Drewster67

Please - my uneducated mind wants to know why I cant gain better HP by good old fashion performance mods?. IE Exhaust/Air Filter/Underdrive pulleys.

Is the chip set the best bang for the buck? and why or should I say How does it work?

Couldnt CPU mapping be bypassed all together?

In comparison to my previous GT Mustang - Underdrive pulleys were the best bang for the buck! Does anyone offer UP for our sharks?????

TIA

Daniel Dudley

Drewster, they work like gangbusters on the 85, 86 MY. My guess is that Porsche was too conservative with the A/F and timing. Not such clear gains on the S4, but does raise the rev limit if you have the brass to go there. I have heard that John Speake can reprogram the S4 chip to GT spec, and that this is quite satisfactory.

jeff jackson

I agree...I was skeptical after my C4 Vette "chip" experience...but, my 86.5 Noticeably improved in performance with the addition of the Autothority chipset. No Dyno info, but I believe the before and after performance claims of Autothority are pretty accurate with regard to the 86.5 model anyway...No way I'd switchem back ... It is a "learning" system though...so it takes a few minutes of operation for the computer to start responding to the new chips...Be patient, and soon you'll know, it was a good buy.

SharkV8

Wassup Andrew...I put the Autothority set in my '85 928S 5-sp last year at "Tha Lockhart Dyno", and it was well worth tha loot!!!!! Long story short it gave me 19 HP and 33 Ft-Lbs doing a 3rd gear pull. I took it all tha way up to 5500 rpm both times. The sound was RADICAL!!!! I was first on the dyno. and it took me 15 min. to install the chip set after my first 3 runs. Piece of cake if you take your time. The instructions were very well written. The drive around the block after I installed the chip set was a Blast to say tha least!!!! I got my set from 928 Spec. (TKS Dave & Jeannie). It was a chunk of loot, but you get what you pay for......
SharkV8

Jim_H

My understanding is pre S4's can benefit. S4's onward Porsche wasn't so conservative with timing because of knock sensors.

Imo000

I’ve been always estimating (the seat of the pants) around 20 - 25hp gain and now it’s proven. The ’85-’86 32Vs get a noticeable improvement when chipped. There is no need to sped hundreds of $$$ on an Authority set. I bought mine from ebay for $75 and by far was the best bang for the buck. Gained two tenths in the quarter mile (~25hp) with only the chips. I still have the chip set in the car and it works fine with the supercharger.

RDS928S

Drewster,
Autothority chip set at ~ $400.00 and a $500.00 X-pipe will net you approx. 45 hp and mucho torque.
Where can you get almost 50 extra ponnies for less than a grand?

Those are the two best bang for the buck mods out ther other than the 928 motorsports poly graphite bushings.
Now if you want your car to handle that'a the way to go. Cheap too!

RDS

jeff jackson

Yes...and if you shop around...you can get the chips for less than $200, for genuine Autothority chips...and as Imo pointed out, generic "duplicated" chips, can be found on Ebay for less than $100.

whitefox

Someone should dyno eBay/Autothority chips before and after on the later cars....

I may have to do it myself.

Imo000

I think one of the big 3 have dynoed an S4 years ago and the gain was minimal. This was the total opposite for the ’85-’86 32Vs.

Jerome Craig

I'd have to agree. I installed the AA chips several years ago and the first thing I noticed was 1st gear starts. Now that I also have an 87 S4 I can kinda do a seat of the pants comparison. The 86.5 w/chips and RMB seems to be more edgy or more aggressive. The car sort of says "I want to play and I want to play...NOW!" The S4 - with no mods - tends to have a linear rush of power - probably the shape of the tq curve - and feels like it could continue to pull all the way into next week.

Even with 225K miles on the clock, I think the 86.5 "feels" a tad bit more aggressive (e.g. quicker) than the 87 with only 86K miles. However, seat of the pants would also make me believe that above 100 the S4 would definitely come into its stride. I was hoping my son and I could have done some side-by-side acceleration runs while he was home over the holidays but we didn't get to it. Besides I'm not too sure I want to encourage him along those lines - not at 19 years old! And not on my insurance!

The other thing I noticed was that with modest suspension mods, the increase in hp and tq makes the 86.5 feel like a smaller, lighter and more nimble car.

anonymousagain

If it helps, I just installed some chips in my 86.5, bone stock AT w/36k mi - ebay $49.95. I was quite skeptical that I'd notice much, but figured 50bucks is worth a try... it is significantly noticeable.

Rarely get a tiny squeal off the line stock; squeal every time w/chips. Mostly, better response everywhere, meatier feel everywhere, rarely use 3rd on the freeway (and the guy in the 350z would have been shocked if he knew 3rd was still available ;-) We're not talking monumental, but I gotta believe 20+ at the wheels like the AA owners report for 85-86's.

Overall assessment: $50 is crazy and my shark just got some distincly sharper teeth; feels agressive and begs to play. Definitely an ear-to-ear grin purchase.

BTW - a kind S4 owner shared with me that he has both AA and same "ebay" and found no seat of the pants difference. Very very subtle in his S4 anyway, but back-to-back comparo's feel identical.

FlyingDog

Now that the Sharktuner is out there, I would think somebody could see what the settings are for the Autothority or generic ebay chips are.

whitefox

http://cgi.ebay.com/ebaymotors/Porsc...spagenameZWDVW

is this the infamous eBay chip?

UKKid35

No Ross, not that. We're taking about a pair of replacement EPROMS that need to be swapped with the originals in the LH ECU and EZK ECU. The pair I purchased from eBay were about $50, contained minimal documentation, and had the horrible side effect of raising the idle by about 200 rpm. It was months before I was able to get hold of a Spanner to run the Idle adaptaion program, but now I'm very happy with them. They do require that you use premium fuel otherwise pinking is likely, even with knock sensors. I'm going to swap the originals back in again one day to see how noticeable the difference is, but my seat of the pants feeling is that they make the car significantly more eager.