PorKen

Not much. It's only a little advanced over the 92 chip.

The extra performance comes from the late intake valve closing, but that lowers the effective compression ratio, thus making 87 octane preferable.

With ethanol, you could make a torque monster by advancing the cam timing. I don't think you can get big HP without a turbo/supercharger with ethanol, though.

PorKen

Self control?

PKT for safe high rpm bursts.

Intake refreshed, X-pipe, NGK non-resistor plugs.

Autos need a couple turns tighter than stock Bowden cable adjustment.


The auto version is done. I just haven't had time to update the website for the 'Black Edition'.

It may be a few weeks before I can finish the 87 octane version for the manual. Until I finish the tank, I'm running a 92 version with an unnecessarily large amount of ignition advance. (Best to have as little ign. advance as possible.)

Stromius

PKBlÄck edition a la MB?? Like it

PorKen

All the major euro makes have Black Edition cars, too. (Porsche included.)

I confess to reading too many sites like - http://www.gtspirit.com/

Avar928

Yea, I was just reading your posts on Cam Timing and playing with the -12* retard and 87 octane. My mouth is watering.

Ahhhhhh yeaaaa Black ahhdisheeyon!

dprantl

What is the total range of the cam gear slot? If you just shifted it all the way to retard as far as it would go, how many degrees would that be? I am assuming Porsche engineered that slot so that even at the limits of the window there would be no physical interference?

Dan
'91 928GT S/C 475hp/460lb.ft

PorKen

On both of my S3s, the max in the slot was about -16°. (One cam tooth is 7.5°.) Much more than I thought there would be.

I picked -12° for my tuning, as the 1-4 side needs -14° cold.


As the slot is close to the center of the gear, a degree at the belt surface is only a tiny movement at the slot. One bolt is offset, to locate the distributor rotor. Fortunately, it is offset advanced. (To make these readings using the 32V'r, use the 1|0 mark after 0|T, instead of 0|T.)

fbarnhill

Hey Ken, that sounds great. One thing, I am using 87 most of the time right now and can't tell much of a difference to be honest. The car accelerates like a bullet and seems to have no isssues what so ever. I am not getting the milage I had hoped for so the Black edition might help more than you think. However, I am wondering if I will have the strength to get the cams to retard that much even with the bump stick. Also, will you write a dummy's version on how best to do it? Also, how much will the Black edition cost for us who have the s3s? Also, I want one of those oil seperater thingies...

Hey Avar, maybe you will want to wait for the black edition to do your cam covers. I think they have to come off to use a big wrench on the cams to turn them this much. I might be wrong and Ken will correct me if so but I think that it will be neccessary. What about it ken?

Thanks,

PorKen

Oy, the auto do take a bite, don't she?


Since I have never dynoed this '86.5 auto, I used one of Glen M's dyno runs from last year, which has a similar setup, S300s, X-pipe, etc., as a baseline.

'86.5 auto, 150K miles, X-pipe, RMB, -12° retard, 87 octane, S300s Black Edition 1.0 chipset


Which car would you rather drive?

(SAE) (UNC 60F)

PorKen

Now, look what happens when you take the airbox lid off, like I did with my '86.5 manual, at the start of this thread...

Bit of a breathing problem with the retard!

(AFR graph added. Note tailpipe AFRs are often 0.5-1.0 point leaner than at the X-pipe.)

PorKen

If the 5-speed loses 12%, I think the S3 auto is not 15%, but closer to 20%. Maybe the S4-up box, with it's larger converter is more effecient?


-8° MT, vs. -12° AT. You can see the effect of keeping torque high does to HP. The AT is catching up with the MT.

I'm going to hazard the MT will dyno >330 STD at -12°.

fbarnhill

Man, I like those numbers with the 12° retard and the black edition chips. Let me know when you are ready for the public to test them.

soupcan

I was going to order some chips for my wife's 86.5 so she can stay a little closer to the Murfmobile, thankfully I decided to see if Ken had any updates.....Black Edition chips for the wife's Black Edition..
Need another test subject Ken?

PorKen

I have to figure out something for the airbox...no lid, but cool air.

Funny, as this was one of the first things I posted about on Rennlist (10 years ago).


The AFR was the same w/o the airbox lid, so it wasn't a turbulence issue, or a leaning out, it was just a lack of air. Also evidenced by the overall gain from 2K to 6.5K.

byrdman454

Ken,
Is the X-pipe mandatory with the black edition chips or just recommended?
Thanks