bolting on the blower.

Long story short, the before dyno seamed a bit low on torque. After chatting with Louie, Porken and Shane, everyone was in agreement something wasn't 100%.

We pulled the belt covers off, the left (drivers) side looked pretty damn close.
Right (passenger) looked to be a tooth off. We moved the right side over one tooth, it was now worse than before except in the opposite direction.
Needless to say the cam timing was as close as anyone could get without pulling the cam covers off and setting cam timing the old fashioned way. Unless you have Ken's tool.

We put the belt back where it was and used Ken's handy tool to set both cam gears to 0 degrees.

Here are the photos of what we found followed by a before / after dyno chart. Each hole is 1 degree:

Left - Drivers side = 4 degrees retarded



Right - Passenger side = 8 degrees retarded







In case anyone asks - both dyno runs were in 3rd gear with the kick down's disconnected and an inductive pickup on the spark plug.

This dyno is 100% indoors so we do not benefit from 30 degree winter air blowing across the front of the car during the runs. We did check the intake temp sensor to make sure we were under that threshold for full ignition timing on both runs.

Big Dave

WOW

Mr. Piff

Im in the process of a rebuild,(first time performing open heart surgery on my S4 with no help other than r-list search functions) so it would seem I should follow your advice and buy the tool.

Happy to see you guys restore that "lost" power, and keep it up.

By the way, will those same cam timing changes work on an 87s4?

Tony

We got even more hp/tq out of Dariens car(86.5). His was way off as well! Something wasnt right on the top end and you could really feel it. The car felt like it would fall flat on its face above 3000 or so rpm. Now it makes the drivers face flat at 2000rpm

I agree, great tool and something everyone should check

Bill Ball

You know, I've had the tool for well over a year and used it on a lot of other people's cars to check cam timing. What the hell's wrong with me? I need to use it on my car - as soon as my taxes are done.

Tim Murphy

I was very impressed with this tool. Stetting cam timing can be a daunting task for even the experienced wrench but this tool makes it very easy to do.

I can see many GTG where this tool gets pulled out. BTW, the belt tension tool fits nicely in the case that the cam tool came in.

Good job guys!!

BC

You guys got a case?

Adam Geist

I did.

IcemanG17

Nice gains....... Now I want to see the dyno graph with Stage III too!!

PorKen

Y'all know that the 32V'r measures in one degree increments, but in a zig-zag order, down 1, up 2, down 3, etc.

With a 1000+ mile belt, the factory settings equate to ¼ (right/passenger): -2°, ⅝ (left/driver): 0°. ¼ is retarded to compensate for engine expansion when hot.

A new belt will stretch about 2°, so Shane's may turn out fine at the retension.

Here is my '86 measured cold, then hot (TDC #1).



Upper belt position is with original tensioner system - past 3mm is bad! Lower is with PKsn'r, same belt.

PorKen

BTW: I've advanced my cams by 3° and I'm luvin' it!

3° for the automatic makes a nice improvement in torque, lower in rpm, and shouldn't affect HP.

3° advance closes the S3 exhaust valves at the same time as S4 cams do.

Shane

Get in line...

That is trade secret territory, but for a $1000 deposit you might be able to see a dyno chart...

I'll be heading over to see it in person on Friday for the very first time and I bought this car back in January!

Hilton

Um.. isn't it 1-4 on the Right hand side (US passenger), 5-8 on the Left hand side (US driver)?

Shane

Show off...

When are you going redyno that thing Ken?

I hear the dyno is open...

PorKen

According to the WSM, left and right are as seen from the driver's seat - not facing the engine.

Perhaps I should say 'stage left', and 'stage right'...for the theatrically inclined...NTTAWWT

Soon, I hope. Louie was mumbling something about fixing his 'S4', whatever that is.