IcemanG17

The one common thread among 85-86.5's is they benefit ALOT from AA chips.......since the early 32V engines did not have knock sensors.....Porsche tuned them very mild.....to prevent detonation....& the early 32V did have more aggresive cams then the S4 or GTS...similar to the GT profile....I would imagine with some sharktuning (does it work on 85-86.5's??) and exhaust mods they should produce GT like power numbers due to the GT like cams & bigger intake.... which is the #'s a few are already producing.....

Lizard928

the 85/86 cams are the same profiles as the GT from everything I have seen.

I forgot to mention that my 86 engine has only one acc on it, the altenator.

Jim bailey - 928 International

The 85-86 has smaller valves so less flow. Porsche was conservative on the ignition timing to limit the possiblity of excessive detonation destroying an engine. Once they had knock sensors and a hall signal generator 1987 > they could retard the timing on each and any cylinder which for what ever reason happened to be pinging. This made it safe to add more ignition timing knowing that the computer could save the engine in most circumstances by back it out as needed.

IcemanG17

Jim
Do you have any flow #'s from stock 85-86.5 heads vs the stock S4 heads? I thought stock S4 heads flow about 270cfm.....so how much less would the 85-86.5 be?

Jim bailey - 928 International

I have no flow numbers for 85-86 Gred Brown might have some...

928SS

that's what greg and some others got just by cutting up the air box on a dyno...

and NOBODY gets one till MINE is shipped, dammit!!

my blackturd has been on order now for 5 or 6 weeks and my old gal's still sitting in the dyno room waiting for it...

imo, it'll probably be the biggest bang for the $$ on my old slug yet

928SS

greg built a stroker w/modified early 32V heads and pulled over 380rwhp... he did some wicked porting w/968 valves, but it's still cheaper than the way I went w/a full on conversion to GT/GTS stuff...

that's also the motor that gained 28rwhp w/the airbox mod to the rear/toward the windshield... iirc, mark K pulled a few ponies doing a similar thing w/his hobart-mobile...

PorKen

But higher velocity. And more lift, versus S4 cams, counters the larger valves?

IcemanG17

The original Devek white car pulled its intake nascar style from the windshield too.....

928SS

good point... I think it's pretty obvious that there's room for improvement in the intake side of things including the plenum..

heck, the "little" 3.8L gt2/gt3 motors pull 465chp NA.. but their intakes look very similar to ITB's... and dr. ott & devek pulled some massive 600rwhp+ on their strokers w/"just" an intake change to an ITB style setup also....

I'd guess a 5L motor would get in the low/mid 500's w/a setup like that... wheee haaa!!

Randy V

That does look slick.

Heck, it might even pass California smog visual inspection.

ew928

What are the odds the smog **** has seen a 928 intake and inquires about the lack of Venturi's.
Then you'll have to edumacate the inspector on the finer differences of the GTS model and it's dual cone intakes. Sure you can get DR to scrawl 928.xxx.xxx part numbers on the tubes.

928SS

it's so easy to R&R every 2 yrs, it's no big deal... perhaps painting the tops of the filter covers black to tone it down a tad might pass w/out a 2nd glance....

it uses 928 tubes on the front section already

mark kibort

That is some pretty ugly stuff on the dyno graph. the fact that there are such big gains in the low rpm range, points to other things going on that are probably independent of the filter in the 3krpm range.

It would be interesting to see a couple of more dyno runs of the system.

mk



Its tough

John Speake

The SharkTuner for the LH2.2 85/86 US 32v and Euro 16v is alreadt released.

The SharkTuner for the 85/86 US 32v EZ-F is due to be released in the near future.